Clinical and angiographic predictors of restenosis after stent deployment in diabetic patients

Background - Restenosis and consequent adverse cardiac events are increased in diabetics undergoing percutaneous coronary intervention. Use of intracoronary stents may ameliorate such risks; however, factors influencing the likelihood of restenosis after stent deployment in this high-risk patient subgroup are unknown. Methods and Results - We retrospectively analyzed all stented diabetic patients in 16 studies of percutaneous coronary intervention, all of which underwent core angiographic analysis at Cardialysis, Rotterdam. Univariate and multivariate analyses, with 37 clinical and angiographic variables, compared those with and without restenosis and predicted restenosis rates calculated through the use of reference charts derived from angiographic data. Within the studies, 418 of 3090 (14%) stented patients with 6-month angiographic follow-up had diabetes. Restenosis (greater than or equal to 50% diameter stenosis at follow-up) occurred in 550 of 2672 (20.6%) nondiabetic and 130 of 418 (31.1%) diabetic patients ( P < 0.001). Univariate predictors of restenosis in diabetics were smaller vessel reference diameter (RD) ( P < 0.001), smaller minimal luminal diameter before stenting ( P = 0.01), smaller minimal luminal diameter and percent diameter stenosis after stenting ( P < 0.001, P = 0.04), greater stented length of vessel ( P < 0.001), and reduced body mass index (BMI) ( P = 0.04). With the use of multivariate analysis, only smaller RD ( P = 0.003), greater stented length of vessel ( P = 0.04), and reduced BMI ( P = 0.04) were associated with restenosis. Reference charts demonstrated an incremental risk of restenosis that appears solely dependent on vessel RD. Conclusions - Restenosis after stent deployment is significantly increased in diabetic patients. Vessel caliber, stented length of vessel, and lower BMI are predictors of in-stent restenosis in patients with diabetes. Furthermore, vessel caliber affected the predicted risk of restenosis incrementally.