Impact of prolonged dual antiplatelet therapy after acute myocardial infarction on 5-year mortality in the FAST-MI 2005 registry

Abstract

BackgroundWe document dual antiplatelet therapy (DAPT) use from discharge to 4years after acute myocardial infarction (AMI), and investigate whether prolonged DAPT (beyond 1year) is related to 5-year mortality. MethodsThe French Registry of Acute ST-elevation or non-ST-elevation Myocardial Infarction (FAST-MI 2005) included 3670 patients with AMI in 223 French centres. We identified predictors of DAPT (aspirin+clopidogrel) beyond 1 and 2years, and relation with all-cause 5-year mortality. ResultsAmong 3319 (96%) patients with discharge data, 2432 (73%) had DAPT, 582 (17%) single antiplatelet therapy (SAPT), and 305 (9%) no antiplatelet treatment. DAPT decreased from 75% at 1year to 29% at 4years, with a corresponding increase in SAPT (p<0.05 for trend). Patients with DAPT were more often male, treated with a drug-eluting stent (DES), and without oral anticoagulants. Independent predictors at 1year of prolonged DAPT were age<75years, in-hospital bleeding, history of MI, use of DES, discharge use of beta-blockers or statins and no chronic anticoagulation. Predictors at 2years were age<75years, male gender, previous MI, diabetes, DES implantation, no chronic oral anticoagulation. By multivariate analysis, there was no difference in 5-year mortality between those on SAPT vs DAPT at 1year. DAPT at 2years was also not significantly related to 5-year mortality (Hazard Ratio 1.3, 95% CI [0.9; 1.8], p=0.21). ConclusionProlonged DAPT in selected AMI patients, observed in 47% at 1year and 21% at 2years, had no impact on 5-year mortality. These findings do not support the use of DAPT beyond 1year after an initial ACS.