Abstract
BACKGROUND/AIM: The relationship between the severity of cardioembolic stroke (CES) and oral anticoagulant (OAC) treatment before stroke onset in very elderly (≥80 years) patients with nonvalvular atrial fibrillation (NVAF) at high bleeding risk remains unknown. PATIENTS AND METHODS: A total of 364 consecutive patients (≥80 years) with CES and NVAF within 48 h following stroke onset were investigated. High bleeding risk was defined as follows: Bleeding history, renal dysfunction (creatinine clearance <30 ml/min), low body weight (≤45 kg), and antiplatelet or nonsteroidal anti-inflammatory drug use. Patients were divided into two groups: High bleeding risk (n=214) and non-high bleeding risk (n=150). We assessed stroke severity and functional outcome between the two groups, and evaluated the effect of therapy with direct OAC (DOAC) on stroke severity in the high-risk group. RESULTS: The high-risk group had a worse modified Rankin Scale (mRS) at discharge than the non-high-risk group [median: 4 (range=2-5) vs. 3 (range=1-4); p=0.02]. Patients in the high-risk group were categorized according to OAC treatment before stroke onset: No OAC (n=148), warfarin (n=46), and DOAC (n=20). The numbers of patients with National Institutes of Health Stroke Scale score (NIHSS) ≥8 on admission in these groups were 104 (70%), 30 (65%), and 8 (40%) (p=0.03), respectively. Multivariate analysis confirmed that DOAC therapy had a lower odds ratio (OR) for severe stroke (NIHSS ≥8) on admission (OR relative to no OAC=0.22, 95% confidence interval=0.08-0.62; p=0.005) and poor functional outcome (mRS ≥4) at discharge (OR=0.31, 95% confidence interval=0.11-0.90; p=0.03). CONCLUSION: Very elderly patients with CES at high bleeding risk have unfavorable functional outcomes. DOAC administration may be associated with reduced stroke severity.