Prognostic value of low-level exercise testing in patients with myocardial infarction.

The prognostic value of low-level exercise testing (EXT) before hospital discharge was assessed in 111 patients with uncomplicated acute myocardial infarction (AMI). Of 111 patients, 94 were followed for 1 year after AMI to find that 22 carried a poor prognosis: reduction in duration of EXT (6 patients), postinfarction angina (2 patients), congestive heart failure (3 patients), coronary bypass graft surgery (7 patients) and reinfarction (4 patients). The prognosis was poor in 3.7% of 54 patients who tolerated exercise for 721 seconds or longer (4.2 METs) and 50% of 40 patients tolerating it no longer than 720 sec (p less than 0.0001). Of 22 patients who turned out to be carriers of a poor prognosis, 12 (54.5%) had an ST segment change during EXT, but 10 of the 12 patients were asymptomatic. Our results suggest that reduction in duration of exercise and asymptomatic ST segment changes during EXT provide important clues to establishing the short-term prognosis of AMI.