ACC/AHA Guideline Update for Perioperative Cardiovascular Evaluation for Noncardiac Surgery---executive Summary a Report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (committee to Update the 1996 Guidelines on Perioperative Cardiovascular Evaluation for Noncardiac Surgery).

HomeCirculationVol. 105, No. 10ACC/AHA Guideline Update for Perioperative Cardiovascular Evaluation for Noncardiac Surgery—Executive Summary A Report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee to Update the 1996 Guidelines on Perioperative Cardiovascular Evaluation for Noncardiac Surgery) Free AccessReview ArticlePDF/EPUBAboutView PDFView EPUBSections ToolsAdd to favoritesDownload citationsTrack citationsPermissions ShareShare onFacebookTwitterLinked InMendeleyReddit Jump toFree AccessReview ArticlePDF/EPUBACC/AHA Guideline Update for Perioperative Cardiovascular Evaluation for Noncardiac Surgery—Executive Summary A Report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee to Update the 1996 Guidelines on Perioperative Cardiovascular Evaluation for Noncardiac Surgery) Committee Members Kim A. Eagle, MD FACC, Chair, Peter B. Berger, MD FACC, Hugh Calkins, MD FACC, Bernard R. Chaitman, MD FACC, Gordon A. Ewy, MD FACC, Kirsten E. Fleischmann, MD MPH, FACC, Lee A. Fleisher, MD FACC, James B. Froehlich, MD, Richard J. Gusberg, MD FACS, Jeffrey A. Leppo, MD FACC, Thomas Ryan, MD FACC, Robert C. Schlant, MD FACC, William L. WintersJr, MD MACC, Raymond J. Gibbons, Task Force Members:, MD FACC, Chair, Elliott M. Antman, MD FACC, Vice Chair, Joseph S. Alpert, MD FACC, David P. Faxon, MD FACC, Valentin Fuster, MD PhD, FACC, Gabriel Gregoratos, MD FACC, Alice K. Jacobs, MD FACC, Loren F. Hiratzka, MD FACC, Richard O. Russell, MD FACC and Sidney C. SmithJr, MD FACC Committee Members Search for more papers by this author , Kim A. EagleKim A. Eagle Search for more papers by this author , Peter B. BergerPeter B. Berger Search for more papers by this author , Hugh CalkinsHugh Calkins Search for more papers by this author , Bernard R. ChaitmanBernard R. Chaitman Search for more papers by this author , Gordon A. EwyGordon A. Ewy Search for more papers by this author , Kirsten E. FleischmannKirsten E. Fleischmann Search for more papers by this author , Lee A. FleisherLee A. Fleisher Search for more papers by this author , James B. FroehlichJames B. Froehlich Search for more papers by this author , Richard J. GusbergRichard J. Gusberg Search for more papers by this author , Jeffrey A. LeppoJeffrey A. Leppo Search for more papers by this author , Thomas RyanThomas Ryan Search for more papers by this author , Robert C. SchlantRobert C. Schlant Search for more papers by this author , William L. WintersJrWilliam L. WintersJr Search for more papers by this author , Raymond J. GibbonsRaymond J. Gibbons Search for more papers by this author , Elliott M. AntmanElliott M. Antman Search for more papers by this author , Joseph S. AlpertJoseph S. Alpert Search for more papers by this author , David P. FaxonDavid P. Faxon Search for more papers by this author , Valentin FusterValentin Fuster Search for more papers by this author , Gabriel GregoratosGabriel Gregoratos Search for more papers by this author , Alice K. JacobsAlice K. Jacobs Search for more papers by this author , Loren F. HiratzkaLoren F. Hiratzka Search for more papers by this author , Richard O. RussellRichard O. Russell Search for more papers by this author and Sidney C. SmithJrSidney C. SmithJr Search for more papers by this author Originally published12 Mar 2002https://doi.org/10.1161/circ.105.10.1257Circulation. 2002;105:1257–12671. IntroductionThese guidelines represent an update of those published in 1996 and are intended for physicians who are involved in the preoperative, operative, and postoperative care of patients undergoing noncardiac surgery. They provide a framework for considering cardiac risk of noncardiac surgery in a variety of patient and surgical situations. The overriding theme of these guidelines is that preoperative intervention is rarely necessary simply to lower the risk of surgery unless such intervention is indicated irrespective of the preoperative context. The purpose of preoperative evaluation is not simply to give medical clearance but rather to perform an evaluation of the patient’s current medical status; make recommendations concerning the evaluation, management, and risk of cardiac problems over the entire perioperative period; and provide a clinical risk profile that the patient, primary physician, anesthesiologist, and surgeon can use in making treatment decisions that may influence short- and long-term cardiac outcomes. The goal of the consultation is to identify the most appropriate testing and treatment strategies to optimize care of the patient, provide assessment of both short- and long-term cardiac risk, and avoid unnecessary testing in this era of cost containment.A. Development of GuidelinesThese guidelines are based on an update of a