JACC V.I. 12. Na . 2August 1988,52945

ACC/AHA TASK FORCE REPORT

Guidelines for Percutaneous Transluminal Coronary AngioplastyA Report of the American College of Cardiology/American Heart AssociationTask Force on Assessment of Diagnostic and Therapeutic CardiovascularProcedures (Subcommittee on Percutaneous Transluminal Coronary Angioplasty)

SUBCOMMITTEE MEMBERS

THOMAS J . RYAN, MD, FACC, Chairman

FLOYD D. LOOP, MD, FACCDAVID P . FAXON, MD, FACC

KIRK L . PETERSON, MD, FACCROLF M. GUNNAR, MD, FACC

T. JOSEPH REEVES, MD, FACCJ . WARD KENNEDY, MD, FACC

DAVID O. WILLIAMS, MD . FACCSPENCER R . KING Ill, MD, FACC

WILLIAM L . WINTERS, 1R., MD, FACC

TASK FORCE MEMBERSCHARLES FISCIH, MD, FACC, ChairmanROMAN W. DSSANCTIS, MD, FACCHAROLD T. DODGE. MD. FACCT. JOSEPH REEVES, MD, FACCSYLVAN LEE WEINOERG, MD, FACC

PreambleIt is becoming more apparent each day that despite a strongnational commitment to excellence in health care, the re-sources and personnel are finite . It is, therefore, appropriatethat the medical profession examine the impact of develop-ing technology on the practice and cost of medical care .Such analysis, carefully conducted, could potentially impacton the cost of medical care without diminishing the effec-tiveness of that care .

To this end, the American College of Cardiology and theAmerican Heart Association in 1980 established a TaskForce on Assessment of Diagnostic and Therapeutic Cardio-vascular Procedures with the following charge :

The Task Force of the American College of Cardiology andthe American Heart Association shall define the role ofspecific noninvasive and invasive procedures in the diag .nuns and management of cardiovascular disease .The Task Force shall address, when appropriate, the contri .bmion, uniqueness, sensitivity . specificity, indications,

Address for reorinls Mr . David I . Ftild, Assonale Executive VicePresident, American College of Cardiology, 9111 Old Gcorgelown Road,aclhesda, Marylend 20814 .01955 by me American College of Cardiology

529

contraindications and cost-effectiveness of such specificprocedures .The Task Force shall include a Chairman and four members,two representatives from the American Heart Associationand two representatives from the American College ofCardiology. The Task Force may select ad hoc membersas needed upon the approval of the Presidents of bothorganioations. Recommendations of the Task Farce emforwarded to the President of each organization .

The members of the Task Force are : Roman W . De-Sanctis, MD, Harold T . Dodge, MD, T . Joseph Reeves, MD,Sylvan Lee Weinberg, MD and Charles Fisch, MD, Chair-man.

The Subcommittee on Peecutaeeous Transluminal Coro-nary Angioplasty was chaired by Thomas J . Ryan, MD, andincluded the following members : David P. Faxon, MD, RolfM . Gunnar, MD, J . Ward Kennedy, MD, Spencer B . King111, MD, Floyd D. Loop, MD, Kirk L . Peterson, MD, T.Joseph Reeves, MD, David 0 . Williams, MD and William L.Winters, Jr ., MD.

This document was reviewed by the officers and otherresponsible individuals of the two organizations and re-ceived final approval in March 1988. It is being publishedsimultaneously in Circulation and Journal of the American

0735-1097/88153 .30

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College of Cardiology. The potential impact of this docu-meet on the practice of cardiology and some of its unavoid-able shortcomings are clearly set out in the introduction .

Charles Fisch, MD, FACC

I. Introduction

The American College of Cardiology/American HeartAssociation Task Force on Assessment of Diagnostic andTherapeutic Cardiovascular Procedures was formed to makerecommendations regarding appropriate utilization of tech-nology in the diagnosis and treatment of patients withcardiovascular disease . Coronary angioplasty is one suchimportant technique . We are currently witnessing an ex-traordinary expansion of the use of coronary angioplasty asan alternative means of achieving myocardial revasculariza-tion. An estimated 133,000 angioplasty procedures wereperformed in the United States in 1986, up from 32,300 in1983 (I). Such growth is attributable not only to demon.stoned clinical benefit but also to recent technical advancesthat have led to improved techniques and higher successrates . In turn, this has led to some broadening of theindications for coronary angiography and . in some settings,overuse of both coronary angiography and angioplasty hasbeen suggested . Accordingly, it was recommended that thisSubcommittee review current indications and develop guide-lines for the use of coronary angioplasty . In doing so. wehave proceeded on the premise that, because diagnosticcoronary angiography is essential for undertaking coronaryangioplasty, all of the indications and guidelines for prudentcoronary angiography, promulgated in an earlier ACC/AHATask Force report, have been met (2).

Because the technique of angioplasty is in evolution andthe intermediate-term results are not yet fully elucidated,these recommendations are likely to change over the years .This report is not intended to provide strict indications orcontraindications for the procedure because multiple varia-bles must be weighed in selecting the individual for balloonangioplasty treatment . These relevant considerations in-clude occupational needs, the family setting, associatedillnesses and individual preferences concerning life style .Rather, the report is intended to provide general guidelinesthat may he helpful to the practitioner as well as to healthcare administrators and other professionals interested in thedelivery of today's medical care . The American College ofCardiology and the American Heart Association recognizethe fact that the ultimate judgment regarding the propriety ofany specific procedure is the responsibility of the physiciancaring for the patient. The guidelines should not be consid-ered all inclusive or exclusive of other methods that may beavailable for the care of the individual patient . The Subcom-mittee will not offer detailed recommendations concerningthe specific resources required to perform coronary angio-plasty or to train individuals performing the procedure . It is

JACC V.0. 12, No. 2August 19811:529.45

essential that physicians performing angioplasty and otherrelated procedures arc adequately trained, that facilities andequipment used are capable of obtaining the necessaryradiographic information and that the safety record of thelaboratory is acceptable. Some current thoughts related totraining, credentialing and facilities required to engage inpresent day angioplasty are presented in Appendixes A andB .

The format of this report includes some general consid-erations that provide a brief historical review of the growthand development of the procedure, identification of contrain-dications to its use and a statement acknowledging generalrisks associated with angioplasty . This is followed by a briefdiscussion of considerations unique to angioplasty and in-clude an enumeration of those factors currently recognizedas influencing a successful outcome, the requirement forr argicat backup, angioplasty performed at the time of initialcatheterization, management of the patient after angioplasty,the problems of restenosis and incomplete revascalarizationand the need for institutional mortality/morbidity reviewcommittees . Lastly, specific guidelines for the application ofcoronary angioplasty are presented; these have been devel-oped according to anatomic (single versus maltivessel dis-ease), clinical (asymptontatic versus symptomatic patients)and physiologic (presence or absence of inducible ischemia)considerations . Most importantly, the indications for angio-plasty are judged categorically to be either class 1 .11 or 111 1,based primarily on a multifactorial risk assessment weighedagainst expected outcome. Also included are judgments offeasibility, appropriateness to the clinical setting and overallefficacy viewed in the light of present day knowledge andtechnology.

Ii . General Considerations

A. BackgroundSymptomatic coronary artery disease is present in >6

million individuals in the United States . Despite the avail-ability of effective medics) therapy, a significant proportionof patients are candidates for a revascularization procedurebecause of unacceptable symptoms or potentially life-threatening lesions . An estimated 284,000 coronary arterybypass operations were performed in 1996, no from 188,800in 1983 ; similarly, coronary angioplasty procedures haveincreased from 32,300 in 1983 to 133,000 in 1986 (I). Untilrecently, angioplasty has been performed most often onpatients with single vessel coronary disease whereas coro-nary byi:ass surgery now is used more often to treat multi-vessel coronary disease, with the majority of patients cur-rently receiving three or more bypass grafts . The use of

'Classes 1 .11 and Ill are Defined on pages 538 to 539 in section IV of thisrepay .

