Abstract
OBJECTIVE: To investigate the optimal duration of dual antiplatelet therapy (DAPT) in patients with diabetes mellitus (DM) requiring complex percutaneous coronary intervention (PCI). METHODS: A total of 2403 patients with DM who underwent complex PCI from January to December 2013 were consecutively enrolled in this observational cohort study and divided according to DAPT duration into a standard group (11-13 months, n = 689) and two prolonged groups (13-24 months, n = 1133; > 24 months, n = 581). RESULTS: Baseline characteristics, angiographic findings, and complexity of PCI were comparable regardless of DAPT duration. The incidence of major adverse cardiac and cerebrovascular event was lower when DAPT was 13-24 months than when it was 11-13 months or > 24 months (4.6% vs. 8.1% vs. 6.0%, P = 0.008), as was the incidence of all-cause death (1.9% vs. 4.6% vs. 2.2%, P = 0.002) and cardiac death (1.0% vs. 3.0% vs. 1.2%, P = 0.002). After adjustment for confounders, DAPT for 13-24 months was associated with a lower risk of major adverse cardiac and cerebrovascular event [hazard ratio (HR) = 0.544, 95% CI: 0.373-0.795] and all-cause death (HR = 0.605, 95% CI: 0.387-0.944). DAPT for > 24 months was associated with a 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). The risk of major bleeding was not increased by prolonging DAPT to 13-24 months (HR = 1.356, 95% CI: 0.766-2.401) or > 24 months (HR = 0.967, 95% CI: 0.682-1.371). CONCLUSIONS: For patients with DM undergoing complex PCI, prolonging DAPT might improve the long-term prognosis by reducing the risk of adverse ischemic events without increasing the bleeding risk.