Air pollution and multimorbidity increase risk of atrial fibrillation risk: Study

A recent study published in the BMJ Heart journal uncovered strong evidence that air pollution and multiple chronic health conditions independently and synergistically elevate the risk of developing atrial fibrillation (AF).

This study tracked a total of 4,80,344 participants over a median follow-up of 12.5 years, documenting 28,977 new cases of AF. Air pollution exposure was estimated at participants’ residential addresses, focusing on key pollutants: PM2.5 (fine particulate matter), PM10 (coarse particulate matter), nitrogen oxides (NOx), and nitrogen dioxide (NO₂).

The study categorized individuals into 3 multimorbidity clusters using latent class analysis based on 35 long-term conditions (LTCs) as Cardiometabolic multimorbidity (e.g., diabetes, hypertension), Mental health multimorbidity (e.g., depression, anxiety) and Non-cardiovascular disease (non-CVD) multimorbidity (e.g., arthritis, asthma).

When compared with individuals without long-term conditions, those with cardiometabolic multimorbidity had an 84% higher risk of AF (Hazard Ratio [HR]: 1.84), while non-CVD multimorbidity carried a 2.13-fold increased risk. The Mental health multimorbidity also showed elevated risks, though slightly less than the other clusters.

Meanwhile, air pollution alone showed alarming associations where each 1 µg/m³ increase in PM2.5 raised AF risk by 37% (HR 1.37) and PM10 was associated with an 18% increased risk (HR 1.18). NOx and NO₂ had more modest but still significant impacts (HRs 1.06 and 1.03, respectively)

The individuals with both high PM2.5 exposure and non-CVD multimorbidity had a 6-fold increased AF risk (HR ~6.0). This combination produced a relative excess risk due to interaction (RERI) of 2.31 which indicates that the joint effect exceeded the sum of individual risks. Also, if PM2.5 levels were reduced to the 10th percentile of the cohort's exposure distribution, up to 52% of AF cases could be prevented in those with cardiometabolic multimorbidity, and 26%–49% in other multimorbidity clusters.

These findings highlight the importance of environmental health policy and targeted clinical monitoring for individuals with multiple chronic illnesses. The research suggests that air quality improvement could drastically reduce AF incidence, particularly among the most vulnerable. Reinforcing the urgent need for integrated public health strategies could help manage both environmental and clinical risk factors.

Source:

Zhang, J., Chen, G., Wei, S., Li, W., Lip, G. Y. H., & Lin, H. (2025). Impact of air pollution and multimorbidity on the risk of incident atrial fibrillation. Heart (British Cardiac Society). https://doi.org/10.1136/heartjnl-2024-325451