Version May 2024
INTRODUCTION — Some patients undergoing noncardiac surgery are at risk for an adverse cardiovascular event (ie, myocardial ischemia, myocardial infarction [MI], heart failure, arrhythmia, stroke, or cardiac death). The risk is related to patient- and surgery-specific factors. Identification of increased risk provides the patient, anesthesiologist, and surgeon with information that helps them better understand the benefit-to-risk ratio of a procedure and may lead to interventions that decrease risk.
This topic will review the initial preoperative cardiac evaluation, which includes an attempt to quantify risk, and focus on the patient with known or suspected ischemic heart disease. The evaluation of cardiac risk in other specific patient populations is discussed separately:
●(See "Noncardiac surgery in adults with aortic stenosis".)
●(See "Rheumatic mitral stenosis: Overview of management", section on 'Management of noncardiac surgery'.)
●(See "Noncardiac surgery in patients with mitral or aortic regurgitation".)
Interventions to reduce cardiac risk in patients with relatively high perioperative risk are discussed separately. (See "Management of cardiac risk for noncardiac surgery".)
Other concerns regarding preoperative evaluation are discussed separately:
●(See "Preoperative medical evaluation of the healthy adult patient".)
●(See "Perioperative medication management".)
●(See "Preoperative evaluation for anesthesia for noncardiac surgery".)
DEFINITIONS — Perioperative cardiac risk is variably defined and may include risks of myocardial ischemia and injury, myocardial infarction (MI), heart failure, arrhythmias, stroke, and death.
●Major adverse cardiac events – In studies of the incidence and risk factors for perioperative cardiac events, major adverse cardiac events have typically been defined as MI and cardiac arrest or cardiac death [1,2]. This outcome has also been referred to as perioperative adverse cardiac events [2].
●Myocardial injury after noncardiac surgery – Myocardial injury after noncardiac surgery (MINS) is now recognized as a category of adverse perioperative cardiac events. MINS is defined as an elevated troponin during the first 30 days after noncardiac surgery, presumed to be of ischemic etiology. MINS occurs in 10 to 20 percent of patients and is associated with worse outcomes at 30 days after surgery. Importantly, MINS is not included as a complication in most perioperative cardiac risk tools or calculators. MINS is discussed in detail separately. (See "Perioperative myocardial infarction or injury after noncardiac surgery".)
●Surgical risk – The terms low, intermediate, and high risk are typically used to classify the risk associated with major adverse cardiac events in surgical procedures; these have been employed in many guidelines and studies of perioperative risk. These definitions are based on the reported rates of cardiac death, nonfatal cardiac arrest, or nonfatal MI, as follows:
•High risk – >5 percent
•Intermediate risk – ≥1 to ≤5 percent
•Low risk – <1 percent
The utility and accuracy of such definitions is being questioned due to possibly decreasing procedural risk over time and changes in perioperative care that may affect risk. However, these estimates of risk are still used in guidelines and in risk assessment algorithms (table 1). (See 'Incidence and risk factors' below.)
The 2014 American College of Cardiology/American Heart Association (ACC/AHA) Guideline on Perioperative Cardiovascular Evaluation and Management for noncardiac surgery defined elevated risk procedures as those with a combined surgical and patient risk of major adverse cardiac events ≥1 percent [3].
REASONS TO ASSESS RISK — All patients scheduled to undergo noncardiac surgery should have an assessment of the risk of a perioperative adverse cardiovascular event [3]. In some cases this assessment will be minimal, whereas in others it may be extensive. The purposes of this assessment are to:
●Help the patient and health care providers weigh the benefits and risks of the surgery (see 'Discussing risk with the patient' below)
●Determine the need for management strategies to reduce risk (see "Management of cardiac risk for noncardiac surgery")
●Optimize the timing or location (eg, hospital or ambulatory surgery center) of surgery
●Assess the need for more intensive postoperative monitoring (eg, intensive care unit, continuous or invasive cardiac monitoring)
Similar to other aspects of preoperative assessment, cardiac risk assessment may reveal problems that have not been diagnosed or optimally treated. Since most operations are elective, there may be time to optimize management of conditions identified during preoperative risk assessment.
INCIDENCE AND RISK FACTORS — The incidence of perioperative major adverse cardiac events may be decreasing. A 2016 study using information in a large administrative database of United States hospital admissions (2004 to 2013) found that the frequency of major adverse cardiovascular and cerebrovascular events (MACCE; in-hospital, all-cause death, acute myocardial infarction [MI], or acute ischemic stroke) declined from 3.1 to 2.6 percent, driven by a decrease in frequency of perioperative death and acute MI [4]. The incidence of perioperative ischemic stroke increased from 0.52 percent in 2004 to 0.77 percent in 2013. These events were most common after vascular, thoracic, and transplant surgery. The incidence of perioperative stroke is discussed in detail separately. (see "Perioperative stroke following noncardiac, noncarotid, and nonneurologic surgery", section on 'Incidence and risk factors'); However, the incidence of perioperative major adverse cardiac events varies widely based on both patient factors, the intrinsic risk of the surgical procedure, and the skill and reported outcomes of the surgical center [2], thus the need for individualized preoperative assessment and risk stratification.
Patient risk factors — Patient risk factors for perioperative adverse cardiac events have been identified, and some have been incorporated into risk screening tools, which are discussed below. (See 'Using risk assessment tools' below.)
