Prolonging dual antiplatelet therapy improves the long-term prognosis in patients with diabetes mellitus undergoing complex percutaneous coronary intervention

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.