Oral Anticoagulation and Adverse Outcomes after Ischemic Stroke in Heart Failure Patients without Atrial Fibrillation

Background: The safety and effectiveness of oral anticoagulation (OAC) after an ischemic stroke in older patients with heart failure (HF) without atrial fibrillation remains uncertain. Methods: Utilizing Get With The Guidelines Stroke national clinical registry data linked to Medicare claims from 2009-2014, we assessed the outcomes of eligible patients with a history of HF who were initiated on OAC during a hospitalization for an acute ischemic stroke. The cumulative incidences of adverse events were calculated using Kaplan-Meier curves and adjusted Cox proportional hazard ratios were compared between patients discharged on or off OAC. Results: A total of 8,261 patients from 1,370 sites were discharged alive after an acute ischemic stroke and met eligibility criteria. Of those, 747 (9.0%) were initiated on OAC. Patients on OAC were younger (77.2 +/- 8.0 vs. 80.5 +/- 8.9 years, p<0.01). After adjustment for clinical covariates, the likelihood of 1 year mortality was higher in those on OAC (aHR: 1.22, 95% CI 1.05-1.41, p<0.01), while no significant differences were noted for ICH (aHR: 1.34, 95% CI 0.69-2.59, p=0.38) and recurrent ischemic stroke (aHR: 0.78, 95% CI 0.54-1.15, p = 0.21). The likelihood of all-cause bleeding (aHR: 1.59, 95% CI 1.29-1.96, p<0.01) and all-cause re-hospitalization (aHR: 1.14, 95% CI 1.02-1.2 7, p = 0.02) was higher for those on OAC. Conclusion: Initiation of OAC after an ischemic stroke in older patients with HF in the absence of atrial fibrillation is associated with death, bleeding and re-hospitalization without an associated reduction in recurrent ischemic stroke. If validated, these findings raise caution for prescribing OAC to such patients.