Abstract 18447: Comparative Seasonal Variation in Outcomes Among Patients Hospitalized for Heart Failure in Cold- and Warm-Climate States

Abstract

Background: Despite emerging evidence that extreme heat and air pollution exposure are linked to adverse cardiovascular disease outcomes, paradoxical seasonal trends in heart failure hospitalizations and deaths have been observed, with peaks occurring in winter months. This study aimed to explore how seasonal variations in heart failure admissions differ among individuals hospitalized in cold-climate and warm-climate states. Methods: Population-level, state-wide data were used to explore outcomes among all individuals hospitalized for heart failure in Texas (1999-2016) and New York (1994-2007). Seasonal variation was assessed using time of discharge (January-March, April-June, July-September, October-December). Multivariable logistic and linear regression were used to explore the relationship between time of discharge and the primary outcomes of interest: mortality and length of stay (LOS). Analyses were adjusted for age, sex, race, ethnicity, and comorbidities (hypertension, hyperlipidemia, diabetes, CAD, arrhythmias, anemia, COPD, tobacco use). Results: Among individuals hospitalized for heart failure in both Texas and New York, mortality and LOS were significantly increased during winter months compared to spring, summer, and early fall (Table). While similar seasonal trends were observed across states, the observed effect sizes were smaller in the Texas population. Conclusions: Among patients hospitalized for heart failure in Texas and New York, there is an increase in mortality and LOS during winter months. However, the differences in effect sizes after controlling for traditional risk factors suggests that other variables (i.e., temperature fluctuations) may affect these seasonal trends and warrants further exploration.