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internal mammary artery grafting has risen dramatically inrecent years, from an estimated 6,000 procedures in 1983 to67,000 in 1986 (1) . The leading indication for surgery contin-ues to be the relief of angina, an approach supported byfindings of recent randomized trials that have shown that,compared with medical therapy, surgical revascutarizatiunsignificantly reduces symptoms and improves the quality oflife (3). At the same time there has been an expansion of thesubsets of patients in whom it is recognized that bypasssurgery improves survival. This improvement in survival hasbeen established for patients with left main coronary arterydisease (>50% stenosis) (4) and certain patients with threevessel coronary disease (5-7 ;. Additional information fromthe Coronary Artery Surgery Study Registry would alsosuggest that coronary bypass surgery improves survival inpatients with three vessel disease and normal ventricularfunction if either severe symptoms exist or an exercise test ispositive for ischemia or chest pain (8,9)

B . Immediate and Long-Term Results

Coronary angioplasty was first introduced by AndreasGruentzig in September 1977 (10) as an alternative form ofrevascutarization ; it thus constitutes a relatively new form oftherapy . During the early years of its application. Gruentzigand others used coronary angioplasty predominantly to treatpatients with discrete, proximal . noncalcified subtotal occlu-sive lesions in a single coronary artery . In subsequent yearsthe technique has been applied successfully to patients withmuttivessel disease, multiple subtotal stenases in the samevessel, accessible complete occlusions of recent vintage,partial occlusion of saphencus vein or internal mammaryartery grafts and recent total thrombotic occlusions in acutemyocardial infarction, as well as to iaolaled high risk patientswith congestive heart failure and cardiogenic shock .

By 1980 Gruenrzig had performed the procedure on 169symptomatic patients, 4030 of whom had muttivessel dis-ease. The follow-up of these patients now extends to as longas to years and documents persistent long-term benefit withonly 5 cardiac deaths; 90 patients remain asymptontatic.However, repeat angioplasty was regeired in 27 patients andcoronary bypass surgery in 19 (11) .

NHLBI Registry. Because of the promising early clinicalexperience, the National Heart, Lung, and Blood Institute(NHLBI) established a Percutaneous Transluminal Coro-nary Angioplasty (PTCA) Registry in 1979 to help evaluatethe technique. Through 1902, a total of 3,079 patients wereentered into the voluntary Registry and numerous analysesfrom this data bank have substantiated the effectiveness andsafety of angioplasty i12) . As with any new procedure,technical advances have resulted in improved success andwider appticabiiiiy of the procedure . Prompted by thesechanges, the National Heart, Lung, and Blood Institutereopened the Registry is 1985 to evaluate more recent trends

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531ACC)ANA TASK FORCE REPORT

in angiaplasty . Sixteen centers agreed to voluntarily collectdata on an additional 2.500 patients. These recent additionsto the Registry indicate that the immediate success rate(defined as >20% change in tuminat diameter narrowingwithout the occurrence of death, myocardial infarction orbypass operation during hospitalization) increased to 78%compared with 61% in the initial patient cohort (i3). Despitea recognized change in the case mix to more complex cases .the rate of nonfatal myocardial infarction decreased front 4 .9to 4 .3% and emergency coronary artery bypass graft surgeryfrom 5 .8 to 3.4%; the mortality rate remained unchanged (1 .2versus 1 .0%). Whereas only 25% of patients in the initialRegistry had multivesseldisease, 53% were so categorized inthe most recent Registry . This subgroup of patients in thenew Registry (that is, patients with muttivessel coronaryartery disease) hed an overall success rate of 73% . However.when the data are analyzed for completeness of revascular-ization, defined in the conventional manner as no residuallesions of >50% narrowing, only one-third of the patientsqualified (14). Such data must be viewed in the context thatballoon angioplasty is not currently undertaken when lesionshave 50 to 60% luminal diameter narrowing or when chronictotal occlusions are present.

The long-term benefit of angioplasty has been examinedin the first FTCA Registry group for which >5 years offollow-up are available (IS) . After hospital discharge theannual mortality rate is low . approxinstely 1% per year, andthe rate of nonfatal myocardial infarction is also low at 2%per year. Symptomatic improvement in the successful caseswas high with 70% of the patients pain-free at 4 years .Freedom from major cardiac events (death . myocardialinfactian, need for bypass so . geryl over a 5 year period offollow-up of a large series from one major center wasreported ro be 79% (16). These data, although they do notaddress the problem of resterrosis and arc derived from apopulation in which 75% of the patients had single vesseldisease, do indicate that tong-term clinical benefit withoutincreased risk of death or myocardial infarction can beexpected after angioplasty . Follow-up information on pa-tients exclusively with muttivessel disease is less complete .Cowley et al. (17) reported initial success in 92% of patientswith muttivessel coronary artery disease . with 48% of thepatients asymptontatic and 82% symptomatically improvedal a mean foitow.up time of 24 months. A follow-up study of605 patients undergoing angioplasty for multivessel diseaseat Emery University demonstrated a 3 year freedom fromcardiac event rite of 83% (18). Preliminary findings in theNational Heart, Lung, and Blood Institute Registry indicatea freedom from, death, myocardial infarction or surgery afterI year of follow-up in 75% of 402 patients with muttivesseldisease (19) . In these studies restenosiv with subsequenthospitaliza-ior for redilation was not considered a cardiacevent but viewed as an integral part of the strategy ofangiaplasty.

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Comparison with bypass surgery. Whereas angioplastynow is applied successfully to patients with multivesselcoronary artery disease (13,20), it must be viewed in com-parison with coronary bypass surgery. The operative mor-tality rate for patients undergoing elective bypass surgeryhas steadily fallen and now approximates 2% in most centers(21). Although it is recognized that >50% of bypass graftswill occlude after 10 years (22), internal mammary arterybypass grafts may provide a superior Conduit with improvedlong-term patency. Indeed, recent studies (23) suggest that apatency rate of >90e at IG years can be achieved . Thelong-term clinical benefit of bypass surgery is well defined,with a survival rate of 82% at 8 years for double vesseldisease and 79% for triple vessel disease as reported fromthe Coronary Artery Surgery Study (24). Symptomatic im-provement can be expected in 70% and asymptomatic statusin 50°k after 5 years . For patients who have received aninternal mammary artery graft to the left anterior descendingcoronary artery, with or without associated vein grafts, thereis evidence of both improved sm rival and a reduction inmajor cardiac events after 10 years of follow-up comparedwith findings in patients who received vein grafts only (23).

Inherent differences exist between angioplasty and bypasssurgery. When successful, the former is less traumatic, lesscostly and requires a shorter hospital stay than the latter .However, bypass surgery is applicable to a wider group ofpatients because dilation of longstanding total occlusionsand diffuse disease is often not possible with angioplasty .Angioplasty, in certain instances, leaves patients with in-complete revascularization, which understandably is a morecommon phenomenon with increasing severity of disease(14,25). There are those (26) who advocate a strategy of"intentional" incomplete revascularization in some patientswith multivessel disease, and they report follow-up datasuggesting that these patients are no more symptomatic thanare individuals who have complete revascularization . Otherreports (25,27) on the long-term follow-up of patients withmultivessel disease indicate that those who have incompleterevascularization after angioplasty are more symptomaticthan are those who have complete revascularization .

Restenoses. Angioplasty outcome is also complicated byrestenusis, the . phenomenon of renarrowing of the dilatedarterial segment within 8 months of the procedure . Sympto-matic restenosis occurs in 20 to 25% of patients, whereasangiographic studies suggest that the rate of restenusis is asfrequent as 30 to 35% (28,29) and may be as high as 45% forlesions at the origin of the left anterior descending artery .Preliminary studies in patients with multivessel diseasesuggest that restenusis may also be more frequent as morelesions are dilated (30). Experience indicates that restenosiscan be managed very successfully by repeat angioplasty (31) ;however, the procedure exposes the patient to additionalmorbidity, mortality and cost . Nevertheless, angioplasty isinitially less expensive and inherently less invasive than is

tACC V.I. 12, No. 2August 1999d29-05

bypass surgery and is a more attractive alternative to manypatients because a rapid return u) normal functional status ispossible .

C. Contraindications to AngioplastyIn general, the contraindications to angioplasty include all

of the relative contraindications enumerated for the perfor-mance ofcoronary angiography as outlined In the guidelinesof an earlier ACCIAHA report (2). Before undertakingangioplasty it is imperative that the patient clearly under-stand the procedure, its potential complications and thealternatives of medical therapy or bypass surgery . Addition-ally, the importance of a relative contraindication to angio-plasty will vary with the symptomatic state as well as thegeneral medical condition of the individual patient . Certainrisks may be appropriate in severely symptomatic individu-als who, for example, are not candidates for bypass surgery,whereas these risks would be inadvisable for an asympto-matic or mildly symptomatic individual . With this caveat thefollowing are enumerated as generally accepted contraindi-cations to the performance of angioplasty :

1 . Absolute contraindication:a) There is no significant obstructing lesion.b) Multivessel disease with severe diffuse atheroscle-

rosis is present for which an alternative form ofrevascularization would be unequivocally more ef-ficacious .

c) There is a significant obstruction (>50%) in the leftmain coronary artery and this main segment is notprotected by at least one completely patent bypassgraft to the left anterior descending or left circum-flex artery.

d) There is no formal cardiac surgical program withinthe institution .

