Seasonal variation of acute myocardial infarction deaths in Chile

Background: Hospitalization and deaths due to cardiovascular diseases (CVD), have a peak in frequency during winter. Aim: To assess the existence of seasonal variation in deaths due to acute myocardial infarction (AMI) in Chile. Material and Methods: Analysis of death report databases available at the website of the Chilean Ministry of Health. The seasonality of deaths due to AMI (codes ICD-10 I21, I22, I23) occuring in Chile between 2001-2016 were analyzed using a geometric model assuming a sinusoidal cyclic pattern. Results: During the period 2001-2016, a total of 94,788 deaths due to AMI were registered, corresponding to 93,349 corrected deaths. Of the latter, 29.2% occurred in winter, 24.9% in spring, 24.0% in autumn and 21.8% in summer. The geometric model showed a marked sinusoidal pattern for the aggregated data. The peak-to-low ratio of deaths was 1.41 (95% CI 1.38-1.44). The peak of deaths occurred during July in 14 out of 16 years analyzed. Conclusions: In Chile, deaths due to AMI have a marked seasonal pattern, characterized by a higher number of deaths in winter and a lower number in summer.