Abstract
BACKGROUND: Elderly patients with heart failure (HF) often present with multiple comorbidities and complex medication regimens. However, research on polypharmacy and potentially inappropriate medication (PIM) in Asian population with HF remains limited. METHODS: The research studied elderly patients with HF (≥ 65 years) from the Ningbo Yinzhou District medical database from 2011 to 2022. The cohort categorized them into four groups based on the number of drug types recorded during the 90-day period following their diagnosis: non polypharmacy (0–4 drugs), polypharmacy (5–9 drugs), hyperpolypharmacy (10–14 drugs), and super hyperpolypharmacy (≥ 15 drugs). PIM was identified based on the 2019 Beers Criteria from inpatient and outpatient records. Dose-dependent PIM criteria were excluded due to the lack of dosage information. The primary outcome was a composite of cardiovascular death or HF hospitalization, while secondary outcomes included worsening chronic heart failure (WCHF), all-cause mortality, and hospitalizations. RESULTS: In 7,361 elderly patients with HF, 82.3% were prescribed five or more medications, and 53.2% had PIM. Female sex and hyperlipidemia were negatively associated with polypharmacy, whereas diabetes, chronic obstructive pulmonary disease, coronary artery disease, and healthcare utilization were positive predictors. Polypharmacy emerged as the strongest determinant of PIM, increasing the risk by 152%. With increasing medication burden, risks for the primary outcome, WCHF, and mortality exhibited an initial decrease followed by an increase; the polypharmacy group demonstrated superior survival compared to controls, with the polypharmacy group showing the best survival probability. Conversely, all-cause hospitalization exhibited a linear stepwise increase, with the super hyperpolypharmacy group facing the poorest prognosis (108.9 per 100 person-years). Hyperpolypharmacy and super hyperpolypharmacy increased the primary outcome risk by 22% and 53%, respectively. Furthermore, super hyperpolypharmacy significantly elevated risks for WCHF, recurrent HF hospitalization, and all-cause rehospitalization by 26%, 64%, and 25%, respectively. PIM did not significantly mediate these adverse associations. CONCLUSION: Polypharmacy and PIM were prevalent and significant concerns among elderly patients with HF, and excessive polypharmacy was associated with adverse outcomes, although PIM did not mediate these associations. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12877-025-06948-9.