Antithrombotic strategies and outcomes in acute coronary syndrome with atrial fibrillation.

Atrial fibrillation (AF) frequently occurs with acute coronary syndromes (ACS) and adds complexity to the selection of an appropriate antithrombotic strategy. We determined whether associations of antithrombotic treatment with bleeding, stroke, and death differ between patients with ACS with and without AF. Residents of Olmsted County, Minnesota, hospitalized with incident ACS during 2005 to 2010 were classified according to the presence or absence of AF either before or during the index ACS hospitalization. Antithrombotic strategy at discharge was categorized as double/triple agents versus no/single agent. Patients were followed through 2012, and propensity scores were used to estimate associations of treatment with bleeding, ischemic stroke, and mortality. Of 1,159 patients with incident ACS, 252 (21.7%) had concomitant AF (ACS + AF). Over a median follow-up of 4.3 years, 312 bleeds, 67 ischemic strokes, and 268 deaths occurred. The overall risks of bleeding, stroke, and death were similar between treatment strategies. Although limited by the small number of events, a suggestion of a lower risk of ischemic stroke for patients with ACS + AF on double/triple therapy was observed; the hazard ratios for stroke with double/triple versus no/single therapy were 0.30 (0.07 to 1.26) and 1.10 (0.52 to 2.33) in those with and without AF, respectively (p value for interaction = 0.10). In conclusion, the choice of antithrombotic strategy is not associated with the risk of ischemic stroke, bleeding, or death in patients with ACS overall. Patients with ACS + AF on double/triple therapy may experience reduced risks of stroke, although future studies are needed to confirm this finding.