Trends and Characterization of Hospitalizations with Heart Failure in Italy Before and During the COVID-19 Pandemic.

Background/Objectives: Heart failure (HF) imposes a significant healthcare burden in aging populations. The COVID-19 pandemic disrupted care, raising concerns about chronic disease management. We analyzed temporal trends in HF hospitalizations in Italy (2008-2022), assessing the influence of demographics, clinical complexity, seasonality, and the pandemic. Methods: Using national discharge records, we strictly identified hospitalizations with a primary HF diagnosis via ICD-9-CM codes. Admissions were stratified by age, sex, season, and clinical severity according to the Elixhauser Comorbidity Index. Temporal trends were analyzed using a Negative Binomial Generalized Linear Mixed Model with the time component modeled through a segmented regression to account for pre-pandemic, pandemic (2020), and late-pandemic dynamics. Results: We identified 3,162,075 primary HF admissions, yielding a crude hospitalization rate of 35.11 per 10,000 person-years. Patients with an intermediate comorbidity burden (Elixhauser 13-20) accounted for 59.3% of the total volume. Multivariable analysis identified male sex (RR = 2.24, p < 0.001 ***), age ≥ 75 years (RR = 95.04 vs. 25-44, p < 0.001 ***), and winter seasonality as strong independent predictors. Trend analysis revealed a structural long-term decline across all severity tiers, driven by a sharp drop in 2020 (RR = 0.80, p < 0.001 ***) coincident with a spike in in-hospital mortality. While patients with low-to-intermediate comorbidity exhibited a partial rebound in 2021-2022 (overall RR = 1.06, p < 0.001 ***), admissions for highly complex patients (score > 20) showed an accelerated late-pandemic decline. Conclusions: HF hospitalizations in Italy remain a substantial burden driven by advanced age and clinical comorbidity. Our 15-year population-level data indicate no sustained, structural late-pandemic surge in HF admissions. The observed fluctuations were likely driven by severe healthcare disruptions and patient care avoidance rather than a true epidemiological shift, highlighting the urgent need for resilient chronic care systems during emergencies.