Stress echocardiography for the risk stratification of patients following coronary bypass surgery

ObjectivesThe aim of the study was to assess the prognostic value of stress echocardiography after surgical revascularization.MethodsWe evaluated 500 (100 women) patients who had undergone exercise or pharmacological SE after a median of 69 months after coronary artery by-pass grafting (CABG). Of these, 351 (70%) complained of symptoms suggestive of ischemic origin while 149 (30%) were tested for asymptomatic progression of the disease.ResultsSE was positive for ischemia in 196 (39%) patients. During a median follow-up of 25 months, 61 patients died, 33 had a nonfatal myocardial infarction, and 112 underwent late (> 3 months) revascularization. Multivariable Cox' regression analysis indicated age (HR = 1.04; 95% CI 1.01–1.06; p < 0.003), and peak WMSI (HR = 3.07; 95% CI 1.96–4.81; p = 0.0001) as independent predictors of hard (total mortality and myocardial infarction) events. SE information provided a significant improvement in predictive power of the statistical model (chi-square increase 34%, p < 0.0001 for hard and 91%, p < 0.0001 for major events, respectively). Survival analysis showed ischemia at SE to be associated with significantly higher hard and major event rate in both symptomatic and asymptomatic patients.DiscussionSE represents an effective tool for the risk stratification of patients with previous CABG independently of the presence of symptoms suggestive of ischemic origin.