To treat or not to treat very elderly naïve patients with atrial fibrillation with vitamin K antagonists (VKA): results from the VENPAF cohort.

Despite the recommendations in the guidelines, physicians still underuse warfarin in very elderly patients with non-valvular atrial fibrillation (NVAF). The risks of stroke and major bleeding both increase with age, but it is still not clear whether the beneficial effects of vitamin K antagonists (VKA) in preventing stroke outweigh the related bleeding risks in fragile, very elderly patients. The bleeding rates reported in real-world observational studies differ considerably. The aim of this study was to retrospectively assess the incidence of major bleeding in VKA-naïve patients over 80 years old with NVAF at a large anticoagulation clinic. Significant predictors of major bleeding were also investigated. Sixty-five major bleeding events (3.4 per 100 patient-years) and 25 thromboembolic events (1.3 per 100 patient-years) were recorded in a sample of 798 patients with a median follow-up of 2.2 years. Patients over 85 years old had significantly more major bleeding events than the 80- to 84-year olds (4.7 vs. 2.6 per 100 patient-years, p 0.014). Spontaneous bleeding was also significantly more common (3.0 vs. 1.3 per 100 patient-years, p 0.008) in the very elderly group. Age and diabetes were the only independent risk factor for bleeding on multivariate Cox analysis (Age HR 1.80, 95% CI 1.10-2.93; diabetes HR 1.76, 95% CI 1.00-3.09). These data show a sharp increase in major bleeding episodes among the very elderly with atrial fibrillation. Further studies are warranted with a view to identifying patients at risk.