RESUMEN
This study sought to compare the clinical features and outcome of a first acute myocardial infarction [AMI] with onset of symptoms during or within 30 minutes of exercise, at rest and in bed.Information collected using a standard questionnaire was used to relate activity at the onset of symptoms and in-hospital outcome in 500 consecutive patients admitted to our heart center with a first AMI between 2000-2002.Patients with exercise-related onset were more likely to be younger and male. Those with onset in bed were more likely to be older and have a history of stable or unstable angina. By way of comparison between patients whose symptoms began at rest and exercise, those with exercise-related onset had lower in-hospital mortality after adjusting for age and gender [odd's ratio [OR] 0.53, 95% confidence interval [CI] 0.39-0.93 [p= 0.03]]. Compared with patients whose symptoms began at rest, patients with onset in bed had a higher mortality rate [OR 1.42, 95% CI 1.03 - 1.98 [p= 0.028]].The incidence of moderate or severe left ventricular dysfunction was also lower for exercise-related onset [OR 0.79, 95% CI 0.6-1.01 [p=0.32-but not statistically significant]] and higher when onset was in bed [OR 1.5, 95% CI 1.2-1.77 [p= 0.039]].There is an association between activity at onset and outcome of AMI. Differences in pathophysiology or in the population at risk could explain this observation