Frailty and Congestion in Patients with Heart Failure: Clinical Interaction and Prognostic Implications

Background/Objectives: Frailty and congestion are highly prevalent in patients with heart failure (HF) and are independently associated with adverse outcomes. However, their interrelationship and combined prognostic significance remain incompletely understood. We aimed to investigate the association between frailty and congestion phenotypes in older patients with HF and to evaluate their combined impact on clinical outcomes. Methods: We prospectively included 308 ambulatory patients aged ≥65 years with chronic HF from a specialized HF clinic between 2022 and 2024. Frailty was assessed using the Fried phenotype. Congestion was defined by clinical signs and/or elevated NT-proBNP (≥1000 pg/mL) and CA125 (≥35 U/mL). Associations between congestion and frailty were evaluated using logistic regression and restricted cubic spline analyses. The primary endpoint was a composite of all-cause mortality or HF hospitalization at 1 year. Results: Frailty was present in 49.7% of patients and congestion in 79.9%. Frailty prevalence increased progressively across congestion phenotypes, from 21.0% in patients without congestion to 70.8% in those with combined clinical and biochemical congestion (p < 0.001). Congestion was also associated with worse nutritional status and reduced muscle strength. In multivariable analyses, frailty and congestion remained independently associated with adverse outcomes. Their coexistence identified the subgroup with the highest risk of death or HF hospitalization (HR 25.54, 95% CI 3.46–188.26; p = 0.001). Conclusions: In older ambulatory patients with HF, frailty and congestion frequently coexisted and identified patients at increased risk of adverse outcomes, particularly when clinical and biochemical congestion were present. These findings support combining frailty evaluation with congestion assessment for prognostic stratification.