Superior diagnostic performance of perfusion-cardiovascular magnetic resonance versus SPECT to detect coronary artery disease: the secondary endpoints of the multicenter multivendor MR-IMPACT II (Magnetic Resonance Imaging for Myocardial Perfusion Assessment in Coronary Artery Disease Trial)

Background: perfusion-cardiovascular magnetic resonance (cmr) is generally accepted as an alternative to spect to assess myocardial ischemia non-invasively. however its performance vs gated-spect and in sub-populations is not fully established. the goal was to compare in a multicenter setting the diagnostic performance of perfusion- cmr and gated-spect for the detection of cad in various populations using conventional x-ray coronary angiography (cxa) as the standard of reference. methods: in 33 centers (in us and europe) 533 patients,eligible for cxa or spect,were enrolled in this multivendor trial. spect and cxa were performed within 4 weeks before or after cmr in all patients. prevalence of cad in the sample was 49% and 515 patients received mr contrast medium. drop-out rates for cmr and spect were 5.6% and 3.7%,respectively (ns). the study was powered for the primary endpoint of non-inferiority of cmr vs spect for both,sensitivity and specificity for the detection of cad (using a single-threshold reading),the results for the primary endpoint were reported elsewhere. in this article secondary endpoints are presented,i.e. the diagnostic performance of cmr versus spect in subpopulations such as multi-vessel disease (mvd),in men,in women,and in patients without prior myocardial infarction (mi). for diagnostic performance assessment the area under the receiver-operator-characteristics-curve (auc) was calculated. readers were blinded versus clinical data,cxa,and imaging results. results: the diagnostic performance (= area under roc = auc) of cmr was superior to spect (p = 0.0004,n = 425) and to gated-spect (p = 0.018,n = 253). cmr performed better than spect in mvd (p = 0.003 vs all spect,p = 0.04 vs gated-spect),in men (p = 0.004,n = 313) and in women (p = 0.03,n = 112) as well as in the non-infarct patients (p = 0.005,n = 186 in 13 vessel disease and p = 0.015,n = 140 in mvd). © 2012 schwitter et al.; licensee biomed central ltd.