Quantification of myocardial perfusion reserve at 1.5 and 3.0 Tesla: a comparison to fractional flow reserve

Abstract

The objective of this study was to compare quantitative analysis of cardiac magnetic resonance (CMR) perfusion at 1.5 and 3 T against fractional flow reserve (FFR) as measured invasively. FFR is considered by many investigators to be a reliable standard to determine hemodynamically significant coronary artery stenoses. Quantitative 1.5 and 3 T CMR is capable to noninvasively determine myocardial perfusion reserve, but have not been compared against each other and validated against FFR as standard reference. Patients with suspected or known coronary artery disease (CAD) underwent CMR at at both field strengths, 1.5 and 3 T, and FFR. 34 patients were included into the study. Quantitative myocardial perfusion reserve was calculated in 544 myocardial segments at 1.5 and 3 T, respectively. FFR was measured in 109 coronary arteries. FFR ≤ 0.8 was regarded relevant. Reduced FFR (≤0.8) was found in 38 coronary arteries (19 LAD, 8 LCX and 11 RCA). Receiver operator curve analysis yielded higher area under the curve for 3 T CMR in comparison to 1.5 T CMR (0.963 vs. 0.645, p < 0.001) resulting in higher sensitivity (90.5 vs. 61.9 %) and specificity (100 vs. 76.9 %). Quantitative analysis of CMR myocardial perfusion reserve at 1.5 and 3 T is capable to detect hemodynamic significance of coronary artery stenoses. Diagnostic accuracy at 3 T is to be superior to 1.5 T.

Diagnostic Accuracy of Stress Myocardial Perfusion Imaging Compared to Invasive Coronary Angiography With Fractional Flow Reserve Meta-Analysis

“…Studies such as Fractional Flow Reserve Versus Angiography for Multivessel Evaluation (FAME) and Clinical Outcomes Utilizing Revascularization and Aggressive Drug Evaluation (COURAGE) initiated a shift from PCI as the treatment of choice based on anatomic CAD to a more nuanced use of PCI guided by the hemodynamic significance of CAD and by recognizing that optimal medical therapy is equal or favorable in many patients with CAD. 18,19 Furthermore, FAME demonstrated that the routine measurement of FFR results in significantly reduced mortality and myocardial infarction rates at 2 years of follow-up in patients with multivessel CAD undergoing PCI with drug eluting stents. 18 Noninvasive assessment of hemodynamic CAD with stress MPI may further benefit patient outcome and costs.…”

“…18,19 Furthermore, FAME demonstrated that the routine measurement of FFR results in significantly reduced mortality and myocardial infarction rates at 2 years of follow-up in patients with multivessel CAD undergoing PCI with drug eluting stents. 18 Noninvasive assessment of hemodynamic CAD with stress MPI may further benefit patient outcome and costs.…”

“…However, we considered any comparison with anatomic CAD by ICA as inappropriate because ICA alone has poor diagnostic performance for intermediate coronary stenoses and the decision to perform a PCI based on hemodynamic significance improves patient outcomes. 18,21,22 Moreover, recent evidence demonstrates that FFR has a continuous and independent relationship with subsequent major adverse cardiac events and lower FFR values benefit more from revascularization. 23 However, there is an ongoing discussion on the true reference standard for the measurement of myocardial ischemia.…”

CT fractional flow reserve: the next level in non-invasive cardiac imaging

“…Although the reported PPV varies across these studies, the NPV is consistently high (Table 2). In a direct comparison, 3.0 T MPI-MR was found to be superior to 1.5 T MPI-MR for the detection of FFR-positive lesions [44]. In 1493 patients with known or suspected CAD, a negative dobutamine stress MR was associated with a <0.5 % 4-year event rate in patients with a low or intermediate pre-test probability of CAD [45].…”

Fractional flow reserve derived from coronary CT angiography in stable coronary disease: a new standard in non-invasive testing?

“…For example, in a recent metaanalysis of 12 studies reporting the diagnostic performance of CMR in stable CAD using FFR as the reference standard, on a coronary territory basis, pooled sensitivity was 88 % and pooled specificity was 89 %, suggesting high diagnostic accuracy of CMR for detection of flow-limiting stenosis [47]. Among the studies, however, the rate of actual FFR measurements in vessels included in analysis varied from 12 % to 100 %, with fewer than 75 % of vessels undergoing direct FFR interrogation in 10 of the studies [47][48][49]. This may lead to significant error, since it is well known that patients with< 50 % stenosis on ICA may have functionally significant stenosis (FFR≤0.80) [50], and that patients with stenosis severity>50 %, or even>70 %, often have FFR values>0.80 [2,3].…”