Predicting of postoperative cardiac events using ambulatory ECG monitoring prior to abdominal aortic surgery.

OBJECTIVES The purpose of this study was to estimate the value of preoperative electrocardiographic (ECG) monitoring in predicting postoperative cardiac events in patients undergoing abdominal aortic surgery. DESIGN A prospective open study. SETTING University Hospital. MATERIALS One hundred consecutive patients were studied before aortic or aortofemoral surgery by ambulatory ECG monitoring for 24 hours. CHIEF OUTCOME MEASURES An ischaemic episode by ECG criteria was defined as a > or = 1 mm horizontal or downsloping ST segment depression measured 60 msec after the J point and persisting for at least 40 sec. MAIN RESULTS Twenty-four patients had preoperative ambulatory ischaemia. Twenty patients had postoperative cardiac events including three with fatal myocardial infarction, one with a nonfatal infarction, eight with unstable angina, three with pulmonary oedema and five with atrial fibrillation. Sixteen out of 24 (67%) patients with ambulatory ischaemia had postoperative cardiac events (p < 0.01). Only four events occurred among 76 patients without ischaemia (p < 0.005). The sensitivity of ambulatory ischaemia predicting cardiac events was 80% with a specificity of 90%, the predictive value of ischaemia was 67% and the predictive value of a negative result was 95%. CONCLUSIONS Preoperative ECG monitoring for myocardial ischaemia could non-invasively identify patients at high risk for postoperative cardiac morbidity and mortality after vascular surgery.