Medline, EMBASE, Cochrane library, and Best Evidence search of the English literature from 1995 through 2000, a review of selected journals, and the expert opinions of 12 committee members representing various disciplines of cardiovascular care, including general cardiology, interventional cardiology, noninvasive testing, vascular medicine, vascular surgery, anesthesiology, and arrhythmia management. As a result of these searches, more than 400 relevant new articles were identified. In addition, draft guidelines were submitted for critical review and amendment to the executive officers representing the American College of Cardiology (ACC) and the American Heart Association (AHA).A large proportion of the data used to develop these guidelines are based on observational or retrospective studies or knowledge of management of cardiovascular disorders in the nonoperative setting. Although the collective body of knowledge about the identification of high- and low-risk patients by perioperative clinical and noninvasive evaluation is substantial, the number of prospective or randomized studies that have been performed to establish the value of different treatments on perioperative outcomes is small. The ACC/AHA classifications of evidence used in this report to summarize the indication for a particular therapy or treatment are as follows:Class I: Conditions for which there is evidence and/or general agreement that a given procedure/therapy is useful and effective.Class II: Conditions for which there is conflicting evidence and/or a divergence of opinion about the usefulness/efficacy of performing the procedure/therapy.Class IIa: Weight of evidence/opinion is in favor of usefulness/efficacy.Class IIb: Usefulness/efficacy is less well established by evidence/opinion.Class III: Conditions for which there is evidence and/or general agreement that a procedure/therapy is not useful/effective and in some cases may be harmful.Two versions of the full-text guidelines are available on the World Wide Web sites of both the American College of Cardiology (www.acc.org) and the American Heart Association (www.americanheart.org); one version highlights the updated material (deleted text in strikeout and new text in red), and the other fully incorporates the changes. This document was approved for publication by the governing bodies of the ACC and the AHA, will be reviewed annually by the Task Force, and will be considered current unless the Task Force revises or withdraws them from distribution.B. General ApproachThe preoperative cardiac evaluation must be carefully tailored to the circumstances that have prompted the consultation and to the nature of the surgical illness (e.g., acute surgical emergency) as opposed to urgent or elective cases. Successful perioperative evaluation and treatment of cardiac patients undergoing noncardiac surgery requires careful teamwork and communication between the patient, primary care physician, anesthesiologist, consultant, and surgeon. In general, indications for further cardiac testing and treatments are the same as those in the nonoperative setting, but their timing is dependent on such factors as the urgency of noncardiac surgery, the patient’s risk factors, and specific surgical considerations. Coronary revascularization before noncardiac surgery to enable the patient to “get through” the noncardiac procedure is appropriate only for a small subset of patients at very high risk. Preoperative testing should be limited to circumstances in which the results will affect patient treatment and outcomes. A conservative approach to the use of expensive tests and treatments is recommended.C. Preoperative Clinical EvaluationThe initial history, physical examination, and electrocardiogram (ECG) assessment should focus on identification of potentially serious cardiac disorders, including coronary artery disease (CAD) [e.g., prior myocardial infarction (MI) and angina pectoris], heart failure (HF), symptomatic arrhythmias, presence of pacemaker or implantable cardioverter defibrillator (ICD), or a history of orthostatic intolerance.1 The presence of anemia may also place a patient at higher perioperative risk.2–4In addition to identifying the presence of pre-existing manifested heart disease, it is essential to define disease severity, stability, and prior treatment. Other factors that help determine cardiac risk include functional capacity, age, comorbid conditions (e.g., diabetes mellitus, peripheral vascular disease, renal dysfunction, and chronic pulmonary disease), and type of surgery (vascular procedures and prolonged, complicated thoracic, abdominal, and head and neck procedures are considered higher risk).Numerous risk indices have been developed over the past 25 years on the basis of multivariate analyses.5–14 In addition to the presence of CAD and HF, a history of cerebrovascular disease, preoperative elevated creatinine greater than 2 mg per deciliter, insulin treatment for diabetes mellitus, and