RESUMO
AIM: To identify the meteorological factors or their combinations, which are most significant for the development of acute coronary syndrome (ACS) in different seasons. SUBJECTS AND METHODS: A Statistica package was used to make an exploration analysis of the data of the A.S. Puchkov Central Emergency Medical Care Station on 63,412 admissions of patients diagnosed with acute myocardial infarction (AMI) to Moscow hospitals in 2009-2012 and those of the Hydrometeorology Center of Russia on weather conditions in the period under study. RESULTS: Among the 63,412 patients, there were more men than women (p < 0.000005). Two long frost periods and three long abnormal heat periods were recorded in 2009-2012. In summer, the number of patients with a prehospital diagnosis of AMI was an average 19-22% less than in the other seasons. There was no peak in the number of hospitalizations during the abnormally hot summer of 2010. Air temperature proved to be a factor that was most strongly associated with the trend in AMI hospitalizations in men (MS = 1011.52, MSor = 27.27; p < 0.00005) and women (MS = 895.36, MSor = 25.37; p < 0.00005). The number of hospitalizations was negatively associated with daily average temperature in its positive range. In summer, the interdaily temperature difference turned out to be statistically significant; the highest number of hospitalizations was noted when it grew 6 °C colder. On days off, the number of admitted patients was 25% less than that on weekdays. CONCLUSION: The trend in hospitalizations for a referral diagnosis of AMI has a significant seasonal component. Their number was minimal in summer, including in the abnormally hot summer of 2010. Air temperature is the most important factor. Positive temperature was found to be strongly negatively correlated with diagnosed AMI hospitalizations.