Which frailty tool best predicts morbidity and mortality in ambulatory patients with heart failure? A prospective study

Abstract

Background: Frailty is common in patients with heart failure (HF) and is associated with adverse outcome, but it is uncertain how frailty should best be measured. Objectives: To compare the prognostic value of commonly-used frailty tools in ambulatory patients with HF. Methods: We assessed, simultaneously, 3 screening tools (clinical frailty scale (CFS); Derby frailty index (DFI); acute frailty network (AFN) frailty criteria), 3 assessment tools (Fried criteria; Edmonton frailty score (EFS); deficit index (DI)) and 3 physical tests (handgrip strength, timed get-up-and-go test (TUGT), five-metre walk test (5MWT)) in consecutive patients with HF attending a routine follow-up visit. Results: 467 patients (67% male, median age = 76 years, median NT-proBNP = 1156 ng/L) were enrolled. During a median follow-up of 554 days, 82 (18%) patients died and 201 (43%) patients were either hospitalised or died. In models corrected for age, Charlson score, haemoglobin, renal function, sodium, NYHA, atrial fibrillation (AF) and body mass index, only log[NT-proBNP] and frailty were independently associated with all-cause death and/or hospitalisation. A base model for predicting mortality at 1 year including NYHA, log[NT-proBNP], sodium and AF, had a C-statistic = 0.75. Amongst screening tools: CFS (C-statistic = 0.84); amongst assessment tools: DI (C-statistic = 0.83) and amongst physical test: 5MWT (C-statistic = 0.80), increased model performance most compared to base model (p < 0.05 for all). Conclusion: Frailty is strongly associated with adverse outcomes in ambulatory patients with HF. When added to a base model for predicting mortality at 1 year including NYHA, NT-proBNP, sodium and AF, CFS provides comparable prognostic information to assessment tools taking longer to perform.