PROGNOSTIC-SIGNIFICANCE OF PEAK EXERCISE CAPACITY IN PATIENTS WITH CORONARY-ARTERY DISEASE

Objectives. The aim of this study was to investigate the prognostic si gnificance of peak oxygen uptake in patients with coronary artery dise ase who had an exercise test that could be sustained to exhaustion wit hout limiting symptoms. Background. Many studies have reported an inve rse association between the level of exercise reached during a stress test and mortality or cardiovascular morbidity. These studies have use d submaximal or symptom-limited exercise testing in patients with a re cent myocardial infarction. Methods. Peak oxygen uptake was measured i n male patients greater than or equal to 4 weeks after myocardial infa rction (312 patients) or coronary artery surgery (215 patients) by use of a graded uninterrupted exercise test performed to exhaustion. Apar t from peak oxygen uptake, several risk factors for cardiovascular dis ease, patient and exercise characteristics and drug treatment were con sidered in the Cox proportional hazards model. Results. During the tot al follow-up period of 3,213 patient-years, 53 patients died. Of these 53 patients, 33 died of cardiovascular causes. All-cause and cardiova scular mortality decreased with increasing peak oxygen uptake, even af ter adjustment for significant covariates. The relative hazard rates o f 0.43 and 0.29 indicate that a hypothetic increase in peak oxygen upt ake by 1 liter/min could be associated with decreases in all-cause and cardiovascular mortality of 57% and 71%, respectively. Conclusions. E xercise capacity is an independent predictor for subsequent all-cause and cardiovascular mortality in patients able to perform an exercise t est until exhaustion.