Abstract
Background
The FDA regulated GadaCAD1 trial and the nearly identical GadaCAD2 clinical trial aimed to determine whether gadobutrol-enhanced CMR can detect significant CAD.
Methods
Two multicenter, international trials enrolled patients with known or suspected CAD and used cine MRI, gadobutrol enhanced stress/rest perfusion, and late gadolinium enhancement. Endpoints, primary, and secondary minimum performance thresholds versus QCA and stress cine MRI are summarized in the table. There were 3 blinded, core-lab CMR readers per trial (6 readers overall) and 2 core-lab QCA readers. A meta-analysis combined results from all 6 CMR readers.
Results
765 patients were analyzed (GadaCAD1: n=376, GadaCAD2: n=389). The meta-analysis of 6 readers had 79% sensitivity, 87% specificity, and AUC of 0.82 to detect a 70% QCA stenosis and met all study endpoints (figure & table). Versus a 50% QCA stenosis, the meta-analysis also met all study endpoints. At an individual reader level, all 6 readers met all study endpoints versus a 70% QCA stenosis. Versus a 50% QCA stenosis, only 1 of 6 readers exceeded the minimum performance threshold for sensitivity but all 6 readers met all other endpoints. For all readers, stress perfusion was more sensitive than stress wall motion (p<0.05).
Diagnostic Accuracy Results
Conclusions
CMR stress perfusion has high diagnostic accuracy for significant CAD. The ROC analysis and overall results support prior literature that a 70% QCA threshold is a more appropriate threshold for physiologically significant CAD.
Acknowledgement/Funding
Bayer
Diagnostic Accuracy of Stress Perfusion CMR in Comparison With Quantitative Coronary Angiography
