Effect of bare metal stenting on angiographic and clinical outcomes in diabetic and nondiabetic patients undergoing percutaneous coronary intervention of nonacute occluded coronary arteries: A report from the total occlusion study of Canada (TOSCA)

The outcome after PTCA and coronary stenting of nonacute total coronary occlusions in the diabetic population is unknown. The main objective of the present report was to compare the angiographic and 1-year clinical outcomes in the diabetic and nondiabetic patients who were enrolled in the Total Occlusion Study of Canada (TOSCA), a prospective randomized controlled multicenter trial of primary stenting versus PTCA alone in nonacute native coronary artery occlusions. Of the 410 patients enrolled, 68 (16.5%) were diabetics. At 6-month follow-up, stenting resulted in significant improvement in angiographic outcome compared to PTCA alone in both diabetic and nondiabetic populations. Angiographic restenosis was significantly reduced by stenting in the nondiabetic population (69.3% vs. 55.2%; P = 0.009). A reduction in restenosis of a similar magnitude was observed with stenting in the diabetic population (71.1% vs. 59.3%; P = NS). At 1-year clinical follow-up, composite adverse cardiac event rates were similar for both strategies regardless of diabetic status. Target vessel revascularization was reduced by stenting compared to PTCA in diabetics (20% vs. 31.6%) and nondiabetics (21.5% vs. 30%). A significant reduction for any vessel revascularization following stenting compared to PTCA was observed in the nondiabetic population (28.5% vs. 38.8%; P = 0.05) but not in the diabetic subgroup (36.7% vs. 42%; P = NS). In conclusion, stenting appeared to be superior to PTCA alone, resulting in similar magnitude of reduction in angiographic restenosis and target vessel revascularization rates in diabetics and nondiabetics. Restenosis rates in all groups remain high. This analysis forms an important background for future studies that are needed to examine the effect of stenting with drug-eluting stents in diabetics as well as nondiabetics with nonacute coronary occlusions.