Importantly, the determination of specific definitions for most of the risk factors have been based upon the nonsurgical literature rather than studies in surgical patients.
●Existing cardiovascular disease – Patients with recent MI (prior 60 days) [5] or unstable angina, decompensated heart failure, high-grade arrhythmias, or hemodynamically important valvular heart disease (aortic stenosis in particular [6]) are at very high risk for perioperative cardiovascular complications. (See 'Very high-risk patients' below.)
Patients with underlying cardiovascular disease, including peripheral artery disease or cerebrovascular disease, have an increased risk of perioperative cardiac complications for the following reasons:
•They constitute a selected population with a high incidence of significant coronary artery disease [7,8]. In addition, left ventricular systolic dysfunction is more common in patients with cerebrovascular disease or peripheral artery disease [9].
•In patients with underlying coronary artery disease, hemodynamic and other physiologic changes associated with surgery may predispose to myocardial ischemia. These include volume shifts and blood loss, increased perioperative myocardial oxygen demand due to the surgical stress response, and perioperative platelet activation [10].
Perioperative risk associated with heart failure, valvular heart disease, and atrial fibrillation is discussed separately:
•(See "Noncardiac surgery in patients with mitral or aortic regurgitation".)
•(See "Atrial fibrillation in patients undergoing noncardiac surgery", section on 'Epidemiology'.)
●Poor functional status – Poor functional status may increase perioperative risk, whereas good functional status has been associated with lower risk. Experts and some guidelines recommend routinely assessing functional status as part of preoperative assessment [3,11]. The Canadian Cardiology Society Guidelines do not make a recommendation for functional assessment, citing limited evidence at the time the guideline was created.
Functional status is not included in the Revised Cardiac Risk Index (RCRI) or American College of Surgeons National Surgical Quality Improvement (ACS NSQIP) risk calculator. Dependence, which could be a measure of function, is one parameter included in the Myocardial Infarction or Cardiac Arrest (MICA) perioperative risk calculator [1].
Several studies have found that patients who are unable to perform average levels of exercise (4 to 5 metabolic equivalents [METs]) may be at increased risk of perioperative complications, including adverse cardiovascular events [12-17]. Oxygen uptake and the definition of metabolic equivalents are discussed separately. (See "Cardiopulmonary exercise testing in cardiovascular disease", section on 'Aerobic parameters'.)
Methods for assessing functional status and their ability to predict risk are discussed below. (See 'Assessing functional status or exercise capacity' below.)
●Older age – Increasing age has been associated with increased risk of perioperative cardiac complications. It is unclear whether older age is an independent risk factor or if increasing risk is due to underlying known or subclinical cardiac comorbidities (See "Normal aging", section on 'Cardiovascular system'.).
Various age cutoffs have been used in guidelines and risk scoring tools. The Canadian Cardiology Society and European Society of Cardiology (ESC) guidelines for preoperative cardiac risk assessment use age 65 as a cutoff for increased risk [11,18], However, there is likely a continuum of increasing risk with increasing age. As an example, in a database study of over 400,700 adults who underwent inpatient noncardiac surgery in Sweden, the risk of MI within 30 days of surgery increased steadily with age, from 1.64 (95% CI 1.28-2.10) in patients 65 to 69 years old to 5.47 (95% CI 4.48-6.69) in patients ≥85 years of age, compared with patients ≤65 years of age [19].
●Diabetes – Diabetes is a risk factor for cardiovascular disease and has been found to be a risk factor for perioperative cardiac complications. Diabetes requiring insulin was found to be an independent risk factor for major cardiac complications in the derivation of the RCRI, whereas derivation of other risk-scoring tools (eg, American College of Surgeons Surgical Risk Calculator, Geriatric Sensitive Perioperative Cardiac Risk Index, Vascular Quality Initiative Cardiac Risk Index) have found diabetes treated with oral agents or with insulin to be associated with increased perioperative risk [20-22].
●Kidney dysfunction – Chronic kidney disease increases the risk of cardiovascular disease and has been associated with increased perioperative cardiac risk. However, the level of kidney dysfunction that increases perioperative risk is unclear. Various cutoffs for kidney dysfunction have been used in the development and validation of risk scoring tools. A creatinine >2.0 mg/dL was used for derivation of the RCRI and was found to be an independent risk factor for major cardiac complications [23]. For the MICA calculator, a creatinine of >1.5 mg/dL is used as a risk factor [1], and the American College of Surgeons Surgical Risk Calculator includes acute renal failure (defined as increased blood urea nitrogen plus two creatinine results >3 mg/dL) as a risk factor [24]. A revised version of the RCRI (the Reconstructed RCRI) uses glomerular filtration rate (GFR) <30 mL/minute as a risk factor, which was found to be a better predictor of major cardiac complications than an elevated creatinine [25].
Intrinsic surgical risk — By convention, the level of intrinsic surgical risk is defined by the reported rate of postoperative nonfatal MI or cardiac death. Low risk is defined as <1 percent, intermediate risk as 1 to 5 percent, and high risk as >5 percent (table 1).
