Abstract 5449: Diagnostic Performance of Perfusion Cardiovascular Magnetic Resonance Compared With Gated Myocardial Perfusion SPECT in Patients With Known or Suspected Coronary Artery Disease

Abstract

Background: Perfusion cardiac magnetic resonance (CMR) is emerging a clinically valuable imaging technique in patients with known or suspected coronary artery disease (CAD) and it has some potential advantages over myocardial perfusion scintigraphy. Aim : To evaluate the diagnostic performance of adenosine perfusion CMR vs gated single-photon emission computed tomography (SPECT) compared with the gold-standard of quantitative coronary angiography (QCA) in patients with known or suspected CAD. Methods : Ninety-five patients scheduled for coronary angiography underwent both adenosine perfusion CMR and adenosine technetium-99m-tetrofosmin SPECT. Stress CMR perfusion imaging was performed with a hybrid-EPI sequence after 4 minutes of 140 μ g/kg/min adenosine and 0.1mmol/kg of gadolinium, and followed by late enhancement imaging. Tc-99m SPECT was performed with a 1day stress-rest protocol. CAD was defined as diameter stenosis ≥50% on QCA. Two blinded observers per modality analyzed the images both qualitatively (presence/absence of inducible ischemia) and quantitatively: myocardial perfusion reserve index (MPRI) by CMR and sum difference score (SDS) by SPECT. A MPRI ≤2 by CMR was considered abnormal. The comparison of CMR vs SPECT was based on receiver operating characteristic (ROC) analysis. Results : Analysis of all patients showed that perfusion CMR had similar diagnostic performance to SPECT: area under ROC curve (AUC): 0.74±0.050 vs 0.683±0.052 for SPECT, p=0.29 based on qualitative assessment and 0.675±0.054 vs 0.583±0.024 for SPECT, p=0.10 based on MPRI and SDS. Similar results were observed in the subgroup of patient with previous myocardial infarction. (n=34, 38%-defined as the presence of late myocardial enhancement by CMR). However, in the subgroup of patients without previous myocardial infarction, CMR MPRI had significantly better diagnostic performance than SPECT SDS: AUC 0.695±0.063 vs 0.552±0.029, respectively, p=0.027. Conclusions : In patients with known or suspected CAD, perfusion CMR has a similar diagnostic performance to Tc-99m gated SPECT and has particular advantage in patients without previous infarction. CMR represents a valuable alternative imaging modality to assess CAD.