Air pollution, cardiac arrhythmias, and sudden cardiac death across short-term and long-term exposure models: A systematic review and meta-analysis

BACKGROUND Ambient air pollution is an established cardiovascular risk factor, but its relation to arrhythmia-related outcomes has been synthesised less comprehensively than other cardiovascular endpoints. OBJECTIVE We conducted a systematic review and meta-analysis of studies examining ambient air pollution and arrhythmia-related outcomes. METHODS Primary meta-analyses were restricted to short-term particulate matter associations standardised to 10 μg/m3. Secondary analyses examined broader short-term models on the original study scale, long-term models were analysed separately, and an exploratory global multilevel model was used to account for multiple effect estimates within studies. RESULTS Thirty-two studies represented over 34 million participants or analysed cases across designs. In the primary analyses, short-term PM2.5 exposure standardised to 10 μg/m3 was associated with atrial fibrillation (4 studies; pooled relative risk [RR] 1.045, 95% CI 1.025-1.066; I2=0.66%) and with sudden cardiac arrest or sudden cardiac death (7 studies; RR 1.052, 1.031-1.075; I2=49.0%). Short-term PM10 exposure standardised to 10 μg/m3 was associated with sudden cardiac arrest or sudden cardiac death (3 studies; RR 1.024, 1.012-1.036; I2=0%). Expanded short-term analyses yielded similar pooled estimatesLong-term PM2.5-AF estimates were highly heterogeneous (pooled ratio 1.077, 95% CI 1.002-1.158; I2=99.9%), limiting interpretation. Additional sensitivity models yielded directionally consistent estimates. CONCLUSIONS Short-term exposure to particulate air pollution was associated with risks of atrial fibrillation and sudden cardiac arrest/sudden cardiac death. Given the observational evidence base, findings should be interpreted cautiously and viewed as consistent with, rather than definitive evidence of, an association between particulate exposure and arrhythmia-related events.