Higher perioperative risk is generally associated with the following types of surgeries:
●Intraperitoneal
●Intraabdominal
●Intrathoracic
●Major vascular procedures
●Longer procedures
●Those associated with greater blood loss and intraoperative fluid shifts
Lower risk is associated with the following surgeries:
●Laparoscopic
●Endovascular
●Orthopedic
●Peripheral procedures
●Breast surgery
However, there are wide variations in surgical risk within these categories (table 2). Thus, the most accurate assessment of surgical risk may come from web-based calculators (eg, the ACS NSQIP calculator) that include very procedure-specific risk assessment and also include patient risk factors. This concept is discussed in detail separately. (See "Preoperative evaluation for anesthesia for noncardiac surgery", section on 'Surgical risk'.)
Patients who undergo emergency surgery are at increased risk of an adverse perioperative cardiovascular event at any level of baseline risk [26]. In addition, institutional and/or individual surgeon experience with the procedure may increase or lower the risk and should be considered when discussing risk with the patient.
Surgical risk is discussed in more detail separately. (See "Preoperative evaluation for anesthesia for noncardiac surgery", section on 'Surgical risk'.)
INITIAL EVALUATION
History and physical examination — Preoperative evaluation should include a history and physical examination focused on the cardiovascular system, as shown in a table (table 3). Depending on the specific history and/or physical examination finding, further testing and treatment may be indicated.
Assessing functional status or exercise capacity — Functional status should be assessed as part of preoperative evaluation, primarily for risk stratification; poor functional status is associated with increased perioperative risk. Functional assessment may also help determine whether the patient has sufficient exercise capacity to elicit cardiac symptoms.
Options — We use the Duke Activity Status Index (DASI) questionnaire to assess functional status in most patients (table 4).
Functional capacity can be assessed by asking patients to report their ability to perform activities of daily living, with either standardized reference questions (eg, ability to climb two flights of stairs) or more formally with a questionnaire (eg, the DASI). Asking the patient reference questions is referred to as subjective assessment in the literature.
Exercise capacity can also be assessed with cardiopulmonary exercise testing (CPET), though this is not used for routine preoperative screening. (See "Cardiopulmonary exercise testing in cardiovascular disease", section on 'Clinical applications'.)
Functional status can be expressed in metabolic equivalents (METs). One MET is defined as 3.5 mL O2 uptake/kg/minute, which is the resting oxygen uptake in a sitting position (see "Cardiopulmonary exercise testing in cardiovascular disease", section on 'Aerobic parameters'). Poor functional status has traditionally been defined by the inability of the patient to perform 4 METs of activity. The reference questions used during subjective assessment are those that have been determined to equate to specific MET levels, as described below. Raw DASI scores can be converted to METs using a formula or a calculator.
The DASI questionnaire — The DASI questionnaire consists of 12 questions about the ability to perform common activities at varying levels of exertion (table 4). For scoring, the questions are weighted and positive answers are totaled. The maximum possible score is 58.2, with higher scores indicating better functional capacity. A DASI score >34 denotes very low perioperative risk [14].
The score can be converted to METs using a formula that was determined during the initial DASI derivation study [27]. The formula is shown in the table (table 4).
In a follow-up analysis of data from the Measurement of Exercise Tolerance before Surgery (METS) study, a DASI score <34 (equivalent to approximately 5 METs based on CPET) was associated with increased odds of 30-day mortality or myocardial injury (odds ratio [OR] 1.05 per 1 point decrease below 34, 95% CI 1.01-1.05) [14]. However, many patients are unable to achieve a DASI score of 34, and we prefer to use a score of <25 (approximately 4 METs) to define increased risk. The METS study did not have a large enough sample to study the subgroup with a DASI <25 points, but since this cutoff is associated with only a slightly higher incidence of complications than a cutoff of <34, it is likely a clinically meaningful threshold to identify patients at higher preoperative surgical risk. The DASI questionnaire has been translated and validated in several languages other than English [28-30].
Subjective assessment — Subjective assessment of functional capacity refers to having the clinician evaluate the patient, typically by asking questions about functional ability and then making a subjective assessment of fitness. This assessment is variable depending on the number and choice of questions asked. Various activity scales provide the clinician with a set of questions to determine a patient's functional capacity in terms of METs [31]. These scales may not be as useful in geriatric or other patients who have limited mobility. For most patients, we consider the following to be indicators of a patient’s functional status:
●Can take care of self, eg, eat, dress, or use the toilet (1 MET)
●Can walk up two flights of stairs or a hill or walk on level ground at 3 to 4 mph (4 METs) [3,16,32]
●Can do heavy work around the house, such as scrubbing floors or lifting or moving heavy furniture, or climb two flights of stairs (between 4 and 10 METs)
●Can participate in strenuous sports such as swimming, singles tennis, football, basketball, and skiing (>10 METs)
Value and choice of assessment method — We use the DASI questionnaire to assess functional status in most patients. The literature on the value of methods for preoperative functional assessment is conflicting. However, the preponderance of evidence suggests that the DASI questionnaire predicts postoperative cardiac complications better than subjective assessment. The three studies described here came to differing conclusions regarding the predictive value of functional assessment. Taken together, these studies suggest that although certain components of patient self-assessment may be associated with peri-operative major adverse cardiac events, self-assessment may not add clinically meaningful prognostic information to current risk assessment methods.
