Cardiovascular assessment for noncardiac surgery

Abstract

Cardiac complications such as myocardial infarction and cardiac death are a common cause of morbidity and mortality in patients undergoing noncardiac surgery. Risk stratifying these patients by evaluating their clinical history, risk factors, functional capacity and surgery-specific risk in conjunction with noninvasive and invasive tests, is essential to optimize patients for surgery. Patients with low clinical risk and good functional status, undergoing low- or intermediate-risk surgery, have an excellent prognosis and may proceed straight to surgery. Stable patients with previous coronary revascularization may also safely undergo surgery. Patients requiring emergency surgery should proceed immediately as the benefits will outweigh the delay associated with cardiac risk assessment. However, worse peri-operative outcomes are associated with previous or current cardiac disease, diabetes, renal dysfunction, poor exercise tolerance and high-risk surgery. Controversy surrounds patients with high clinical risk undergoing elective high-risk surgery. In this case, noninvasive testing may be of value, with best evidence favouring dobutamine stress echocardiography. Coronary revascularization in risk limitation is unproven and peri-operative β -blockade is best indicated. Coronary revascularization should be reserved for patients with unstable angina or stable angina refractory to medical therapy. We review the issues surrounding peri-operative risk stratification and the therapies that exist to prevent complications.