Factors associated with frailty and six-month readmission in older patients with atrial fibrillation: a single-center retrospective cohort study

To examine clinical factors associated with frailty and evaluate short-term outcomes among older hospitalized patients with atrial fibrillation (AF). This single-center retrospective cohort study included 198 patients aged ≥ 60 years with documented AF who were hospitalized between January 2018 and December 2024. According to the FRAIL scale, 28 patients were classified as robust, 68 as pre-frail, and 102 as frail. Demographic characteristics, AF-related features, medications and management strategies, laboratory and echocardiographic parameters, functional and cognitive performance, and nutritional risk were compared across frailty categories. Univariable and multivariable logistic regression analyses were used to examine factors associated with frailty. Time to first all-cause readmission within 180 days was evaluated using Kaplan–Meier and Cox proportional hazards analyses. Known AF duration, multimorbidity, polypharmacy, functional impairment, cognitive impairment, nutritional risk, homocysteine, and C-reactive protein differed across frailty categories. In the multivariable model, higher homocysteine levels (adjusted OR per 5-μmol/L increase, 1.34; 95% CI 1.09–1.65), higher C-reactive protein levels (adjusted OR per 5-mg/L increase, 1.15; 95% CI 1.02–1.31), lower Montreal Cognitive Assessment scores (adjusted OR per 1-point increase, 0.63; 95% CI 0.49–0.81), and higher Nutritional Risk Screening 2002 scores (adjusted OR per 1-point increase, 2.28; 95% CI 1.58–3.28) were independently associated with frailty. Readmission within 90 days did not differ significantly among groups, whereas 180-day readmission occurred in 3.7% of robust, 4.6% of pre-frail, and 20.4% of frail patients ( P = 0.004). Each 1-point increase in FRAIL score was associated with a higher adjusted hazard of first readmission (HR, 1.53; 95% CI 1.14–2.05). In this small exploratory cohort, frailty was associated with higher homocysteine and C-reactive protein levels, poorer cognitive performance, greater nutritional risk, and a higher risk of first all-cause readmission within 180 days. Larger prospective studies are needed to confirm these findings.