Oral anticoagulation in very elderly patients with atrial fibrillation: Results from the prospective multicenter START2-REGISTER study

Direct oral anticoagulants (DOACs) have shown similar efficacy and safety with respect to warfarin in patients with atrial fibrillation (AF). However, the proportion of patients aged ≥85 years enrolled in clinical trials was low and the applicability of their results to very elderly patients is still uncertain. We have carried out a prospective cohort study on AF patients aged ≥85 years enrolled in the Survey on anticoagulaTed pAtients RegisTer (START2-Register) and treated with either VKAs or DOACs, with the aim to evaluate mortality, bleeding and thrombotic rates during a long-term follow-up. We enrolled 1124 patients who started anticoagulation at ≥85 years with VKA (58.7%) or DOACs (41.3%), Clinical characteristics of patients were similar, except for a higher prevalence of coronary artery disease and renal failure in VKAs patients and of a history of previous bleeding and previous stroke/TIA in patients on DOACs. Median CHA2DS2VASc and HAS-BLED scores were similar between the two groups. During follow-up, 47 major bleedings (rate 2.3 x100 pt-yrs) and 19 stroke/ TIA (0.9 x100 pt-yrs) were recorded. The incidence of bleeding was similar between patients on VKAs and DOACs. Patients on DOACs showed a higher rate of thrombotic events during treatment (rate 1.84 and 0.50,respectively). Mortality rate was higher in patients on VKAs than in patients on DOACs (HR 0.64 (95% CI 0.46-0.91). In conclusion, we confirm the overall safety and effectiveness of anticoagulant treatment in very elderly AF patients, with lower mortality rates in DOACs patients, similar bleeding risk, and a higher risk for cerebral thrombotic events in DOACs patients.