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PERIOPERATIVE EVALUATION AND MANAGEMENT OF CARDIAC PATIENTS FOR NONCARDIAC
SURGERYDavid W Kabel MD, FACC
Preoperative Evaluation- Paradigm Change
Shift of emphasis From preoperative risk stratification and
testing To perioperative management of risk Prevention of major adverse cardiac events
(MACE)
Challenge to previous guidelines Stress testing Revascularization Beta blocker therapy
Scope of the Problem
30 million+ non-cardiac surgeries in the US annually
One third have known CAD or cardiac risk factors
500,000 considered high risk for cardiac complications
Operative mortality is declining Better preop risk stratification Better perioperative management Less invasive procedures Mortality is declining for high risk procedures as
well
Purpose of Preoperative Evaluation
Assessment of perioperative risk to guide the decision to proceed with or the choice of surgery
Determination of the need for changes in management
Identification of cardiovascular conditions that warrant long term management
Perioperative Team Approach
Shared decision making Patient preferences and goals PCP Surgeon Anesthesiologist Specialists as needed Requires considerable advanced planning
in high risk patients with multi-system disease
Definition of Risk
Previously determined as low medium or high risk
Now only 2 categories Low risk-<1%
Cataracts Dermatologic and minor cosmetic Require no preop evaluation
High risk-1% or greater Further workup depends on type of operation
and patient characteristics
Revised Cardiac Risk Index
One point for each risk factor Known ischemic heart disease Heart failure (current or past history) History of CVA or TIA Insulin dependent diabetes Creatinine> 2.0 High risk surgery-”Suprainguinal
vascular, intraperitoneal, or intrathoracic surgery”
RCRI-Scoring
Points Cardiac complications %
0 0.4%
1 0.9%
2 7% 10
3+ 11% 2
American College of Surgeons Risk Calculator
Data from 525 hospitals and 1 million patients to develop this
Considers type of surgery by CPT code
Multiple patient factors are considered
www.riskcalculator.facs.org
Type of Surgery-Low Risk(<1%)
These surgeries usually require no additional preoperative cardiac evaluation Breast Dental Endocrine Eye Gynecology Reconstructive Minor orthopedic(arthroscopy) Minor urologic(cystoscopy)
Type of Surgery- High Risk(>5%)
Aortic surgery-(Open procedures)
Major peripheral vascular
Not high risk because of the nature of the procedure
Almost all patients have multiple risk factors
Perioperative Evaluation-Historical Points
Known CAD Previous revascularization
Bypass PCI-When and what was done?-Bare metal vs DES
Exertional symptoms Previous cardiac evaluation
When, and what did it show? Exercise tolerance
Most important predictor of perioperative outcome Determines ability to increase O2 delivery
perioperatively
Risk and Exercise Tolerance
Assessing Functional Status
Exercise Tolerance and Risk
Functional Capacity of 4 METS confers low risk status
Can’t be evaluated in patients with mobility problems Orthopedic procedures, especially joint
replacement COPD PAD with claudication
Very high risk population Known vascular disease AAA repair represents highest risk
Preoperative Evaluation-Physical Exam
Signs of heart failure Rales JVD Edema S3
Tachycardia-Is patient in atrial fibrillation? Bradycardia-Heart block, SSS Murmur of aortic stenosis Pulmonary findings-Wheezes Any of these findings necessitate further
workup
Major Predictors of Increased CV Risk
Unstable coronary syndromes Decompensated heart failure Arrhythmias
Ventricular tachycardia AV block and sick sinus Uncontrolled atrial fibrillation or flutter
Severe valvular disease Especially aortic stenosis
These patients need further evaluation prior to noncardiac surgery
Unstable Coronary Syndromes
Class III or IV symptoms
Poor exercise tolerance
Indications for stress testing or cath are same as for those not undergoing noncardiac surgery
Patients with chronic stable angina (Class II) do not require preoperative stress testing
Heart Failure
Greater perioperative risk than ischemia
Should have EF measured
BNP may have prognostic significance if normal
Optimize therapy prior to surgery
Beta blockers and possibly ACEIs and ARBs should be continued perioperatively
Valvular Heart Disease
Severe aortic stenosis AVA <1.0 cm2 or mean AV gradient >40 mm Hg, even
in absence of symptoms Should have AVR prior to noncardiac surgery,
preferably with a tissue prosthesis TAVR for high risk patients New guidelines suggest that asymptomatic patients
