Aims: Some recent studies have reported-superior outcomes for diabetic patients following coronary bypass surgery compared with coronary angioplasty. However, the available data are conflicting, are based on relatively small numbers of diabetic patients, and have limited duration of follow-up. The aims of this study were to compare risk adjusted long-term survival in diabetic patients following first-time revascularization via either coronary bypass surgery or coronary angioplasty; and, to identify variables independently associated with mortality.
Methods and results: This was a two centre database project involving 15809 patients undergoing either coronary angioplasty or coronary bypass surgery as their initial revascularization procedure. Diabetes was present in 1938 (12%). Mean follow-up was 4.6+/-2.7 years for angioplasty and 6.6+/-4.3 years surgery diabetic patients. Multivariable time-related analyses in the hazard function domain for death were performed. Overall ten-year survival for pharmacologically treated diabetics was better after coronary bypass surgery (60%) than angioplasty (46%, <0.0001). However, the risk-adjusted survival advantage conferred by bypass surgery over angioplasty was strongest for patients receiving oral agents for diabetic control (75% vs 62%) and less impressive for diet (84% vs 81%) and insulin-treated diabetics (63% vs 64%). The major factors independently associated with worse outcome after angioplasty were incomplete revascularization, and the use of a sulfonylurea agent. The use of the left internal mammary graft improved survival in surgical patients.
Conclusions: In general, diabetic patients had better long-term survival after bypass surgery than angioplasty. Incomplete revascularization and sulfonylurea therapy worsened outcome after angioplasty, and use of the left internal mammary improved outcome after bypass surgery.