Does the prognostic value of dobutamine stress echocardiography differ among different age groups?

Abstract

Age is associated with reduced exercise capacity and greater prevalence of coronary artery disease. Whether the prognostic information obtained from dobutamine stress echocardiography (DSE), a stress test commonly used for patients unable to perform an exercise test, provides differential information based on age is not well known. We studied 6,655 consecutive patients referred for DSE. Patients were divided into 3 age groups: (1) <60 years (n = 1,389), (2) 60 to 74 years (n = 2,978), and (3) ≥75 years (n = 2,288). Mean follow-up was 5.5 ± 2.8 years. End points included all-cause mortality and cardiac events, including myocardial infarction and late (>3 months) coronary revascularization. Peak stress wall motion score index was an independent predictor of cardiac events in all age groups (<60 years: hazard ratio [HR] 1.14, P = .02; 60-74 years: HR 1.70, P < .0001; ≥75 years: HR 1.10, P = .006). In patients ≥75 years, peak wall motion score index (HR 1.10, P < .0001) and abnormal left ventricular end-systolic volume response (HR 1.25, P = .03) were independent predictors of death. In patients aged 60 to 74 years, abnormal left ventricular end-systolic volume response (HR 1.43, P = .0003) was independently related to death, whereas in patients <60 years, the echocardiographic data assessed during stress were not a predictor. Dobutamine stress echocardiography provided independent information predictive of cardiac events among all age groups and death in patients ≥60 years. However, among patients <60 years, stress-induced echocardiographic abnormalities were not independently associated with mortality. Comorbidities, which have precluded exercise testing, may be most relevant in predicting mortality in patients <60 years undergoing DSE.