AIMS: Acute myocardial infarction (AMI) can be precipitated or triggered by discrete transient exposures including physical exertion. We evaluated whether the risk of having an AMI triggered by physical exertion exhibits an exposure-response relationship, and whether it varies by ambient temperature or by taking place indoors or outdoors. METHODS AND RESULTS: We conducted a case-crossover study within the Myocardial Infarction Registry in Augsburg, Germany in 1999-2003. One thousand three hundred and one patients reported levels of activity and time spent outdoors on the day of AMI and three preceding days in an interview. The case-crossover analyses showed an association of physical exertion with AMI symptom onset within 2 h, which was strong for strenuous exertion (METs >or= 6) [relative risk (RR) 5.7, 95% confidence interval (CI) 3.6-9.0), and still significant for moderate exertion (METs = 5) (RR 1.6, 95% CI 1.2-2.1) compared to very light or no exertion. Strenuous exertion outside was associated with a four-fold larger RR of AMI symptom onset than exertion performed indoors, which was not explained by temperature. CONCLUSION: This study confirms previous results and shows a graded exposure-response relationship between physical exertion intensity and triggering of AMI onset. These findings may have implications for behavioural guidance of people at risk of AMI.
AIMS: Acute myocardial infarction (AMI) can be precipitated or triggered by discrete transient exposures including physical exertion. We evaluated whether the risk of having an AMI triggered by physical exertion exhibits an exposure-response relationship, and whether it varies by ambient temperature or by taking place indoors or outdoors. METHODS AND RESULTS: We conducted a case-crossover study within the Myocardial Infarction Registry in Augsburg, Germany in 1999-2003. One thousand three hundred and one patients reported levels of activity and time spent outdoors on the day of AMI and three preceding days in an interview. The case-crossover analyses showed an association of physical exertion with AMI symptom onset within 2 h, which was strong for strenuous exertion (METs >or= 6) [relative risk (RR) 5.7, 95% confidence interval (CI) 3.6-9.0), and still significant for moderate exertion (METs = 5) (RR 1.6, 95% CI 1.2-2.1) compared to very light or no exertion. Strenuous exertion outside was associated with a four-fold larger RR of AMI symptom onset than exertion performed indoors, which was not explained by temperature. CONCLUSION: This study confirms previous results and shows a graded exposure-response relationship between physical exertion intensity and triggering of AMI onset. These findings may have implications for behavioural guidance of people at risk of AMI.
Authors: Robert B Nichols; William F McIntyre; Salina Chan; David Scogstad-Stubbs; Wilma M Hopman; Adrian Baranchuk Journal: Clin Res Cardiol Date: 2011-09-09 Impact factor: 5.460
Authors: Harpreet S Chahal; Elizabeth Mostofsky; Murray A Mittleman; Neville Suskin; Mark Speechley; Allan C Skanes; Peter Leong-Sit; Jaimie Manlucu; Raymond Yee; George J Klein; Lorne J Gula Journal: Can J Cardiol Date: 2015-12-28 Impact factor: 5.223
Authors: Elizabeth Mostofsky; Eva Laier; Emily B Levitan; Wayne D Rosamond; Gottfried Schlaug; Murray A Mittleman Journal: Am J Epidemiol Date: 2010-12-15 Impact factor: 4.897