Treatment and Outcomes in Elderly and Very Elderly Patients Aged 75-85 and ≥ 85 Years with Atrial Fibrillation. A Prospective National Study.

Background: Atrial fibrillation (AF) is a major risk factor for stroke and the prevalence increases with age. Oral anticoagulants (OACs) are effective, but are frequently underused in elderly patients, primarily because of concerns about efficacy and safety issues. We examine the treatment and outcomes in a large contemporary cohort of elderly patients with AF older than 75 years, and in the subgroup of patients older than 85.

Methods: A prospective historical cohort study, conducted using the Clalit Health Services Research Institute database, between 2004 and 2011. All patients older than 75 with non-valvular atrial fibrillation (NVAF) were included. We studied patients aged 75-85 and patients older than 85. Primary end-points were all-cause mortality, ischemic stroke and major hemorrhage.

Results: During the study period we identified 17,574 patients aged 85 and older (average age 89.3±3.8, 41% male) and 31,866 patients between the ages of 75-85 (average age 79.5±2.8, 46% male) with NVAF. all patients were classified as high-risk for thrombo-embolic events. Mean follow-up was 48.8 months. Only 16.7% of the elderly patients were treated with Warfarin, compared with 30.8% of the patients aged 75-85. Stroke incidence was 6.7% for ages 75-85 and 5.1% over age of 85. Mortality was 69.8% for age>85 and 45.7% for age 75-85. In multivariate analysis among elderly population Coumadin was a protective predictor for stroke (HR 0.85) and mortality (HR 0.62). Cerebral bleeding incidence was 1.2% among ages 75-75 and 1% for age>85. Gastrointestinal bleeding rates were 3.3% and 2.7%, respectively. Warfarin treatment was neither predictive nor protective of intracranial bleeding.

Conclusion: OAC therapy is associated with a positive benefit-risk balance in elderly patients, reduced stroke and increased survival. Irrespective of age, treatment decisions regarding stroke thromboprophylaxis in all patients with AF should be based on individual potential benefits and risks of treatment and patient preferences.