2 . Relative contraindications:a) A coagulopathy is present : Conditions associated

with bleeding abnormalities or hypercoaguablestates may be associated, respectively, with unac-ceptable risks of serious bleeding or thromboticocclusion of a recently dilated vessel .

III There is no clinical evidence for spontaneous orinducible myocardial ischemia .

c) In multivessel angioplasty, the patient's conditionis such that coronary occlusion resulting from anyone dilation could result in cardiogenic shock . Thisgroup of patients is characterized, for example, bypatients who have large areas of myocardial dys-function as a result of previous myocardial infarc-tion and who have arteries with high grade lesionswhose acute occlusion would result in cumulativedamage equal to approximately 40 to 50% of thetotal myocardium .

d) The anticipated su •c ess rate of dilation is low (for

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example, chronic total occlusions >3 months old orsubtotal lesions exceeding 20 mm in length) .

e) The lesion under consideration is a borderline ste-notic lesion (usually <60% stenosis). Such lesionsshould not be dilated because of the demonstratedrisk of a restensetic lesion at the same site of evengreater severity. In some instances, objective evi-dence of myocardial ischemia related to the lesioncan change the designation from a "borderline" toa "significant" lesion that would be appropriate fardilation .

0 Variant or vasospastic angina is present in patientswith <60% stenoses.

g) The lesion under consideration is in a noninfarct-related artery in patients with multiecsscl diseasewho are undergoing cardiac catheterization duringthe acute phase of myocardial infarction.

In addition to these generally accepted relative contrain-dications, there are other conditions in which clinicians haveconsiderable reservation about the risk/benefit ratio of angio-plasty. Over and above a fundamental risk of mortality andmorbidity there is the added dimension of risk of failure ofthe procedure as a result of early closure as well as asubstantial risk of restenosis . The risks are viewed as acontinuum and it is their aggregate weight that shouldultimately determine whether a specific procedure should orshould not be undertaken (see section 111F).

D. Risks Associated With Angioplasty

Because coronary angioplasty requires visualization ofthe coronary anatomy as well as systemic arterial andvenous access, patients undergoing the procedure are at riskfor the same potential complications that are known to beassociated with diagnostic cardiac catheterization . Includedare arterial or venous obstructions, vessel perforations,bleeding, hypersensitivity reactions and infection . Myocar-dial infarction, stroke and death can also occur as a result ofcardiac catheterization but are infrequent .

Specific complications can occur that are directly relatedto the coronary angioplasty procedure . Balloon inflationresults in localized trauma to the coronary artery wall ; thenet result is usually atheroma fracture and arterial expansionthat produce an increase in the luminal area available forblood transport . At times, balloon inflation or guide wire orcatheter manipulation can cause more extensive arterial walldamage with medial dissection and the creation of en occlu-sive intimal flap . Thrombus formation also may occur at thedilation site. Either of these two latter consequences canexacerbate coronary narrowing and result in progression toabrupt total coronary artery occlusion . In the absence of awell developed collateral circulation, acute coronary occlu-sion usually results in severe myocardial ischemia andmyocardial infarction that, if extensive or in the setting of

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533ACCIAHA TASK FORCE REPORT

preexisting impaired left ventricular systolic function, maycause hemodynamic collapse and death . The most recentdata in the National Heart, Lung, and Blood InstituteReg'stry (derived from very experienced centers) indicatethat the procedure is still associated with a 1% in-hospitalmortality rate and an incidence rate of non-fatal myocardialinfarction of approximately 4%, although the aced 'or emer-gency bypass surgery has decreased to about 3 .5% (13). In arecent study (12), investigators reported a death rate of 0 .2%for patients undergoing elective angioplasty at two experi-enced centers .

If coronary occlusion should occur, recrossing the oc-cluded segment and repeating balloon inflation, inserting aperfusion catheter or using thrombolytic or vasodilatoragents can, on occasion, reestablish coronary artery patencyand relieve ischemia . Prolonged maneuvers to this end arediscouraged because emergency surgical revascularizationmay be delayed . The use of intraaortic balloon ceunterpul-sation in the setting of acute coronary occlusion may reducethe magnitude of ischemia and augment systemic perfusion .When needed, surgical revascularization should be under-taken immediately because of known time limitations onpreserving ischemic myocardium . The probability of myo-

cardial infarction is high and mortality is increased whencoronary artery surgery is undertaken on an emergencybasis ; reports (33-35) indicate a 25 to 40 incidence rate ofnonfaral new Q wave infarctions among patients undergoingemergency surgery after a failed angioplasty .

Other infrequent complications unique to coronary angio-plasty include intmcoronary embolization of atherosclerolicor thrombotic material, coronary perforation, laceration orrupture of a coronary artery with subsequent hemopericar-dium and tamponade .

E. Need for Surgical Backup

An experienced cardiovascular surgical team should beavailable within the institution' for emergency surgery for

all angioplasty procedures. The Subcommittee feels stronglythat there should be no exception to this requirement andholds the position that all arrangements requiring the trans-portation of patients to off site surgical facilities for suchemergency surgery fail to meet the necessary standards ofcare exercised by prudent physicians and cannot be con-doned.

A formal surgical consultation for elective angioplastyprovides a means for a second opinion to the cardiologist,

"'Within the institution" is generally intended to mean within the samehospital. In those instances in which two adjacent hospitals arc physicallyconnected such that emergency uanspon by stretcher or gumey can beachieved rapidly and ed tively, the transport of patients between the twohospitals for emergency cardiac surgical services would not be viewed as "ofsite ."

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the patient and the family, and represents the ideal approachbecause it underscores the reality of potential, serious com-plications and the need for a team approach . However, thisis often impractical, may introduce delay in the procedureand lengthen the hospital stay . It is appropriate, however, toobtain prior surgical and anesthesiology consultations on allpatients identified as being at high risk for abrupt vesselclosure as well as those patients judged to be high risksurgical candidates because of age, markedly impaired ven-tricular function or associated medical disorders such aschronic pulmonary disease, cerebrovascular disease and thelike . The exact arrangement for surgical standby will varyfrom institution to institution depending on such obviousfactors as the number of operating rooms available forcardiac surgery and the number of surgeons, perfusionists,nurses and other personnel (35). The primary and essentialrequirement is the capacity to provide rapid surgical supportwhen angioplasty fails ; otherwise, optimal patient care be-comes seriously compromised .

On-going experience in large multicenter trials under.scores the need for urgent revascularizalion by emergencybypass surgery in the setting of both elective and emergencyangioplasty . Thus it is reaffirmed that all angioplasty proce-dures should be undertaken only in institutions that haveformally approved cardiac surgical programs.

F. Need for Institutional Review

A rigorous mechanism of valid peer review must beestablished and on-going within each institution performingcoronary angioplasty because 1) angioplasty is an interven-tional procedure associated with known risks of seriouscomplications including death ; 2) it is a therapeutic modalitywhose efficacy has a recognized association with operatorskill and experience; and 3) in certain instances, the proce-dure can be viewed as a remunerative undertaking per-formed by the same physician who initiates and interpretsthe diagnostic studies leading to the procedure itself. In thislatter circumstance it is imperative that the responsiblephysician arrange for a consulting opinion from an appropri-ate specialist .

Although institutional review can take many forms andwill vary according to such factors as the size of institutionsand departments, the number of staff and the volume ofprocedures, there are some basic requirements for suchreview to be meaningful . At a minimum, the opportunitymust exist for cardiologists and cardiac surgeons knowledge-able about the procedure to review the overall results of theprogram on a regular basis. Specific attention should bedirected to success and failure rates and complicationsleading to morbidity, including emergency surgical proce-dures, and mortality. The review should also examine thequality and accuracy of cinearteriographic studies and the

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appropriateness of indications and it should discuss con-traindications .

The surgical profession has long since provided a work-able model for addressing these and similar issues withregularly scheduled mortality and morbidity conferencesthat include appropriate committee (for example, tissue)reports and impose attendance requirements that are de-signed to assure impartial peer review. Institutions withmedical or surgical groups, or both, that cannot adequatelymeet this obligation should undertake regional review withcooperating institutions or abandon their program in angio-plasty.

