Preoperative cardiac risk assessment

Introduction

Approximately 27 million patients undergo noncardiac surgery every year in the US. [1] Of those, about 50,000 have a perioperative MI. Furthermore, over half of the 40,000 perioperative deaths each year are caused by cardiac events. [2] Patients over 65 years of age are at higher risk of cardiac disease, cardiac morbidity, and death. Considering that this patient population will greatly increase over the coming decades, the number of patients with significant perioperative cardiac risk undergoing noncardiac surgery can be expected to increase globally.

Most perioperative cardiac morbidity and mortality is related to MI, heart failure, or arrhythmias. Therefore, preoperative evaluation and perioperative management emphasize the detection, characterization, and treatment of CAD, left ventricular (LV) systolic dysfunction, and significant arrhythmias in appropriate patients. These include patients with known or suspected CAD, arrhythmias, history of heart failure, or current symptoms consistent with these conditions. In the asymptomatic patient, a more extensive history and physical exam is warranted in people aged 50 years or older.

The purpose of individual preoperative cardiac risk assessment is to:

• Assess the medical status of the patient and the cardiac risks posed by the planned noncardiac surgery

• Recommend appropriate strategies to reduce the risk of cardiac problems over the entire perioperative period, and to improve long-term cardiac outcomes.

The main overall goals of assessment are to:

• Identify patients at increased risk of an adverse perioperative cardiac event

• Identify patients with a poor long-term prognosis due to cardiovascular disease. Even though the risk at the time of noncardiac surgery may not be prohibitive, appropriate treatment will affect long-term prognosis.

The nature of the evaluation should be individualized to the patient and the specific clinical scenario:

• Patients presenting with an acute surgical emergency require only a rapid preoperative assessment, with subsequent management directed at preventing or minimizing cardiac morbidity and death. Such patients can often be more thoroughly evaluated after surgery

• Patients undergoing an elective procedure with no surgical urgency can undergo a more thorough preoperative evaluation. [3]

Stepwise management approach

Eight steps to the optimal perioperative outcome (see below) [4]

1. Assess clinical features

• The history and physical exam should help to identify markers of cardiac risk and assess the patient's cardiac status.

• High-risk cardiac conditions include recent MI, decompensated heart failure, unstable angina, symptomatic arrhythmias, and symptomatic valvular heart disease. [5]

2. Evaluate functional status

• Patients who are able to exercise on a regular basis without limitations generally have sufficient cardiovascular reserve to withstand stressful operations.

3. Consider surgery-specific risk

• The type of surgery has important implications for perioperative risk. Noncardiac surgery can be stratified into high-risk, intermediate-risk, and low-risk categories (see below 'risk stratification according to type of noncardiac surgery').

4. Decide whether further noninvasive evaluation is needed

• Patients who are at low cardiac risk based on clinical features and functional status, and are undergoing low-risk surgery, do not generally require further evaluation.

• Patients who are at high cardiac risk based on clinical features, have poor functional status, and are being considered for high-risk noncardiac surgery may benefit from further evaluation.

5. Decide when to recommend invasive evaluation

• Indications for preoperative coronary angiography are similar to those in the nonoperative setting and include patients with evidence of high cardiac risk based on noninvasive testing, angina unresponsive to adequate medical therapy, unstable angina, and proposed intermediate-risk or high-risk noncardiac surgery after equivocal noninvasive test results.

• Angiography and revascularization are not routinely indicated for patients with stable CAD.

6. Optimize medical therapy

• Patients should be given optimal medical therapy, both perioperatively and in the long term, based on their underlying cardiac condition.

7. Perform appropriate perioperative surveillance

• In patients with known or suspected CAD, the possibility of perioperative ischemia or MI can be estimated based on the magnitude of biomarker elevation, new ECG abnormalities, hemodynamic instability, and the quality and intensity of chest pain or other symptoms.

8. Design maximal long-term therapy

• Assessment for hypercholesterolemia, smoking, hypertension, diabetes, physical inactivity, peripheral vascular disease, cardiac murmurs, arrhythmias, conduction abnormalities, and/or perioperative ischemia may lead to evaluation and treatments that reduce future cardiovascular risk.

History and physical examination

The patient history should aim to:

• Identify cardiac conditions (e.g., recent or past MI, decompensated heart failure, prior unstable angina, significant arrhythmias, valvular heart disease)

• Identify serious comorbid conditions (e.g., diabetes, peripheral vascular disease, stroke, renal insufficiency, pulmonary disease)

• Determine patient's functional capacity

• Document all current medications, allergies, tobacco use, and physical exercise habits.