●The METS trial was a multicenter international cohort study including approximately 1400 patients with ≥1 risk factor for cardiac complications or for coronary artery disease who underwent elective noncardiac surgery [12]. All patients underwent CPET, were assessed subjectively, completed the DASI questionnaire, and had N-terminal pro-B-type natriuretic peptide (NT proBNP) levels drawn. The following findings were reported:
•Subjective assessment did not predict postoperative myocardial infarction (MI), myocardial injury, or myocardial complications.
•Lower DASI scores predicted 30-day death or MI and 30-day death or myocardial injury.
•Reduced peak oxygen consumption and anaerobic threshold measured by CPET were not associated with postoperative MI or myocardial injury.
•Higher NT proBNP levels predicted 30-day death or MI and one-year death.
●In a prospective cohort of approximately 4500 high risk patients who underwent major noncardiac surgery in Sweden, inability to climb two flights of stairs was an independent predictor of major adverse cardiac events (eg, MI, acute heart failure, life-threatening arrhythmia) at 30 days and one year after surgery [32]. Included patients were either ≥65 years of age or ≥45 years with a history of cardiovascular disease (MI, peripheral artery disease, or stroke). Patients in this study were at relatively high cardiac risk given their age or medical history.
●MET-REPAIR was an international prospective cohort study that compared the value of patient-reported measures of functional capacity versus clinical risk factors for predicting major adverse cardiovascular events in hospital and at 30 days in 15406 high risk patients who underwent elective noncardiac surgery [17]. The patient-reported functional measures were: estimated functional capacity in METs using a questionnaire; the number of floors that could be climbed without resting; perceived cardiopulmonary fitness compared with peers; and level of regular physical activity. The primary outcome of major adverse cardiovascular events was defined as a composite of cardiovascular mortality, nonfatal cardiac arrest, acute myocardial infarction, stroke, and congestive heart failure. The discriminatory ability of the functional measures was compared with an internally derived set of clinical risk factors. The study found:
•Major adverse cardiovascular events occurred in 274 patients (1.8%)
•Each of the self-reported functional capacity measures was independently associated with major adverse cardiovascular events; however, none improved discrimination over using clinical risk factors.
•Self-reported functional capacity slightly improved discrimination over using the Revised Cardiac Risk Index (RCRI) plus patient age
•Self-reported functional capacity did not improve discrimination over the National Surgical Quality Improvement Myocardial Infarction or Cardiac Arrest (NSQIP MICA) risk assessment tool. (See 'Using risk assessment tools' below.)
Electrocardiogram for some patients — We usually obtain an electrocardiogram (ECG) for patients with known cardiovascular disease, significant arrhythmia, or significant structural heart disease if they are to undergo an intermediate- to high-risk surgery. If the patient reports no recent or interim cardiac symptoms, we do not repeat an ECG if one has been done in the past 12 months. We do not routinely perform a preoperative ECG in patients who undergo low-risk surgery (<1 percent estimated risk of cardiac death or nonfatal MI) [3,11]. (See 'Intrinsic surgical risk' above.)
This approach is similar to recommendations that appear in the American College of Cardiology/American Heart Association (ACC/AHA) and European Society of Cardiology (ESC) guidelines on preoperative cardiovascular evaluation for noncardiac surgery [11,33].
In a two-institution prospective study including approximately 3000 patients >50 years of age scheduled for elective noncardiac surgery with at least one night postoperative stay, left and right bundle branch blocks on preoperative ECG predicted postoperative MI and death but were of no predictive value over indicators in the patient history (ie, high-risk surgery and history of ischemic heart disease) [34].
Laboratory testing — Preoperative blood testing should be based on clinical history. Other than a serum creatinine, no routine screening blood tests are indicated specifically for evaluation of cardiac risk. Because kidney dysfunction is a risk factor for adverse perioperative cardiac events, serum creatinine is used in some risk calculators. It is reasonable to rely upon test results found to be normal within the prior four months unless there has been an interim change in a patient's clinical status. (See "Preoperative medical evaluation of the healthy adult patient", section on 'Timing of laboratory testing'.)
Biomarkers (brain natriuretic peptide [BNP] and troponin) may be helpful for some patients, as discussed here.
Preoperative brain natriuretic peptide — We do not suggest routinely using BNP or NT-proBNP for preoperative risk stratification as their use has not yet been associated with improved clinical outcomes. However, BNP/NT-proBNP may be helpful in patients for whom the decision to undergo preoperative cardiac testing is unclear. In this setting, a low BNP/NT-proBNP value may suggest that the patient’s risk is relatively low. A higher level would warrant additional discussion and shared decision-making between the patient, surgeon, and consultant.
BNP is a natriuretic hormone initially identified in the brain but released primarily from ventricular cardiomyocytes in response to stress or stretch. The prohormone, proBNP is cleaved into BNP and an inactive cleavage particle, NT-proBNP. Both BNP and NT-proBNP are elevated in many pathologic conditions, as shown in a table (table 5). Levels of these hormones may have prognostic value for perioperative cardiac risk stratification. This is discussed separately. (See "Natriuretic peptide measurement in non-heart failure settings", section on 'Postoperative complications'.)
The optimal cutoff levels for BNP and NT-proBNP for perioperative risk stratification have not been determined. We use an NT-proBNP of 200 pg/mL or a BNP of 92 ng/L to help decide whether or not to pursue stress testing or coronary computed tomography angiography (CCTA) in patients with unclear cardiac risk in whom testing would influence management (algorithm 1).
