Abstract 13517: Comparison of Sulfur Hexafluoride Microbubble(SonoVue)-Enhanced Myocardial Echocardiography to Single Photon Emission Computerized Tomography at Rest and Vasodilator Stress in the Assessment of Significant Coronary Artery Disease:A Large European Multicentre Study

Abstract

Background: Single centre studies have shown that myocardial perfusion assessed by SonoVue (sulphur hexafluoride microbubbles)-enhanced myocardial contrast echocardiography (MCE) is an alternate technique to single-photon-emission tomography (SPECT) for assessment of coronary artery disease (CAD). Our large multicentre study assessed the diagnostic value of these techniques for CAD detection compared to invasive coronary angiography (CA).

Methods and results: Patients presenting with chest pain at 34 European centers underwent rest/vasodilator stress SonoVue-enhanced MCE, ^99mTc ECG-gated SPECT and CA within a one-month period. MCE was performed in real time and using end-systolic post-flash frames for ≥8 cardiac cycles. SPECT was acquired as standard. Three independent off-site blinded readers for MCE and 3 for SPECT graded myocardial perfusion by segment (17-segment model) based on the difference between corresponding rest and stress results. The results from the 3 readers were collapsed into one diagnosis per patient per technique. Quantitative CA was assessed at a centralized off-site laboratory. Of the 630 patients (males: 73%; mean age: 64 yrs; 75% hypertensive; 71% hyperlipedemic; 27% diabetic, 25% previous AMI, 31% previous PCI) enrolled 516 underwent all three examinations. Of these, 161 (31.2%) had ≥70% stenosis at CA (131: single vessel disease; 30: multi-vessel disease). Significantly higher sensitivity was obtained on MCE vs SPECT (75.2% vs 52.4%; P <0.0001) although specificity was lower (52.4% vs 80.6%; P <0.0001), reflecting the high prevalence of co-existing cardiovascular morbidity. Similar sensitivity/specificity values for MCE and SPECT were obtained in patients with no history of AMI (66%/57.3% and 44.3%/83.2%, respectively). Sensitivity for the detection of single and multi-vessel disease was also higher for MCE (73% and 87%) vs SPECT (43% and 77%).

Conclusions: Sensitivity of MCE was superior to SPECT for detection of CAD. Lower specificity on MCE was likely due to the high prevalence of co-existing cardiovascular morbidity. Lack of radiation exposure, wider availability and superior sensitivity makes MCE a suitable first-line diagnostic procedure compared to SPECT in this patient group.