Warfarin use among older atrial fibrillation patients with non-ST-segment elevation myocardial infarction managed with coronary stenting and dual antiplatelet therapy

Background We sought to determine the risk of readmission for bleeding and major cardiac events in stented non-ST-segment elevation myocardial infarction (NSTEMI) atrial fibrillation (AF) patients. Methods For this patient population, selection of an antithrombotic strategy poses a unique challenge in clinical practice, and comparative outcome data are sparse. We linked NSTEMI patients aged ≥65 years in the CRUSADE Registry (2003-2006) to Medicare claims data. We examined patients with AF who received coronary stenting and either dual antiplatelet therapy (DAPT, aspirin + clopidogrel) or triple therapy (DAPT + warfarin) upon discharge. Multivariable Cox analysis was used to compare the 1-year risks of major cardiac events and readmission for bleeding. Results We identified 1,648 stented NSTEMI AF patients. Of these, 1,200 (73%) received DAPT, and 448 (27%) received triple therapy at hospital discharge. Predicted thromboembolic and bleeding risks did not appear to influence the decision to receive DAPT or triple therapy. At 1 year, 20.4% had a major cardiac event, and 13.5% were admitted for bleeding. Use of triple therapy relative to DAPT at discharge was associated with a similar adjusted risk of major cardiac events (adjusted hazard ratio 0.94, CI 0.73-1.21) but a trend toward increased risk of readmission for bleeding (hazard ratio 1.29, CI 0.96-1.74, P =.09). Conclusions In routine practice and in contrast with practice recommendations, most elderly NSTEMI patients with AF who undergo percutaneous coronary intervention with stent placement receive DAPT rather than triple therapy at discharge. Those receiving triple therapy versus DAPT had a similar risk of an ischemic event but a trend toward increased bleeding.