Comparison of quantitative coronary angiography and first-pass perfusion magnetic resonance imaging for the detection of an impaired coronary perfusion in nonsevere coronary stenosis

Purpose: To compare quantitative coronary angiography (QCA) and first-pass perfusion magnetic resonance imaging (FPP-MRI) in symptomatic patients with nonsevere coronary stenosis to detect a reduced coronary flow velocity reserve (CFVR). Materials and Methods: In 35 patients, FPP-MRI and CFVR measurements were performed in 40 coronary arteries with a diameter stenosis (DS) < 70% by QCA. From FPP-MRI a myocardial perfusion reserve index (MPRI) was calculated. CFVR was calculated as the ratio of the average peak flow velocity during infusion of adenosine and at rest and was considered reduced if < 2. Diagnostic performance of MPRI and DS to detect a reduced CFVR was compared by receiver operating characteristic (ROC) curve analysis. Results: CFVR was reduced in 16 coronary arteries (40%). Mean DS did not differ in coronary arteries with a reduced CFVR (41.0% +/- 13.3) and a normal CFVR (36.5% +/- 12.3; P = 0.281). Mean MPRI was lower in coronary arteries with a reduced CFVR (1.12 +/- 0.12) compared to a normal CFVR (1.33 +/- 0.2; P < 0.001). Sensitivity, specificity, and area under the ROC curve (AUC) were higher for MPRI (81%, 79%, 0.84) than for DS (56%, 58%, 0.60). Conclusion: FPP-MRI detects impaired CFVR in symptomatic patients with nonsevere coronary stenosis more accurately than QCA and can identify patients with symptomatic ischemia.