Characteristics, management, and outcome of patients with acute myocardial infarction treated with bypass surgery. Myocardial Infarction Triage and Intervention Investigators.

BACKGROUND

Although multiple studies have addressed the efficacy of bypass surgery in patients with stable angina, there are relatively few studies that have evaluated the optimal timing, risk of hospital mortality, and long-term outcome for patients with bypass surgery performed in the setting of acute infarction.

METHODS AND RESULTS

With data collected from all admitted patients with acute myocardial infarction to 19 Seattle-area hospitals between 1988 and 1994, we studied the characteristics, hospital course, and long-term outcome in 1299 patients who underwent bypass surgery. There was no difference in hospital mortality in patients operated on during the first 24 hours after admission compared with those operated on later in the hospital course (8.3% versus 7.2%; P=.60). Factors that predicted hospital mortality in those who underwent bypass surgery included increased age, prior bypass surgery, infarct extension, and stroke. Long-term outcome in those who underwent bypass surgery was excellent, with low rates of subsequent coronary angiography (7.4% at 3 years) and coronary angioplasty (2.6% at 3 years). Three-year survival was better in bypass recipients than in those treated medically (83% versus 66%; P < .0001), and this difference remained after multivariate adjustment for baseline differences (hazard ratio, 0.68; 95% CI, 0.55 to 0.85).

CONCLUSIONS

Patients can be safely operated on early in the course of acute infarction, risk factors for hospital mortality are not substantially different from factors identified in the noninfarct setting, and bypass surgery in select patients after acute infarction is associated with low repeat procedure use and excellent long-term survival.