On physical exam, patients with severe aortic stenosis, elevated jugular venous pressure, pulmonary edema, and/or third heart sound are at high surgical risk.

Functional capacity assessment

The functional capacity of the patient to perform common daily activities has been shown to correlate well with maximum oxygen uptake by treadmill testing. [3] On assessment, patients with <4 metabolic equivalents (METS) are considered to have poor functional capacity and are at relatively high risk of a perioperative event, while patients with >10 METS have excellent functional capacity and are at very low risk of perioperative events, even if they have known CAD. Patients with a functional capacity of 4 to 10 METS are considered to have fair functional capacity and are generally considered at low risk of perioperative events.

1 MET

• Eat, dress, use the toilet

• Walk indoors around the house

• Walk on level ground at 2 mph (3.2 km/hour)

• Perform light housework such as washing dishes.

4 METs

• Climb a flight of stairs (usually 18-21 steps)

• Walk on level ground at 4 mph (6.4 km/hour)

• Run short distances

• Perform vacuuming or lift heavy furniture

• Play golf or doubles tennis.

>10 METs

• Swimming

• Singles tennis

• Basketball

• Skiing.

Cardiac risk stratification using clinical predictors

The presence of ≥1 of the following active cardiac conditions is considered high risk, mandates intensive management, and may result in delay or cancellation of surgery unless the surgery is urgent. [3]

• Unstable coronary syndromes

  • Unstable or severe angina

  • Recent MI.

• Decompensated heart failure

• Significant arrhythmias

  • Mobitz II atrioventricular block

  • Third-degree atrioventricular block

  • Symptomatic ventricular arrhythmias

  • Supraventricular arrhythmias (including atrial fibrillation) with uncontrolled ventricular rate (heart rate >100 bpm at rest)

  • Symptomatic bradycardia

  • Newly recognized ventricular tachycardia.

• Severe valvular disease

  • Severe aortic stenosis (mean pressure gradient >40 mmHg, aortic valve area <1.0 cm^2, or symptomatic)

  • Symptomatic mitral stenosis (progressive dyspnea on exertion, exertional presyncope, or heart failure).

Patients are considered at intermediate risk if there are no active cardiac conditions as defined above, but the patient has 1 or more of the following clinical risk factors: [3]

• History of heart disease

• History of compensated or prior heart failure

• History of cerebrovascular disease

• Diabetes mellitus

• Renal insufficiency.

Patients are considered at low risk if the active cardiac conditions and clinical risk factors defined above are absent. [3]

Diagnostic tests can be used to refine the risk assessment. Some allow for risk stratification to be reassessed based on the test results (e.g., stress testing).

Risk stratification according to type of noncardiac surgery

High-risk surgery

• Emergency major operations, particularly in older people (>70 years)

• Aortic or peripheral vascular

• Extensive operations with large volume shifts.

Intermediate-risk surgery

• Intraperitoneal or intrathoracic

• Carotid endarterectomy

• Head and neck

• Orthopedic

• Prostate.

Low-risk surgery

• Endoscopic procedures

• Superficial biopsy

• Cataract

• Breast.

Diagnostic tests

Patients at low or high risk of an adverse perioperative cardiac event can typically be identified following history and examination. Patients at low risk generally require no additional testing before noncardiac surgery. However, those with intermediate or high risk undergoing elective noncardiac surgery may require additional testing.

1. Preoperative resting 12-lead ECG

• Not indicated in asymptomatic persons undergoing low-risk surgical procedures

• Recommended for patients with:

  • At least 1 clinical risk factor and undergoing vascular surgical procedures (clinical risk factors include history of ischemic heart disease, compensated or prior heart failure, cerebrovascular disease, diabetes mellitus, renal insufficiency)

  • Known coronary heart disease, peripheral arterial disease, or cerebrovascular disease, who are undergoing intermediate-risk surgical procedures. [3]

2. Preoperative noninvasive evaluation of LV function, using either echocardiography or nuclear testing

• Reasonable or recommended for patients with:

  • Dyspnea of unknown origin

  • Current or prior heart failure with worsening dyspnea or other change in clinical status if LV function has not been evaluated within 12 months.

• Routine perioperative evaluation of LV function is not recommended.

3. Stress testing

• Useful to detect myocardial ischemia and functional capacity

• Indicated in patients with active cardiac conditions (e.g., unstable angina, decompensated heart failure, or severe valvular heart disease) who typically need further evaluation

• Reasonable for patients with ≥3 clinical predictors of cardiac risk and poor functional capacity (<4 METs) who require vascular surgery, if the test will change the patient's management

• Not useful for patients undergoing low-risk noncardiac surgery.

