Is vigorous physical activity contraindicated in subjects with coronary heart disease? Evidence from the Caerphilly...

A large study of British civil servants reported that, in men with electrocardiogram ischaemia but no symptoms, vigorous habitual leisure activity might be associated with increased subsequent risk of myocardial infarction (MI). We examine this for MI and stroke in a general population of British men.

Between 1984 and 1988, 2398 middle-aged men were recruited into the cohort in Caerphilly, South Wales, UK. Physical activities during leisure and at work were assessed by validated questionnaires. Follow-up was for 12 years, and both fatal and non-fatal cardiovascular events (MI, stroke or MI, and stroke) were recorded. After adjustment for age and other confounders, men in the highest third of vigorous physical activity experienced decreased risk of MI, relative to men in the lowest third; hazard ratios (HR) (95% CI) were 0.71 (0.50, 1.03), 0.42 (0.19, 0.92), and 0.60 (0.38, 0.94) in men with symptomatic, asymptomatic coronary heart disease (CHD), and no evidence of CHD at baseline, respectively. HRs for stroke were non-significantly raised for subjects with asymptomatic CHD (1.36 (0.47, 3.91).

Habitual vigorous activity was not associated with increased risk of subsequent MI in subjects with established CHD, but additional data for stroke would be useful.