Abstract 3769: Magnetic Resonance Imaging for Myocardial Perfusion Assessment in Coronary Artery Disease Trial (MR-IMPACT II): A Phase III Multicenter, Multivendor Trial Comparing Perfusion Cardiac Magnetic Resonance Versus Single Photon Emission Computed Tomography For The Detection of Coronary Artery Disease
Background: Single center studies and the MR-IMPACT phase II study suggested cardiac magnetic resonance imaging (CMR) as an alternative to single photon emission computed tomography (SPECT) for the detection of coronary artery disease (CAD). Goal: To compare the diagnostic performance of CMR vs quantitative coronary angiography (CXA, gold-standard) and SPECT (comparator) in a large multicenter, multivendor phase III clinical trial.
Methods and Results: In 33 centers (10 US, 23 Europe), 533 patients scheduled for CXA were enrolled. CMR and stress-rest Tc-99m (60% gated-SPECT) or Tl-201-SPECT examinations were performed within 4weeks prior/after CXA. CMR included a hyperemic and rest first-pass perfusion study with 0.075mmol/kg GdDTPA-BMA (OmniscanTM, GE Healthcare) per injection followed by late enhancement imaging. CAD was defined as diameter stenosis ≥50% on CXA and/or previous myocardial infarction(s). Both, CMR and SPECT data were scored blindly by 3 readers each. The scores of the CMR and SPECT readers were averaged and receiver-operator-characteristics (ROC) curves for both modalities were generated. In 515 patients dosed, 114 adverse events (AEs) occurred in 74 patients (none severe, 5 AEs assumed drug-related, all 6 serious AEs not drug-related). In 465 patients (=efficacy population), 227 (48.8%) had stenoses ≥50% and 129 (27.7%) had infarctions. For CMR and SPECT, 8.6% and 2.4% of the images were non-evaluable, respectively. For results see Figure.
Conclusions: In this largest multicenter, multivendor phase III clinical MR - SPECT trial, ROC analyses demonstrate good performance of CMR perfusion imaging for CAD detection and superiority over SPECT, suggesting CMR as an alternative for SPECT imaging.