Determinants of midterm outcome of partial left ventriculectomy in dilated cardiomyopathy

1998;66:1585-1591 Ann Thorac SurgHiguchi, Fernando Bacal, Giovanni Bellotti and Adib D. Jatene

Noedir A.G. Stolf, Luiz Felipe P. Moreira, Edimar A. Bocchi, Maria de Lourdes cardiomyopathy

Determinants of midterm outcome of partial left ventriculectomy in dilated

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Determinants of Midterm Outcome of Partial LeftVentriculectomy in Dilated CardiomyopathyNoedir A. G. Stolf, MD, Luiz Felipe P. Moreira, MD, Edimar A. Bocchi, MD,Maria de Lourdes Higuchi, MD, Fernando Bacal, MD, Giovanni Bellotti, MD, andAdib D. Jatene, MDInstituto do Coracao da Faculdade de Medicina da Universidade de Sao Paulo, Sao Paulo, Brazil

Background. Partial left ventriculectomy has been pro-posed for treatment of severe cardiomyopathies. Thisstudy reports midterm results of this procedure in 37patients with dilated cardiomyopathy.

Methods. All patients were in New York Heart Associ-ation class III (16) or IV (21). Partial ventriculectomy wasassociated with mitral annuloplasty in 27 patients andwith mitral replacement in 2.

Results. There were seven operative deaths (18.9%).During a mean follow-up of 18.2 6 9.3 months, 9 morepatients died. Actuarial survival was 56.7% 6 8.1% at 6and 24 months. Analysis of factors influencing outcomeshowed that midterm survival was significantly affectedonly by myocardial cell diameter. Otherwise, functionalclass improved from 3.5 6 0.5 to 1.8 6 0.9 in the survivors(p < 0.001). Furthermore, left ventricular diastolic volumedecreased from 523 6 207 to 380 6 148 mL (p < 0.001), andleft ventricular ejection fraction increased from 17.1% 6

4.6% to 23% 6 8% (p < 0.001), whereas significantchanges in cardiac index, stroke index, and pulmonarypressures were found at 1 month of follow-up. Althoughleft ventricular diastolic volume tended to increase in thelate postoperative period, left ventricular ejection fractionand hemodynamic variables did not change significantly.

Conclusions. Partial ventriculectomy improves leftventricular function and congestive heart failure in pa-tients with dilated cardiomyopathy for up to 24 monthsof follow-up. Nevertheless, this procedure’s clinical ap-plication is limited by the high mortality observed in thefirst postoperative months. Otherwise, new perspectivesmay be advised by the identification that partial ventri-culectomy results seem to be influenced by compromisedmyocardial cells.

(Ann Thorac Surg 1998;66:1585–91)© 1998 by The Society of Thoracic Surgeons

Surgical reduction of left ventricular (LV) volume hasbeen proposed as an alternative treatment of severe

cardiomyopathies. The primary objective of this proce-dure is to decrease LV wall tension by the reduction ofthe chamber volume to mass relationship, resulting inpartial restoration of myocardial contractility and slow-ing progression of the underlying disease.

Since the pioneering efforts of Batista and coworkers[1], partial left ventriculectomy has been evaluated byseveral authors throughout the world [2–8]. Initial resultsof this surgical technique demonstrated the improve-ment of LV function and reversal of congestive heartfailure in patients with dilated cardiomyopathies [3–6, 8].Nevertheless, high incidences of heart failure progres-sion and arrhythmia-related deaths have been reportedin the early postoperative period in most of those series[2–4, 7, 8]. Furthermore, no documentation is found yetregarding long-term survival and prolonged benefitsafter this procedure.

The purpose of this report is to outline the clinical andLV function effects of partial left ventriculectomy, asso-ciated when necessary with mitral insufficiency correc-

tion, for up to 2 years of follow-up in patients withadvanced heart failure caused by idiopathic dilated car-diomyopathy. The influence of preoperative and surgicalfactors on patients’ outcomes is also analyzed.