●In a patient-level data meta-analysis of 18 studies of the prognostic value of BNP/NT-proBNP for noncardiac surgery, BNP ≥92 ng/L and NT-proBNP ≥300 ng/L were the thresholds associated with increased risk of cardiac death or nonfatal MI [35].
●In a substudy (10,402 patients) from an international prospective cohort study (VISION) that defined and evaluated various aspects of myocardial injury after noncardiac surgery (MINS), increasing NT-proBNP was associated with an independent and incremental risk of vascular death and myocardial injury or MI within 30 days of surgery [36]. Adding NT-proBNP to clinical stratification based on the Revised Cardiac Risk Index (RCRI) improved cardiac risk predication compared with RCRI alone. This study suggested that an NT-proBNP value <200 pg/mL, associated with a 2 percent risk of MI or death, might be a better prognostic cutoff than the RCRI score alone (the C statistic for RCRI and the outcome or death or MI improved from 0.65 to 0.73 with the addition of NT-proBNP). A C-statistic provides information on how well a risk prediction tool or set of risk factors can discriminate between an event (eg, MI or death) and no event. The ability of a biomarker to increase the C-statistic over and beyond a standard risk prediction tool is one metric commonly used to test its clinical utility [37].
Preoperative troponin — We do not routinely measure troponin preoperatively. Although an elevated preoperative troponin may be predictive of ischemic postoperative cardiac complications [38-41], whether troponin is useful over and above other methods for risk stratification has not been determined, and it is unclear how an elevated troponin should be used in managing asymptomatic patients. We recommend obtaining a preoperative troponin as a baseline if postoperative troponins will be measured (eg, patients at high risk of perioperative MI). Perioperative screening with troponin is discussed in detail separately. (See "Perioperative myocardial infarction or injury after noncardiac surgery", section on 'High-risk patients'.)
The ACC/AHA guidelines do not recommend obtaining a preoperative troponin level, and most clinicians do not routinely order them. However, the 2022 ESC guidelines recommend obtaining preoperative troponins in patients >65 years old or with cardiac risk factors undergoing intermediate to high-risk surgery [11].
USING RISK ASSESSMENT TOOLS — There are a number of tools or indices available for perioperative risk prediction, each with advantages and disadvantages. For patients who are at risk (ie, >65 years of age or >45 years of age with known cardiovascular disease), we suggest using a combination of the revised cardiac risk index (RCRI) and an online calculator based on the National Surgical Quality Improvement (NSQIP) database (eg, Myocardial Infarction or Cardiac Arrest [MICA] [1] or American College of Surgeons Surgical Risk Calculator [ACS-SRC]). Guidelines for preoperative risk assessment recommend using a risk assessment tool for at-risk patients [3,18]. In most cases, the risk-scoring tools will produce similar results when they are used correctly. If the results differ significantly, clinicians should determine which risk factors are responsible for the discrepancy and which are most important when assessing risk.
It is important for the clinician to understand how the risk calculators were derived, which patient populations were studied, how the risk factors were defined, and what outcomes were measured in order to use them correctly. These issues are described briefly below. In general, the risk calculators are in agreement with each other; however, if there is a significant divergence, further investigation and discussion is necessary to determine which one best reflects the individual patient’s estimated cardiac risk. Additionally, the clinician must determine how they will use the indices to inform the patient with respect to key decisions regarding proceeding with surgery or any interventions or the value of further evaluation.
The perioperative risk assessment tools discussed here include differing outcomes, and differing time periods for cardiac events. As examples, the RCRI is used to score the risk of a composite outcome that would occur during postoperative hospitalization (table 6). The MICA calculator provides a percent risk for only myocardial infarction (MI) or cardiac arrest but as an outcome occurring within 30 days of surgery [1].
Risk assessment tools can be used to estimate whether the patient is at low, average, or high risk of major adverse cardiac events. However, the percent risk provided by these tools varies widely, as they were developed in different patient populations and used different definitions of risk factors, postoperative complications, and follow-up [42,43]. Importantly, the RCRI, ACS-SRC, and MICA calculators as originally derived did not provide an estimate of myocardial injury after noncardiac surgery (MINS). Some validation studies have revised estimates of risk derived from the RCRI based on studies that included patients having emergency surgery or MINS as an outcome, resulting in higher risk estimates [18]. Those percentage risk results should not be used in existing risk assessment algorithms that were based on the original risk assessment tools (eg, the American College of Cardiology/American Heart Association [ACC/AHA] algorithm).
The American University of Beirut Medical Center (AUB)-HAS2 Cardiovascular Risk Index is the most recently developed scoring tool [44]. It is not in widespread use in the United States but was discussed in the 2022 guidelines from the European Society of Cardiology (ESC) [11].
●RCRI – The RCRI is the simplest risk tool to use and has been extensively studied and externally validated. It consists of six parameters, as shown in a table (table 6). The RCRI predicts not only MI and cardiac arrest but also ventricular fibrillation, pulmonary edema, and complete heart block during hospitalization.
RCRI underestimates risk in major vascular surgery, particularly abdominal aortic aneurysm repair. It was derived for patients who had an in-patient hospital stay of at least two days. Thus, if inappropriately used for ambulatory surgery or low-risk procedures, it will overestimate risk.
