Efficacy of anticoagulation for secondary stroke prevention in older people with non-valvular atrial fibrillation: a prospective case series study

Background and purpose: despite large randomised trials that demonstrated the efficacy of oral anticoagulants in the primary and secondary prevention of stroke in patients with non-valvular atrial fibrillation (AF), anticoagulation therapy remains largely under-used in older patients, who are at risk of first ever or recurrent stroke. The aim of the present study was to assess the influence of anticoagulation therapy on long-term prognosis in the oldest old stroke patients with AF after adjusting for baseline risk factors. Methods: we evaluated prospectively a consecutive series of 207 older people (>75 years) with AF and first ever ischaemic stroke. During the follow-up period (mean 88.4 months, range 3-120), the study population was under either oral anticoagulants (n = 72) or aspirin (n = 135). Death and recurrent vascular events (stroke and systemic embolism) were documented. Statistical analyses were performed by means of the Kaplan-Meier product limit method and the Cox proportional hazards model. Results: the cumulative 10 year mortality and recurrence rate were 92.5% (95% CI 85.7-99.3) and 66.1% (95% CI 43.1-89.1), respectively. Cox regression analysis revealed increasing age, functional dependency at hospital discharge and antiplatelet versus anticoagulation therapy as independent determinants of mortality. Antiplatelet versus anticoagulation therapy was the sole determinant of vascular recurrence. Anticoagulation was associated with decreased risk of death (hazards ratio (HR) 0.47, 95% CI 0.31-0.72, P = 0.001)) and recurrent thromboembolism (HR 0.31, 95% CI 0.16-0.62, P = 0.002). Conclusions: our results suggest that the benefits of anticoagulation for secondary stroke prevention in AF patients extend to the oldest old. Prospective randomised clinical trials are needed to verify the potential benefit of anticoagulation in such patients.