Prevalence and predictors of dual antiplatelet therapy prolongation beyond one year in patients with acute coronary syndrome.

There are limited real-world data on prevalence and predictors of dual antiplatelet therapy (DAPT) prolongation beyond one year after acute coronary syndrome (ACS). We have explored such issue in the START ANTIPLATELET Registry, which is a prospective, observational, multicenter, Italian registry performed in seven Italian cardiology institutions including patients admitted for ACS and followed up to one year. Out of a total population of 840 ACS patients, 596 patients had completed 12-month follow-up being on DAPT. Decision to prolong DAPT beyond one year was taken in 79 patients (13%), whereas in 517 patients DAPT was stopped. The strongest predictors of DAPT continuation were a new cardiovascular events after the index admission event (OR 3.3, 95% CI 1.4-7.7), no bleeding complications (OR 3.2, 95% CI 1.2-8.3) and no anemia during one-year follow-up (OR 2.6, 95% CI 1.1-5.9); other independent predictors were renal failure (OR 2.5, 95% CI 1.3-5.0) and peripheral artery disease (OR 1.8, 95% CI 1.1-3.0). The choice of DAPT prolongation was not correlated with younger ager, presence of diabetes mellitus, coronary angioplasty as initial treatment strategy or type of implanted stent (drug-eluting vs bare metal). In conclusion, this study provides a real-world snapshot on the factors influencing the option to continue DAPT beyond one year after ACS; a low bleeding risk seems to influence the choice to prolong DAPT more than a high ischemic risk.