Background: The purpose of this study was to evaluate outcomes after coronary bypass surgery versus coronary angioplasty in 525 patients with pharmacologically treated diabetes. Diabetic patients constitute a significant portion of patients considered for coronary revascularization. Some studies have shown no difference in long-term outcome when comparing revascularization mode. Recently, the Bypass Angioplasty Revascularization Investigation reported better survival with bypass surgery over angioplasty in treated diabetic patients. However, the above studies have been limited by small cohorts of diabetic patients.
Methods and results: By using a single-institution comprehensive database, a retrospective cohort design was used to study 525 consecutive pharmacologically treated diabetic patients who underwent coronary revascularization. Patients treated with surgery (n=246) were statistically similar when comparing age, gender, angina class, and ejection fraction to patients (n=279) treated with angioplasty. Follow-up was complete in 95% of bypass patients and 99% of angioplasty patients. Mean follow-up was 55.5 months. Complete revascularization was accomplished more often in the surgery group (79%) than in the angioplasty group (42%; P<.001). During a 6-year follow-up, repeat revascularization (8% versus 64%; P=.001), cardiac events (32% versus 41%; P=.04), and death (30% versus 37%; P=.08) occurred less in the bypass patients than the angioplasty patients. Multivariable analysis identified age >70 years, ejection fraction <40%, class IV angina, and incomplete revascularization, but not mode of revascularization, as correlates of late mortality.
Conclusions: For most pharmacologically treated diabetic patients, freedom from death, myocardial infarction, and subsequent revascularization during long-term follow-up is superior with bypass surgery compared with angioplasty. This worse outcome was mediated in part by the frequent occurrence of incomplete revascularization with angioplasty.