Cardiovascular Disease, Frailty, and Multimorbidity as Predictors of Adverse Outcomes in Older Adults Admitted to Acute Geriatric Settings: A Secondary Analysis

Background Despite the high prevalence of concomitant cardiovascular disease (CVD), multimorbidity and frailty, the clinical characteristics and longer-term outcomes for older adults admitted to acute geriatric settings remain poorly understood. Method A secondary analysis of the Western Sydney Clinical Frailty Registry was undertaken. Frailty was assessed using the Clinical Frailty Scale. CVD was defined as a history of either heart failure (HF), stroke, or atrial fibrillation. Multimorbidity was assessed using the updated Charlson Comorbidity Index. Adverse outcomes of interest included rehospitalisation and mortality. The incidence rate and the survival probabilities were calculated for the occurrence of adverse outcomes. Cox proportional hazard models were fitted to identify the predictors of rehospitalisation and mortality. Results The mean age of the 592 older adults was 81.20±7.76 years, and 59.0% of the participants were female. Almost half had a history of CVD (n=265), 174 were classified as non-frail, 295 were mild-to-moderately frail, and 123 were severely frail. The incidence rate of rehospitalisation and mortality was 12.15 per 100 person-months. Participants with a history of HF or atrial fibrillation had significantly lower event-free survival (χ 2 (1)=19.27; p=0.00, χ 2 (1)=5.22; p=0.02, respectively), whereas a history of stroke was not significantly associated with reduced event-free survival (χ 2 (1)=0.04, p=0.84). Key predictors of rehospitalisation and mortality included severe frailty, the strongest predictor overall (adjusted hazard ratio [aHR] 2.12; 95% confidence interval [CI] 1.59–2.84), followed by mild to moderate frailty (aHR 1.57; 95% CI 1.23–2.00), HF (aHR 1.47; 95% CI 1.06–2.03) and a higher Charlson score (aHR 1.05; 95% CI 1.01–1.90). Conclusions Frailty, CVD, and multimorbidity are significant predictors of rehospitalisation and mortality in older adults. These results underscore the importance of routine frailty and multimorbidity assessments during hospitalisation to identify high-risk individuals and inform clinical decision-making.