III. Specific Considerations

A . Successful Angioplasty and Its DeterminantsA successful angioplasty procedure is defined as one in

which a o20% change in luminal diameter is achieved, withthefinal diameterstenosis <50% and without the occurrenceofdeath, acute myocardial infarction or the need for emer-gency bypass operation . Atherosclerotic coronary stenosesare considered significant if they have the potential ofimpairing coronary blood flow under physiologic circum-stances. Experimental data indicate that coronary flow re-serve declines as coronary diameter is reduced beyond 50% .It is acknowledged that the visual assessment of coronarynarrowing on cineangiograms is associated with substantialinterobserver and intraobserver variability. Determinationof coronary narrowing by caliper techniques is a readilyavailable methodology that correlates closely with sophisti-cated computer quantitative methods. For the purpose ofthis report, a significant stenoses is defined as one thatresults in a 50% reduction in coronary diameter as determined by caliper method .

After a decade of experience it is now reasonable toexpect an overall success rate of zg5% for single lesiondilations within any angioplasty program . This same ex-perience further indicates that, in addition to operatorexperience, procedural success relates to certain patientcharacteristics and, very importantly, to angiographic char-acteristics of the lesion or lesions to be dilated .

Patient-related factors influencing a successful dilationare primarily age (<65 years) and gender (male), but clinicalvariables such as a history of hypertension, diabetes, priormyocardial infarction, prior bypass surgery and impairmentof left ventricular function are known to be associated withprocedural mortality.

Angiographic patterns outlining the morphologic charac-teristics of vessels and defining lesion-specific characteris-tics have now been identified that greatly influence thelikelihood of a successful dilation . Recognizing the uniquelytechnical aspects of angioplasty and in an attempt to riskstratify any given procedure, the Subcommittee proposesthe following lesion-specific classification as a guide for

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estimating the likelihood of a successful procedure as well asthe likelihood of developing abrupt vessel closure (see alsoTable l, section IV):

Type A lesionsThese are lesions in which the anticipated success rate

should be ?85% and the risk of abrupt vessel closure islow because they are discrete, concentric lesions anddemonstrate all of the following characteristics: readyaccessibility, location in a nonangulated segment (<45°),smoothness of contour, little or no calcification, absenceof total occlusion, nonostial location, absence of majorbranch involvement, absence of thrombus .Type B Lesions

These are lesions in which the anticipated success rateranges from 60 to 85% or the risk of abrupt vessel closureis moderate, or both . They include all lesions that vreneither type A nor type C (see later) and they are usuallyidentified by such characteristics as, but not Railed to,the following: tubular shape, eccentricity, vccessibilityinfluenced by moderate tortuosity of proximal segment,location in a moderately angulated segment (>45', <90°),irregularity of contour, moderate or sevetc calcification,presence of thrombus . ostial location, bifurcation lesionsrequiring double guide wires, total occlusions <3 monthsold . It is recognized that lesions with these characteris-tics, although associated with some increase in 9brnptvessel closure, may in certain instances be associatedwith a comparatively low likelihood of a major complica-tion. This is often the case, for example, in unsuccessfulattempts to dilate total occlusions that are <3 months oldor in the dilation of some type B lesions in which thedistal vessel is supplied by abundant cotlaterals .Type C lesions

These are lesions in which the anticipated success rateis <60% or the risk of abrupt vessel closure is high, orboth, because they demonstrate any of the followingcharacteristics: diffuse disease (>2 cm in length), exces-sive tortuosity of proximal segments, location in anextremely angulated segment (>90°), total occlusion >3months old, inability to protect major side branches,degeneration of older vein grafts with friable lesions.Attempts to dilate such lesions should not be undertakenwhen they are present in vessels supplying lar bre ormoderate areas of viable myocardium .

B . Angioplasty at the Time of Initial CardiacCatheterization

The selection of patients for angioplasty demands carefulreview of the clinical and anatomic features of each case.This is optimally done after diagnostic cardiac catheteriza-tion when unhurried review of the cineangiograms can takeplace (in consultation with colleagues when necessary) todetermine the appropriateness of the case and plan a dilation

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strategy . In addition, the patient, family and referring phy-sician can be consulted, the therapeutic options reviewed

and the risks and benefits of the procedure discussed beforeobtaining informed consent . This process obviously subjectsthe patient to a repeat catheterization with its inherent risksand recognized morbidity, adds additional days of hospital-ization, introduces delay in the patient's return to work and

normal physical activities and clearly adds to the total directand indirect costs involved . These disadvantages are coun-terbalanced by the overriding benefits of a careful preangio-plasty evaluation, improved patient preparedness and, inmany instances, more timely arrangement for surgicalbackup and scheduling . It: particular, the evaluation of thecororar anatomy is often the most difficult aspect in theselection of patients for angioplasty ; decisions made on thebasis of video images can be inaccurate and can lead toincreased risk for the patent . For these reasons, it isrecommended that angioplasty not be performed routinely asan extension of an initial diagnostic catheterization .

There are, however, well defined subsets of patients forwhom it is appropriate to contemplate performing angio-plasty at the time of the initial diagnostic cardiac catheter-ization. This group would include patients with unstableangina who cannot be discharged from the hospital without arevascularization procedure and who are suspected of hav-ing single vessel coronary disease on the basis of age,absence of prior myocardial infarction of known coronarydisease and recent onset of symptoms. Because a highproportion of these patients have single vessel disease ame-nable to angioplasty, it is reasonable to prepare the patientfor this possibility before diagnostic cardiac catheterizationby obtaining informed consent and a complete preangio-plasty evaluation. Similarly, individuals who have had priorangioplasty and are undergoing catheterizaton to evaluatethe possibility of restenosis represent a group of patientswhose coronary anatomy is generally known in advance andwhose clinical management is facilitated by performingangioplasty immediately after the diagnostic study whenindicated . In selected patients with acute myocardial infarc-tion in whom adequate reperfusion is not obtained bythrombolytic therapy, angioplasty may be of benefit . Insuch patients when multivessel disease is present, onlythe vessel related to the area of infarction should be di-lated . If angioplasty is to be considered in lieu of throm-bolytic therapy, it is recommended that the procedure beapplied to patients who present within 4 h of the onset ofsymptoms unless there is strong evidence for ongoing ische-mia . Whatever the clinical circumstances, it is imperativethat high quality fluoroscopic and video replay images orpromptly developed tine films be available before undertak-ing angioplasty at the time of initial diagnostic catheteriza-tion.

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RYAN ET AL.ACC/AHA TASK FORCE REPORT

C. Postangioplasty Management

Immediately after coronary angioplasty attention is di-rected to monitoring for evidence of recurrent ischemia andto assure appropriate hemostasis at the site of catheterinsertion . Specific protocols for sheath removal, continua-tion of anticoagulation and antiplatelet therapy will varyfrom institution to institution . Ordinarily, heparin anticoag-ulation used during the procedure is not reversed withprotamine for fear of inducing thrombosis at sites of ballooninflation. When angioplasty is performed percutaneously,the indwelling vascular sheaths usually can be removedwithin 3 to 4 h after the last bolus injection of heparin . Incertain instances, such as the setting of extensive intimaldisruption, thrombus formation or embolization, a constantinfusion of heparin may be des ired . Sheaths are then re-moved after the termination of the heparin infusion or aftertemporary cessation of therapy .

A small proportion of patients in whom angioplasty wasjudged angiographically successful will experience symp-toms of myocardial ischemia during this observation periodafter the procedure . If electrocardiographic (ECG) abnor-malities suggesting ischemia are detected there is a substan-tial risk of abrupt vessel closure, which has been associatedwith a comparatively high mortality rate (10 to 12%) (36). Anindividualized judgment must be made as to whether addi-tional angioplasty, emergency bypass surgery or continuedmedical therapy is appropriate . Accordingly, the equipmentand services required to perform repeat angiography and, ifnecessary, repeat angioplasty, need to be available 24 h aday in institutions that undertake a program in angioplasty .

Patients should be instructed about risk factor modifica-tion before hospital discharge . Depending on the individualcase, this advice would include hypertension control, diabe-tes management, serum lipid reduction, abstinence fromtobacco, weight control and timing of the return to fullactivity. Patients should be informed of the importance ofcontacting their physicians if symptoms recur .

