Critical Temperature Thresholds for Identifying Vulnerability to Heat-Related Excess Cardiovascular Morbidity and...

Area of Science:

• Environmental Health
• Epidemiology
• Cardiovascular Disease Research

Background:

• Extreme heat is a known environmental hazard linked to increased cardiovascular disease (CVD) morbidity and mortality.
• Limited research exists on temperature effects across multiple temporal scales and community-specific vulnerability to heat.

Purpose of the Study:

• To analyze the association between temperature and CVD deaths and emergency department visits across various temporal scales.
• To identify community-specific heat vulnerability profiles based on sociodemographic factors and environmental conditions.

Main Methods:

• Utilized neighborhood-level CVD mortality and emergency department visit data, linked with sociodemographic information and high-resolution temperature/humidity estimates.
• Employed generalized additive models to estimate excess heat-related rates across temporal scales.
• Used principal component analysis and k-means clustering to classify community areas by heat vulnerability.

Main Results:

• Higher temperatures showed significant associations with increased CVD and coronary heart disease mortality across warm-season, monthly, and daily scales.
• Peak warm-season thresholds for CVD mortality were observed at 25.6°C, and daily peaks at 39.5°C.
• Identified three distinct community vulnerability profiles based on socioeconomic status, demographics, and heat/humidity exposure.

Conclusions:

• Temperature thresholds for cardiovascular mortality differ by temporal scale and CVD subtype, with significant impacts on overall CVD and coronary heart disease mortality.
• Integrating temperature-mortality data with community vulnerability profiles can enhance heat warning systems and inform localized adaptation strategies.