Fried Frailty Phenotype and 6-Month Risk of First All-Cause Rehospitalisation Among Older Outpatients with Heart Failure and LVEF >40%: A Multicentre Prospective Cohort Study

Background: Heart failure (HF) with left ventricular ejection fraction (LVEF) > 40% is common in older adults and carries a substantial risk of post-discharge rehospitalisation. However, the prognostic association of the Fried frailty phenotype with short-term rehospitalisation remains incompletely characterised. Methods: We conducted a multicentre prospective cohort study of adults aged ≥ 60 years with HF and LVEF > 40% who were enrolled 1– 3 months after HF hospitalisation at two tertiary HF outpatient clinics in Ho Chi Minh City, Vietnam. Frailty was assessed at enrolment using the Fried frailty phenotype and defined as meeting ≥ 3 criteria. For prognostic analyses, robust and pre-frail participants were combined into a non-frail group and compared with frail participants. Participants were followed for 6 months from enrolment to ascertain first all-cause rehospitalisation. Cox proportional hazards regression assessed the association between frailty and rehospitalisation, and the incremental prognostic contribution of frailty was evaluated using Harrell’s C-statistic and the likelihood-ratio test. Results: Among 313 participants, the median age was 72.0 years (interquartile range, 66.0– 81.0), 53.4% were male, and 190 (60.7%) were frail. First all-cause rehospitalisation occurred in 118 participants (37.7%): 33 of 123 non-frail participants (26.8%) and 85 of 190 frail participants (44.7%). Frailty was associated with a higher risk of rehospitalisation in univariable analysis (HR, 1.89; 95% CI, 1.27– 2.83) and after adjustment for prespecified covariates (adjusted HR, 1.80; 95% CI, 1.09– 2.95; p = 0.021). Adding frailty increased Harrell’s C-statistic from 0.717 to 0.723, corresponding to a change of 0.006 (95% CI, − 0.004 to 0.027), and improved overall model fit according to the likelihood-ratio test (p = 0.017). Conclusion: Frailty was common and associated with a higher 6-month risk of first all-cause rehospitalisation among older outpatients with HF and LVEF > 40%. Adding frailty improved overall model fit, whereas the estimated change in discrimination was small and its confidence interval included no improvement. The models were not internally or externally validated; independent validation is warranted.