Frailty Predicts Incident Atrial Fibrillation in Women but Not in Men: The Kuopio Ischaemic Heart Disease Risk Factor Study.

INTRODUCTION: Frailty and atrial fibrillation (AF) are common aging problems and increasing globally. The association(s) between frailty and AF has been inconclusive. The purpose of this prospective population-based cohort was to investigate the associations between frailty and incident AF in older men and women. METHODS: In total 839 participants, women (n = 458) and men (n = 381), aged 61-74 years from the Kuopio Ischaemic Heart Disease Risk Factor Study were included (March 1, 1998, to December 31, 2001). At the baseline, frailty prevalence was 49.3% (n = 414), and non-frailty 50.7% (n = 425) of the total population. Frailty was ascertained with the presence of 3-5 and prefrailty 1-2 of the following criteria: weight loss (highest 20% over 7 years), self-reported tiredness, weakness (measured by handgrip strength), slow walking speed (walking pace), and low physical activity (lowest 20%). AF events were obtained by record linkages from the national computerized hospitalization registry in Finland up to December 31, 2019. Multivariate Cox proportional hazard regression estimated the hazard ratio (HR) of incident events, adjusted for potential confounders. RESULTS: During the mean follow-up of 14.2 years, 288 AF cases (169 women; 119 men) occurred. After adjustment for possible confounders, the HRs (95% confidence intervals [CIs]) for AF was 1.46 (1.48-1.85) in the frail population, compared to the non-frail group. The association was observed only among older frail women (multivariable-adjusted HR 1.78, 95% CI [1.28-2.48]) (p for interaction = 0.04). No statistically significant associations were observed between frailty and future AF incident among men (multivariable-adjusted HRs 1.12, 95% CI (0.77-1.63)). CONCLUSIONS: In this population-based epidemiological cohort, the risk of developing AF was increased in women affected by frailty at baseline but not in men.