with severe AS may have surgery Requires hemodynamic monitoring postop
Severe mitral stenosis Can usually be treated with balloon valvuloplasty
Regurgitant lesions are well tolerated in the absence of previous heart failure if LV function is normal
Arrhythmias-Atrial Fibrillation
Chronic atrial fibrillation and flutter Control ventricular rate with beta blockers Determine if bridging with Lovenox is necessary Some procedures can be done without stopping
anticoagulants Newly diagnosed atrial fibrillation
Control ventricular rate, preferably with beta blockers
Proceed with surgery Institute anticoagulation and specific anti-
arrhythmic therapy postoperatively Medical or electrical cardioversion postoperatively
Bradycardias
Mobitz I Review medications No need for pacing if asymptomatic, proceed with
surgery Mobitz II and 3rd degree block
Review medications If reversible causes not present, permanent pacemaker
indicated before surgery Sick sinus syndrome
Review medications If asymptomatic, proceed with surgery If symptomatic, permanent pacemaker indicated May be useful to walk patient and observe HR response
Preoperative Stress Testing and Outcomes
May lead to adverse outcomes Appropriate in selected patients
High risk surgery Poor exercise tolerance Symptoms of possible ischemia
Exertional chest pain, tightness, heaviness DOE
Routine stress imaging in asymptomatic patients is poor at identifying patients who will have adverse outcomes
Preoperative revascularization does not affect outcomes
Preoperative PCI
BARI trial No improvement in outcomes vs medical
treatment of angina preoperatively Increased operative mortality if PCI within
12 days before surgery Similar outcomes for PCI vs Bypass Results duplicated in several trials
Preoperative CABG
No benefit in several studies CASS CARP
CASS registry High risk vascular surgery patients
randomized to CABG vs medical treatment Medical rx-2.4% mortality CABG-0.9% mortality BUT PREOP BYPASS HAD 1.4% MORTALITY,
MAKING MEDICAL AND CABG ARMS EQUIVALENT
CARP Study Mortality
Why Doesn’t Revascularization Improve Outcomes?
Stress imaging is poor in identifying patients with adverse outcomes
Angiography not always good at detecting disease Less occlusive plaque is often the most unstable
In autopsy studies, the infarct vessel was often not the most stenotic on previous cath
Surgery and anesthesia can cause plaque disruption and hyper-coaguable states
In nonsurgical populations revascularization has no benefit over medical treatment in stable patients
Problems Introduced by Preoperative Revascularization Delayed surgery
Anticoagulation and antiplatelet issues
Morbidity and mortality inherent in the revascularization procedure
Cost effectiveness
Class of Recommendations
I-Conditions for which there is evidence for and/or general agreement that the procedure or treatment is beneficial, useful, and effective
IIa- Weight of evidence is in favor of usefulness or efficacy
IIb-Usefulness or efficacy is less well established by evidence or opinion
III-Evidence or general agreement that the procedure or treatment is not useful or effective and in some cases may be harmful
EKG-Recommendations
LV Function-Recommendations
Stress Testing-Recommendations
Stress Imaging-Recommendations
Perioperative Drug Therapy
Beta blockers
Statins
ACEIs, ARBs
Aspirin
ADP receptor antagonists(antiplatelet drugs)
Beta Blockers-Current Guidelines Class I
Continue beta blocker therapy in patients receiving Rx for angina, arrhythmias, hypertension or other Class I indications
Level of evidence-B
Beta Blockers-Class IIa
Management of beta blockers postop should be guided by clinical circumstances, independent of when the drug was started
May require temporary discontinuation due to hypotension, bradycardia, or other conditions
LOE-B
Beta Blockers-Class IIb
Patients with intermediate- or high-risk myocardial ischemia noted in preoperative risk stratification testing (LOE C)
Patients with 3+ RCRI risk factors (LOE B) Patients with compelling long-term
indications for beta blocker therapy but no other RCRI risk factors (LOE B)
Initiate beta blocker therapy long enough in advance to assess safety and tolerability (LOE B)
Beta Blockers-Class III
Patients with absolute contraindications to beta blocker therapy
Risks outweigh benefits
Do not start on the day before or the day of surgery (LOE B)
Beta Blockers-General Considerations
Little evidence to support >30 day timeline
Can be started 2-7 days before
Optimal dosing and timing not defined
Elevated perioperative stroke risk However, incidence of MACE much higher
than stoke.