4. Coronary angiography

• Indicated in patients with:

  • Evidence of high cardiac risk, based on noninvasive testing (see below)

  • Angina unresponsive to adequate medical therapy or unstable angina

  • Proposed intermediate-risk or high-risk noncardiac surgery after equivocal noninvasive test results.

• It is contraindicated in patients with stable angina. [5] [6]

5. Brain natriuretic peptide (BNP)

• BNP appears to be independently predictive for major adverse cardiac events following elective vascular surgery. [7]

• Use of BNP to predict cardiovascular events in the first 30 days after vascular surgery can significantly improve the predictive performance of the revised cardiac risk index. [8]

Cardiac risk stratification using stress testing

1. Exercise ECG

• Provides an estimate of functional capacity, detects myocardial ischemia, and assesses hemodynamic performance during stress. Exercise ECG is the preferred choice when noninvasive testing is indicated and the patient can walk.

• Perioperative risk stratification based on exercise ECG:

  • Low risk: ability to exercise moderately (4-5 METs) without symptoms; patients who can achieve >75% of maximum predicted heart rate without ECG changes

  • Intermediate risk: patients with abnormal ECG response at >75% of predicted heart rate

  • High risk: patients with abnormal ECG response at <75% of predicted heart rate.

2. Stress imaging

• Indicated in patients with abnormal baseline ECG (e.g., LVH, digitalis effect, left bundle branch block). Pharmacologic perfusion imaging is indicated in patients undergoing orthopedic, neurosurgical. or vascular surgery and who are unable to exercise, or who have left bundle branch block or have a pacemaker.

  • Dipyridamole is contraindicated in patients treated with theophylline and patients with severe obstructive lung disease or critical carotid stenosis.

  • Dobutamine stress echocardiography is comparable with dipyridamole thallium testing as a preoperative evaluation tool, but it should be avoided in patients with severe hypertension, significant arrhythmias, or poor echocardiographic images.

Perioperative risk stratification based on stress imaging:

• More than 4 myocardial segments of redistribution indicate significant risk for perioperative events

• Redistribution in 3 coronary artery territories and reversible LV cavity dilation indicate higher risk of events

• Total area of ischemia is more predictive than severity of ischemia in a given segment.

Perioperative therapy

Perioperative therapy includes:

• Preoperative revascularization with coronary artery bypass grafting or percutaneous coronary intervention

• Beta-blockers

• Statins

• Alpha-2 agonists.

Preoperative revascularization with coronary artery bypass grafting or percutaneous coronary intervention

Angiography and revascularization before noncardiac surgery [3]

• Indicated in patients with stable angina who have significant left main coronary artery stenosis; 3-vessel disease (survival benefit is greater when LV ejection fraction <0.50); or 2-vessel disease with significant proximal left anterior descending stenosis and either an ejection fraction <0.50 or a demonstrable ischemia on noninvasive evaluation

• Recommended in patients with unstable angina or non-ST-segment elevation MI, or with acute ST-elevation MI

• Not routinely indicated in patients with stable CAD. Several randomized trials have shown that preoperative coronary artery revascularization before elective major vascular surgery does not alter the long-term outcome in patients with stable CAD. Furthermore, preoperative percutaneous coronary intervention did not reduce the risk of death, MI, or other major cardiovascular events when added to optimal medical therapy. [5] [6]

A coronary stent is used in most percutaneous revascularization procedures. In this case, further delay in noncardiac surgery may be beneficial. Elective noncardiac surgery is not recommended within 4 to 6 weeks of bare metal coronary stent implantation or within 12 months of drug-eluting coronary stent implantation; or in patients who will need to discontinue thienopyridine therapy (e.g., clopidogrel, ticlopidine) or aspirin and thienopyridine therapy perioperatively. [3] Discontinuing aspirin or clopidogrel may cause acute stent thrombosis with very high morbidity and mortality.

Beta-blockers

The perioperative use of beta-blocker therapy during noncardiac surgery may be beneficial in reducing ischemia, risk of MI, and death in patients with known CAD. [9]

Beta-blocker therapy

• Should be continued in patients being treated for angina, symptomatic arrhythmias, hypertension, or other American College of Cardiology/American Heart Association (ACC/AHA) class I guideline indications.

