What is the optimal duration of triple anti-platelet therapy in patients with acute myocardial infarction undergoing drug-eluting stent implantation?

Background: The optimal duration of triple anti-platelet therapy (DTAP) remains unclear in patients with acute myocardial infarction (AMI).

Methods: We retrospectively analyzed 716 AMI patients who received TAP (aspirin, clopidogrel, and cilostazol) after drug-eluting stent (DES) implantation from November 2005 to May 2008. Mean age was 61.9 ± 11.70 years (male gender 74.1%) and mean duration of TAP was 98.1 ± 115.34 days. We compared the major adverse cardiovascular events [MACE, defined as the composite of cardiac death, non-fatal AMI, stent thrombosis, and target vessel revascularization (TVR)] between the group of DTAP ≥ 3 months (n = 497) and those of < 3 months (n = 219).

Results: There were no significant differences in the incidences of cardiac death, non-fatal AMI, stent thrombosis, and TVR at 1-year follow-up between the two groups. However, the group of DTAP ≥ 3 months had lower incidence of MACE than those < 3 months (5.9% vs. 10.7%, p = 0.044). The rate of bleeding complications was similar between the two groups. By Cox regression analysis with propensity score adjustment, Killip class IV and DTAP ≥ 3 months were independent predictors of 1-year MACE [hazard ratio (HR) = 10.417; 95% confidence interval (CI) = 1.587-68.377, p = 0.015 and HR = 0.508; 95% CI = 0.269-0.956, p = 0.036].

Conclusions: Our data show that the DTAP ≥ 3 months is associated with better clinical outcomes compared with that of < 3 months in patients with AMI undergoing DES implantation without increasing bleeding complications.