Association Between Meteorological Conditions and Acute Myocardial Infarction (AMI) Incidence: A Seasonal Analysis Using the Oita AMI Registry

Background Weather is recognized as an environmental risk factor for acute myocardial infarction (AMI). This study explores the meteorological factors linked to a higher incidence of AMI. Methods and results The study involved 403 patients from the Oita AMI Registry who were admitted to 20 medical facilities with an AMI diagnosis between April 2012 and September 2013. We defined "frequent onset days" (F-days) as days when three or more patients were admitted for AMI, in contrast to "non-frequent onset days" (non-F-days), which were days with fewer than three admissions. This period was categorized into four seasons: spring, summer, autumn, and winter. The meteorological data used in this study came from the Japan Meteorological Agency. During autumn, F-days were associated with a significantly older patient population (77.4 ± 11.7 years vs. 68.3 ± 13.8 years, p = 0.02) and a higher population of female patients (57.1% vs. 17.4%, p = 0.003) compared to non-F-days. Additionally, the body mass index was significantly lower on F-days compared to non-F days (21.5 ± 3.5 kg/m² vs. 23.6 ± 3.2 kg/m², p = 0.03). In summer, the average atmospheric pressure was significantly higher on F-days than on non-F-days for day-1 (1009.8 ± 2.8 hPa vs. 1007.1 ± 3.7 hPa, p = 0.03) and day-2 (1010.1 ± 2.7 hPa, compared to 1007.2 ± 3.7 hPa, p = 0.02). In autumn, among the variables that showed significant differences, only female patients remained independently associated with the risk of F-days in the multivariate analysis (p = 0.007). Conclusions Our research indicated that elevated atmospheric pressure during summer was associated with a higher occurrence of AMI on days with frequent onset of cardiac events. In autumn, women were independently associated with a higher occurrence of AMI on such days.