Abstract 17485: Risk of Heart Failure Hospitalizations With Exposure to Colder Temperature and Regional Variations Among Older Adults in the United States

Abstract

Introduction: Extreme cold was associated with excess heart failure (HF) deaths in ecological studies. The relationship between colder temperatures and HF hospitalizations is not well understood. Hypothesis: Lower minimum temperatures (T min ) increase the risk of HF hospitalization among older adults and the impact varies by climate regions. Methods: A time-stratified case-crossover study among adults aged ≥66 hospitalized for HF was conducted using a 20% sample of Medicare data (2008-2019, Nov-Feb). Daily T min from the Parameter-elevation Relationships on Independent Slopes model were linked to Medicare data by zip code of residence. We used bidirectional sampling to select up to 5 controls. We used conditional logistic regression with a restricted cubic spline to model non-linear effects between T min and HF hospitalization in all patients and regional subgroups. Results: Among 529,879 cases (mean age 79, 61% female, 86% white), the risk of HF hospitalization peaked at 4 °F (OR 1.29 [CI 1.28-1.30]) and plateaued over colder T min relative to the median T min (31.5°F). Above 31.5 °F, the risk was reduced by 18% for every 10 °F (Figure 1). This inverse relationship between T min and HF hospitalizations during the winter were most prominent in colder regions (Figure 2). Conclusions: T min ≤4 °F increased the risk of HF hospitalizations by upwards of 29% compared to the national median T min . The plateau at more extreme T min may be due to avoidance of outdoor exposure. A similar behavioral response may occur in warmer regions, whereas some degree of cold exposure is inevitable in colder regions. HF patients should be aware of the risks from exposure to colder temperatures during winter months.