Comparison of Long-Term Outcomes After Percutaneous Coronary Intervention in Patients With Insulin-Treated vs. Non-Insulin Treated Diabetes Mellitus.

Abstract

There are conflicting data on whether patients with insulin-treated diabetes mellitus (ITDM) have poorer outcomes compared to non-insulin treated diabetic (non-ITDM) patients following percutaneous coronary intervention (PCI). We therefore compared clinical outcomes following PCI in ITDM versus non-ITDM patients. We prospectively collected data on 4,579 patients with diabetes undergoing PCI between 2005 and 2014 in a large multi-centre registry and dichotomised them as having ITDM (n=1,111) or non-ITDM (n=3,468). The non-ITDM group was further divided into diet control only (diet-DM; n=786) and those taking oral hypoglycaemic agents (OHG-DM; n=2,639), and clinical outcomes were compared with ITDM patients. Median follow-up for long-term mortality was 4.2 years (IQR 2.0-6.6 years). ITDM patients were more likely to be female, obese, and have severe renal impairment (all p<0.001). Procedural characteristics were similar other than a greater use of drug-eluting stents in ITDM patients. On multivariable analysis, ITDM was an independent predictor of 12-month major adverse cardiovascular and cerebrovascular events (MACCE; OR 1.26, 95% CI 1.02-1.55, p=0.03). Dividing the non-ITDM group further by treatment, a progressively higher rate of 12-month MACCE across the 3 groups was observed (13.5% vs. 17.9% vs. 21.8%; p<0.001). Long-term mortality was similar in the diet-DM and OHG-DM groups, but significantly higher in the ITDM group on Kaplan-Meier analysis (log-rank p<0.001). In conclusion, there is a clear gradient of adverse outcomes with escalation of therapy from diet control to OHGs to insulin.