Establishing an Air Health Index for Predicting the Risk of Acute Myocardial Infarction Onset Associated with Air Pollution and Ambient Temperature

Air pollutants and ambient temperature are important cardiovascular disease determinants, and communicating their overall risk is important for cardiovascular patient management. We developed a composite Air Health Index (AHI) by linking high-resolution exposure data with 1,207,625 acute myocardial infarction (AMI) cases across 325 Chinese cities. The AHI for AMI aggregates excess morbidity risks from fine particulate matter, nitrogen dioxide, ozone, and ambient temperature into a normalized scale (0–10+). Compared with existing metrics, the AHI for AMI showed better predictive performance for AMI onset than the Air Quality Index (AQI) and Air Quality Health Index (AQHI). Each interquartile range increase in the AHI for AMI was associated with a 5.97% (95% confidence interval [CI]: 5.32%–6.63%) increase in AMI incidence, surpassing the AQHI (3.33%, 95% CI: 2.93%–3.72%) and AQI (2.04%, 95% CI: 1.73%–2.35%). The AHI for AMI showed a nearly linear exposure–response relationship with no evident threshold and accounted for 8,534 per 100,000 AMI cases nationally. These associations were consistently validated in an independent external data set, supporting the robustness and generalizability of the index. In conclusion, the AHI for AMI provides an integrative and practical framework for assessing environmental health risks, offering actionable guidance for cardiovascular patient management.