Patients and Methods

Study PopulationPatients selected for partial left ventriculectomy by theHeart Failure and Heart Transplantation Program of theHeart Institute, University of Sao Paulo Medical School,were those with significant functional limitation despiteattempts to optimize medical therapy with maximaldoses of diuretics and angiotensin-converting enzymeinhibitors or vasodilators. They also had reduced LVfunction characterized by radioisotopic ejection fractionless than or equal to 25% and persistently high fillingpressures. Medical or psychosocial contraindications toheart transplantation were present or this procedure wasrefused by the patients, and they signed a special in-formed consent form according to our Ethical and Scien-tific Review Board.

Accordingly, partial left ventriculectomy was per-formed in 37 patients with idiopathic dilated cardiomy-opathy between April 1995 and August 1997. Sixteenpatients were in New York Heart Association (NYHA)

Presented at the Thirty-fourth Annual Meeting of The Society of ThoracicSurgeons, New Orleans, LA, Jan 26–28, 1998.

Address reprint requests to Dr Stolf, Instituto do Coracao, Av. Dr. EneasCarvalho Aguiar, 44. Sao Paulo, SP, Brazil. CEP: 05403-000.

© 1998 by The Society of Thoracic Surgeons 0003-4975/98/$19.00Published by Elsevier Science Inc PII S0003-4975(98)00959-X



class III and 21 were in persistent class IV. Nine of thesepatients also had reversible cardiogenic shock with tem-porary use of intravenous inotropic drugs. Mean dura-tion of symptoms was 3.9 years, and patients had at leasttwo hospitalizations for heart failure treatment in theyear preceding the operation. Patients’ ages ranged from28 to 72 years (mean, 46.1 years), and 30 patients weremen. Preoperative laboratory data are summarized inTable 1. Two patients had atrial fibrillation and 22 pa-tients had nonsustained ventricular tachycardia episodesdocumented by Holter recordings. Absence of significantcoronary artery compromise was shown in every patient.Mitral valve insufficiency was present in 31 patients,being moderate in 12 and mild in 19 patients. Sevenpatients also had significant tricuspid valve insufficiency,being moderate in 5 and severe in 2 patients.

Surgical ProcedurePartial left ventriculectomy was performed as an isolatedprocedure or associated with atrioventricular valves an-nuloplasty or replacement. The procedures were usuallydone during standard cardiopulmonary bypass withmoderate hypothermia and on the beating heart. Whenmitral valve replacement was necessary, it was per-formed during hypothermic myocardial arrest inducedby the infusion of cold-blood cardioplegia.

Left ventricular volume reduction was performed ac-cording to the technique initially described by Batistaand associates [1]. A slice as large as possible of theventricular myocardium was resected between the pap-illary muscles, from the apex of the heart up to 2 or 3 cmfrom the mitral annulus. The left ventricle was thenrepaired with a double 3-0 polypropylene suture an-chored in bovine pericardium strips.

Mitral valve annuloplasty was done in the presence ofany degree of mitral regurgitation. The mitral valve wasassessed through the left atrium and the mitral annuluswas reduced by plication of the posterior leaflet regionwith sutures anchored in a bovine pericardium strip. In

patients with malposition of the papillary muscles, pre-cluding an effective myocardial resection, these muscleswere resected and the mitral valve was replaced by abovine pericardium bioprosthesis. The De Vega tricuspidannuloplasty was performed in patients with moderate tosevere tricuspid regurgitation. Endocardial automaticcardioverter-defibrillators were routinely implanted inpatients who presented with episodes of sustained ven-tricular tachycardia or ventricular fibrillation.

Follow-up ProtocolPatients were studied at the first postoperative monthand every 6 months of follow-up by means of radioiso-topic angiography and right heart catheterization. Theycontinued to use diuretics and angiotensin-convertingenzyme inhibitors or vasodilators. Amiodarone was rou-tinely used at the first 2 weeks of follow-up and inpatients who presented with episodes of sustained ven-tricular tachycardia or atrial fibrillation.

