Abstract 16194: Ischemia on Dobutamine Stress Echocardiography predicts Major Cardiac Events in Patients with Previous Coronary Artery Bypass Graft Surgery
Previous studies have evaluated the prognostic value of dobutamine stress echocardiography (DSE) in several groups of patients. Although its accuracy for ischemia detection in patients after CABG has been demonstrated, few data exist about the utility of DSE for risk stratification in this setting. We assessed the hypothesis that, in patients with previous CABG, ischemia on DSE is an independent predictor of major cardiac events (nonfatal infarction or cardiac death).
Methods: Patients with coronary artery disease and previous CABG who underwent DSE were identified from our database. Those with non conclusive DSE (8), severe aortic disease (1), or unwilling to participate (5) were excluded. We finally studied 136 patients (86,8% men, mean age 62±8 years). Cox proportional hazards regression model was used to identify predictors of major cardiac events. Follow-up was censored at the time of any revascularization procedure or death from non-cardiac causes.
Results: DSE detected ischemia in 67 patients (49,3%). 34 major cardiac events (20 deaths, 14 myocardial infarctions) were registered during a median follow-up of 7.2 years (IQR 5.2 to 9.2). Survival free of major cardiac events was significantly lower in patients with a positive DSE (Log Rank test: p = 0.001). Five-year event-free survival rate was 98% (95% CI 96% to 100%) for patients without ischemia on DSE and 77% (95% CI 67% to 87%) for those with dobutamine-induced ischemia. In multivariate analysis, ischemia during DSE was the strongest independent predictor of major cardiac events (HR 3.22, 95%CI 1.46 to 7.13). Other independent predictors were female gender, time elapsed from CABG to DSE and peak rate-pressure product. The addition of stress echocardiographic variables to clinical and resting echocardiographic data provided incremental information in predicting major cardiac events (chi-square 22.48 to chi-square 34.96, p = 0.002).
Conclusions: In patients with previous CABG, DSE provided prognostic information incremental to clinical and resting echocardiographic parameters. Stress-induced ischemia was an independent predictor of major cardiac events and identified a higher risk group of patients. DSE is useful in the prognostic assessment of patients with previous CABG.
- © 2010 by American Heart Association, Inc.