The RCRI is one of the few prospectively derived risk calculators, but it is now over 20 years old, was done at a single institution, and used creatine kinase-MB (CK-MB) rather than the more sensitive fifth-generation troponin T for postoperative surveillance.
●NSQIP calculators – The NSQIP calculators (ACS-SRC, MICA) were derived from a much larger database of surgical patients than the RCRI. The ACS-SRC is more comprehensive, predicting risk of not only cardiac complications but others as well. The database used a definition of MI that might underestimate non-q wave MIs, and troponins were not measured routinely. The MICA calculator is available online [45].
●AUB-HAS2 – This tool consists of six parameters (history of heart disease, symptoms of heart disease [angina or dyspnea], age ≥75 years, anemia [Hgb <12mg/dL], having vascular surgery, and having emergency surgery) with two points given for each of the surgical parameters [44]. Patients are assigned a score of 0, 1, 2, 3 or > 3 based on the number of parameters present and are designated as low risk (score 0 or 1), intermediate risk (score 2 or 3), or high risk (≥3) for death, MI, or stroke within 30 days of surgery. The AUB-HAS2 tool was derived in 3284 consecutive patients who had noncardiac surgery at the AUB Medical center and was validated with a cohort of >1,100,000 patients in the NSQIP database.
MANAGEMENT BASED ON RISK — We use estimated risk of major adverse cardiac events to categorize patients into low- or higher-risk groups. (See 'Using risk assessment tools' above.)
The risk will help determine whether surgery should proceed as scheduled or whether further testing (eg, stress testing or echocardiography) is warranted. Additional testing is only indicated if the results will change decision-making or perioperative management. Alternatives may include changing to a lower-risk procedure or a nonsurgical alternative (eg, radiation and/or chemotherapy or palliative care), or postponing surgery so that a procedure such as coronary revascularization or heart valve replacement can take place (algorithm 1).
The 2014 guidelines from the American College of Cardiology and American Heart Association (ACC/AHA) includes a widely used algorithm for deciding on preoperative evaluation, which is provided here (algorithm 2). Those guidelines are being revised.
For all patients:
●Indications for coronary artery revascularization – The indications for coronary artery revascularization before noncardiac surgery are similar to those for a patient not undergoing surgery. Revascularization is not recommended solely to improve perioperative outcome. This is discussed in detail separately. (See "Management of cardiac risk for noncardiac surgery", section on 'Revascularization before surgery'.)
●Indications for medical optimization – For patients who are not being treated with guideline-directed medical therapy (aspirin, statin, blood pressure control, treatment of heart failure, arrhythmia management), these therapies should be instituted if time permits. (See "Management of cardiac risk for noncardiac surgery".)
Very high-risk patients — Patients with recent myocardial infarction (MI; prior 60 days) [5] or unstable angina, decompensated heart failure, high-grade arrhythmias, or hemodynamically important valvular heart disease (aortic stenosis in particular [6]) are at very high risk for perioperative cardiovascular complications. All such patients should be optimally treated, with possible referral to a cardiologist for further evaluation and management. If they are already being followed, it is important to communicate with the patient’s cardiologist for past history and baseline status. (See "Noncardiac surgery in adults with aortic stenosis" and "Perioperative management of heart failure in patients undergoing noncardiac surgery", section on 'Severity of heart failure syndrome'.)
Patients who require emergency or urgent surgery are at increased risk of a perioperative cardiovascular event at any level of baseline risk [26]. In most cases, the benefit of proceeding with surgery outweighs the risk of waiting to perform additional testing.
High-risk patients — In patients with known or suspected heart disease (ie, cardiovascular disease, significant valvular heart disease, symptomatic arrhythmias), we perform further cardiac evaluation (eg, stress testing) only if the results will change clinical decision-making and perioperative management. There is no evidence that further diagnostic or prognostic evaluation or prophylactic coronary revascularization improves surgical outcomes. Preoperative cardiac evaluation and testing may differ for patients being evaluated for liver or kidney transplant. (See "Liver transplantation in adults: Patient selection and pretransplantation evaluation", section on 'Cardiac stress testing'.)
Low-risk patients — For most patients with estimated risk of perioperative major adverse cardiac events <2 percent, we do not recommend further cardiac testing. Other experts and the ACC/AHA guidelines use <1 percent for this cutoff [33] (algorithm 1). Patients at higher risk may require testing as discussed below.
TESTING TO FURTHER DEFINE RISK
Stress testing or stress echocardiogram — Stress testing is not indicated in the perioperative patient solely because of the surgery if there is no other indication, unless it will change decision-making or perioperative care. As an example, for patients who need surgery within 30 to 60 days (eg, cancer surgery, surgery for infection), revascularization may not be appropriate even if a stress test was positive, as surgery would have to be delayed if revascularization was performed (algorithm 1). (See "Management of cardiac risk for noncardiac surgery", section on 'Revascularization before surgery'.)
Similarly, if the patient would not accept revascularization even if the stress test is positive, testing may not be indicated. (See 'Discussing risk with the patient' below.)
However, if the results of stress testing suggest that the patient is at very high risk of major adverse cardiac events, the surgeon might change the decision to operate or the extent of the planned surgery, even if the patient would not accept revascularization.
