PREDICTORS OF DAPT USE IN PATIENTS BEYOND 1 YEAR POST MYOCARDIAL INFARCTION: INSIGHTS FROM THE TIGRIS OBSERVATIONAL STUDY

Abstract

International guidelines vary in their recommendations for dual antiplatelet therapy (DAPT) use beyond 1 year post-myocardial infarction (MI). In the current analysis, we sought to identify predictors of DAPT use in patients ≥1 year post-MI prior to publication of the DAPT score and the most recent iterations of international guidelines for the use of DAPT in the management of patients with MI. TIGRIS (NCT01866904) was a prospective, multi-center (369 centers in 25 countries), observational study of patients 1 to 3 years post-MI between June 2013 and November 2014. We performed a multivariable logistic regression analysis to identify independent predictors of DAPT use at 396 days post-MI (365 days plus a 31-day overrun period to allow intended DAPT discontinuation at 1 year). Patients on oral anticoagulation or on treatment with ticagrelor were excluded. Of 8464 patients enrolled (mean age 66 years, women 24%, ST-elevation MI 53%, prior MI 10%, multivessel disease 66%), the index MI was managed with a percutaneous coronary intervention in 82% of patients, coronary artery bypass grafting in 7%, and medically in 11%. The prevalence of DAPT use was 78% at the time of hospital discharge and 40% at 396 days post-MI. There was significant variability in practice patterns of DAPT use post-MI across the different geographical regions (Figure). In the subset of patients on DAPT at 396 days post-MI, aspirin was combined with clopidogrel in 84%, prasugrel in 12%, and other antiplatelet agents in 4%. DAPT use at 396 days post-MI was independently associated with geographic region, age, use of PCI for the index MI, and a history of multivessel disease or angina (Table). Several variables included in the DAPT score and addressed in international guideline recommendations for the use of antiplatelet therapies (e.g. diabetes, second prior MI, hypertension, peripheral artery disease, heart failure, smoking, and renal insufficiency) were not independent predictors of DAPT use at 396 days. DAPT use declined from hospital discharge to 1 year post-MI. Overall, DAPT use ≥1 year post-MI was prevalent and appeared to be influenced by regional practices. Further research is needed to determine how the DAPT score and international guidelines have affected long-term DAPT use practice patterns.View Large Image Figure ViewerDownload Hi-res image Download (PPT)