International patterns of dual antiplatelet therapy duration after acute coronary syndromes.

Objective: To describe international patterns of dual antiplatelet therapy (DAPT) duration after acute coronary syndrome (ACS), and explore its determinants and correlation with clinical events.

Methods: EPICOR (long-tErm follow-uP of anti-thrombotic management patterns In acute CORonary syndrome patients) is a prospective, international, observational study of 10 568 ACS hospital survivors enrolled in 555 centres from 20 countries across Europe and Latin America between 2010 and 2011, with telephone follow-up at quarterly intervals up to 24 months to assess treatment continuation and clinical events.

Results: Of 8593 patients discharged on DAPT, 4859 (57%) remained on uninterrupted DAPT at end of follow-up. There were minor differences in rates of DAPT discontinuation according to age, gender, risk factors, therapeutic strategy or region, but major differences between countries. By study end, 555 of evaluable patients (5.7%) died, 727 (10.0%) experienced new cardiovascular (CV) events, 496 new coronary events (6.82%) and 154 (2.11%) clinically relevant bleeding (14 (6.7%) fatal). Most CV events and deaths (85%) occurred while on DAPT. DAPT interruption was associated with increased risk of CV events in the following week (HR 2.29; 95% CI 1.08 to 4.84) but not specifically with time to first coronary event or mortality.

Conclusions: Despite guideline recommendations, most patients with ACS in Europe and Latin America remained on DAPT beyond 12 months, country being the most important determinant of DAPT duration. Increase in short-term CV risk was seen after switching from DAPT to less medication, as compared with continued DAPT, with no long-term effect on coronary or mortality risk.

Trial Registration Number: NCT01171404; Results.