Association of non-cardiac comorbidities and sex with long-term Re-hospitalization for heart failure

Heart failure (HF) often coexists with non-cardiac comorbidities (NCC), but their association with long-term HF re-hospitalizations is not defined. Using the Lombardy Regional Health Database, that includes >10 million residents, we assessed the risk of re-hospitalization for HF after first HF discharge as a function of NCC, employing age- and sex-adjusted Cox proportional-hazard models. Kaplan Meier curves for HF re-hospitalizations were stratified for number of NCC. End of follow-up was June 30th 2021. Between January 1st 2015 to December 31st 2019, 88,528 consecutive patients were discharged from hospital with a primary diagnosis of HF; over 42.8 ± 18.3 months follow-up, 79,533 HF re-hospitalizations occurred (32.94/100 patient/year). Number of NCC, age, and male sex were significantly associated with re-hospitalization risk. Compared to those without NCC, females and males with >4 NCC had a 3.08 (CI 2.73–3.47) and a 2.62 (CI 2.39–2.87) fold higher risk, respectively. Risk of all-cause death increased with number of NCC (hazard ratio (HR): 1.42 (1.38–1.46) for HF patients with 1–2 NCC, HR: 1.90 (1.82–1.98) for patients with 3–4 NCC, HR: 2.20 (2.01–2.40) for those with HF and >4 NCC), as it did the number of days spent in hospital because of HF (from 19.91±19.25 for patients without NCC to 45.35±33.00 days for those with >4 NCC, p < 0.0001). In conclusion, this study shows that in patients hospitalized with HF, HF re-hospitalizations, all-cause mortality, and time spent in hospital increased with number of NCC. NCC associates with a worse clinical trajectory in patients with HF.