USEFULNESS OF EXERCISE ECHOCARDIOGRAPHY IN PREDICTING CARDIAC EVENTS IN AN OUTPATIENT POPULATION

The prognostic value of exercise echocardiography in an outpatient pop ulation is not well defined. A total of 1,020 consecutive patients ref erred for exercise echocardiography in an ambulatory care setting were studied by reviewing their medical records and exercise echocardiogra phic data. Of these, 71 (7%) were excluded due to technically inadequa te tests, leaving 949 patients who were included in the analysis. A po sitive exercise echocardiogram (EE) was defined as an appearance of a new wall motion abnormality or worsening of a baseline abnormality. Ca rdiac events, defined as myocardial infarction, coronary angioplasty, coronary bypass surgery, and death, were documented during ct 12-month follow-up period. Cardiac events occurred in 17% of patients (26 of 1 52) with a positive exercise echocardiogram (EE): and in 2.5% (20 of 7 97) with a negative EE (p <0.001). The incidence of myocardial infarct ion (2.6% vs 0.4%, p <0.02), coronary angioplasty (7% vs 1%, p <0.001) , and coronary bypass surgery (9% vs 1%, p <0.001) were higher in pati ents with a positive versus a negative EE. There was 1 death in the po sitive study group and none in the negative group. Significant indepen dent variables (p <0.05) that predicted cardiac events included a posi tive exercise electrocardiogram, history of coronary angioplasty, nons pecific ST-T changes on the baseline electrocardiogram, double product <25,000, men, chest pain on exercise test, and a positive exercise el ectrocardiogram. On a stepwise logistic regression model, exercise ech ocardiography emerged as an independent predictor of future cardiac ev ents in an outpatient population. This predictive value was enhanced i n the presence of a positive exercise electrocardiogram compared with a negative exercise electrocardiogram (24.2% vs 7.9%, p <0.03). Our st udy suggests that exercise echocardiograhy is an independent predictor of future cardiac events in an outpatient population. (C) 1998 by Exc erpta Medica, Inc.