high-risk surgery have all been associated with increased perioperative cardiac morbidity. Despite these risk indices, there was consensus among the committee members to place clinical risk factors into 3 categories of predictors (see Section II-A).II. Further Preoperative Testing to Assess Coronary RiskWhich patients are most likely to benefit from preoperative coronary assessment and treatment? The lack of adequately controlled or randomized clinical trials to define the optimal evaluation strategy led to the proposed algorithm based on collected observational data and expert opinion (see Fig. 1). Since publication of the guidelines in 1996, several studies have suggested that this stepwise approach to the assessment of CAD is both efficacious and cost-effective. Download figureDownload PowerPointFigure 1. Stepwise approach to preoperative cardiac assessment. Steps are discussed in text. *Subsequent care may include cancellation or delay of surgery, coronary revascularization followed by noncardiac surgery, or intensified care.A stepwise bayesian strategy that relies on assessment of clinical markers, prior coronary evaluation and treatment, functional capacity, and surgery-specific risk is outlined in Figure 1. A framework for determining which patients are candidates for cardiac testing is presented in algorithmic form. Successful use of the algorithm requires an appreciation of the different levels of risk attributable to certain clinical circumstances, levels of functional capacity, and types of surgery. These are defined below, after which the algorithm is reviewed step by step.A. Clinical MarkersThe major clinical predictors (Table 1) of increased perioperative cardiovascular risk are a recent unstable coronary syndrome such as an acute MI (documented MI less than 7 days previously), recent MI (more than 7 days but less than 1 month before surgery), unstable or severe angina, evidence of a large ischemic burden by clinical symptoms or noninvasive testing, decompensated HF, significant arrhythmias (high-grade atrioventricular block, symptomatic arrhythmias in the presence of underlying heart disease, or supraventricular arrhythmias with uncontrolled ventricular rate), and severe valvular disease. Table 1104956. Clinical Predictors of Increased Perioperative Cardiovascular Risk (Myocardial Infarction, Heart Failure, Death)ECG indicates electrocardiogram.*The American College of Cardiology National Database Library defines recent MI as greater than 7 days but less than or equal to 1 month (30 days); acute MI is within 7 days.†May include “stable” angina in patients who are unusually sedentary.‡Campeau L. Grading of angina pectoris. Circulation. 1976;54:522–523.MajorUnstable coronary syndromes• Acute or recent myocardial infarction with evidence of important ischemic risk by clinical symptoms or noninvasive study• Unstable or severe angina (Canadian class III or IV)Decompensated heart failureSignificant arrhythmias• High-grade atrioventricular block• Symptomatic ventricular arrhythmias in the presence of underlying heart disease• Supraventricular arrhythmias with uncontrolled ventricular rateSevere valvular diseaseIntermediateMild angina pectoris (Canadian class I or II)Previous myocardial infarction by history or pathological Q wavesCompensated or prior heart failureDiabetes mellitus (particularly insulin-dependent)Renal insufficiencyMinorAdvanced ageAbnormal ECG (left ventricular hypertrophy, left bundle-branch block, ST-T abnormalities)Rhythm other than sinus (e.g., atrial fibrillation)Low functional capacity (e.g., inability to climb one flight of stairs with a bag of groceries)History of strokeUncontrolled systemic hypertensionIntermediate predictors of increased risk are mild angina pectoris, a more remote prior MI (more than 1 month before planned surgery), compensated HF, preoperative creatinine greater than or equal to 2.0 mg per deciliter, and diabetes mellitus. Minor predictors of risk are advanced age, abnormal ECG, rhythm other than sinus, low functional capacity, history of stroke, and uncontrolled systemic hypertension.A history of MI or abnormal Q waves by ECG is listed as an intermediate predictor, whereas an acute MI (defined as at least 1 documented MI less than or equal to 7 days before the examination) or recent MI (more than 7 days but less than or equal to 1 month before the examination) with evidence of important ischemic risk by clinical symptoms or noninvasive study is a major predictor. This definition reflects the consensus of the ACC Cardiovascular Database Committee. In this way, the separation of MI into the traditional 3- and 6-month intervals has been avoided.6,15 Current management of MI provides for risk stratification during convalescence.16 If a recent stress test does not indicate residual myocardium at risk, the likelihood of reinfarction after noncardiac surgery is low. Although there are no adequate clinical trials on which to base firm recommendations, it appears