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

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 (PM) as well as fine and coarse PM (PM) 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 PM 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 PM levels. Short-term exposure to increased PM and PM levels at a 1-day lag was associated with elevated risks of ACS (PM: OR = 1.012 per + 10 µg/m, 95% CI 1.003, 1.021; PM: OR = 1.014 per + 10 µg/m, CI 1.002, 1.025) for all patients. Analysis showed that exposure to PM 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/m, CI 1.001, 1.024), but not O group (OR = 1.011 per + 10 µg/m, CI 0.994, 1.029). Additional analysis showed positive associations between exposure to PM and risk of ACS, with 7-days moving average models stratified by blood group revealing that exposures to PM and PM were associated with elevated risk of ACS for patients with group O. Short-term exposures to PM and PM were associated with elevated risk of ACS. Short-term exposure to PM 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.