Prediction of mortality by exercise echocardiography - A strategy for combination with the Duke treadmill score

Background-In studies generally involving short follow-up, exercise echocar diography has been shown to predict composite end points. We sought to stud y the prediction of mortality with this test and to devise a strategy for c ombination with standard exercise testing. Methods and Results-Clinical, exercise testing, and echocardiographic data were collected in 5375 patients (aged 54+/-14 years, 3880 men) undergoing e xercise echocardiography. The Duke treadmill score was derived from the res ults of treadmill exercise testing. Resting left ventricular (LV) function and the presence and severity of ischemia were interpreted by expert observ ers. Follow-up at 10.6 years (mean 5.5+/-1.9 years) was complete in 5211 pa tients (97%). The Duke score classified 59% of patients as low risk, 39% as intermediate risk, and 2% as high risk. Resting LV dysfunction was present in 1445 patients (27%), and the exercise echocardiogram was abnormal in 25 25 patients (47%), Death occurred in 649 patients (12%). Over the first 6 y ears of follow-up, those with normal exercise echocardiograms had a mortali ty of 1% per year. Ischemia was an independent predictor of mortality. In s equential Cox models, the predictive power of clinical data was strengthene d by adding the Duke score, resting LV function, and the results of exercis e echocardiography. Exercise echocardiography was able to substratify patie nts with intermediate-risk Duke scores into groups with a yearly mortality of 2% to 7%. Conclusions-A normal exercise echocardiogram confers a low risk of death, a nd positive results are an independent predictor of death; ischemia is incr emental to other data. This test may be particularly useful in patients wit h intermediate-risk Duke treadmill scores.