Left ventricular radioisotopic angiography was ob-tained after in vivo labeling of red blood cells by techne-tium 99m. Gated blood pool imaging was acquired in leftanterior oblique view with a Siemens model LEM1camera (Siemens, Union, NJ). The images were analyzedin a Microvax model 3300 computer (Siemens), and LVvolumes and ejection fraction were calculated. Rightheart catheterization was performed with a thermodilu-tion balloon-tipped catheter positioned in the left pulmo-nary artery.

Statistical AnalysisCumulative mortality and event rates over time weredetermined by the Kaplan-Meier method, and differ-ences between them were assessed by the log-rank test.Repeated measures analysis of variance and the Dun-net’s test were used to compare data obtained before andafter the operation. Data are presented as mean 6standard deviation, whereas survival rates are presentedas mean 6 standard error of the mean.

The association of variables with survival was assessedby means of univariate analysis using the unpairedStudent’s t test and Fisher’s exact test. Variables with a pvalue less than 0.10 in univariate analysis were submittedto logistic regression. For this analysis, we consideredonly the events that occurred during the first 7 months offollow-up, and patients undergoing urgent heart trans-plantation after partial ventriculectomy were included asdeaths.

Results

Immediate Surgical ResultsEight patients underwent isolated partial left ventriculec-tomy, and this procedure was associated with mitralvalve annuloplasty in 27 patients and mitral valve re-placement in the remaining 2 patients. Seven of thosepatients who underwent mitral valve operation also hadDe Vega tricuspid valve annuloplasty.

Intraoperative transesophageal echocardiography after

Table 1. Preoperative Laboratory Dataa

Variable Value

Doppler echocardiographyLV diastolic diameter (mm) 82.8 6 8.9LV segmental wall shortening (%) 11.8 6 2.7

Radioisotopic angiographyLV diastolic volume (mL) 522 6 186LV ejection fraction (%) 16.6 6 5.1RV ejection fraction (%) 20.9 6 6.6

Right heart catheterizationCardiac index (L z min21 z m22) 2.11 6 0.49Pulmonary wedge pressure (mm Hg) 24.9 6 9.1Pulmonary vascular resistance

(dyne z s z cm25)238 6 138

Plasma catecholamine levelNorepinephrine (mg/dL) 591 6 275

a Values are shown as mean 6 standard deviation.

LV 5 left ventricular; RV 5 right ventricular.

1586 STOLF ET AL Ann Thorac SurgPARTIAL VENTRICULECTOMY MIDTERM RESULTS 1998;66:1585–91



discontinuation of bypass revealed no mitral regurgita-tion in 28 patients and mild regurgitation in 9. Theresected myocardial specimen measured 10.9 6 2 cm inlength and 5 6 0.8 cm in width, corresponding to anestimated LV myocardial resection of 19.1% 6 2.5%. Thisparameter was assessed from the echocardiographic es-timation of LV perimeter. Morphometric analysis of myo-cardial samples stained with hematoxylin-eosin andtrichrome showed mean myocyte diameter of 21.9 66.2 mm and mean percentage of fibrosis of 14.5% 6 6.3%.

All patients were weaned from cardiopulmonary by-pass with dobutamine and sodium nitroprusside, and 13patients also required intraaortic balloon counterpulsa-tion. Two patients presented with refractory heart failureand required insertion of a centrifugal pump or pneu-matic ventricular assist device for LV assistance on thesecond postoperative day. Another patient had dehis-cence of the mitral valve annuloplasty and was reoper-ated on for mitral valve replacement 5 days after theinitial operation.

Episodes of sustained ventricular tachycardia occurredin 9 patients (21.6%) at the first 2 weeks of follow-up.Transient periods of renal failure developed in 5 patients(13.5%), and pulmonary complications occurred in 7(18.9%). The mean peak serum level of the myocardialcomponent of the creatine kinase enzyme was 111 6 54IU.