In the American College of Cardiology/American Heart Association (ACC/AHA) guidelines on perioperative cardiovascular evaluation, stress testing may be considered for surgical patients with elevated risk of major adverse cardiac events and poor functional capacity if further testing will impact decision-making or perioperative care [3]. The 2022 European Society of Cardiology (ESC) guidelines are similar but much more liberal in their recommendations for stress testing for patients undergoing intermediate- to high-risk surgery who have poor functional capacity and high likelihood of coronary artery disease or high clinical risk, as well as patients who are asymptomatic with poor functional capacity and previous coronary artery bypass graft surgery (CABG) or percutaneous coronary intervention (PCI), or with clinical risk factors for ischemia. The Canadian Cardiovascular Society (CCS) guidelines do not recommend assessing functional capacity or performing stress testing at all in the guidelines or algorithm, and instead rely on brain natriuretic peptide (BNP) or N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels to determine perioperative monitoring [18]. (See 'Preoperative brain natriuretic peptide' above.)
Stress testing with exercise (with or without imaging) and pharmacologic stress testing with imaging have been well studied in patients scheduled to undergo noncardiac surgery. Although there is a clear relationship between the degree of myocardial ischemia found and prognosis, there is no evidence that preoperative prophylactic revascularization to prevent ischemia, in addition to recommended medical therapy, improves outcomes [46-55].
Some experts routinely obtain preoperative stress imaging in patients who are scheduled for major vascular surgery that is an intrinsically high-risk surgery typically performed in high-risk patients, and in other high-risk operations or when functional capacity cannot be determined (eg, knee or hip arthroplasty). However, we agree with guidelines from the ACC/AHA [3] that such testing should not routinely be performed even in these patients solely because of the surgical procedure.
Stress testing is discussed in detail separately. (See "Selecting the optimal cardiac stress test" and "Stress testing for the diagnosis of obstructive coronary heart disease".)
Preoperative coronary computed tomography angiography — Although the role of coronary computed tomography angiography (CCTA) in preoperative cardiac evaluation has not been defined, it has been suggested as another option to define cardiac risk and is viewed as a noninvasive alternative to coronary angiography. In a study of 955 patients with, or at risk of, atherosclerotic disease who underwent noncardiac surgery, CCTA was shown to improve estimation of risk of perioperative cardiovascular death or myocardial infarction (MI); however, the findings of atherosclerotic plaque on CCTA led to a greater than fivefold overestimation of risk among patients who did not experience perioperative events. [56]. Because of this overestimation, it has not been used or studied extensively in the perioperative setting. However, some clinicians would consider using CCTA rather than proceeding directly to coronary angiography if there was suspicion that a positive stress test was a false positive.
CCTA is discussed in detail separately. (See "Cardiac imaging with computed tomography and magnetic resonance in the adult".)
Cardiopulmonary exercise testing — Cardiopulmonary exercise testing (CPET) has been utilized extensively in the United Kingdom as a screening test prior to cancer surgery to identify patients at high risk of postoperative complications. However, the literature on the benefits of preoperative CPET is conflicting, and the role of CPET in preoperative evaluation has not been established. It is not routinely used in the United States. The results of CPET have been used to guide decisions regarding prehabilitation prior to surgery.
In a meta-analysis of 52 studies of adults who underwent cancer surgery, higher peak oxygen consumption (VO2) was associated with lower rates of postoperative complications and no pulmonary complications [57].
CPET is discussed in detail separately. (See "Cardiopulmonary exercise testing in cardiovascular disease".)
Resting echocardiography — Resting echocardiography is not indicated for evaluation of ischemic heart disease in the perioperative patient but may be indicated to evaluate valve function in patients with a significant murmur or left ventricular function in patients with suspected heart failure or dyspnea of unknown cause. (See "Perioperative management of heart failure in patients undergoing noncardiac surgery", section on 'Initial tests'.)
The presence of significant left ventricular systolic dysfunction, left ventricular outflow tract obstruction, or severe valvular heart disease is associated with a worse outcome, particularly postoperative heart failure, at the time of noncardiac surgery.
●(See "Noncardiac surgery in patients with mitral or aortic regurgitation".)
DISCUSSING RISK WITH THE PATIENT — The patient’s primary care provider should make an initial assessment of the individual patient’s risk and should start the discussion of risk prior to making a referral for surgery. Ultimately, the discussion of risks and potential benefits of surgery should involve coordination among the patient, their primary care provider, surgeon, anesthesiologist, and any consultants, comprising the concept of shared decision-making. However, by the time of the surgical consultation and face-to-face discussion, patients and surgeons may already be predisposed towards the decision to operate (or not).
In a single-institution prospective observational study of 45 patients who underwent surgical consultation for possible cholecystectomy or hernia repair, by the time of the consultation, patients and surgeons were already predisposed toward certain decisions by preceding events occurring elsewhere [58].
Shared decision-making with the patient is important at the time of surgical decision-making, but it has limitations [59]. For example, many patients will defer to the surgeon regarding the decision to undergo surgery, while others may have already decided that they want to undergo surgery despite the risk. It is important to understand the patient’s risk tolerance and willingness to change management based upon the results of the preoperative evaluation. In other settings, presenting the patient with best- and worst-case scenarios may be helpful for shared decision-making, and this may be beneficial when discussing perioperative cardiac risk as well [60,61].
RECOMMENDATIONS OF OTHERS — All of the major society guidelines for preoperative cardiac assessment recommend preoperative patient and surgical risk assessment [3,11,18]. However, they differ in significant ways on methods of assessment for elective surgery.