D . RestenosisAlthough the initial outcome for coronary angioplasty

procedures has improved progressively over the last 10years (reaching primary success rates in native coronaryarteries as high as 90 to 95% in well chosen patients), theincidence of restenosis over the first 6 to 8 months afterdilation has remained unchanged at approximately 30%. Therate of restenosis in native arteries depends partly on itsdefinition ; in the National Heart, Lung, and Blood InstituteRegistry, restenosis was defined as a loss of 50% of the gainachieved in luminal diameter at the time of the successfulangioplasty, or a 30% increase in narrowing at the site ofstenosis (28) . Follow-up of 557 patients undergoing repeatcoronary angiography, indicated that restenosis was associ-

JACC V.I . 12, No. 2August 1988 :529-45

ated with the recurrence of symptoms in the ntgjority ofpatients ; likewise, relatively few patients with single vesseldisease harbora clinically silent restenosis . The rate of silentrestenosis was 14% in the National Heart, Lung, and BloodInstitute Registry, and a 4% rate was reported in a combinedstudy from the Cardiology Branch of the National Heart,Lung, and Blood Institute and Georgetown University(28,37). On the basis of multivariate analysis, independentfactors that predispose to restenosis Include angioplasty inthe left anterior descending coronary artery, absence ofintimal dissection immediately after angioplasty, residualgradient after dilation >15 mm Hg, a large residual stenosisafter angioplasty, and unstable angina (29) . Univariate anal-ysis has pointed to several other risk factors for restenosis,including male gender, diabetes mellitus, patients withchronic total occlusions, thrombus, an initial transstenoticgradient >40 mm Hg and recent, as opposed to long-standing, occurrence of angina . In addition, several centershave reported (38) that lesions that involve the origin of avessel or its branch points are more prone to restenosis .Factors that have not been correlated with risk of restenosisinclude age, functional class, history of previous myocardialinfarction, hypertension, history of smoking, serum choles-terol, presence of calcification at the site of dilation, mor-phologic features of the lesion, lesion length, inflation pres-sure and medications on discharge .

Patients who develop clinical or angiographic evidence,or both, of restenosis in native coronary arteries are readilytreated with a second dilation procedure . For repeat angio-plasty, the primary success rate is higher than for the initialprocedure (85 versus 63% in the National Heart, Lung, andBlood Institute Registry), a relatively low myocardial infarc-tion rate of 1 .5%, and a reduced incidence of completeocclusion with need for emergent coronary artery bypassgraft surgery (2 versus 3.5%).

A significantly higher restenosis rate of 50 17s is notedwhen coronary angioplasty is performed in the proximalanastomosis or body of a saphenous vein bypass graft . Bycontrast, dilations performed in the distal graf lartery anas-tomotic site exhibit restenosis rates comparable with thoseof native vessel sites .

E . Incomplete RevascularizationAs coronary angioplasty is being utilized in ever more

complex clinical and pathoanatomic situations, concern isnow expressed that patients are being subjected to "incom-plete revascularization" or less than optimal correction oftheir pathophysiologic state . in patients with multivesseldisease, some operators attempt to dilate all accessible,significant lesions whereas others approach only the lesiondeemed most likely to cause myocardial ischemia (the so-called culprit lesion) . The surgical experience is relativelyconvincing that "complete revascularization," that is, graft

IACC Vol. 12 . No.2August 1995:529-05

insertion around all moderate to severe coronary stenoses,leads to a superior therapeutic result . Follow-up studies (39)of patients with surgical revascularization suggest that com-plete revascularization not only relieves signs and symptomsof myocardial ischemia, but also it is more effective thanincomplete revascularization in protecting against futurecoronary events .

During surgery, partial or incomplete revascularizationusually results from the extent or distribution of a patient'scoronary artery disease and less often is a reflection of theskills and diligence of the surgical team . In patients under-going angioplasty, partial revascularization is likely to occurfor several reasons in addition to the extent and distributionof coronary disease and the extent of myocardial fibrosis .Quite clearly it also relates to the specific anatomy thatdetermines the accessibility of lesions for angioplasty . Theoccurence of restenosis in one or more of .he dilated lesionsalso may result in the development of partial revasculariza-tion. Although early graft closure after bypass surgery alsoconverts complete to partial revascularization, this is a lesscommon phenomenon than restenosis after arterial dilatior .

At present, partial revascularization after coronary angio-plasty is an inherent limitation of the procedure and can beexpected to occur frequently in patients undergoing multi-vessel angioplasty. Notwithstanding, the advocates of angio-plasty in patients with multivessel disease point to thesuccessful relief of symptoms and the elimination of objec-tive signs of ischemia after stress tests in a high percentageof such patients in whom all lesions cannot be successfullydilated . Moreover, the claim is made that angioplasty palli-ates the disease process and often allows a period of clinicaltemporizing before surgical revascularization is required.Angioplasty also allows for a strategy of performing thedilation procedure on successive days or weeks . Multiplesuccessive interventions are feasible and, although there issome degree of cumulative risk, angioplasty differs in thisregard from aortocoronary bypass graft surgery, in whichthe opportunity for serial repeat thoracotomies is under-standably more limited .

There has not been sufficient accumulation of clinicalexperience, either retrospectively or prospectively, to judgethe relative advantage of angioplasty versus aortocoronarybypass graft surgery for relief of signs and symptoms ofmyocardial ischemia and infarction in multivessel disease.The adequacy of myocardial revascularization by angio-plasty, particularly in comparison with that provided bysurgery, will require randomized prospective studies inwhich coronary pathoanatomic subsets are closely matched .The National Heart, Lung, and Blood Institute has fundedtwo such studies to date : one at Emory University thatbegan in July 1987 and the multicenter BARI Trial (BypassAngioplasty Revascularization Investigation) that began inthe fall of 1987 . Also of importance will be the long-termfollow-up of large numbers of patients treated by these two

RYAN ET AL.

537ACCIAHA TASK FORCE REPORT

competing interventions with matched cohorts compared bymultivariate analysis,

F. Cumulative Consequences of FailedAngioplasty

Inherent to the strategy of coronary angioplasty is the"price of failure." This is more than the risk of a seriouscomplication and embraces the consideration that 5 to 15%of these procedures will be initially unsuccessful and that 3to 6% of patients will require urgent or emergent surgery tobypass a coronary artery occluded during the procedure .Furthermore, approximately 30% of the patients who havean initially successful procedure will develop restenosis ofthe dilated segment within 8 months and will require asecond angioplasty or bypass surgery . Thus, there are anumber of patients in whom the risk relative to the cost andmorbidity associated with angioplasty as a primary therapymay be considerably higher than that of some patients whoare treated from the outset with revascularization surgery .

These consequences of early failure must be consideredin clinical decision making and in evaluating the relativemerits of bypass surgery versus coronary angioplasty in agiven patient . Although there is little specific information onthe price of failure in patients with multivessel angioplasty, itis likely that it is higher than for single vessel angioplasty andindeed there will be categories of patients in whom multi.vessel angioplasty is not prudent .

IV . Indications for AngioplastyPreamble

The approach to every angioplasty procedure requires aknowledgeable judgment that weighs the likelihood of asuccessful Procedure* against the likelihood of failure andthe risk of complications (abrupt vessel closure, morbidity,mortality and restenosis) . In attempting to prioritize indica-tions for angioplasty, the Subcommittee was greatly intlu-enced by the specific considerations discussed in section III :t) factors favoring a successful dilation; 2) factors associatedwith abrupt vessel closure ; 3) restenosis ; 4) incompleterevascularization ; and 5) the consequences of failure of theprocedure.

Experience to date suggests that the factors favoring asuccessful procedure are age <65 years, male gender, singlevessel disease, single lesion angioplasty, subtotal occlu-sions, absence of calcification, accessibility of the lesion andnormal ventricular function. Counterbalancing these varia-bles that support the likelihood of successful angioplasty are

'A successful procedure is defined mans in which a .20% change inluminal diameler is achieved with the final dianxter stenosis <55%, withoutthe occurrence of death, acme myaasdial infarction or bypass Operationdoting he,pilaheulion .

538 RYAN FT AL.ACCIAHA TASK FORCE REPORT

Table 1. Characteristics of Type A, B and C Lesions

•

Discrete i<10 mm length)Concentric

•

Readily accessible•

Nonengulated segment, <45'•

Smooth contour

•

Tabular (101 . 20 mm length)•

Eccentric•

Moderate lanumily of proximal segment•

Moderately angulated segment, >45', <90' Irregelarcontour

•

DiBpse (>2 em lorgih)•

Excessive lonaosily of proximal segment•

Extremely angulated segment >90'

the preprocedural factors that favor abrupt vessel closureduring or shortly after angioplasty, These are viewed asbeing female gender, length of lesion, eccentric lesions,bifurcation/side branch lesions, angulation of the segmentbeing dilated, other stenoses in the same vessel and thepresence of thrombus (40) .

