(SLB-047) Increased Risk of Hospitalization in Patients with Atrial Fibrillation Exposed to High Particulate Matter

Background: Air pollution, especially exposure to high particulate matter (PM2.5) and extreme weather events, has been a growing public health concern for patients with cardiovascular diseases (CVD) due to their heightened vulnerability.

Objectives: This study aimed to examine the risk of hospitalizations and emergency room (ER) visits associated with short-term exposures to PM2.5 and extreme heat in patients with established atrial fibrillation (AF).
Methods

Methods: Using 2021 Medicare data, we identified patients with established AF before January 1, 2021, residing in western U.S. states, including Arizona, California, Colorado, Idaho, Montana, New Mexico, Nevada, Oregon, Utah, Washington, and Wyoming. Outcomes included hospitalizations or ER visits for any CVD and AF-related diagnoses. Case days were defined as the date of a CVD event, with control days matched by day of the week within the same month. Conditional logistic regression was applied to estimate the odds ratios for CVD outcomes associated with exposure to extreme heat (daily temperature > 85th of decadal average) and high PM2.5 (>9 µg/m³).

Results: The final cohort included 26,158 patients (mean age 79  9.0 years) with established AF. Exposing to high levels of PM2.5 were associated with 10% [95% confidence interval (CI) 1%-20%] increased odds of hospitalizations for CVD. Specifically, high PM2.5 was associated with a 24% (95%CI 3%-48%) increased odds of hospitalization and a 34% (95%CI 6%-70%) higher odds of ER visits for all AF-related diagnoses. No significant associations were observed between extreme heat and CVD outcomes.

Conclusions: High levels of PM2.5 significantly increased the risk of hospitalizations and ER visits for CVD, particularly AF-related events, in patients with established AF. This elevated risk may be attributed to increased oxidative stress and pulmonary arterial pressures induced by PM2.5 exposure. These findings highlighted the importance of improving air quality to mitigate cardiovascular risks in the vulnerable population.