Seven patients died during the hospital period (18.9%).The causes of death were cardiogenic shock in 2 patients;biventricular failure in the patient maintained with thecentrifugal pump; multiple organ failure in the patientrequiring pulsatile mechanical circulatory support; sep-ticemia and cardiogenic shock in the patient reoperatedon because of mitral annuloplasty dehiscence; incessantsustained ventricular tachycardia in 1 patient; and bleed-ing associated with disseminated intravascular coagula-tion in 1 patient.

Quality of Life and SurvivalThirty patients were discharged from the hospital andwere followed up from 2 to 36 months (mean, 18.2months). Ten of these patients had automatic cardio-verter-defibrillator implantation.

Eight patients were rehospitalized during the first 6months of follow-up because of heart failure progressionand another 3 because of sustained ventricular tachycar-dia episodes. Five of these patients were listed for hearttransplantation, and this procedure was urgently per-formed in 1 of them 7 months after partial ventriculec-tomy. On the other hand, 9 patients died during thisfollow-up period, and the survival curve presented in Fig1 shows survivals of 62.1% 6 7.9% at 3 months and 56.7%6 8.1% at 6 and at 30 months of follow-up. The cause ofdeath was progressive heart failure in 5 patients, and 4patients died suddenly or because of incessant ventricu-lar tachycardia. Progressive heart failure was associatedwith pulmonary thromboembolism in 1 patient, and 2 ofthose patients who died because of arrhythmia-relatedevents were using amiodarone; 1 had an automatic inter-nal cardioverter-defibrillator.

Univariate analysis of preoperative and surgical riskfactors showed that only greater myocyte diameter wassignificantly associated with an unfavorable outcomeduring the first 7 months of follow-up (Table 2). In thisregard, logistic regression demonstrated that the risk ofdeath or necessity of urgent heart transplantation in thatperiod increased exponentially and achieved values ofmore than 40% when the mean myocyte diameter wasgreater than 22 mm (Fig 2). The survival curves accordingto this parameter are depicted in Fig 3 and show that the2-year survival of patients with less marked myocardialcell hypertrophy was 73.6% 6 10.1%, whereas thosepatients with severe myocyte compromise had a survivalrate of 31.2% 6 11.5% at the same period.

Regarding the functional status, NYHA class signifi-cantly improved from 3.5 6 0.5 to 1.8 6 0.9 at 6 months offollow-up in the 20 long-term survivors ( p , 0.001). Thenumber of hospitalizations during the follow-up periodalso decreased for those patients from 2.3 to 0.2 perpatient per year ( p , 0.001). In addition, 9 of thesurviving patients are currently in functional class I, 9 arein class II, and only 2 are in class III. Some of thesepatients are using fewer drugs and lower doses than theydid in the preoperative period.

Circulatory Function EvaluationData obtained by radioisotopic angiography in 30 pa-tients showed that significant improvement of LV ejec-tion fraction (from 17.1% 6 4.6% to 23% 6 8%, p , 0.001)was found at the first postoperative month associatedwith significant decrease in LV diastolic volume (from523 6 207 to 380 6 148 mL, p , 0.001). Figure 4 showsthat these modifications were maintained during the firstyear of follow-up in the 20 patients who survived long-term. Otherwise, LV diastolic volume tended to increase,whereas LV ejection fraction maintained the recordedimprovement for up to 2 years after partial left ventricu-lectomy in the 10 patients with complete follow-up.

Hemodynamic evaluation showed that significant in-creases of cardiac and stroke indexes were associated

Fig 1. Kaplan-Meier survival curve after partial left ventriculec-tomy. Numbers in parentheses indicate patients at risk at each pe-riod. Values are presented as mean 6 standard error of the mean.

1587Ann Thorac Surg STOLF ET AL1998;66:1585–91 PARTIAL VENTRICULECTOMY MIDTERM RESULTS



with a significant decrease in pulmonary wedge pressureimmediately after the operation (Table 3). At 6 months offollow-up, these modifications were maintained in the 20patients who survived long term. This study additionallydemonstrated that the improvement of those indexespersisted for up to 2 years of follow-up, whereas pulmo-nary wedge pressure values tended to increase after thefirst 6 months.

