Prognostic impact of frailty based on a comprehensive frailty assessment in patients with heart failure

Aims This study aimed to evaluate the impact of frailty and living function domains based on the Kihon Checklist (KCL), a questionnaire for a comprehensive frailty assessment, on prognosis in patients with acute heart failure (AHF). Methods and results The Kochi Registry of Subjects with Acute Decompensated Heart Failure (Kochi YOSACOI) study was a prospective multicentre cohort study enrolling 1061 patients hospitalized for AHF from May 2017 to December 2019 in Japan. We divided patients into three groups according to the severity of frailty using the KCL and compared clinical outcomes after discharge. The primary endpoint was all-cause death, and the secondary outcomes were cardiovascular death, heart failure (HF) rehospitalization, and the composite event of cardiovascular death and HF rehospitalization. Of 936 patients (median age, 81 years; 48.9% women) who could be assessed for frailty, we identified frailty in 501 patients (53.5%), prefrailty in 290 patients (31.0%), and non-frailty in 145 patients (15.5%). Compared with prefrail and non-frail patients, frail patients were older (83 vs. 79 and 72 years, P < 0.001), were more likely to be women (53.9% vs. 43.1% and 43.4%, P = 0.005), and were more likely to have a history of previous HF hospitalization (35.4% vs. 25.3% and 19.6%, P < 0.001) and multimorbidity (90.8% vs. 81.0% and 73.8%, P < 0.001). Frail patients had a lower rate of discharge to home (79.7% vs. 94.8% and 96.5%, P < 0.001). During the 2 year follow-up period, frail patients had a higher incidence rate of all-cause death, cardiovascular death, and HF rehospitalization (log-rank P < 0.001, P < 0.001, and P = 0.003, respectively). After adjusting for other prognostic factors, multivariate analysis showed that frailty was associated with all-cause death [adjusted hazard ratio (HR): 2.917, 95% confidence interval (CI): 1.326-6.417, P = 0.008] and cardiovascular death (adjusted HR: 7.026, 95% CI: 1.700-29.030, P = 0.007). Among all domains of the KCL, the cognitive function domain was associated with a higher risk of all-cause death (P = 0.004) and cardiovascular death (P < 0.001). The depression domain remained associated with a higher risk of HF rehospitalization (P = 0.045). The risk for all-cause death increased with an increase in total KCL score (adjusted HR: 1.819, 95% CI: 1.300-2.547, P < 0.001). Conclusions The KCL is a useful tool for risk stratification of adverse outcomes in patients with AHF. Functional declines in psycho-emotional domains including cognitive function and depressed mood contribute to adverse outcomes.