# Associations of air pollution with acute coronary syndromes based on A/B/AB versus O blood types: case-crossover study

## TL;DR

Short-term exposure to air pollution increases the risk of heart attacks, with effects varying based on blood type.

## Contribution

This study reveals blood type-specific differences in the acute effects of air pollution on heart attacks.

## Key findings

- PM2.5 and PM10 exposure at 1-day lag increased ACS risk for all patients.
- PM2.5 risk was higher for A/B/AB blood types at 1-day lag, but not for O blood type.
- O blood type showed increased risk for PM2.5 and PM10 after a 7-day exposure period.

## Abstract

Short-term exposure to air pollutants may contribute to an increased risk of acute coronary syndrome (ACS). This study assessed the role of short-term exposure to fine particulate matter (PM2.5) as well as fine and coarse PM (PM10) air pollution in ACS events and the effect of blood groups on this phenomenon. A retrospectively collected database of 9026 patients was evaluated. The study design was a case-crossover using a conditional logistic regression model. The main analysis focused on PM2.5 levels with a 1 day lag until the ACS event, using threshold-modelled predictor for all patients. Secondary analyses utilized separate threshold-modelled predictors for 2–7-days moving averages and for patients from specific ABO blood groups. Additional analysis was performed with the non-threshold models and for PM10 levels. Short-term exposure to increased PM2.5 and PM10 levels at a 1-day lag was associated with elevated risks of ACS (PM2.5: OR = 1.012 per + 10 µg/m3, 95% CI 1.003, 1.021; PM10: OR = 1.014 per + 10 µg/m3, CI 1.002, 1.025) for all patients. Analysis showed that exposure to PM2.5 was associated with increased risk of ACS at a 1-day lag for the A, B or AB group (OR = 1.012 per + 10 µg/m3, CI 1.001, 1.024), but not O group (OR = 1.011 per + 10 µg/m3, CI 0.994, 1.029). Additional analysis showed positive associations between exposure to PM10 and risk of ACS, with 7-days moving average models stratified by blood group revealing that exposures to PM2.5 and PM10 were associated with elevated risk of ACS for patients with group O. Short-term exposures to PM2.5 and PM10 were associated with elevated risk of ACS. Short-term exposure to PM2.5 was positively associated with the risk of ACS for patients with A, B, or AB blood groups for a 1-day lag, while risk in O group was delayed to 7 days.