Comment

The present investigation showed that the midtermcourse of patients with dilated cardiomyopathy whounderwent partial left ventriculectomy, associated whennecessary with mitral insufficiency correction, was char-acterized by the maintenance of clinical and hemody-namic benefits documented early after the operation.This fact occurred despite the tendency of LV redilatationobserved after the first year of follow-up.

Otherwise, high incidences of heart failure progressionand arrhythmia-related deaths occurred in the earlypostoperative period in this series, precluding an opti-

mistic conclusion about partial left ventriculectomy inclinical application. The identification of the influence ofcompromised intrinsic myocardial cells on this proce-dure’s outcome, however, opens the possibility of refin-ing patient selection criteria, helping to establish its exactrole in the treatment of dilated cardiomyopathies.

Ventricular Function ChangesImprovement of LV ejection fraction after partial leftventriculectomy has been demonstrated by several au-thors [2, 4–6, 8]. However, this modification occurs basedon geometric rearrangement and may not theoreticallyrepresent an improvement in stroke volume or an in-crease in myocardial contractility [9]. On the other hand,hemodynamic benefits have also been reported after thissurgical procedure in some clinical series. More pre-cisely, significant increments in stroke volume and car-

Fig 2. Logistic regression curve of risk of death or necessity of ur-gent heart transplantation during the first 7 months of partial leftventriculectomy follow-up according to the mean diameter of leftventricular myocardial cells.

Fig 3. Plots of survival rates free of the necessity of urgent hearttransplantation for patients with mean myocardial cell diameter(MCD) in the left ventricle less than or greater than 22 mm. Valuesare presented as mean 6 standard error of the mean.

Table 2. Unifactorial Analysis of Factors Associated WithOutcomea

Parameter Survivors Deaths/HTp

Value

LV myocardial celldiameter (mm)

21 6 2.1 23.3 6 2.8 0.023

Stroke index (mL/m2) 25.2 6 7.4 21 6 4.7 0.106LV stroke work index

(g z m z m22)20.5 6 9.4 16.3 6 5.1 0.110

LV ejection fraction (%) 17.8 6 5.2 15.1 6 4.7 0.129LV myocardium width

(mm)7.2 6 1.3 8.1 6 1.7 0.133

LV segmental wallshortening (mm)

12.3 6 2.7 11.1 6 2.6 0.199

Cardiac index(L z min21 z m22)

2.19 6 0.53 2 6 0.42 0.256

Norepinephrine serumlevel (mg/dL)

535 6 269 652 6 281 0.319

LV diastolic diameter(mm)

81.5 6 7.3 84.5 6 10.5 0.327

RV ejection fraction (%) 20.1 6 6.6 22 6 6.8 0.414Pulmonary wedge

pressure (mm Hg)24.1 6 10.7 25.9 6 6.9 0.563

Pulmonary vascularresistance(dyne z s z cm25)

226 6 146 254 6 136 0.568

Functional class (NYHA) 3.5 6 0.5 3.6 6 0.5 0.603Percent of LV myocardial

fibrosis14.7 6 6.8 14.1 6 5.9 0.786

LV diastolic volume (mL) 545 6 194 560 6 187 0.859Percent of LV myocardial

resection19.1 6 2 19.1 6 2.9 0.935

CKMB enzyme serumlevel (IU)

111 6 49 111 6 61 0.987

a Values are shown as mean 6 standard deviation.

CKMB 5 creatine kinase myocardial branch; HT 5 heart transplan-tation; LV 5 left ventricular; NYHA 5 New York Heart Associa-tion; RV 5 right ventricular.




diac output were demonstrated in the presence of de-creased pulmonary pressures [2, 4, 6]. Although partialventriculectomy was associated with different proceduresand performed in patients with different causes of heartfailure in one of these studies [2], hemodynamic changeswere also detected in our series, which included onlypatients with idiopathic dilated cardiomyopathy.