• Should be considered in patients undergoing vascular surgery at high cardiac risk (as defined either by preoperative testing or on the basis of clinical features), who are undergoing intermediate-risk surgery.

• Routinely giving high-dose beta-blockers in the absence of dose titration is not useful and may be harmful to patients not taking beta-blockers who are undergoing noncardiac surgery.

• Similarly, routine administration of perioperative beta-blockers, particularly in higher fixed-dose regimens begun on the day of surgery, is not recommended.

Therapy can be started with metoprolol 25 mg orally given twice daily, and increased to maintain heart rate <60 bpm, or bisoprolol 5 to 10 mg orally once daily. It should be started days to weeks before elective surgery and continued for 48 hours to 7 days after surgery. Perioperative extended-release metoprolol has been shown to reduce the risk of MI, cardiac revascularization, and clinically significant atrial fibrillation 30 days after randomization, compared with placebo. However, one study suggests that the use of beta-blockers in patients with, or at risk of, atherosclerotic disease may result in significant excess risk of death, stroke, and clinically significant hypotension and bradycardia. Caution is therefore recommended in the routine use of beta-blockers. [10] Further prospective studies are required to assess potential risks and benefits before noncardiac surgery.

Statins

• The available evidence suggests a protective effect of perioperative statin use on cardiac complications during noncardiac surgery. Statin therapy results in 44% reduction in mortality after noncardiac surgery. [11]

• Therapy should be continued in patients treated with statins who are scheduled for noncardiac surgery.

• Statin therapy is reasonable in patients undergoing vascular surgery regardless of the cardiac risk.

Alpha-2 agonists

• There is some evidence for the perioperative use of alpha-2 agonists such as clonidine to reduce perioperative cardiovascular events in patients undergoing noncardiac surgery.

• Alpha-2 agonists for perioperative control of hypertension may be considered for patients with known CAD or at least 1 clinical risk factor who are undergoing surgery. [3]

Surveillance

For perioperative myocardial ischemia

• Intraoperative and postoperative ST-segment monitoring can be useful to monitor patients with known CAD or those undergoing vascular surgery.

For perioperative MI

• Postoperative troponin measurement is recommended in patients with ECG changes, or with chest pain typical of acute coronary syndrome. [3]

Special circumstances

Symptomatic aortic stenosis

• Severe aortic stenosis poses a significant risk for noncardiac surgery. Guidelines suggest that elective noncardiac surgery should generally be postponed or cancelled in such patients. [3]

• Patients require aortic valve replacement before elective but necessary noncardiac surgery.

Asymptomatic aortic stenosis

• If the aortic stenosis is severe but asymptomatic, the surgery should preferably be postponed or cancelled if the valve has not been evaluated within the previous year.

• In patients who refuse cardiac surgery, or who are otherwise not candidates for aortic valve replacement, noncardiac surgery has a mortality risk of approximately 10%. If a patient is not a candidate for valve replacement, percutaneous balloon aortic valvuloplasty may be reasonable as a bridge to surgery in hemodynamically unstable adult patients with aortic stenosis, who are at high risk for aortic valve replacement surgery; and in adult patients with aortic stenosis in whom aortic valve replacement cannot be performed because of serious comorbid conditions. Percutaneous valve replacement is emerging as a therapeutic modality and may be an option in the future.

Patients on psychotropic medications [12]

• Antidepressant treatment for chronically depressed patients should not be discontinued prior to anesthesia.

• Patients chronically treated with a tricyclic antidepressant should undergo cardiac evaluation prior to anesthesia.

• Irreversible MAOIs should be discontinued at least 2 weeks prior to anesthesia. In order to avoid relapse of underlying disease, medication should be changed to a reversible MAOI.

• The incidence of postoperative confusion is significantly higher in schizophrenic patients if medication is discontinued prior to surgery. Thus, antipsychotic medication should be continued perioperatively in patients with chronic schizophrenia.

• Lithium administration should be stopped 72 hours before surgery. It can be restarted afterward if the patient has normal ranges of electrolytes, is hemodynamically stable, and is able to eat and drink.

