Temporal trends in incidence, clinical characteristics and outcomes among young adults with heart failure: a territory-wide study from 2014 to 2023 on 19,537 patients.

Background: Heart failure (HF), traditionally considered a disease of the elderly, is increasingly common in younger people, but temporal data remain scarce. This cohort study aimed to examine temporal trends in incidence, comorbidities, risk factor profiles, and clinical outcomes among young HF patients. Methods: Using a territory-wide administrative database in Hong Kong, we identified 19,537 young adults aged <65 years with incident HF between 2014 and 2023. Data on baseline characteristics, echocardiographic parameters, comorbidities and prescribed medications were retrieved. Annual standardised incidence rates (IRs) of HF were calculated by direct age- and sex-standardisation. Comparisons were made between two 5-year periods: 2014-2018 and 2019-2023. Multivariable regression models were applied to assess temporal shifts in risk factor profiles. The primary outcome was one-year all-cause mortality, with incidence rates reported per 100 person-years. Kaplan-Meier survival curves were plotted to illustrate survival trends. Findings: Among the cohort (median age 57.1 years, 69% men), IRs of young HF increased by 20% (IRR 1.20, 95% CI 1.13-1.27) from 2014 to 2023. Concurrent with fewer comorbidities, young HF patients in 2019-2023 were more likely to present with obesity, cardiomyopathy, lower socioeconomic status, and be aged 45-65 years, contrasting with the conventional risk factors (including history of sudden cardiac arrest) predominant in the 2014-2018 cohort (all Interpretation: The incidence of HF among young adults increased substantially between 2014 and 2023. During this period, the risk factor profile shifted considerably, with a pronounced rise in HFrEF subtype. Despite improved therapeutic management and better use of GDMT, reductions in one-year mortality were modest. Proactive public health strategies are urgently needed to address these emerging challenges in this population. Funding: This work was funded by grants from the National Natural Science Foundation of China (No. 82270400) and the Natural Science Foundation of Guangdong Province (No. 2023A1515010731).