Unplanned Readmissions and Long-Term Mortality Risk After Incident Heart Failure Hospitalisation in Western Australia, 2001–2015

Aims: To investigate the frequency and predictors of unplanned readmissions after incident heart failure (HF) hospitalisation and the association between readmissions and mortality over two years. Methods: We performed a retrospective cohort study using Western Australian morbidity and mortality data to identify all patients, aged 25–94 years, who survived an incident (first-ever) HF hospitalisation (principal diagnosis) between 2001–2015. Ordinal logistic regression models determined the covariates independently associated with unplanned readmission(s). Cox proportional hazards models with time-varying exposures determined the hazard ratios (HR) of one or more readmissions for mortality over two years after incident HF. Results: Of 18,693 patients, 53.4% male, mean age 74.4 (standard deviation [SD] 13.6) years, 61.3% experienced 32,431 unplanned readmissions (39.7% cardiovascular-related) within two years. Leading readmission causes were HF (19.1%), respiratory diseases (12.6%), and ischaemic heart disease (9.6%). All-cause death occurred in 27.2% of the cohort, and the multivariable-adjusted mortality HR of 1 (versus 0) readmission was 2.5 (95% confidence interval [CI], 2.3–2.7) increasing to 5.0 (95% CI, 4.7–5.4) for 2+ readmissions. The adjusted mortality HR of 1 and 2+ (versus 0) HF-specific readmission was 2.0 (95% CI, 1.8–2.1) and 3.6 (95% CI, 3.2–3.9), respectively. Coexistent cardiovascular and other comorbidities were independently associated with increased readmission and mortality risk. Conclusion: This study underlines the high burden of recurrent unplanned cardiovascular and other readmissions within two years after incident HF hospitalisation, and their additive adverse impact on mortality. Integrated multidisciplinary management of concomitant comorbidities, in addition to HF-targeted treatments, is necessary to improve long-term prognosis in HF patients.