PREDICTIVE VALUE OF MAXIMAL OXYGEN CONSUMPTION IN CARDIAC REHABILITATION PATIENTS

Abstract

515 The purpose of the present study was to identify the value of maximal oxygen consumption (VO2max) measured during symptom-limited treadmill testing in cardiac rehabilitation patients for predicting future coronary events. Subjects consisted of 292 consecutive patients (51 women), aged 21-85 years, who were completing Phase II cardiac rehabilitation after an index coronary event. Patients were followed for an average of 3.0±0.8 years after the treadmill test, during which time 14 patients experienced recurrent hard events (myocardial infarction, cardiac death, out-of-hospital cardiac arrest). Adjusting for age and gender, three factors were predictive of a recurrent hard event using the Cox Proportional Hazards regression model: 1) not having coronary bypass surgery during the index hospitalization (risk ratio=5.3; p=.0146); 2) significant psychological distress (risk ratio=4.0; p=.0160); 3) low VO2max (risk ratio=0.85 per ml/kg/min; p=.0146). Treadmill time alone did not achieve statistical significance in the model (p>.35). In addition, low VO2max was characteristic of patients (n=7) who received an interventional procedure within 30 days of the treadmill test and patients (n=10) admitted for congestive heart failure within the follow-up period. These data identify the prognostic significance of VO2max measured by treadmill testing at the conclusion of Phase II cardiac rehabilitation and support its continured assessment.