Prognostic Value of Objective Social Isolation and Loneliness in Older Patients With Heart Failure: Subanalysis of FRAGILE-HF and Kitasato Cohort

Social factors encompass a broad spectrum of nonmedical factors, including objective (social isolation [SI]) and perceived (loneliness) conditions. Although social factors have attracted considerable research attention, information regarding their impact on patients with heart failure is scarce. We aimed to investigate the prognostic impact of objective SI and loneliness in older patients with heart failure. This study was conducted using the FRAGILE-HF (Prevalence and Prognostic Value of Physical and Social Frailty in Geriatric Patients Hospitalized for Heart Failure; derivation cohort) and Kitasato cohorts (validation cohort), which included hospitalized patients with heart failure aged ≥65 years. Objective SI and loneliness were defined using the Japanese version of Lubben Social Network Scale-6 and diagnosed when the total score for objective and perceived questions on the Lubben Social Network Scale-6 was below the median in the FRAGILE-HF. The primary outcome was 1-year death. Overall, 1232 and 405 patients in the FRAGILE-HF and Kitasato cohorts, respectively, were analyzed. Objective SI and loneliness were observed in 57.8% and 51.4% of patients in the FRAGILE-HF and 55.4% and 46.2% of those in the Kitasato cohort, respectively. During the 1-year follow-up, 149 and 31 patients died in the FRAGILE-HF and Kitasato cohorts, respectively. Cox proportional hazard analysis revealed that objective SI, but not loneliness, was significantly associated with 1-year death after adjustment for conventional risk factors in the FRAGILE-HF. These findings were consistent with the validation cohort. Objective SI assessed using the Lubben Social Network Scale-6 may be a prognostic indicator in older patients with heart failure. Given the lack of established SI assessment methods in this population, further research is required to refine such methods.