Preoperative assessment of the geriatric surgical patient [13]

• Data from the National Hospital Discharge Survey demonstrate increasing hospital utilization by elderly persons. [14] [15] Responding to the need for quality improvement in geriatric surgical care, the American College of Surgeons National Surgical Quality Improvement Program and the American Geriatrics Society formulated best practice guidelines to ensure optimal care of the geriatric surgical patient during the perioperative period. [13] The guideline development panel prioritized a number of preoperative domains specific to elderly individuals (e.g., cognitive impairment, frailty, polypharmacy, etc) and, additionally, issues commonly encountered in this population (e.g., risk of malnutrition, lack of family or social support, etc). Consensus statements and evidence-based recommendations for improving the preoperative assessment of the geriatric surgical patient were summarized in a checklist by the panel: [13]

  • Perform a complete history and physical examination

  • Assess cognitive ability and capacity to understand the anticipated surgery

  • Screen for depression

  • Identify and document risk factors for developing postoperative delirium

  • Screen for alcohol and other substance abuse/dependence

  • Perform a preoperative cardiac evaluation according to the American College of Cardiology/American Heart Association algorithm for patients undergoing noncardiac surgery [3] [9]

  • Identify risk factors for postoperative pulmonary complications and implement preventive strategies

  • Document functional status and history of falls

  • Determine baseline frailty score

  • Evaluate nutritional status and consider preoperative interventions if the patient is at severe nutritional risk

  • Document medication history and consider appropriate perioperative adjustments. Monitor for polypharmacy

  • Determine the patient's treatment goals and expectations in the context of the possible treatment outcomes

  • Determine the patient's family and social support system

  • Order appropriate preoperative diagnostic tests focused on elderly patients.

American College of Cardiology/American Heart Association (ACC/AHA) guidelines synopsis

Urgency of noncardiac surgery [3]

• It is important to determine the urgency of noncardiac surgery. In many cases, patient- or surgery-specific factors dictate immediate surgery and may not allow for further cardiac assessment or treatment. Perioperative medical management, surveillance, and postoperative risk stratification is appropriate in these cases.

Cardiac testing not required [3]

• Patients with bypass surgery in the previous 5 years or percutaneous coronary intervention from 6 months to 5 years previously, and no clinical evidence of ischemia, generally have low risk of cardiac complications from surgery. They may proceed without further testing, particularly if they are functionally very active and asymptomatic.

• Patients with favorable invasive/noninvasive testing in the previous 2 years generally require no further cardiac workup, if they have been asymptomatic since the test and are functionally active.

Noninvasive cardiac testing [3]

• Results of noninvasive testing can be used to define further management, including intensified medical therapy or the decision to proceed directly with surgery or cardiac catheterization. Cardiac catheterization may lead to coronary revascularization and is particularly justifiable when it is likely to improve the patient's long-term prognosis (e.g., in those with left main stenosis, or 3-vessel disease and impaired LV function).

• Poor functional capacity or a combination of high-risk surgery and moderate functional capacity, in a patient with intermediate clinical predictors of cardiac risk, may mean there are benefits to further noninvasive cardiac testing.

• In highly functional asymptomatic patients, management will rarely be changed on the basis of results of any further cardiovascular testing. It is therefore appropriate to proceed with the planned surgery. Estimation of functional status is an important aspect of the guidelines.

Risk of noncardiac surgery according to clinical predictors of cardiac risk, functional capacity, and type of surgery [3]

• Patients with minor or no clinical predictors of cardiac risk and moderate or excellent functional capacity can safely undergo noncardiac surgery.

• Patients with intermediate clinical predictors of cardiac risk and moderate or excellent functional capacity can generally undergo low- or intermediate-risk surgery with low event rates.

• Patients with unstable coronary syndrome, decompensated heart failure, symptomatic arrhythmias, or severe valvular heart disease who are scheduled for elective noncardiac surgery should have surgery canceled or delayed until the cardiac problem is clarified and treated.

• The type of surgery may itself identify a patient with a greater likelihood of underlying heart disease and higher perioperative morbidity and mortality. Perhaps the most extensively studied example is vascular surgery, in which underlying coronary and cerebrovascular disease is present in a substantial portion of patients. If the patient is undergoing vascular surgery, studies suggest that testing should be considered only if it will change management. Other types of surgery may be associated with similar risks to vascular surgery, but have not been studied extensively.

