Most readmissions after heart failure are due to non-cardiovascular conditions, and taking multiple non-cardiac medications may identify patients most at risk, a new study suggests.
Study: Predictors of non-cardiovascular readmission in multimorbid adults with heart failure in Australian hospitals: a retrospective cohort study. Image credit: PeopleImages/Shutterstock.com
Adults with heart failure who take multiple non-cardiovascular medications may be at increased risk of being readmitted for non-cardiac symptoms, according to a recent study published in . clinical medicine journal.
Most heart failure readmissions are caused by non-cardiac diseases
Heart failure is a complex clinical syndrome in which the heart is unable to pump enough blood to meet the body’s metabolic demands. This condition has a significant global and population health impact, affecting 64 million people worldwide and a significant number in Australia.
Despite advances in treatment, readmissions are common, two-thirds of them due to non-cardiovascular causes, and many are thought to be preventable. Most interventions focus on cardiovascular-specific factors, and as a result, our understanding of non-cardiovascular readmissions is limited. This highlights a significant research gap in identifying the underlying determinants and risk factors of these events.
Although guideline-based treatment has effectively reduced heart failure-related hospitalizations, non-cardiovascular hospitalizations remain prevalent and poorly understood. Drug-related harms, such as adverse drug reactions, fall injuries, and drug-disease interactions, are often the cause of preventable hospitalizations in elderly multimorbid patients.
The relationship between potentially inappropriate non-cardiovascular drug use and subsequent readmission remains poorly defined and reflects an important gap in current knowledge. Addressing this gap by identifying modifiable drug-related risk factors is essential to inform strategies to reduce hospitalizations for preventable non-cardiovascular diseases.
Australian hospitals tracked readmissions for one year
The current retrospective cohort study used admission data from four major hospitals in Adelaide, South Australia, from August 2016 to June 2022, with follow-up until June 2023. The study included approximately 198,000 hospitalized patients per year.
Adults aged 45 years and older with heart failure and multiple medical conditions who were hospitalized for the first time during the study period were included. Only patients whose heart failure was actively managed and documented during hospitalization were considered.
Eligible hospitalizations were unplanned, acute, managed in a general comorbidity unit, and required a hospital stay of at least 48 hours. Patients who did not survive or were transferred were excluded. Study variables included age, gender, International Classification of Diseases (ICD-10) codes, and routine discharge medications from the electronic medical record (EMR). Charlson comorbidity index (excluding heart failure) and drug class were determined using ICD-10 and Anatomic Therapeutic Chemistry (ATC) codes.
In the current study, we defined non-cardiovascular polypharmacy as the use of five or more unique non-cardiovascular drugs. This was hypothesized to increase the risk of all-cause and non-cardiovascular readmissions due to drug-related harms. Acute readmissions were tracked at 3-month intervals for 1 year after discharge.
Non-cardiovascular readmissions exceeded cardiac hospitalizations
The study followed 4,912 adults with heart failure and multiple chronic conditions who were discharged to home or residential care. The cohort was elderly, with a median age of 82 years, and nearly half of the participants were women. Patients typically had six additional chronic conditions in addition to heart failure, and more than half were classified as frail, highlighting the complex health needs of the study population.
Patients were prescribed a median of 10 medications, split almost evenly between cardiovascular and non-cardiovascular treatments, with 56% meeting the definition of non-cardiovascular polypharmacy by taking five or more non-cardiovascular medications.
In the year following discharge, hospitalizations for non-cardiovascular diseases were more common than hospitalizations for cardiovascular diseases. By 12 months, 32% of patients had at least one non-cardiovascular readmission, compared with 19% for cardiovascular disease, and 28% died. Many patients experienced multiple hospitalizations during follow-up.
The burden of chronic disease is high, and the most common comorbidities include hypertension, high cholesterol, acid reflux, ischemic heart disease, diabetes, chronic lung disease, and depression. As follow-up progressed, the cumulative incidence of first all-cause readmission approached 37% by 12 months, and the corresponding cumulative incidence of death reached 15%.
Patients taking five or more non-cardiovascular drugs had a worse overall prognosis. The cumulative incidence of all-cause readmissions reached 39% at 12 months and 32% in patients without noncardiovascular polypharmacy, but the cumulative incidence of death was also higher (17% vs. 10%).
Furthermore, regression analysis showed that non-cardiovascular polypharmacy was independently associated with a 48% increased odds of non-cardiovascular readmission within 1 year. The likelihood of readmission also increased with each additional cardiovascular event, but age and gender were not independently associated with non-cardiovascular readmission. In contrast, adults aged 75 and older were more likely to experience an all-cause readmission during follow-up.
Addressing the overlooked risks of polypharmacy
The current study found that older adults with heart failure who took multiple non-cardiac medications had higher rates of non-cardiovascular readmissions and mortality. These findings suggest that noncardiac polypharmacy may contribute to harm or reflect a greater burden of disease.
Optimizing medication regimens and addressing comorbidities may reduce unnecessary hospitalizations. Improving outcomes for multimorbid adults living with heart failure requires a holistic, patient-centered approach to drug management.
However, as this is a retrospective observational study, it cannot be proven that non-cardiovascular polypharmacy is a direct cause of readmission. The authors also note that the results may not be generalizable to specialist hospitals, community or private hospitals, community-dwelling adults, or health systems outside Australia.
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Reference magazines:
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Inglis, J.M. et al. (2026). Predictors of non-cardiovascular readmission in multimorbid adults with heart failure in Australian hospitals: a retrospective cohort study. Journal of Clinical Medicine. 15(13), 5275. Doi: https://doi.org/10.3390/jcm15135275. https://www.mdpi.com/2077-0383/15/13/5275
