Association of Air Pollution with Ventricular Arrhythmias and Physical Activity: A Natural Experiment from US Wildfires.

Abstract

Background: The association between particulate matter (PM) air pollution and ventricular arrhythmias is not well established. In patients with cardiac implantable electronic devices (CIED), publicly available day-level air pollution data provide a unique opportunity to study acute and subacute effects of particulate matter pollution.

Objective: To evaluate the association of air pollution with ventricular arrhythmias, physical activity, and CIED markers of heart failure.

Methods: We performed a retrospective cohort study using the CERTITUDE database of CIED patients. The primary predictors were Air Quality Index (AQI), PM<10μm in diameter (PM₁₀), and PM<2.5μm in diameter (PM_2.5). We cross-linked day-level air pollutant levels to patient zip codes. We determined the association of air pollution to CIED parameters using (1) a case-crossover analysis using a conditional logistic regression and (2) a time-varying exposure analysis using an Andersen-Gill model.

Results: The study cohort included 28349 patients (32% female, age 72.8±11.9), of whom 17448 (61.6%) had pacemakers and 9079 (32%) had defibrillators. AQI and PM_2.5 were associated with significant changes in physical activity, heart rate, and thoracic impedance. When limiting to the 8687 patients living in Western US Fire States (AZ/CA/CO/NM/NV/OR/UT/WA), there was a strong association between PM_2.5 and PVC burden, with an odds ratio of 7.72 (95% confidence interval: 7.48-7.96; p<0.0001) for PM_2.5≥13.7. Multiple sensitivity analyses demonstrated the stability of our findings.

Conclusion: In a large cohort of CIED patients, AQI and PM_2.5 had significant associations with PVC burden, physical activity and heart rate. These data also demonstrate the feasibility of linking environmental data with patient sensor data to evaluate exposure-outcome relationships.