All-Cause Death and Major Adverse Events in Atrial Fibrillation with Frailty: Observations from the Korea National Health Insurance Service Data

Background: Atrial fibrillation (AF) is an indicator of frailty in old patients. This study aimed to investigate the effect of frailty on the use of oral anticoagulants (OAC) and clinical outcomes in a nationwide cohort of patients with new-onset AF. Methods: This study included 451,368 participants without AF from the Korea National Health Insurance Service-Health Screening cohort between 2002 and 2009. The Hospital Frailty Risk Score was retrospectively calculated for each patient using all available International Classification of Disease 10th revision diagnostic codes. According to the aggregate score, patients were divided into two groups: the participants without frailty (<5 points) and the participants with frailty (>= 5 points). The primary outcome was death from any cause, and the secondary outcomes were cardiovascular death, ischemic stroke, major bleeding, and heart failure admission. Results: With up to 7.2 +/- 1.5 years of follow-up, 11,953 participants (median age, 67 [interquartile range, 59.5-74.5] years; 7200 [60.2%] males) developed new-onset AF. Among the patients with AF, 3224 (26.9%) had frailty. Frailty was significantly associated with old age, female sex, polypharmacy, and other comorbidities. In patients with AF, frailty was negatively associated with OAC prescription after new-onset AF (p < 0.001). Compared to patients without frailty, patients with frailty had a significantly higher incidence and risk of all-cause death (hazard ratio [HR] 2.88, 95% confidence interval [CI] 2.65-3.14), cardiovascular death (HR 2.42, 95% CI 2.10-2.80), ischemic stroke (HR 2.25, 95% CI 2.02-2.51), major bleeding (HR 2.44, 95% CI 2.17-2.73), and heart failure admission (HR 1.29, 95% CI 1.09-1.52). In subgroup analysis, when compared to the non-OAC group, the risks associated with frailty were significantly lower in the OAC group for all-cause death, cardiovascular death, ischemic stroke, and heart failure admission. Conclusions: Frailty was negatively associated with the use of OAC and was a predictor of poor prognosis owing to the association of frailty with death, thromboembolic events, bleeding, and heart failure admission. However, OAC use was associated with lower risks related to frailty for all-cause death and major adverse cardiovascular events in patients with AF.