reasonable to wait 4 to 6 weeks after MI to perform elective surgery.B. Functional CapacityFunctional capacity can be expressed in metabolic equivalent (MET) levels (Table 2). Multiples of the baseline MET value can be used to express aerobic demands for specific activities. Perioperative cardiac and long-term risks are increased in patients unable to meet a 4-MET demand during most normal daily activities.17–19 The Duke Activity Status Index and other activity scales provide the clinician with a set of questions to determine a patient’s functional capacity.20–22 Energy expenditures for activities such as eating, dressing, walking around the house, and dishwashing range from 1 to 4 METs. Climbing a flight of stairs, walking on level ground at 6.4 km per hour, running a short distance, scrubbing floors, or playing a game of golf represents 4 to 10 METs. Strenuous sports such as swimming, singles tennis, and football often exceed 10 METs. Table 2104956. Estimated Energy Requirements for Various ActivitiesMET indicates metabolic equivalent.Adapted from the Duke Activity Status Index20 and AHA Exercise Standards.961 METCan you take care of yourself?4 METsClimb a flight of stairs or walk up a hill?Eat, dress, or use the toilet?Walk on level ground at 4 mph or 6.4 km per h?Walk indoors around the house?Run a short distance?Walk a block or two on level ground at 2 to 3 mph or 3.2 to 4.8 km per h?Do heavy work around the house like scrubbing floors or lifting or moving heavy furniture?Participate in moderate recreational activities like golf, bowling, dancing, doubles tennis, or throwing a baseball or football?4 METsDo light work around the house like dusting or washing dishes?Greater than 10 METsParticipate in strenuous sports like swimming, singles tennis, football, basketball, or skiing?C. Surgery-Specific RiskSurgery-specific cardiac risk of noncardiac surgery is related to 2 important factors: the type of surgery itself and the degree of hemodynamic stress associated with the procedures. The duration and intensity of coronary and myocardial stressors can be helpful in estimating the likelihood of perioperative cardiac events, particularly for emergency surgery. Surgery-specific risk for noncardiac surgery can be stratified as high, intermediate, and low (Table 3). 23 High-risk surgery includes major emergency surgery, particularly in the elderly; aortic and other major vascular surgery; peripheral vascular surgery; and anticipated prolonged procedures associated with large fluid shifts and/or blood loss. Intermediate-risk procedures include intraperitoneal and intrathoracic surgery, carotid endarterectomy, head and neck surgery, orthopedic surgery, and prostate surgery. Low-risk procedures include endoscopic and superficial procedures, cataract surgery, and breast surgery. Table 3104956. Cardiac Risk* Stratification for Noncardiac Surgical Procedures*Combined incidence of cardiac death and nonfatal myocardial infarction. †Do not generally require further preoperative cardiac testing.High (Reported cardiac risk often greater than 5%)• Emergent major operations, particularly in the elderly• Aortic and other major vascular surgery• Peripheral vascular surgery• Anticipated prolonged surgical procedures associated with large fluid shifts and/or blood lossIntermediate (Reported cardiac risk generally less than 5%)• Carotid endarterectomy• Head and neck surgery• Intraperitoneal and intrathoracic surgery• Orthopedic surgery• Prostate surgeryLow (Reported cardiac risk generally less than 1%)• Endoscopic procedures• Superficial procedure• Cataract surgery• Breast surgeryThe following steps correspond to the algorithm presented in Figure 1.Step 1 What is the urgency of noncardiac surgery? Certain emergencies do not allow time for preoperative cardiac evaluation. Postoperative risk stratification may be appropriate for some patients who have not had such an assessment before.Step 2 Has the patient undergone coronary revascularization in the past 5 years? If so, and if clinical status has remained stable without recurrent symptoms/signs of ischemia, further cardiac testing is generally not necessary.24Step 3 Has the patient had a coronary evaluation in the past 2 years? If coronary risk was adequately assessed and the findings were favorable, it is usually not necessary to repeat testing unless the patient has experienced a change or new symptoms of coronary ischemia since the previous evaluation.Step 4 Does the patient have an unstable coronary syndrome or a major clinical predictor of risk? When elective noncardiac surgery is being considered, the presence of unstable coronary disease, decompensated HF, symptomatic arrhythmias, and/or severe valvular heart disease usually leads to cancellation or delay of surgery until the problem has been identified and treated.Step 5 Does the patient have intermediate clinical predictors of risk? The presence or absence of prior MI by history or ECG, angina pectoris, compensated or prior