Abstract 2929: Diagnostic Accuracy and Prognostic Value of Dobutamine Stress Myocardial Perfusion Echocardiography in the Elderly
Background: Coronary artery disease (CAD) is the leading cause of death in the elderly. Although there is an increasing number of studies showing the value of real-time contrast echocardiography (RTCE) during dobutamine stress echocardiography (DSE) for detecting CAD, no data exist regarding the value of this technique for predicting prognosis in elderly patients.
Objective: To determine the diagnostic accuracy and prognostic value of dobutamine stress RTCE in an elderly patient population (≥70 years old).
Methods: We studied 411 patients ≥70 years old who underwent dobutamine stress RTCE for known or suspected CAD. All patients consented to participate in the Dobutamine Stress Real Time Perfusion Database which records clinical event rates. Myocardial perfusion (MP) and wall motion (WM) analysis with RTCE were performed using low-mechanical index pulse sequence schemes following intravenous injections of commercially available contrast agents. Quantitative coronary angiography (QCA) was performed within one month from the stress test in 60 patients. Significant CAD was defined as ≥50% stenosis in ≥ one coronary artery. Follow-up events were defined as cardiac death and non-fatal myocardial infarction (MI). Logistic regression analysis was performed to identify significant independent predictors of outcome based on underlying clinical diagnoses, medication use, and imaging variables (resting ejection fraction, WM and MP responses during DSE).
Results: Sensitivity of MP imaging for detecting angiographic CAD in the elderly was 98% (CI = 94–100), specificity was 60% (CI = 30–90), and accuracy was 92% (CI = 85–98). During a median follow-up of 21 months (range: 1 day to 66 months) a total of 46 (11.2 %) events occurred (31 cardiac deaths, and 15 non-fatal MI). Although both abnormal WM and MP responses during DSE were significant univariate predictors of outcome,stepwise logistic regression indicated that abnormal MP (Chi Square 22.3; CI 0.024 – 0.215;p < 0.001) was the most significant predictor of outcome when compared to all clinical, medication, and imaging variables.
Conclusion: In elderly patients, MP imaging during DSE accurately detects the presence of CAD, and provides incremental predictive value in determining patient outcome.