Purpose: To summarize available evidence on preoperative cardiac risk stratification so that the internist may 1) use clinical and electrocardiographic findings to stratify a patient's perioperative risk for myocardial infarction and death; 2) decide which tests provide useful additional risk-related information; and 3) understand the benefits, risks, and evidence surrounding the decision to undertake coronary revascularization before elective noncardiac surgery.
Data sources: A MEDLINE search and review of the reference lists of identified articles. Sensitivities, specificities, and likelihood ratios for diagnostic tests were calculated, and a quality rating for study methods was applied.
Data extraction: Myocardial infarction and mortality were the major outcomes considered, and a quality rating for study methods was applied.
Data synthesis: Clinical and electrocardiographic findings, organized by multivariate prediction indices, accurately identify patients as having low, intermediate, or high risk for myocardial infarction or death. Pharmacologic stress imaging with thallium or echocardiography probably improves risk stratification for intermediate-risk patients having vascular surgery. These tests have not been shown to be effective prognostic indicators for patients having nonvascular surgery. No studies of angiography for risk prediction have been reported. Decision analyses and retrospective series suggest that the risks incurred by doing coronary angiography and revascularization before elective surgery outweigh the benefits. Prospective, controlled studies of coronary revascularization are lacking. Evidence from a randomized, controlled trial has shown a survival benefit with the perioperative use of beta-blockers in patients at risk for coronary artery disease.
Conclusions: Evaluation of all surgical patients by use of clinical indices is recommended. Low-risk patients need no further evaluation before surgery. High-risk patients need optimal management of their high-risk problems, including (if appropriate) beta-blocker use, and may need to have their elective procedures canceled. Intermediate-risk patients probably benefit from further noninvasive stress testing, especially if they are having vascular surgery. Further clinical trials are needed for most areas of concern.