Glycemic Control Status after Percutaneous Coronary Intervention and Long-Term Clinical Outcomes in Patients with Type 2 Diabetes Mellitus

Background - Data on the association between glycemic control after percutaneous coronary intervention and clinical outcomes are limited and controversial in diabetic patients. Methods and Results - We studied 980 patients with type 2 diabetes mellitus undergoing percutaneous coronary intervention using drug-eluting stents. Based on 2-year glycosylated hemoglobin A (HbA1c) levels, we divided patients into 2 groups of HbA1c<7.0 (n=489) and HbA1c≥7.0 (n=491). Propensity score-matched analysis was performed in 322 pairs. The primary outcome was major adverse cardiac and cerebrovascular events (MACCE), defined as a composite of cardiac death, myocardial infarction, repeat revascularization, or stroke. Median follow-up duration was 5.4 years. The 7-year incidence of MACCE was lower in the HbA1c<7.0 group than in the HbA1c≥7.0 group (26.9% versus 40.3%; adjusted hazard ratio, 0.75; 95% confidence interval, 0.57-0.98; P=0.03). After propensity score matching, the 7-year incidence of MACCE was still lower in the HbA1c<7.0 group than in the HbA1c≥7.0 group (27.5% versus 37.4%; hazard ratio, 0.71; 95% confidence interval, 0.52-0.97; P=0.03), mainly because of a reduction in repeat revascularization (19.9% versus 29.5%; hazard ratio, 0.66; 95% confidence interval, 0.47-0.93; P=0.02). In subgroup analyses, the benefit of glycemic control for MACCE was more prominent in patients with residual SYNTAX score (Synergy Between PCI With Taxus and Cardiac Surgery) >4 than in those with the residual SYNTAX score ≤4 (P interaction =0.004). Conclusions - HbA1c<7.0 measured 2 years after percutaneous coronary intervention was associated with a reduced rate of MACCE. Our data suggest that high HbA1c levels 2 years after percutaneous coronary intervention may identify a population at increased risk of adverse events, especially repeat revascularization.