Several issues exist regarding partial left ventriculec-tomy technical aspects. The impact of its association withmitral insufficiency correction remains uncertain. Signif-icant modifications in LV function were reported afterisolated mitral annuloplasty in patients with severe mi-tral regurgitation [10]. On the other hand, patients in thepresent series had only mild or moderate mitral valvedysfunction, and similar modifications in LV functionwere documented whether or not partial ventriculectomywas associated with mitral valve operation [4].

Some authors advocate a more aggressive approachregarding myocardial resection, with the necessity ofassociated mitral valve replacement or papillary muscletranslocation in more than 30% of cases [3, 8]. Otherwise,similar results have been described in those series inrelation to LV function modifications documented in the

current investigation. Furthermore, we previously re-ported the absence of correlation between LV ejectionfraction changes and the level of LV diastolic diameterreduction [4].

Although in theory the reduction of LV volume couldresult in a secondary impairment of diastolic function [9],pressure-volume loops obtained immediately after par-tial left ventriculectomy in 11 patients of the presentpopulation demonstrated that this operation was respon-sible for significant decreases in LV systolic and diastolicwall stresses [11]. That study also showed the significantincrease of maximal elastance and decreases in end-diastolic pressure and in stress-strain loops after theoperation.

Because the LV wall stress is an important determinantof myocardial oxygen consumption, its reduction canreduce myocardial oxygen demand. Therefore, in a di-lated, failing left ventricle, besides the partial restorationof afterload matching and myocardial contractility, slowprogression of the underlying cardiomyopathy couldresult from LV wall stress modifications. The mainte-nance of LV ejection fraction values and of hemodynamicimprovement for up to 2 years of follow-up in this report

Fig 4. Plots of left ventricular ejection fraction (A) and diastolic volume (B) values obtained by radioisotopic angiography in the preoperativeperiod and up to 24 months after partial left ventriculectomy. Values are presented as mean 6 standard deviation. *p , 0.05 compared withpreoperative data of matched patients.

Table 3. Sequential Hemodynamic Dataa

Variable Preoperative Value

Months of Follow-up

p Value1 6 12 18 24

CI (L z min21 z m22) 2.27 6 0.53 2.7 6 0.48b 2.72 6 0.42b 2.59 6 0.53b 2.59 6 0.48b 2.43 6 0.53 0.006SI (mL/m2) 26.3 6 7.3 30.4 6 6.5b 34 6 6.2b 33.1 6 8b 32.4 6 6.9b 32.9 6 6.1b 0.02RAP (mm Hg) 9.5 6 4.7 6.9 6 3.9 7.1 6 4.7 6.3 6 5 6.2 6 4.6 7.5 6 6.6 NSPAP (mm Hg) 35.6 6 14.1 29.3 6 11.7 29.1 6 13.7 28.2 6 10.7 28.5 6 11.7 31.3 6 10.4 NSPWP (mm Hg) 26 6 11.7 16.6 6 7.6b 18.1 6 9b 20 6 7.5 21.7 6 8.3 22.7 6 8.6 0.04AoP (mm Hg) 82.3 6 21.8 80.9 6 19.8 88.7 6 18.2 84.5 6 19.9 89.7 6 9.9b 90.5 6 7b 0.04

a Values are shown as mean 6 standard deviation. b p , 0.05 in relation to preoperative data of matched patients.

AoP 5 aortic pressure; CI 5 cardiac index; PAP 5 pulmonary artery pressure; PWP 5 pulmonary wedge pressure; RAP 5 right atrialpressure, SI 5 stroke index.




indicates that this fact may occur clinically. Nevertheless,the tendency of LV redilatation observed after the firstyear of follow-up anticipates the possibility that thisprocedures may become more a biologic bridge than areal alternative to heart transplantation.

