CLimate Impacts on Myocardial infarction deaths in the Athens TErritory: the CLIMATE study

Objective: To evaluate the impact of meteorological variables on daily and monthly deaths caused by acute myocardial infarction (AMI). Methods: All death certificate data from the Athens territory were analysed for AMI deaths in 2001. Daily atmospheric temperature, pressure and relative humidity data were obtained from the National Meteorological Society for Athens for the same year. Results: The total annual number of deaths caused by AMI was 3126 (1953 men) from a population of 2664 776 (0.117%). Seasonal variation in deaths was significant, with the average daily AMI deaths in winter being 31.8% higher than in summer (9.89 v 7.35, p < 0.001). Monthly variation was more pronounced for older people ( mean daily AMI deaths of people older than 70 years was 3.53 in June and 7.03 in December; p < 0.001) and of only marginal significance for younger people. The best predictor of daily AMI deaths was the average temperature of the previous seven days; the relation between daily AMI deaths and seven-day average temperature (R-2 = 0.109, p < 0.001) was U-shaped. Considering monthly AMI death rates, only mean monthly humidity was independently associated with total deaths from AMI (R-2 = 0.541, p = 0.004). Conclusion: Ambient temperature is an important predictor of AMI mortality even in the mild climate of a Mediterranean city like Athens, its effects being predominantly evident in the elderly. Mean monthly humidity is another meteorological factor that appears to affect monthly numbers of AMI deaths. These findings may be useful for healthcare and civil protection planning.