Prolonging Dual Antiplatelet Therapy Improves Long-term Prognosis in Diabetic Patients Undergoing Complex Percutaneous Coronary Intervention with Drug-eluting Stents

Background: The optimal dual antiplatelet therapy (DAPT) duration after percutaneous coronary intervention (PCI) remains controversial, especially for patients at high risk of ischemic events. Diabetes mellitus (DM) and complex coronary interventions have been considered as high risk factors for ischemic events. We aim to investigate if prolonging DAPT duration in diabetic patients after drug-eluting stent (DES) implantation can reduce long-term adverse events. Methods: This study is an observational cohort study carried out in the largest cardiovascular center in China. 10,724 patients who underwent PCI from January, 2013 to December, 2013 were consecutively enrolled. The inclusion criteria included: documented history of DM; underwent DES implantation; free of adverse events within 1 year after operation; and had at least one high thrombotic risk technical aspects. These patients were divided into three groups according to DAPT duration: Standard group (11 ≤ DAPT ≤ 13 months) and prolonged group (13 24 months). Baseline characteristics and 5-year clinical outcomes were collected and analyzed. Results: A total of 2,403 diabetic patients with complex PCI were included in the current analysis (Standard DAPT n=689; Prolonged DAPT n=1714). Baseline and angiographic characteristics, and complexity of PCI were comparable among patients with different DAPT durations. Patients in 13<DAPT≤24 months group had lowest incidence of MACCE, all cause death and cardiac death. After adjustment of confounding factors, the 13-24 months DAPT duration was related with lower risk of MACCE (HR: 0.544, 95%CI: 0.373-0.795) and all cause death (HR: 0.605, 95%CI: 0.387-0.944). DAPT duration >24 months was related with lower risk of all-cause death (HR: 0.681, 95%CI: 0.493-0.942) and cardiac death (HR: 0.620, 95%CI: 0.403-0.952). Prolonging DAPT duration did not increase the risk of major bleeding (1324 months: HR: 0.967, 95%CI: 0.682-1.371). Conclusions: For diabetic patients undergoing complex PCI, prolonging DAPT duration might improve long-term prognosis by reducing the risk of adverse ischemia events and without increasing the risk of bleeding.