Direct current cardioversion and the impact of short-term exposure to air pollution: a report from the nationwide EP-PARTICLES study

Abstract Background Air pollution and atrial fibrillation (AF) represent significant public health challenges, impacting global health considerably. Numerous studies have focused on areas with high or very high air pollution concentrations, our study examines a unique area in Poland characterized by low to moderate air pollution levels. Our research also addresses a commonly overlooked in research type of pollution - Polish smog. Due to its composition rich in particulate matter and the conditions in which it is formed - is characterized by extremely adverse health effects. Aim To explore the correlation between short-term air pollution exposure and the incidence of acute direct current cardioversion (DCC) for AF treatment. Methods The study area encompassed three voivodeships from Eastern Poland at the NUTS-2 level, with a population of 5,429,378 individuals. Data on hospitalizations from 2011 to 2020 were obtained from the National Health Fund. We combined air pollution and weather condition data from both ground monitoring stations and satellite observations. Emergency visits for AF and DCC were identified using ICD-9 and ICD-10 codes. For a national perspective, we applied meta-analytical strategies to the municipality-specific outcomes. The results are presented as percentage increases in admissions (% IR) with 95% confidence intervals (95%CI). Results Over the decade, 190,454 hospitalizations for AF were reported with a standardized hospitalization rate (SHR) of 358 per 100,000/year (SD=113) and 30,291 DCC admissions (SHR=56.9 [SD]=26). The mean age for AF vs. DCC cohort was 69.6 (SD=11.2) vs. 68.7 (SD=10.4) years, with females representing 56.1% (N=106,822) of AF cases vs. 46.1% (N=13,953) of DCC admissions (P<0.001). Each 10 µg/m3 increase in PM2.5, PM10, and NO2 concentration on the exposure day led to 1.6% (1.1%–2.1%), 1% (0.8%–1.6%), and 1.8% (1.1%–2.6%) increases in acute AF admissions, respectively, with effects lasting up to 6 days. Women and older individuals were more vulnerable to AF episodes induced by air pollution (P<0.001). A 10 µg/m3 increase in PM2.5 on the day of admission increased DCC admissions by 1.5% (0.1%–2.9%, P=0.04), with effects persisting for up to 3 days. The impact of PM10 was time-delayed: 1.3% (0.2%–2.4%, P=0.02) for LAG1 (i.e. one day after exposure), and 1.1% (0.1%–2.2%, P=0.4) for LAG2. No significant effects of gaseous pollutants on DCC (SO2, NO2, and BaP) were observed, nor any differences in the effects by age or sex. Exposure-response functions show steeper slopes of the PM2.5 associations in the lower ranges of exposures, far below air quality norms set by the World Health Organization. Conclusions Air pollution acts as a triggering factor for acute AF hospitalizations and DCC. The differential impact of air pollution on AF events between groups highlights that women and older individuals are particularly vulnerable. Air pollution exposure should be considered into AF management and prevention strategies.Pooled exposure–response function: % inc