Abstract 4706: Perfusion Stress Echocardiography with Perflubutane Polymer Microspheres Provides Incremental Predictive Value for Coronary Artery Disease Over Clinical Risk Factors
Introduction RAMP (Realtime Assessment of Myocardial Perfusion Imaging) 1 and 2 showed that coronary artery disease (CAD) diagnosis with perfusion stress echocardiography (PSE) and perflubutane polymer microspheres in chest pain patients is as accurate as SPECT perfusion imaging.
Hypothesis PSE provides incremental predictive value over clinical risk factors and ECG for CAD presence.
Methods RAMP analysis population (n=488; mean age 62 years) included chest pain patients who underwent PSE (real-time and triggered) and gated 99mTc SPECT at rest and with dipyridamole stress and had known CAD status by angiography (≥70% stenosis). Severe CAD was defined as >40% left ventricular mass at risk of infarction (jeopardy score). Independent blinded readers (6 PSE, 4 SPECT) interpreted images for the presence of defects (wall motion and/or perfusion). Majority PSE and SPECT assessment was evaluated for CAD association using logistic regression. Covariates included resting ECG and risk factors: age, gender, smoking, diabetes, hypertension, and angina type (typical or unstable).
Results Three hundred (61%) patients had CAD. In multivariate analyses adjusted for known clinical risk factors and ECG, positive PSE and SPECT were significant predictors of CAD (odds ratio (95% CI)=5.7 (3.7–8.7) and 3.6 (2.4–5.4)), respectively. PSE and SPECT added incremental value for prediction of CAD in multivariate models already including clinical factors and ECG (Table 1⇓). Among patients with severe CAD (n=80), clinical factors and ECG predicted only 68% CAD prevalence compared to 83% and 79% predicted by clinical factors, ECG and either positive PSE or SPECT, respectively (p<0.001).
Conclusion PSE with perflubutane polymer microspheres significantly increases the probability of correct CAD diagnosis in stable chest pain patients beyond the probability established by risk factors, symptoms and ECG. Table 1⇓: Incremental Predictive Value of ECG, PSE and SPECT over Clinical Factors