• In nonvascular surgery in which the perioperative morbidity related to the procedures ranges from 1% to 5% (intermediate-risk surgery), there is insufficient evidence to determine the best strategy (either proceeding with the planned surgery with tight heart rate control with beta-blockade, or further cardiovascular testing if it will change management). Cardiac evaluation and care algorithm for noncardiac surgeryAdapted from Fleisher LA, et al. J Am Coll Cardiol. 2007;50:e159-e241

European Society of Cardiology (ESC) and European Society of Anaesthesiology (ESA) guideline synopsis

Step 1. The urgency of the surgical procedure should be assessed. In urgent cases, patient- or surgery-specific factors dictate the strategy, and do not allow further cardiac testing or treatment. In these cases, the attending physician provides recommendations on perioperative medical management, surveillance for cardiac events, and continuation of chronic cardiovascular medical therapy. [16]

Step 2. If the patient is unstable, the underlying cause should be clarified and treated appropriately before surgery. Examples are unstable coronary syndromes, decompensated heart failure, severe arrhythmias, or symptomatic valvular disease. Cancellation or delay of the surgical procedure may be necessary. For instance, patients with unstable angina should be referred for coronary angiography to assess the therapeutic options. Treatment decisions should be discussed by a multidisciplinary team to determine the implications for anesthesiologic and surgical care. For example, initiating dual antiplatelet therapy after coronary artery stent placement might complicate local or regional anesthesia or specific surgical procedures. If the index surgery can be delayed, patients can proceed for coronary artery intervention, namely coronary artery bypass grafting, balloon angioplasty, or stent placement with the initiation of dual antiplatelet therapy. If delay of the index operation is incompatible with optimal medical therapy, the patient should proceed to surgery. [16]

Step 3. The risk of the surgical procedure should be determined. If the estimated 30-day cardiac risk of the procedure in cardiac-stable patients is low, or <1%, it is unlikely that test results will change management and it would be appropriate to proceed with the planned surgical procedure. The attending physician can identify risk factors and provide recommendations on lifestyle and medical therapy to improve long-term outcome. [16]

Step 4. The functional capacity of the patient should be assessed. If an asymptomatic or cardiac-stable patient has moderate or good functional capacity (i.e., >4 METs), perioperative management is unlikely to be changed on the basis of test results irrespective of the planned surgical procedure. Even in the presence of clinical risk factors, it is appropriate to refer the patient for surgery. In patients with ischemic heart disease or risk factor(s), statin therapy and a titrated low-dose beta-blocker regimen can be initiated before surgery. [16]

Step 5. It is recommended that chronic aspirin therapy be continued. Discontinuing aspirin therapy should be considered only in those patients in whom hemostasis is difficult to control during surgery. [16]

Step 6. In patients with a moderate or poor functional capacity, the risk of the surgical procedure should be considered. Patients scheduled for intermediate-risk surgery can proceed for surgery, provided statin therapy and a titrated low-dose beta-blocker regimen are initiated before surgery. In patients with ≥1 clinical risk factors, a preoperative baseline ECG is recommended to monitor changes during the perioperative period. In patients scheduled for high-risk surgery, clinical risk factors should be noted. In patients with up to 2 clinical risk factors, statin therapy and a titrated low-dose beta-blocker regimen are recommended before surgery. In patients with systolic LV dysfunction, evidenced by LV ejection fraction <40%, ACE inhibitors (or angiotensin-receptor blockers in patients intolerant of ACE inhibitors) are recommended before surgery regardless of whether the procedure is intermediate or high risk. Noninvasive testing is recommended in patients with ≥3 clinical risk factors. Noninvasive testing can also be considered before any surgical procedure for patient counseling, or change of perioperative management in relation to type of surgery and anesthesia technique. [16]

Step 7. If noninvasive testing is performed, patients without stress-induced ischemia, or mild to moderate ischemia suggestive of 1- or 2-vessel disease, can proceed with the planned surgical procedure. It is recommended that statin therapy and a titrated low-dose beta-blocker regimen be initiated. In patients with extensive stress-induced ischemia, as assessed by noninvasive testing, individualized perioperative management is recommended, taking into consideration the potential benefit of the proposed surgical procedure compared with the predicted adverse outcome. Also, the effect of medical therapy and/or coronary revascularization must be assessed, not only for immediate postoperative outcome, but also for long-term follow-up. In patients referred for percutaneous coronary artery intervention, the initiation and duration of antiplatelet therapy will interfere with the planned surgical procedure. [16]

The recommended times for the index surgery following coronary revascularization are as follows: [16]

• In patients referred for angioplasty, noncardiac surgery can be performed within 2 weeks after intervention with continuation of aspirin treatment

• In patients with bare metal stent placement, noncardiac surgery can be performed after 6 weeks to 3 months following intervention. Dual antiplatelet therapy should be continued for at least 6 weeks, preferably for up to 3 months. After this period, aspirin therapy should be continued

• In patients with recent drug-eluting stent placement, noncardiac surgery can be performed after 12 months following intervention, before which time dual antiplatelet therapy is recommended. After this period, aspirin therapy should be continued.