HF, preoperative creatinine greater than or equal to 2 mg per deciliter, and/or diabetes mellitus helps to further stratify clinical risk for perioperative coronary events. Consideration of functional capacity and level of surgery-specific risk allows a rational approach to identify patients most likely to benefit from further noninvasive testing.Step 6 Patients without major but with intermediate predictors of clinical risk and moderate or excellent functional capacity can generally undergo intermediate-risk surgery with little likelihood of perioperative death or MI. Conversely, further noninvasive testing is often considered for patients with poor functional capacity or moderate functional capacity but higher-risk surgery, especially for patients with 2 or more intermediate predictors of risk.Step 7 Noncardiac surgery is generally safe for patients with neither major nor intermediate predictors of clinical risk and moderate or excellent functional capacity (4 METs or greater). Additional testing may be considered on an individual basis for patients without clinical markers but with poor functional capacity who are facing higher-risk operations, particularly those with several minor clinical predictors of risk who are scheduled to undergo vascular surgery.Step 8 The results of noninvasive testing can be used to determine the need for additional preoperative testing and treatment. In some patients with documented CAD, the risk of coronary intervention or corrective cardiac surgery may approach or even exceed the risk of the proposed noncardiac surgery. This approach may be appropriate, however, if it significantly improves the patient’s long-term prognosis.For some patients, a careful consideration of clinical, surgery-specific, and functional status attributes leads to a decision to proceed to coronary angiography.III. Management of Specific Preoperative Cardiovascular ConditionsA. HypertensionStage 3 hypertension (systolic blood pressure greater than or equal to 180 mm Hg and diastolic blood pressure greater than or equal to 110 mm Hg) should be controlled before surgery. In many such instances, establishment of an effective regimen can be achieved over several days to weeks of preoperative outpatient treatment. If surgery is more urgent, rapid-acting agents can be administered that allow effective control in a matter of minutes or hours. Beta-blockers appear to be particularly attractive agents. Continuation of preoperative antihypertensive treatment through the perioperative period is critical.B. Valvular Heart DiseaseIndications for evaluation and treatment of valvular heart disease are identical to those in the nonpreoperative setting. Symptomatic stenotic lesions are associated with risk of perioperative HF or shock and often require percutaneous valvotomy or valve replacement before noncardiac surgery to lower cardiac risk.6,25–27 Symptomatic regurgitant valve disease is usually better tolerated perioperatively and may be stabilized preoperatively with intensive medical therapy and monitoring. Regurgitant valve disease can then be treated definitively with valve repair or replacement after noncardiac surgery. Medical therapy and monitoring are appropriate when a delay of several weeks or months before noncardiac surgery may have severe consequences. Exceptions may include severe valvular regurgitation with reduced left ventricular function, in which overall hemodynamic reserve is so limited that destabilization during perioperative stresses is likely.C. Myocardial DiseaseDilated and hypertrophic cardiomyopathy are associated with an increased incidence of perioperative HF.6,28,29 Management is aimed at maximizing preoperative hemodynamic status and providing intensive postoperative medical therapy and surveillance. An estimate of hemodynamic reserve is useful for anticipating potential complications from intraoperative or postoperative stress.D. Arrhythmias and Conduction AbnormalitiesThe presence of an arrhythmia or cardiac conduction disturbance should provoke a careful evaluation for underlying cardiopulmonary disease, drug toxicity, or metabolic abnormality. Therapy should be initiated for symptomatic or hemodynamically significant arrhythmias, first to reverse an underlying cause and second to treat the arrhythmia. Indications for antiarrhythmic therapy and cardiac pacing are identical to those in the nonoperative setting. Frequent ventricular premature beats and/or asymptomatic nonsustained ventricular tachycardia have not been associated with an increased risk of nonfatal MI or cardiac death in the perioperative period,30,31 and therefore, aggressive monitoring or treatment in the perioperative period generally is not necessary.E. Implantable Pacemakers or ICDsThe type and extent of evaluation of a pacemaker or ICD depend on the urgency of the surgery, whether a pacemaker has unipolar or bipolar leads, whether electrocautery is bipolar or unipolar, the distance between electrocautery and pacemaker, and