Functional Status and SurvivalBesides the improvement of LV function, partial leftventriculectomy was responsible for the amelioration ofpatients’ functional class in this series, which agrees withthe overall clinical experience with this procedure [2–6,8]. Most of our surviving patients are in NYHA class I orII for more than 2 years of follow-up, and a significantdecrease in the number of hospitalizations per patientper year was found. The functional benefits of partialventriculectomy in our surviving patients additionallyincluded the improvement of physical capacity and otherparameters, as assessed by a quality-of-life questionnaire[12].

Nevertheless, clinical and LV function improvementsoccurred only in a percentage of patients undergoingpartial left ventriculectomy in this experience. Immediateand early mortalities after the procedure were high andoccurred because of heart failure progression or arrhyth-mia-related events, being responsible for a survival rateof only 56.7% at 6 months of follow-up. McCarthy andassociates [8] also described that only 58% of their 57patients with dilated cardiomyopathy were free fromprocedure failure, defined as death or relisting for trans-plantation, at 1 year of follow-up. Similar results havebeen reported by other authors [2, 3, 7], although theexistence of different causes of heart failure and otherassociated procedures in some series makes comparisonless accurate.

On the other hand, no mortality or important heartfailure decompensation occurred after the first 6 monthsof follow-up in this study. This finding, associated withthe documentation that the underlying disease stoppedprogressing for up to 2 years, could justify partial leftventriculectomy indication as an alternative treatment ofsevere cardiomyopathies, if it was possible to demon-strate whether a given patient had a higher probability ofbenefiting from ventricular reduction.

In this regard, the existence of a significant relationshipbetween myocardial cell diameter and partial left ventri-culectomy results in our experience demonstrated thatthis procedure’s outcome depends on the severity ofmyocardial cell damage. Therefore, the identification ofirreversible structural remodeling of the heart because ofreactive growth processes in myocytes may contribute toa decrease in the number of partial ventriculectomyfailures and to improving its clinical outcomes. Patientsoperated on with a mean diameter of LV myocardial cellsof less than 22 mm in this series had a survival withouturgent heart transplantation of 73% at 30 months offollow-up. These values contrast positively with a recentreport about target heart failure populations for newertherapies [13], which showed a survival probability with-out heart transplantation of only 53% in 2 years forpatients with initial NYHA class III or IV symptoms.

Some authors previously documented that the severityof myocardial cell hypertrophy is related to a worseclinical status in patients with heart failure [14, 15]. Thisparameter was used to monitor the outcomes of somemedications in heart failure treatment [16]. Therefore,evaluation of myocardial specimens obtained by preop-erative endomyocardial biopsies using refined histologicand histochemical examinations may potentially contrib-ute to separating out patients with higher probability ofpartial ventriculectomy failure. In this regard, an absenceof a large difference between the degree of myocardialcell hypertrophy on both sides of the ventricular septumwas observed in patients with dilated cardiomyopathy[15], indicating that similar results may be achieved withuse of either right ventricular or LV approaches.

Besides the myocardial findings, however, an absenceof correlation between partial left ventriculectomy resultsand other risk factors was observed in the current series.This fact occurred despite other surgical interventionsperformed for treatment of severe cardiomyopathies,such as coronary artery bypass grafting [17] and dynamiccardiomyoplasty [18, 19], which seem to be stronglyinfluenced by the patient’s preoperative condition anddegree of LV function compromise.

ConclusionsInterpretation of current clinical experience with partialleft ventriculectomy is limited. Nevertheless, we canconclude that this surgical procedure, associated whennecessary with mitral insufficiency correction, improvesLV function and ameliorates congestive heart failure inpatients with idiopathic dilated cardiomyopathy. Fur-thermore, the midterm course of the surviving patientsseems to be characterized by the stabilization of theunderlying disease for up to 2 years of follow-up.

On the other hand, although early survival after thisoperation appears to be limited by high incidences ofheart failure progression and arrhythmia-related deaths,these events seem to be influenced by compromisedintrinsic myocardial cells. Therefore, the preoperativeidentification of patients with predominant anatomicremodeling instead of patients with severe intrinsic myo-cardial damage could improve partial left ventriculec-tomy outcomes and contribute to consideration of thisprocedure as a real alternative in the spectrum of thesurgical treatment of cardiac failure.