Effect of Resting Heart Rate on Postoperative Cardiac Events
Beta Blockers
Initiate 2-7 or up to 30 days prior to surgery
Titrate to resting pulse rate of 60-80
Titrate to blood pressure of 130/80 or less
Avoid hypotension
Statins
Cardioprotective effects in perioperative period Improves endothelial morphology and function Plaque stabilization
Discontinuation of chronic therapy preoperatively is associated with adverse outcomes
May benefit even started the day before surgery
Start therapy in high risk patients 7-30 days before procedure-Class I, level B
Do not discontinue statin therapy preoperatively-Class I, level C
Effect of Statins on Perioperative Cardiac Events
Statins-Recommendations
ACEIs, ARBs
LV dysfunction Continue for high risk surgery-Class I, level C Consider continuing for low risk surgery-Class
IIa, level C
Hypertension-Consider transient discontinuation to avoid hypotension-Class IIb, level C
Recommendations based on low level of evidence
Aspirin
Aspirin for secondary prevention usually should not be discontinued in patients with previous stents
15 % of recurrent ACS in stable CAD patients due to discontinuing aspirin
Increased risk of stroke Should only stop if expected bleeding risks
and sequelae are greater than known risk of stopping Intracranial or back surgery Posterior eye chamber Prostate
ADP Receptor Antagonists Most often arises after PCI Premature discontinuation increases perioperative
M&M without reducing risk of bleeding Elective surgeries should be postponed
PTCA-2-6 weeks Bare metal stent-30 days-The longer the better Drug eluting stents-12 months
Emergency surgeries should be done on aspirin at least and preferably on dual antiplatelet therapy
Exceptions are intracranial, intraspinal, and retinal surgery
Perioperative MI- The POISE Study
Defined on basis of EKG changes and troponin elevations
65% of MIs were asymptomatic 11% died within 30 days (58% of those
within 48h) Troponin elevation >3x normal was
independent risk factor in absence of symptoms or EKG findings
Conclusion-At risk patients should be monitored for perioperative infarction with EKGs and enzymes for first three days postop
Perioperative and Postoperative Surveillance-Recommendations Class I
Troponin level recommended if signs or symptoms of myocardial ischemia or MI (LOE A)
EKG recommended if Sx or signs of ischemia or MI(LOE B)
Class IIb Usefulness of troponin or EKG in high risk patients
is uncertain without sx of signs of ischemia (LOE B) Class III
Routine screening with EKG or troponin in unselected patients without Sx or signs is not useful for guiding postoperative care
Preoperative Evaluation-What Is Essential?
1-Determine if the patient has had prior revascularization-When and what?
2-Has patient had a cardiac workup in the last several years?-What were the results?
3-Assess the patient’s functional capacity 4-Determine preoperative risk (RCRI or ACS risk
calculator) 5-Determine the pretest probability of cardiac
complications based on type of surgery and institutional experience
6-Assess whether stress testing will alter pretest probability of risk. Most of the time it will not.
Preoperative Evaluation-What Is Essential?
7-For elective surgery, determine if benefits outweigh perioperative risk.
8-Determine if there are opportunities to reduce cardiac complications by modifying preoperative or intraoperative care
9-Develop strategies to minimize perioperative risk, especially beta blockers and statins
10-Utilize careful postoperative monitoring to identify nonfatal cardiac events and modifiable risk factors to tailor long term therapy and follow up
What to Do If You Determine That the Patient is at High Risk Tell the patient
Find out how badly the patient wants the surgery Emphasize that the risks may outweigh the benefits
Call the surgeon How urgent is the operation? Is there a less invasive alternative?
Endovascular or laproscopic procedures Is the surgeon willing to operate with patient on
antiplatelet drugs? Don’t back down if you really think the risk is too
high. Most surgeons do worry about operative mortality.
What to Do if You Determine That the Patient is at High Risk Determine if there are risk factors that can be
modified to reduce risk and allow surgery at a later date Uncompensated heart failure Uncontrolled diabetes Uncontrolled hypertension Arrhythmias COPD
Get a consult There is no reason to do an elective
operation under less than optimal conditions
Emergency Operations
Often no opportunity for preoperative assessment or risk reduction Try to do risk stratification before OR
Postoperative monitoring for cardiac events becomes more important in this setting
Question 1
The most important clinical indicator of perioperative cardiovascular outcome is:
A-Previous revascularization
B-History of heart failure
C-Functional capacity
D-The type of surgical procedure
Question 2
A 74 y/o man is referred prior to THR. He has a history of previous bypass 10 years ago. He is asymptomatic but severely limited by his arthritis. As part of his preop evaluation he should have:
A-A treadmill GXT
B-Cardiac catheterization
C-Pharmacologic stress imaging
D-EKG
Question 3
The man in the previous question is on aspirin, lisinopril, and metformin. Prior to surgery his regimen should be changed as follows:
A-Add a long acting beta blocker
B-Stop aspirin
C-Add a statin
D-Make no changes
Question 4
A 68 y/o woman comes in for preop evaluation for colon resection for carcinoma. She has no symptoms. Her pulse is 110 and irregular, BP 120/74, and an EKG shows atrial fibrillation. She takes losartan and HCTZ. You should: A-Clear for surgery
B-Start anticoagulation and postpone surgery until after cardioversion
C-Start beta blocker therapy and postpone surgery until resting pulse rate <80
Recommended