Assessment of Advanced Coronary Artery Disease

Abstract

Objectives The purpose of this paper was to compare quantitative cardiac magnetic resonance (CMR) first-pass contrast-enhanced perfusion imaging to qualitative interpretation for determining the presence and severity of coronary artery disease (CAD). Background Adenosine CMR can detect CAD by measuring perfusion reserve (PR) or by qualitative interpretation (QI). Methods Forty-one patients with an abnormal nuclear stress scheduled for X-ray angiography underwent dual-bolus adenosine CMR. Segmental myocardial perfusion analyzed using both QI and PR by Fermi function deconvolution was compared to quantitative coronary angiography. Results In the 30 patients with complete quantitative data, PR (mean ± SD) decreased stepwise as coronary artery stenosis (CAS) severity increased: 2.42 ± 0.94 for <50%, 2.14 ± 0.87 for 50% to 70%, and 1.85 ± 0.77 for > 70% (p < 0.001). The PR and QI had similar diagnostic accuracies for detection of CAS > 50% (83% vs. 80%), and CAS > 70% (77% vs. 67%). Agreement between observers was higher for quantitative analysis than for qualitative analysis. Using PR, patients with triple-vessel CAD had a higher burden of detectable ischemia than patients with single-vessel CAD (60% vs. 25%; p = 0.02), whereas no difference was detected by QI (31% vs. 21%; p = 0.26). In segments with myocardial scar (n = 64), PR was 3.10 ± 1.34 for patients with CAS <50% (n = 18) and 1.91 ± 0.96 for CAS >50% (p < 0.0001). Conclusions Quantitative PR by CMR differentiates moderate from severe stenoses in patients with known or suspected CAD. The PR analysis differentiates triple- from single-vessel CAD, whereas QI does not, and determines the severity of CAS subtending myocardial scar. This has important implications for assessment of prognosis and therapeutic decision making.

Diagnostic Accuracy of Stress Perfusion CMR in Comparison With Quantitative Coronary Angiography

“…(21,29–32) The endocardial to epicardial ratio in patients without coronary disease averaged 1.13 which is similar to the previously reported value. (12)…”

“…This may be why our findings differ from previous data. (12) Furthermore, using an epicardial rather than remote endocardial reference may avoid problems with balanced ischemia.…”

Recent Advances in Cardiovascular Magnetic Resonance

“…22,23 The main challenges for CMR perfusion quantification include a lack of standardization of postprocessing approaches and the overall perception that quantitative perfusion CMR protocols are complex and require labor-intensive postprocessing. Regarding the latter, several efforts are underway to simplify the data acquisition protocol, for example, eliminating the need for breath holding or ECG gating and to simplify the quantification procedure by enabling fully automatic postprocessing.…”

Cardiac Mri Assessment of Myocardial Perfusion

“…The concept behind vasodilator stress imaging is that hyperemic flow is decreased in myocardial segments that are supplied by a significantly stenosed epicardial coronary artery (>50%) (Figure 2) [6]. Some studies have used perfusion imaging during dobutamine stress CMR.…”

“…on 30 patients [6]. The sensitivity, specificity and accuracy for the assessment of >50% stenosis on ICA of Q-CMR-P versus MPR was 79, 83 and 80% versus 88, 67 and 83%, respectively.…”