The influence of frailty under direct oral anticoagulant use in patients with atrial fibrillation

Background Frailty is a prognostic factor in patients with atrial fibrillation (AF). However, there is no report on the associations between frailty and clinical adverse events in patients with AF taking direct oral anticoagulants (DOAC). The factors related to the occurrence of clinical adverse events are still under discussion. Therefore, we examined the associations between frailty and clinical adverse events in patients with AF taking DOAC in daily clinical practice. Methods We retrospectively evaluated 240 consecutive patients with AF who had been newly prescribed DOAC in our hospital from April 2016 through May 2017. Data collected included Clinical Frailty Scale (CFS) scores, laboratory results and basic demographic information. Results During the mean follow-up period of 13.4 months, 20 patients died (7.6 per 100 person-years), stroke or systemic embolism occurred in seven patients (2.6 per 100 person-years) and major bleeding occurred in 11 patients (4.2 per 100 person-years). We defined these adverse events as composite end points, and we estimated adjusted HRs and 95% CIs for risk factors using the Cox proportional hazard regression model. Frailty (defined as a CFS score of 5 or more; HR: 3.71; 95%CI: 1.59 to 8.65), female sex (HR: 3.49; 95%CI: 1.73 to 7.07), serum albumin level (HR: 0.47; 95%CI: 0.28 to 0.79) and malignancy (HR: 4.02; 95%CI: 1.83 to 8.84) were independent predictors of the composite end points. Conclusions Frailty, female sex, hypoalbuminaemia and malignancy were associated with clinical adverse events in patients with AF who were prescribed DOAC.