The clinical variables that have been associated withincreased procedural mortality are currently identified as age>65 years, female gender, a history of hypertension, diabe-tes, prior myocardial infarction, prior bypass surgery, mul-tivessel disease, left main coronary disease, a large area ofmyocardium at risk, impairment of left ventricular functionand collateral vessels that supply significant areas of myo-cardium and originate distal to the segment to be dilated (32) .

The factors associated with restenosis are currently rec-ognized as recent onset of angina (<3 months), unstableangina, variant angina, diabetes mellitus, multivessel dis-ease, right ostial lesions, lesions located at the origin of theleft anterior descending coronary artery, lesions in theproximal anastomoses or body of a vein graft, chronic totalocclusions, presence of thrombus, severity of residual lesion(>30%) and a significant residual gradient (>15 to 20 mmHg) (28,29) .

Both clinical judgment and statistical estimates permitappropriate weighting and integration of these variables toformulate likelihood estimates (high, moderate or low) forany given procedure according to

1. the likelihood of a successful dilation,2. the likelihood of abrupt vessel closure with subsequent

morbidity and mortality, and

Lesion-specific ChsratteristiesType A Lesions (high success, >95%: low risk)

•

Little or no calcification•

Less than totally occlusive•

Not meet in location•

No major branch involvement•

Absencr of thrombusType a Lesions (moderate success, 601085% ; moderate risk)

Type C Lesions (low suwese. <60% ; high risk)

•

Moderate to heavy calcification•

Total occ:usons <3 months old•

Ostial in location•

Bifurcation esions requiring double guide wires•

Some thrombus present

•

Total occlusion >3 months old•

Inability to protect major side bmnches•

Degeeetated vein areas with friable lesions'Although the risk of abrupt vessel closure is moderate, in entrain instances the likelihood of e maim,

complicalion maybe Iowa in dilation of totalecclueicex <t months old or when abundant collateral channels supplythe distal vessel .

IACC vol . 12 . No. 2August 1988:52945

3 . the likelihood of restenosis .Although operator experience and individual patient

characteristics are important factors relating to outcome,both procedural success and the development of abruptvessel closure are largely determined by specific character-istics of the vessels and lesions involved . Recognizing theunique technical aspects of angioplasty and with the objec-tive of fostering knowledgeable judgments about risk strati-fication, the Subcommittee has summarized three types oflesion-specific characteristics based on the current state ofknowledge in Table I (see also section 1II-A) .

Type A lesions have those characteristics that allow ananticipated success rate of =_85% and have a low risk ofabrupt vessel closure .

Type B lesions have those characteristics that result in alower than optimal success rate ranging from 60 to 85% orhave a moderate risk of abrupt vessel closure, or both.

Type C lesions have those characteristics that result in anunacceptably low success rate (<60%) or have a high risk ofabrupt closure, or both .

It is recognized that we are dealing with a discipline ofcardiovascular care that is undergoing considerable growthand development; as new insights are gained we can antici-pate further refinement of the guidelines for coronary angio-plasty that are set forth in this document using the followingclassification :

Class I: Conditions for which there is general agreementthat coronary angioplasty is justified . A class I indicationshould not be taken to mean that coronary angioplasty is theonly acceptable therapy .

JACC Vol. 12 . No. 2August 196a'.529-s5

Class II : Conditions for which coronary angioplasty isperformed but there is divergence of opinion with respect toits justification in terms of value and appropriateness.

Class III : Conditions for which there is general agree-ment that coronary angioplasty is not ordinarily indicated .

1 . Single Vessel Coronary Artery DiseaseA . Asymptomatic or Mildly Sympturnatie (functional class 1)

Patients With or Without Medical Therapy. SymptomsAre Defined in Accordance With the Canadian Cardio.vascular Society Cletsjfication (Appendix C)

Class IThis category applies to patients who have a signifi-

cant lesion* in a major epicardial artery that subtends alarge area of viable myocardium and who

I. show evidence of severe myocardial ischemia whileon medical therapy during laboratory testing, i .e .,ischemia induced by low level exercise and mani-fested bya) rat man of ischemic ST segment depression in

multiple leads, orb) reversible thallium perfusion defects in more

than one vascular region, orc) exercise-induced reduction in the ejection frac-

tion or wall motion abnormalities an radionu-elide ventriculographic studies, or both, or

2. have been resuscitated from cardiac arrest or fromsustained ventricular tachycardia in the absence ofacute myocardial infarction, or

3 . must undergo high risk noacardiac surgery, such asrepair of an aortic aneurysm, iliofemoral bypass orcarotid artery surgery, if angina is present or thereis objective evidence of ischemia, or

4 . have a history of myocardial infarction togetherwith a history of hypertension and ischemic STsegment depression on the baseline ECG .

All of these patients should•

have one or more type A lesions in the same vessel orits branches and

•

be in the low risk group for morbidity (abrupt vesselclosure <4%) and mortality (<0.5%) .

Class II (mild or no symptoms, single vessel coronarydisease)

This category applies to patients who have a significantlesion in a major epicardial artery that subtends at least amoderate-sized area of viable myocardium and who

1 . show objective evidence of myocardial ischemiat

r-For the purpose of Ibis report, a significant stuvasis is defined m one that

esults in a 50% reduction in coronary diameter as determined by calipermethod.

tEvidence of myocardial ischemia during laboratory testing is taken to

RYAN ET AL.

5 39ACCIAHA TASK rORCE REPORT

while on medical therapy during laboratory testing,anda) have ar least a moderate likelihood of successful

dilation, andb) have a low risk of abrupt vessel closure, andc) are in the low risk group for morbidity and

mortality .Cla_., III (mild or no symptoms, single vessel coronary

disease)This category applies to all other patients with single

vessel disease and mild or no symptoms who do not fulfiltthepreceding criteria for class I or class 11 . It includes, forexample, patients who

I . have only a small area of viable myocardium atrisk, or

2 . do not manifest evidence of myocardial iscbemiaduring laboratory testing, or

3 . have borderline lesions of <50% diameter reduc-tion, or

4 . have type C lesions, or5 . are in the moderate or high risk group for morbidity

and mortality .

Comments. In some patients, circumstances of occupa-tion or employment may result in a class H indication beingviewed as a class I category. Such patients would includeindividuals whose occupation involves the safety of others(airline pilots, bus drivers, track drivers, air traffic control-lers, for example) and those in certain oecupatiohs thatfrequently require sudden vigorous activity (fire fighters,police officers, athletes, for example) . However, class IIIindications for asymptomatic or mildly symptomatic individ-uais with si gle vessel disease pertain to a risk profile thatprecludes the patient's suitability as a class I or 11 indication .

B . Symptomatic Patients With Angina Pectoris (functionalclasses If to IV, unstable angina) With Medical Therapyand Single Vessel Disease

Class IThis category applies to patients who have a significant

lesion in a major epicardial artery that subtends at least amoderate-sized area of viable myocardium and who

1 . show evidence of myocardial ischemia while onmedical therapy during laboratory testing (in-cluding ECG monitoring at rest), or

2. have angina pectoris that has proved inadequatelyresponsive to medical treatment . "Inadequately

mean exercise-induced ischemia (with or without exercise-induced anginapectoris) manifested by al mar of ischemic ST ses neat depression a one or

e-indaced reversible thallium perfusion defects and/or exercise-induced reduction in the ejection fraction and/or wall main abnormalities cmradionuclide vearioulographic studies .

540

RYAN ET AL .ACGAHA TASK FORCE REPORT

responsive" is taken to mean that patient andphysician agree that angina significantly interfereswith the padsnt's occupation or ability to performhis or her usual activities, or

3 . are intolerant of medical therapy because of uncon-trollable side effects .

All of these patients should•

have at least a moderate likelihood of successful dila-tion and

•

be in the low risk group for morbidity and mortality .