pacemaker dependency. ICD devices should be programmed off immediately before surgery and then on again postoperatively.IV. Supplemental Preoperative EvaluationSpecific recommendations for supplemental preoperative evaluation must be individualized to each patient and circumstance. The following may be appropriate in specific situations: assessment of resting left ventricular function, exercise stress testing, pharmacological stress testing, ambulatory ECG monitoring, and coronary angiography. In most ambulatory patients, the test of choice is exercise ECG testing, which can both provide an estimate of functional capacity and detect myocardial ischemia through changes in the ECG and hemodynamic response. In patients with important abnormalities on their resting ECG (e.g., left bundle-branch block, left ventricular hypertrophy with strain pattern, or digitalis effect), other techniques such as exercise echocardiography or exercise myocardial perfusion imaging should be considered. Recommendations regarding individual testing modalities are given below.A. Resting Left Ventricular FunctionResting left ventricular function has not been found to be a consistent predictor of perioperative ischemic events.32–40Recommendations for Preoperative Noninvasive Evaluation of Left Ventricular FunctionClass IPatients with current or poorly controlled HF. (If previous evaluation has documented severe left ventricular dysfunction, repeat preoperative testing may not be necessary).Class IIaPatients with prior HF and patients with dyspnea of unknown origin.Class IIIAs a routine test of left ventricular function in patients without prior HF.B. 12-Lead ECGThe resting 12-lead ECG does not identify increased perioperative risk in patients undergoing low-risk surgery, but certain ECG abnormalities are clinical predictors of increased perioperative and long-term cardiovascular risk in clinically intermediate- and high-risk patients.41–45Recommendations for Preoperative 12-Lead Rest ECGClass IRecent episode of chest pain or ischemic equivalent in clinically intermediate- or high-risk patients scheduled for an intermediate- or high-risk operative procedure.Class IIaAsymptomatic persons with diabetes mellitus.Class IIbPatients with prior coronary revascularization.Asymptomatic male more than 45 years old or female more than 55 years old with 2 or more atherosclerotic risk factors.Prior hospital admission for cardiac causes.Class IIIAs a routine test in asymptomatic subjects undergoing low-risk operative procedures.C. Exercise or Pharmacological Stress TestingRecommendations for Exercise or Pharmacological Stress TestingClass IDiagnosis of adult patients with intermediate pretest probability of CAD.Prognostic assessment of patients undergoing initial evaluation for suspected or proven CAD; evaluation of subjects with significant change in clinical status.Demonstration of proof of myocardial ischemia before coronary revascularization.Evaluation of adequacy of medical therapy; prognostic assessment after an acute coronary syndrome (if recent evaluation unavailable).Class IIaEvaluation of exercise capacity when subjective assessment is unreliable.Class IIbDiagnosis of CAD patients with high or low pretest probability: those with resting ST depression less than 1 mm, those taking digitalis therapy, or those with ECG criteria for left ventricular hypertrophy.Detection of restenosis in high-risk asymptomatic subjects within the initial months after percutaneous coronary intervention (PCI).Class IIIFor exercise stress testing, diagnosis of patients with resting ECG abnormalities that preclude adequate assessment, e.g., pre-excitation syndrome, electronically paced ventricular rhythm, rest ST depression greater than 1 mm, or left bundle-branch block.Severe comorbidity likely to limit life expectancy or candidacy for revascularization.Routine screening of asymptomatic men or women.Investigation of isolated ectopic beats in young patients.D. Coronary AngiographyRecommendations for Coronary Angiography in Perioperative Evaluation Before (or After) Noncardiac SurgeryClass I:Patients With Suspected or Known CADEvidence for high risk of adverse outcome based on noninvasive test results.Angina unresponsive to adequate medical therapy.Unstable angina, particularly when facing intermediate-risk* or high-risk* noncardiac surgery.Equivocal noninvasive test results in patients at high clinical risk† undergoing high-risk* surgery.Class IIaMultiple markers of intermediate clinical risk† and planned vascular surgery (noninvasive testing should be considered first).Moderate to large ischemia on noninvasive testing but without high-risk features and lower left ventricular ejection fraction.Nondiagnostic noninvasive test results in patients at intermediate clinical risk† undergoing high-risk* noncardiac surgery.Urgent noncardiac surgery while convalescing from acute MI.Class IIbPerioperative MI.Medically stabilized class III or IV angina and planned low-ris