ENHANCING CDC AND EPA HEATRISK AND AIR QUALITY RISK RECOMMENDATIONS: A NARRATIVE REVIEW AND ACTION ALGORITHM FOR CARDIAC PATIENTS

Abstract

Therapeutic Area

CVD Prevention – Primary and Secondary

Background

Cardiovascular disease (CVD) remains the leading cause of mortality worldwide. As its prevalence continues to rise, so does the severity of climate change. The increasing number of days with extreme heat and poor air quality exacerbates cardiovascular outcomes, particularly for individuals with preexisting CVD. While the Centers for Disease Control and Prevention (CDC) and Environmental Protection Agency (EPA) recommend using HeatRisk and the Air Quality Index (AQI) to assess environmental safety, no specific guidelines exist for patients with preexisting CVD, despite their heightened risk. This narrative review addresses this gap by summarizing current data and evaluating how HeatRisk and AQI should be applied to this vulnerable population.

Methods

A literature review was conducted using PubMed and snowballing, focusing on studies published between 2000 and 2025 that examined physiological effects of heat and poor air quality on cardiovascular outcomes. Risk factors, including pregnancy, obesity, geography, and socioeconomic status, were considered, along with existing guidelines from the CDC, EPA, and National Weather Service.

Results

Extreme heat and poor air quality were linked to increased mortality and morbidity in patients with a history of heart failure, ischemic heart disease, stroke, or myocardial infarction. High-risk subgroups identified included women, older adults, residents of warmer climates, individuals with preexisting arrythmias, individuals taking certain medications, pregnant individuals, and those from lower socioeconomic backgrounds. Furthermore, extreme heat and poor air quality exacerbated cardiometabolic risk factors such as hypertension, insulin resistance, and atherosclerosis.

Conclusions

Physicians should educate patients with CVD about the risks associated with extreme heat and poor air quality. Based on this literature review, individuals with ischemic heart disease, heart failure, a history of past stroke or myocardial infarction, or a calculated risk score greater than three should take precautions when the HeatRisk reaches Level 1 (Yellow) and/or the AQI is ≥ 50 (Figure 1). Individuals with a calculated risk score of one or two should consider precautions when HeatRisk reaches Level 2 (Orange) and/or AQI is ≥ 100 (Figure 1).