Combined use of warfarin and oral P2Y12 inhibitors in patients with atrial fibrillation and acute coronary syndrome.

BACKGROUND: Although atrial fibrillation (AF) occurs frequently in patients hospitalized with acute coronary syndrome (ACS), strategies for prevention of thromboembolic complications are poorly characterized. HYPOTHESIS: We sought to examine exposure to warfarin and P2Y12 inhibitors and clinical outcomes among patients with AF and ACS. METHODS: Patients age >65 years hospitalized with a primary diagnosis of ACS and a secondary diagnosis of AF between 2007 and 2010 were identified in the Medicare 5% sample. Medication exposure was ascertained during a 90-day period following the index discharge using Medicare drug claims. Among patients who were alive and not readmitted during the ascertainment period, we examined the cumulative incidence of all-cause mortality and all-cause readmission by medication exposure at 1 year. RESULTS: A total of 2509 Medicare beneficiaries met the inclusion criteria. Among the 1633 patients (65%) who were alive and not readmitted during the 90-day ascertainment period, 24.0% received warfarin, 38.9% received P2Y12 inhibitors, 10.2% received combination therapy, and 26.8% received neither therapy. Readmission rates were high in all groups at 1 year (warfarin, 47.5%; P2Y12 inhibitors, 46.6%; combination therapy, 38.0%; and neither therapy, 39.3%), and the overall 1-year mortality rate was 12.5%. CONCLUSIONS: Among Medicare beneficiaries with AF and ACS, combination therapy with warfarin and P2Y12 inhibitor was uncommon during the 90-day ascertainment period, and more than one-quarter of patients had no claims for warfarin or P2Y12 inhibitors. Rates of all-cause readmission and mortality within 1 year of hospitalization for ACS were high.

Duke Scholars

Author William Schuyler Jones Medicine, Cardiology

Author Manesh Raman Patel Medicine, Cardiology

Author Adrian Felipe Hernandez Medicine, Cardiology

Author Lesley H. Curtis Population Health Sciences