Extreme Ambient Air Pressure and Its Drop Between Neighboring Days Are Associated With an Increased Risk of Acute Myocardial Infarction Onset: A Case‐Crossover Study

Background The association between air pressure and acute myocardial infarction (AMI) has not been assessed at individual level, and the effect of air pressure change between neighboring days (APCN) on AMI onset is unknown. This study aimed to examine the associations of daily air pressure and APCN with the onset of AMI. Methods A time‐stratified case‐crossover study was conducted using data from 473 599 patients with AMI recorded in the Beijing Cardiovascular Disease Surveillance System between 2007 and 2021. The associations between daily air pressure and APCN with AMI onset were assessed using conditional logistic regression and distributed lag‐nonlinear models. Results Both low and high air pressure were significantly associated with an increased risk of AMI, with odds ratios (ORs) of 1.06 (95% CI, 1.01–1.12) and 1.16 (95% CI, 1.11–1.20), respectively. Patients with comorbidities of heart failure and hypertension exhibited increased vulnerability to extremely high air pressure. Moreover, the effects of both extremely low and high air pressure were amplified on days with higher levels of particulate matter <2.5 μm in aerodynamic diameter and temperature. A negative APCN was associated with an elevated risk of AMI, with an OR of 1.19 (95% CI, 1.12–1.25) for an extremely negative APCN (−9.74 hPa) compared with no change in air pressure. Negative APCN risk was notably higher in older adults, women, and individuals with hypertension or diabetes. Conclusions Extreme air pressure and its acute drop between neighboring days are associated with increased AMI onset risk, highlighting the need for enhanced attention in predicting or preventing environment‐attributed cardiovascular risk.