References

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2. Angelini GD, Pryn S, Mehta D, et al. Left ventricular volumereduction for end-stage heart failure. Lancet 1997;350:489.

3. Batista RJV, Santos JLV, Nery P, et al. Partial left ventricu-lectomy to treat end-stage heart disease. Ann Thorac Surg1997;64:634–8.

4. Bocchi EA, Bellotti G, Moraes AV, et al. Clinical outcomeafter left ventricular surgical remodeling in patients withidiopathic dilated cardiomyopathy referred for heart trans-plantation. Circulation 1997;96(Suppl 2):II-165–72.




5. Bombonato R, Bestetti RB, Sgarbieri R, et al. Initial experi-ence with partial left ventriculectomy in the treatment ofterminal cardiac insufficiency. Arq Bras Cardiol 1996;66:189–92.

6. Dreifus G, Al Ayle W, Leroy G, et al. Left ventricularreduction (Batista): a new surgical option in dilated cardio-myopathy. Arch Mal Coeur 1997;90:1521–5.

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DISCUSSION

DR AKIRA T. KAWAGUCHI (Isehara, Kanagawa, Japan): As Ihave been collaborating with Dr Batista, we have presentedresults similar to those reported here on the patients who havebenefited from the procedure and survived up to the angio-graphic study. We wondered what was occurring to the patientswho deteriorated after the procedure and died before anyhemodynamic studies could be carried out. This made usundertake intraoperative pressure–volume analyses in everypatient undergoing this procedure; the results will be presentedtomorrow.

I wonder if you have studied those patients who died aftersurgery and have some data concerning the mechanism behinddeterioration of the ventricular performance. Hopefully, suchinformation would lead us to exclude high-risk patients andmake the partial left ventriculectomy safer and more efficient.Thank you.

DR MOREIRA: I would like to thank the discussants. To answerDr Miller and Dr Carpentier, it is important to remember thatisolated mitral annuloplasty has been performed in patients withdilated cardiomyopathies only in the presence of severe mitralregurgitation. Therefore, its impact was probably not the same inthe current patient population, which included only patients withmild or moderate mitral insufficiency. Furthermore, 8 patients inthis study underwent isolated partial left ventriculectomy, andthey also experienced significant improvements in left ventric-ular ejection fraction and hemodynamic parameters.

In relation to the mechanism responsible for differences inmyocyte size and survival, we need to remember that thepathophysiology of heart failure includes the remodeling pro-cess and the intrinsic myocardial damage. Therefore, the remod-eling process was probably more important than the myocardialcell compromise, represented by higher degree of myocytehypertrophy, in patients with better outcome in the presentexperience.

From these findings, our current protocol for patient selectionfor partial ventriculectomy includes the performance of left andright ventricular endomyocardial biopsies, and when we canidentify patients with mean myocyte diameters greater than22 mm, they are contraindicated for having the procedure. This isthe unique modification that we have made regarding patientselection criteria, as we did not identify any other factor associ-ated with partial ventriculectomy outcome.

Regarding the remarkable prognosis for patients who sur-vived beyond the first 6 months in this study, this fact was notassociated with the length of the disease or the postoperativemedical management. On the other hand, patients who died orneeded heart transplantation after Batista operation were spe-cifically those who did not have improvement on radioisotopicejection fraction and hemodynamic parameters immediatelyafter the operation.

I would like to thank the Society for the opportunity to presentthis paper.




1998;66:1585-1591 Ann Thorac SurgHiguchi, Fernando Bacal, Giovanni Bellotti and Adib D. Jatene

Noedir A.G. Stolf, Luiz Felipe P. Moreira, Edimar A. Bocchi, Maria de Lourdes cardiomyopathy

Determinants of midterm outcome of partial left ventriculectomy in dilated

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Determinants of midterm outcome of partial left ventriculectomy in dilated cardiomyopathy