Impact of atmospheric variables on incidence of acute coronary syndrome amongst Gujarati Asian Indians – IOAPIC study

OBJECTIVES: The study evaluated the effects of climatic conditions and its variables on incidence of ACS in Gujarati Asian Indians. METHODS: In this multicentric, retrospective, observational case control study of a total of 3256 patients, the Electronic Medical Records (EMS) of all 740 patients who were hospitalised for ACS at the 2 tertiary care centres of Ahmedabad over 3 years between January 2017 to December 2019 were compared with demographically matched 2516 non- ACS, CAD controls were compared for the impact of climatic parameters viz. temperature, barometric pressure, humidity as reported by monthly averages by the state meteorological department for monthly incidence of ACS. RESULTS: The highest number of ACS cases were observed during the month of September (N = 127; 27%) followed by August (N = 123; 26%). Higher humidity and decreasing atmospheric pressure were associated with highest occurrence of ACS in the state of Gujarat. ST elevation Myocardial Infarction (STEMI) was the most common type of ACS (N = 598; 80.8%). In ACS, the Coefficient of correlation for humidity was 0.712 (P = 0.009), while that for temperature was 0.506 (P = 0.093). Effect of atmospheric pressure was found to be significant with a negative Coefficient of correlation of −0.571 (P = 0.052). However amongst the controls, the coefficient of correlation for humidity was 0.062 (P = 0.722) and atmospheric pressure Correlation coefficient was 0.107 (P = 0.539) non-significant. CONCLUSIONS: The higher humidity/temperature and lower atmospheric pressure had a positive correlation with the incidence of ACS with highest incidence noted in August and September in the state of Gujarat.