Early exercise tests after uncomplicated acute myocardial infarction before early discharge from hospital

As part of an early mobilization and early discharge scheme, 76 consecutive low-risk patients were selected from a population of 298 acute myocardial infarction (AMI) patients, to undergo an exercise test. The test was done on the 7th day after an AMI. The patients were 57 men and 19 women of mean age 57 and 68 years, respectively. Twelve patients were unable to complete the test, but no serious complications were observed. Average heart rate during the highest exercise load (50 W) was 106 beats/min. The following risk indices (RI) were considered abnormal and were looked for during or after exercise: 1) heart rate greater than 125 (n = 12), 2) major ventricular arrhythmias (n = 3), 3) angina pectoris (n = 9), 4) ST deviation of more than 1 mm (n = 11). Two RIs were found in 9 patients during the exercise test which led to prolonged hospitalization. One RI was found in 26 patients (34%). Eighty-eight per cent (n = 36) of the patients with normal exercise test had an uneventful recovery during the six-month observation period, in contrast to 35% (n = 9) of patients with heart rate greater than 125 recovered normally, a significantly lower number (p less than 0.05) than among patients with a normal exercise test. Reinfarction occurred in one patient with normal exercise test and in six (23%) of those with one RI (p less than 0.01) and two of those with two RIs (N.S.). We conclude that a submaximal bicycle exercise test seven days after an AMI is a safe and useful selection instrument for early discharge from hospital as well as a useful predicting instrument of future complications.