Abstract 4707: Non-invasive assessment of Coronary Artery Disease: a comparison of Cardiovascular Magnetic Resonance Perfusion Imaging at 3 Tesla with Contrast Echocardiography
Cardiovascular magnetic resonance (CMR) is now well established in the assessment of coronary artery disease (CAD), with 3 Tesla (T) being the preferred field strength. The advent of second-generation contrast agents now enables a multiparametric assessment of ischemia with echocardiography, involving simultaneous perfusion and wall motion analysis. We sought to compare two optimized diagnostic strategies in patients with suspected CAD:
combined perfusion and infarct imaging by 3T CMR and
combined perfusion and wall motion analysis by adenosine-stress contrast echocardiography (CE).
Subjects scheduled for elective diagnostic angiography for investigation of chest pain were studied before angiography, with CE and CMR, at stress (140mcg/kg/min IV adenosine) and at rest. For CMR, first-pass perfusion and delayed enhancement images were obtained in the short-axis plane following IV Gadolinium-DTPA bolus injections. For CE, 2-,3- and 4-chamber long-axis images were acquired during IV sulfur hexafluoride infusion. CMR and CE images were interpreted visually by two observers blinded to clinical and angiographic data. For CMR, the diagnosis of CAD was determined by the presence of reversible perfusion defects or delayed enhancement, and for CE, by reversible perfusion or wall motion abnormalities. Quantitative coronary angiography served as the reference standard: CAD was defined as the presence of ≥1 stenosis of ≥50% reference diameter in vessels with diameter ≥2mm. Sixty-two subjects completed the study. The prevalence of CAD was 66%. Compared to CMR, CE provided comparable diagnostic accuracy (89% vs. 87%), sensitivity (88% vs. 90%) and specificity (90% vs. 81%) for detection of significant CAD. There was no significant difference in the identification of single-vessel disease (area under ROC curve 0.77±0.07 for CMR vs. 0.70±0.07 for CE, p=0.43), multi-vessel disease (area under ROC curve 0.83±0.06 vs. 0.75±0.07, p=0.37) or the overall detection of CAD (area under ROC curve 0.86±0.05 for CMR vs. 0.89±0.04, p=0.54). The combination of wall motion and perfusion analysis with CE confers high diagnostic accuracy. Adenosine-stress CE may be clinically useful in the non-invasive assessment of CAD.