Cardiovascular
Additional Moderate Temperature Days Increases Risk of Cardiovascular Emergency Room Visits Across Climate Regions in the US Erin Liedtke* Erin Liedtke Melanie Sona Kelly Jones Shannon Zenk
Rising US temperatures are concerning, yet the impact of moderate temperatures (<37°C) on cardiovascular (CV) health is largely overlooked. As the frequency of moderate temperature days increases, it may be critical that interventions aiming to address heat exposure go into effect at lower temperatures. To the best of our knowledge there has been no investigation that examines the impact of moderate temperatures on cardiovascular emergency room (ER) visits across regions. This study aims to explore the association between exposure to additional days at moderate temperatures and the risk of CV-related ER visits during the hottest months of the year in 3 different climate regions in the US. Using gridded daily weather data, monthly counts of days with highs ranging from 27°C to 37°C between June and September were identified. Poisson regression models were run with ER CV data (N=3,727,219) from the Healthcare Cost Utilization Project in Arizona (AZ), Georgia (GA), North Carolina (NC), and New York (NY) to examine the impact of additional moderate temperature days on ER visit risk. All states demonstrated an increased cardiovascular ER visit risk for additional days above 27°C: AZ (RR 1.28, 95% CI 1.26-1.30), GA (RR 1.21, 95% CI 1.20-1.21), NC (RR 1.14, 95% CI 1.13-1.15), and NY (RR 1.11, 95% CI 1.13-1.14). Our findings also reveal regional differences in risk associated with heat. In different states, additional days at different temperatures reflect a similar risk, notably in NY (33°C, RR 1.38, 95% CI 1.36-1.39) and GA (37°C, RR 1.38, 95% CI 1.31-1.45). Our analysis indicates that moderate temperatures significantly increase the risk of cardiovascular ER visits, demonstrating the importance of designing interventions aimed at mitigating the risks posed by moderate temperatures. Geographical variability in risk underscores the need for region-specific strategies to address cardiovascular health risks associated with moderate temperatures.