Predictors of postoperative myocardial ischemia in patients undergoing noncardiac surgery. The Study of Perioperative Ischemia Research Group

Abstract

Objective: To identify predictors of postoperative myocardial ischemia in patients scheduled to undergo major noncardiac surgery.

Design: Historical, clinical, laboratory, and physiological data were obtained prospectively before and during surgery to identify potential univariate predictors of postoperative myocardial ischemia, which then were entered into multivariate logistic models. Continuous two-lead electrocardiograms before, during, and after surgery were used to identify episodes of myocardial ischemia.

Setting: Department of Veterans Affairs tertiary care hospital.

Patients: A consecutive sample of 474 men at high risk for or with coronary artery disease who were scheduled to undergo major noncardiac surgery (95% compliance rate).

Main outcome measure: Significant variables identified by multivariate logistic models that are associated with postoperative myocardial ischemia.

Results: Five major preoperative predictors of postoperative myocardial ischemia were identified: (1) left ventricular hypertrophy by electrocardiogram; (2) history of hypertension; (3) diabetes mellitus; (4) definite coronary artery disease; and (5) use of digoxin. The risk of postoperative myocardial ischemia increased progressively with the number of predictors present: in 22% of patients with no predictors, in 31% with one predictor, in 46% with two predictors, in 70% with three predictors, and in 77% with four predictors.

Conclusion: Patients subgroups who are at high risk for developing postoperative myocardial ischemia and who might benefit the most from intensive Holter monitoring in the postoperative period now can be identified preoperatively.