Qass If (syr;, ;domatic, single vessel coronary disease)This category applies to patients who have a significant

lesion in a major epicardial artery that subtends at least amoderate-sized area of viable myocardium and who

1 . show evidence of myocardial ischemia while onmedical therapy during laboratory testing (in-cluding ECG monitoring at rest, anda) have one or more type B lesions in the same

vessel or its branches, orb) are in the moderate risk group for morbidity

(abrupt vessel closure <8%) and mortality(<1%), or

2. have disabling symptoms and a small area of viablemyocardium at risk, anda) at least a moderate likelihood of successful

dilation, andb) are in the low risk group for morbidity and

mortality, or3. despite significant angina do not have objective

evidence of myocardial ischemia while on medicaltherapy during laboratory testing, anda) have at least a mod^.rate likelihood of successful

dilation, andb) are in the low risk group for morbidity and

mortality .Class III (symptomatic, single vessel, coronary disease)This category applies to all other symptomatic patients

with single vessel disease who do not fulfill the precedingcriteria for class I or class 11 . It includes, for example,patients who

1 . have only a small area of viable myocardium at riskin the absence of disabling symptoms, or

2. have clinical symptoms not likely indicative ofischemia, or

3. have Type C lesions, or4. are in the high risk group for morbidity and mortal-

ity.

Comments. Patients with single vessel disease who havesignificant symptoms constitute one of the largest groups ofpatients undergoing angioplasty. However, the generallyexcellent prognosis far patients with single vessel disease

JACC Vat, 12 . Na. 2Al- 1"11:529-45

should be a paramount consideration before undertaking aninterventional procedure in these patients . It is imperativethat there be some assurance that the significant symptomsare indeed due to the coronary lesion proposed for dilation .Although significant symptoms may justify a lower tolerancefor the risk of abrupt vessel closure or subsequent resten-osis, one cannot compromise on the risk for significantmortality or morbidity.

l!. Multivessel Coronary Artery Disease

A. Asymptomade orMiWy Symptomotie (lancrionol clan 1)Patients With or Without Medical Therapy

Class IThis category applies to patients who have one significant

lesion in a major epicardial artery that could result in nearlycomplete revascularization because the additional lesion(s)subtends a small viable or nonviable area of myocardium .Additionally, patients in this category must

I . have a large area of viable myocardium at risk, and2 . show evidence of severe myocardial ischemia while

on medical therapy during laboratory testing, or3 . have been resuscitated from cardiac arrest or from

sustained ventricular tachycardia in the absence ofacute myocardial infarction, or

4. be undergoing high risk noncardiac surgery anddemonstrate objective evidence of ischemia, or

5. have a history of myocardial infarction togetherwith a history of hypertension and ST segmentdepression on the baseline ECG.

All of these patients should•

have one or more type A lesions whose successfuldilation would provide relief to all major regions ofischemia, and

•

be in the low risk group for morbidity and mortality .

Class II (mild to no symptoms, multivessel coronary disease)This category applies to patients who

1 . are similar to patients in class I but whoa) have a moderate-sized area of viable myocar-

dium at risk, orb) have objective evidence of myocardial ischemia

while on medical therapy, or2. have significant lesions in two or more major epi-

cardial arteries, each of which subtends at least amoderate-sized area of viable myocardium .

All of these patients should•

show evidence of myocardial ischemia while on medicaltherapy during laboratory testing, and

•

have one or more type A or B lesions whose successfuldilation would provide relief to all major regions ofischemia, and

•

be in the low risk group for morbidity and mortality .

JACC Vat. 12 . No . 2August 1988:529-J5

Class III (mild to no symptoms, multivessel disease)This category applies to all other patients with multives-

sel disease and mild or no symptoms who do not fulfill theabove criteria for class I or class II . It includes, for example,patients who

I . have only a small area of viable myocardium atrisk, or

2. have a subtotally occluded vessel requiring angio-plasty wherein the development of total occlusionof the vessel would result in severe hemodynamiccollapse due to left ventricular dysfunction, or

3. have more than two major arteries with type Blesions, or

4 . have type C lesions in major epicardial vesselsserving moderate or large areas of viable myocar-dium, or

5 . are in the moderate or high risk group for morbidityor mortality (for example, advanced left ventriculardysfunction rejection fraction <2t%] in the absenceof angina or evidence of ischemia) .

B. Symptomatic Patients With Angina Pectoris (functionalclasses II to IV, unstable angina) With Medical Therapyand Multivesset Disease

Class IThis category applies to patients who have significant le-

sions in each of two major epicardial arteries both subtendingat least moderate-sized areas of viable myocardium and who:

1 . show evidence of myocardial ischemia while onmedical therapy during laboratory testing (in-cluding ECG monitoring at rest), or

2. have angina pectoris that has proved inadequatelyresponsive to medical therapy, or

3. are intolerant of medical therapy because of uncon-trollable side effects .

All of these patients should :• have type A and B lesions whose successful dilationwould provide relief of all major regions of ischemia,and

a be in the low risk group for morbidity and mortality .

Class II (symptomatic, multivessel disease)This category applies to patients who have significant

lesions in two or more major epicardial arteries that subtendat least moderate-sized areas of viable myocardium and who

l . are similar to patients in class I but who are in themoderate risk group for morbidity and mortality, or

2 . have angina pectoris but do not necessarily haveobjective evidence of myocardial ischemia while onmedical therapy during laboratory testing .

All of these patients should• have type A and B lesions whose successful dilationwould provide relief of all major regions of ischemia,and

RYAN ET AL .

541ACCIAHA TASK FORCE REPORT

•

be in the moderate risk group for morbidity and mor-tality

3 . have disabling angina that has proved inadequatelyresponsive to medical therapy, anda) be considered a poor candidate for surgery be-

cause of advanced physiologic age or coexistingmedical disorders, and

b) have one or more type A and B lesions thatcannot be successfully dilated, and

c) be in the moderate risk group for morbidity andmortality.

Class III (symptomatle, multive sel coronary, disease)This category applies to all other symptomatic patients

with multivessel disease who do not fulfill the precedingcriteria in class I or class 11. It includes, for example,rave sts who

l . have only a small area of myocardium at risk in theabsence of disabling symptoms, or

2. have a subtotally occluded vessel requiring angio-plasty wherein the development of total occlusionof the vessel would result in severe hemodynamiccollapse due to left ventricular dysfunction, or

3. have type C lesions in major epicardial vesselsserving moderate or large areas of viable myocar-dium, or

4 . are in the high risk group for morbidity or mortality,or both.

Comments . It is to be stressed that risk assessment isdifferent in patients with mulhvessel as compared with singlevessel disease . In t. a former there ideally should be theopportunity for anatimically complete revascularization,although it is recognize:: loot adequate functional revasen-larization can be achieved without necessarily being anatom-ically complete . In every instance the goal is to achieve reliefof ischemia at a risk acceptable for the procedure . Inestimating this risk in multivessel disease it is imperative thateach lesion be considered in the context of all other lesionsprrscnt. Some assessment must then be made of the conse-quences likely to ensue should any one of the attempteddilations fail and result in abrupt vessel closure . For exam-ple, it would be judged inappropriate to attempt dilation of aproximal high grade left anterior descending artery lesion ifthat vessel was supplying many collateral vessels to a largearea of viable myocardium in the distribution of a totallyoccluded dominant right coronary artery .

III . Acute Myocardial Infarction (AngioplastyDuring Initial Hospitalization)

Class IThis category applies to the dilation ofa significant lesion,

in the infarct-related artery only, in patients who

542

RYAN ET AL.ACC/ANA TASK FORCE REPORT

1 . have recurrent episodes of ischemic chest painparticularly if accompanied by ECG changes(postinfarction angina), or

2 . show evidence of severe myocardial ischerniawhileon medical therapy during laboratory testing per-

formed before hospital discharge, or3 . have recurrent ventricular tachycardia or ventricu-

lar fibrillation, or both, while on intensive anti-arrythmic therapy.

All of these patients should :•

have one or more type A lesions and•

be in the low risk group for morbidity and mortality .

Class IIThis category applies to the dilation of significant lesions

in patients whoI . are similar to patients in class I but who

a) have type B lesions, orb) undergo multivessel angioplasty, orc) are in the moderate risk group for morbidity or

mortality, or both, or2. are within the very early hours of an evolving

myocardial infarction, with or without thrombolytic

therapy, or3. are within 12 h of the onset of cardiogenic shock or,

in those who have survived cardiogenic shock, inthe period before discharge, or

4. are asymptomatic and have a significant residuallesion in the infarct-related artery after thromboly-tic therapy, or

5 . show objective evidence of myocardial ischemiadodgyg laboratory testing performed before dis-

charge, or6. have had a non-Q wave myocardial infarction, and

a) have single vessel disease withb) type A lesions, and

c) are in the low risk group for morbidity andmortality .

