Perioperative Cardiac Risk Assessment

Classification of Surgical Procedures

Surgical procedures can be classified as high-risk (>5% cardiac event rate), intermediate-risk (1-5% cardiac event rate), or low-risk (<1% cardiac event rate) based on the type of surgery, with high-risk procedures including major vascular and prolonged surgeries with large fluid shifts, intermediate-risk procedures including intraperitoneal, intrathoracic, and carotid endarterectomy, and low-risk procedures including endoscopic and superficial surgeries, as classified by the American College of Cardiology 1

Patients with active cardiac conditions, such as unstable coronary syndromes, decompensated heart failure, significant arrhythmias, or severe valvular disease, should have surgery delayed for evaluation and treatment, as recommended by the American Heart Association 2
The Duke Activity Status Index (DASI) can be used to quantify functional capacity, with a threshold of 4 METs (equivalent to climbing two flights of stairs) being critical for risk assessment, and patients who can achieve ≥4 METs having significantly lower perioperative risk, as recommended by the American College of Cardiology 3, 4
The DASI is a validated, structured 12-item questionnaire that quantifies functional capacity, with high strength of evidence, as recommended by the American Heart Association 5

The Revised Cardiac Risk Index (RCRI) can be used to identify patients at elevated risk for perioperative cardiac complications, with six independent risk factors, and stratifies patients into risk categories based on the number of risk factors, as recommended by the American College of Cardiology, with moderate strength of evidence 1
The RCRI risk factors and their corresponding definitions are:

Risk Factor	Definition
History of ischemic heart disease	History of myocardial infarction, history of positive treadmill test, current use of nitroglycerin, chest pain considered secondary to coronary ischemia, or ECG with abnormal Q waves
History of congestive heart failure	History of heart failure, pulmonary edema, paroxysmal nocturnal dyspnea, peripheral edema, bilateral rales, S3 heart sound, or chest radiograph showing pulmonary vascular redistribution
History of cerebrovascular disease	History of transient ischemic attack (TIA) or history of stroke
Insulin-dependent diabetes mellitus	Significant risk factor
Preoperative serum creatinine >2.0 mg/dL	Indicates significant renal dysfunction
High-risk surgery	Includes intraperitoneal procedures, intrathoracic procedures, and suprainguinal vascular surgery [3]

Patients with 0 risk factors have a 0.4% risk of major cardiac complications, while those with 1 risk factor have a 0.9% risk, 2 risk factors have a 7% risk, and ≥3 risk factors have an 11% risk, as supported by the European Society of Cardiology 1, 4
Intermediate/high-risk patients with good functional capacity (≥4 METs) can proceed to surgery without further cardiac testing, while those with poor functional capacity (<4 METs) should consider additional cardiac testing if results would change management, as recommended by the American College of Cardiology, with moderate strength of evidence 5, 3

Beta-blockers should be continued in patients already taking them and considered for initiation in patients with ≥3 RCRI factors, with careful dose titration starting at least 2-7 days before surgery, as recommended by the American College of Cardiology, with high strength of evidence 5, 6
Statins should be continued in patients already taking them, and considered for initiation in vascular surgery patients at least 2 days before surgery, as suggested by the American College of Cardiology, with moderate strength of evidence 7, 8
ACE inhibitors/ARBs should be continued perioperatively, with restart as soon as clinically feasible if held, and antiplatelet agents managed based on consensus of treating clinicians, with continuation of aspirin when cardiac risk outweighs bleeding risk, as recommended by the American College of Cardiology, with high strength of evidence 6

For thoracic surgery patients, the Thoracic RCRI (ThRCRI) can be used, which has been recalibrated specifically for lung resection populations, with moderate to high strength of evidence, as recommended by the American College of Chest Physicians 9
Active cardiac conditions should be evaluated and treated before elective surgery, as suggested by the American College of Cardiology, with high strength of evidence 7, 3
Elective surgery should be delayed when appropriate, such as 14 days after balloon angioplasty, 30 days after bare metal stent implantation, and optimally 365 days after drug-eluting stent implantation, with consideration of the RCRI score to determine perioperative risk of Major Adverse Cardiac Events (MACE), as recommended by the American College of Cardiology, with moderate strength of evidence 5, 3

Continuous cardiac monitoring should be implemented for patients with multiple risk factors, and troponin monitoring should be considered for intermediate/high-risk patients, checking preoperatively and at 24/48 hours after surgery to identify myocardial injury after noncardiac surgery (MINS), as recommended by the American College of Cardiology, with moderate strength of evidence 5, 4
Non-invasive cardiac testing should be considered for patients with ≥2 risk factors undergoing intermediate/high-risk surgery if results would change management, as well as pharmacological stress testing for patients with poor functional capacity if results would impact decision-making, as suggested by the American College of Cardiology, with moderate strength of evidence 7, 3