●The 2014 guidelines from the American College of Cardiology and American Heart Association (ACC/AHA) use risk calculators to define low- and elevated-risk groups based on patient- and surgery-specific risk, and then assess functional capacity to determine the need for stress testing or further evaluation, if such testing will change management [3]. They do not rely on biomarkers (ie, brain natriuretic peptide [BNP]). These guidelines are currently being rewritten.
●The 2017 Canadian Cardiovascular Society (CCS) guidelines use the Revised Cardiac Risk Index (RCRI) and focus on using biomarker elevation such as N-terminal pro-B-type natriuretic peptide (NT-proBNP) or BNP as the key determinant of further evaluation postoperatively in high-risk patients [18]. They do not recommend assessment of functional capacity or preoperative cardiac testing.
●The 2022 European Society of Cardiology (ESC) guidelines divide patients by age, risk factors for cardiovascular disease, established cardiovascular disease, and the level of intrinsic surgical risk for their recommendations for assessment with electrocardiogram (ECG), biomarkers, and functional capacity. They are more liberal than the ACC and CCS with recommendations for cardiac testing (echocardiography and stress tests) [11].
SOCIETY GUIDELINE LINKS — Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: Perioperative cardiovascular evaluation and management" and "Society guideline links: Preoperative medical evaluation and risk assessment".)
SUMMARY AND RECOMMENDATIONS
●Definitions of risk – Perioperative cardiac risk is variably defined and may include risks of myocardial ischemia and injury, myocardial infarction (MI), heart failure, arrhythmias, stroke, and death. (See 'Definitions' above.)
•Major adverse cardiac events (also referred to as perioperative adverse cardiac events) is defined as MI, cardiac arrest, or cardiac death.
•Surgical risk is usually defined as low, intermediate, or high based on reported rates of major adverse cardiac events of <1 percent, ≥1 to ≤5 percent, and >5 percent, respectively.
●Risk factors for major adverse cardiac events
•Patient factors – Patients with preexisting cardiovascular disease, poor functional status, older age, diabetes, and/or kidney dysfunction are at increased perioperative cardiac risk. (See 'Patient risk factors' above.)
•Intrinsic surgical risk – Perioperative risk is higher with more invasive surgery, longer procedures, and those associated with major blood loss of fluid shifts, and is particularly high with emergency surgery. (See 'Intrinsic surgical risk' above.)
●Initial evaluation
•All patients should be evaluated with a history and physical examination focused on the cardiovascular system (table 3) and assessment of functional status. For most patients, we use the Duke Activity Status Index (DASI) questionnaire to assess functional status (table 4). (See 'Assessing functional status or exercise capacity' above.)
•We usually obtain a preoperative electrocardiogram (ECG) for patients with known cardiovascular disease who undergo intermediate- to high-risk surgery. (See 'Electrocardiogram for some patients' above.)
•We do not suggest routinely measuring troponins or brain natriuretic peptide (BNP)/N-terminal pro-B-type natriuretic peptide (NT-proBNP) for risk stratification. However, BNP/NT-proBNP may be helpful in patients for whom the decision to undergo preoperative cardiac testing is unclear (algorithm 1).
●Using risk assessment tools – For patients who are at risk (ie, >65 years of age or >45 years of age with known cardiovascular disease), we suggest using a combination of the revised cardiac risk index (RCRI) and an online calculator based on the National Surgical Quality Improvement (NSQIP) database (eg, Myocardial Infarction or Cardiac Arrest [MICA] or American College of Surgeons Surgical Risk Calculator [ACS-SRC]). (See 'Using risk assessment tools' above.)
●Management based on risk – Further evaluation and management should be based on assessment of combined patient and surgical risk. We use the estimated risk of major adverse cardiac events to categorize patients into low- versus higher-risk groups (algorithm 1). (See 'Management based on risk' above.)
•Very high-risk patients – Patients with recent MI, unstable angina, decompensated heart failure, high-grade arrhythmias, or hemodynamically important valvular heart disease should be optimally treated and possibly referred to a cardiologist for further evaluation and management.
•High-risk patients – In patients with known or suspected heart disease (ie, cardiovascular disease, significant valvular heart disease, symptomatic arrhythmias), further evaluation should only be performed if it is indicated in the absence of proposed surgery and the results will change clinical decision-making and perioperative management.
•Low-risk patients – For patients with <2 percent risk of perioperative major adverse cardiac events we do not obtain further cardiac testing. Other experts may use <1 percent as this cutoff.
●Testing to further define risk
•Surgery alone is not an indication for stress testing and stress echocardiography; we only pursue these evaluations if the results would affect decision-making or perioperative care. (See 'Stress testing or stress echocardiogram' above and 'Discussing risk with the patient' above.)
•Resting echocardiography is not indicated for evaluation of ischemic heart disease in the perioperative patient. It may be indicated in patients with a significant murmur, suspected heart failure, or dyspnea of unknown cause. (See 'Resting echocardiography' above.)
ACKNOWLEDGMENT — The UpToDate editorial staff acknowledges James P Morgan, MD, PhD, and Jonathan B Shammash, MD, who contributed to an earlier version of this topic review.
The UpToDate editorial staff also acknowledges Emile Mohler III, MD (deceased), who contributed to an earlier version of this topic review.
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