Prediction of mortality using dobutamine echocardiography

OBJECTIVES We sought to find out whether dobutamine echocardiography (DbE) could provide independent prediction of total and cardiac mortality, increm ental to clinical and angiographic variables. BACKGROUND Existing outcome studies with DbE have examined composite end po ints, rather than death, over a relatively short follow-up. METHODS Clinical and stress data were collected in 3,156 patients (age 63 /- 12 years, 1,801 men) undergoing DbE. Significant stenoses (>50% diameter ) were identified in 70% of 1,073 patients undergoing coronary angiography. Total and cardiac mortality were identified over nine years of follow-up ( mean 3.8 +/- 1.9). Cox models were used to analyze the effect of ischemia a nd other variables, independent of other determinants of mortality. RESULTS The dobutamine echocardiogram was abnormal in 1,575 patients (50%). Death occurred in 716 patients (23%), 259 of whom (8%) were thought to hav e died from cardiac causes. Patients with normal DbE had a total mortality of 8% per year and a cardiac mortality of 1% per year over the first four y ears of follow-up. Ischemia and the extent of abnormal wall motion were ind ependent predictors of cardiac death, together with age and heart failure. In sequential Cox models, the predictive power of clinical data alone (mode l chi-square 115) was strengthened by adding the resting left ventricular f unction (model chi-square 138) and the results of DbE (model chi-square 181 ). In the subgroup undergoing coronary angiography, the power of the model was increased to a minor degree by the addition of coronary anatomy data. CONCLUSIONS Dobutamine echocardiography is an independent predictor of deat h, incremental to other data. While a normal dobutamine echocardiogram pred icts low risk of cardiac death ton the order of 1% per year), this risk inc reases with the extent of abnormal wall motion at rest and stress, (J Am Co il Cardiol 2001;37:754-60) (C) 2001 by the American College of Cardiology.