Class 111

This category applies to all other patients in the immedi-ate postinfarction period (during initial hospitalization) whodo not fulfill the preceding criteria for class I and class II .For example:

I . undertaking dilation of additional lesions in a vesselother than the infarct related artery within the earlyhours of infarction (0 to 6 h), or

2 . dilation of residual lesions that are borderline (50 to60% diameter reduction), or

3 . dilation of type C lesions, or4. undertaking angioplasty in patients in the high risk

group for morbidity and mortality .

IACC V .I. 12 . No. 2August 1988:529-45

Comments. The role of angioplasty in the management ofpatients during the course of an acute myocardial infarctionis currently the subject of intense investigation. Althoughthere is evidence that the procedure can be used effectivelyas a primary means of establishing reperfusion in the veryearly hours of an evolving infaretion(41,42), many imp( rtantquestions remain unresolved such as the impact of 1-oce-dural delay required to undertake angioplasty, the influenceof thrombus on abrupt vessel closure and subsequent resten-osis.

The use of angioplasty in conjunction with thrombolytictherapy is of particular interest and is thought by many tohold great promise . A note of caution is warranted, however,in light of the findings of three separate large randomizedtrials (43-45) that have recently reported adverse effectswhen angioplasty was performed immediately, rather thanlater, after the administration of tissue plasminogen activa-tor. The optimal timing and long-term benefit of angioplastyin the management of patients with acute infarction arequestions that must await further data .

APPENDIX A

Training and CredentialingIt is generally acknowledged that specialized skills are

required for coronary interventional techniques. Training inthese procedures necessitates thorough skills in diagnosticand therapeutic cardiology and particularly cardiac catheter-ization and angiography. Whereas the majority of individualscurrently performing angioplasty learned the technique byobserving experts and attending "how-to" seminars, thecomplexity of the procedure and the recognized need forhands-on experience dictate that formal training programs inangioplasty become the required means of learning . En-trance requirements to such programs should follow thecompletion of a structured cardiology fellowship trainingprogram as outlined in the guidelines set forth in the Be ,thesda Conference on Adult Cardiology Training (J Am CollCardiol 1986:7:1205-6) .

There is a growing consensus within the cardiologycommunity that, for the individual who plans to performcoronary angioplasty, an additional year of training beyond 3years of fellowship training that includes extensive experi-ence with angiography, is required . A suggested minimum of125 coronary angioplasty procedures, including 75 per-formed as the primary operator, has been recommended asthe experience required to develop the appropriate skill andjudgment. Equally important is the demonstration of contin-ued experience on the completion of a formal trainingprogram. A minimal case load for a single physician isestimated to be about one case per week . Continued perfor-mance of angioplasty should be dependent on the demon-stration of success and complication rates that meet ex-

JACC Val. 12, No .2August lout529-45

peeled standards . Regular attendance at major angioplastypostgraduate courses would provide continuing education innewer angioplasty techniques and equipment .

Alternate routes of training for established angiographersshould be developed. Individualized training programs thatprovide an extensive, primary operator experience can equipsuch an angiographer to perform angioplasty expertly . Inthis setting, the quality and manner of the direct supervisionare of greater importance than the absolute number of casesto be performed in this "tutorial" setting . In general, it isbelieved that such a training experience should includeinvolvement in no less than 50 cases .

The physicians with appropriate training and demon-strated competence in the performance of angioplasty arethose who should receive proper credenlialing to performangioplasty in hospitals . It is recognized that hospitals arecurrently under intense pressure to grant privileges to car-diologists who have not had adequate training so as toprotect the hospitals' referral base. This practice should rotbe condoned ; rather, the responsible leadership of institu-tions offering coronary angioplasty as part of their healthcare program should insist on the documentation of accred-ited training and the maintenance of skills of its approvedoperators by some reasonable standard of practice .

In the present climate it should be clear that not everycardiologist desiring to perform angioplasty should performthe procedure. Similarly, not every institution anxious tooffer the procedure as part of its health care program can beallowed to do so. A significant volume of cases per institu-tion and per operator is essential for the maintenance ofassured quality and safe care . It is the strong sense of thisSubcommittee that these issues should not be resolved in themarketplace but within the structure of organized medicine .Formal credentialing should quickly be put into place andthe oversight of the operational aspects and maintenance ofskills should fall within the province of organized cardiology .It would seem that existing national organizations have boththe resources and the manpower to meet this major obliga-tion in a prompt and effective manner . The hospital industrymust likewise alter its current practices regarding this spe-cific form of high technology care. Success, failure, deathand morbidity mandate some form of regionalization andcentraiization of resources . To accomplish this mission in aresponsible fashion, a deregulated industry must, in shortorder, demonstrate that it can accomplish this stated missionby its own sense of community responsibility, or it shouldgive way to state and federal regulation .

APPENDIX B

Requisite Facilities for Coronary Angioplasty

The rate of growth for coronary angioplasty within theUnited States over the past decade has clearly had an impact

RYAN ET AL .

5 43ACCIAEA TASK FORCE RErx RT

on the need for well equipped, well staffed cardiaccatheterization laboratories .

The minimal requirements for facilities in any hospitalwhere coronary angioplasty is to be performed are

1 . A cardiac laboratory that is well equipped with aphysiologic recording system, a high resolution fluo-roscopic and cineangiographic X-ray unit, full emer-gency resuscitation equipment including circulatoryassist devices and a full complement of drugs fortreatment of myocardial ischemia or infarction, orboth;

2 . A surgical operating suite that is equipped to providegeneral anesthesia and extracorporeal circulation andhas a full complement of instruments for thoracic andcardiac surgery and a full complement of drugs usedfor management of the cardiac patient .

The optimal resources for a cardiac catheterization andradiographic facility have been carefully and exhaustivelydetailed in "Optimal Resources For Examination Of TheHeart And Lungs: Cardiac Catheterizatioa And Radio-graphic Facilities" (Circulation 1983 ;68 :893A-930A). Thisreport sets guidelines for administration, space, equipment,personnel and working arrangements for diagnostic cardio-vascular laboratories . Basically all of the recommendationsset forth in that document apply to any laboratory planningto perform angioplasty procedures .

In addition, however, it is recommended that a laboratoryperforming coronary angioplasty have available the follow-ing:

I . An ample inventory of balloon dilation catheters rang-ing from 2.0 to 4.0 mm, a complete range of existingguide wires of variable flexibility and steerability andtwo or more calibrated balloon inflation devices .

2. A high resolution fluoroscopic system and an optimalTV chain that allows ready visualization of a 0 .014inch guide wire and where still frames or "road mapimages" can be displayed simultaneously with the realtime fluoroscopic image.

3. Either biplane fluoroscopic capability or preferably anangulating X-ray tube image intensifier arm that allowsready three-dimensional determination of the ana-tomic position of a guide wire or balloon catheter .

4. Radiation exposure control systems that would in-clude such items as an X-ray beam with automaticcollirlatiolt, a carbon fiber scattered radiation grid,carbon fiber table top and a correct tube filter . Furtherreduction of radiation exposure to personnel can beachieved by gap filling during cinematography, using areference monitor for path finding and video discs forautomatic storage and replay . All personnel should befurther protected from radiation exposure by the useof appropriate lead aprons, eyeglasses, thyroid protec-tion and additional shielding of the X-ray tube .

5 . The specific requisite space, equipment, personnel and

544

RYAN ET AL.ACCAHA TASK FORCE REPORT

administration of a cardiac surgery operating suitehave been outlined previously in dstait by the later-society Commission for Heart Disease Resources (Cir-culation 1975 ;52 :A23-41) .

APPENDIX C

Grading of Angina of Effort by the CanadianCardiovascular Society*

1 . "Ordinary physical activity does not cause . . . .angina," such as walking and climbing stairs . Anginawith strenuous or rapid or prolonged exertion atwork or recreation.

II . "Slight limitation of ordinary activity ." Walking orclimbing stairs rapidly, walking uphill, walking orstair climbing after meals, or in cold, or in wind, orunder emotional stress, or only during the few hoursafter awakening . Walking more than 2 blocks on thelevel and climbing more than one flight of ordinarystairs at a normal pace and in normal conditions .

Ill . "Marked limitation of ordinary physical activity ."Walking one to two blacks on the level and climbingone flight of stairs in normal conditions and at normalpace.

IV. "Inability to carry on any physical activity withoutdiscomfort-anginal syndrome may be present atrest ."

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