Diagnostic Performance of Resting and Hyperemic Invasive Physiological Indices to Define Myocardial Ischemia

Abstract

The diagnostic performance of invasive physiological indices showed no differences in the prediction of myocardial ischemia defined by CFR. Using RFR as a reference, FFR showed a better discrimination and reclassification ability than resting indices.

Clinical Quantification of Myocardial Blood Flow Using PET: Joint Position Paper of the SNMMI Cardiovascular Council and the ASNC

“…Although there has been only limited exploration of the relationships between the instantaneous wave-free ratio and MFR assessed by PET, 196 inconsistencies between the instantaneous wave-free ratio and FFR are common. [197][198][199] Nonetheless, two randomized trials have demonstrated that a strategy using an instantaneous wave-free ratio of more than 0.89 to defer revascularization yielded noninferior outcomes to a strategy using an FFR of more than 0.8.…”

Fractional Flow Reserve in Angiographically Insignificant Stenoses: Unmasking the Lesion or Creating Disease?

“…In this patient population, however, in which a low‐FFR value may have previously been rationalized away as an indirect sign of high flow and a healthy microcirculation, the (comparatively) unfavorable major adverse cardiac event (MACE) outcomes reported by Lee et al potentially imply an altogether different prognosis. The finding that, at 2‐year follow‐up, deferred angiographically insignificant stenosis with low FFR showed significantly higher event rates than those with high FFR (3.3% versus 1.2%; hazard ratio: 3.371; 95% confidence interval, 1.346–8.442; P =0.009) is very interesting, not least because it appears at odds with the oculostenotic reflex, the physiological mechanisms outlined above, and previous studies …”

“…The problem for us as interventionalists is that we have become accustomed to thinking about ischemia in terms of hyperemic transstenotic pressure ratios; however, even quick revision of supply–demand mechanics reminds us that the ischemia results from a reduction in coronary flow, not simply a reduction in coronary pressure. This notion is supported by numerous studies in the literature that proved ischemia detection with FFR fallible to demonstrably high coronary flow situations …”

Pooled diagnostic accuracy of resting distal to aortic coronary pressure referenced to fractional flow reserve: The importance of resting coronary physiology

“…However, this does not mean that each measurement cannot be similarly effective in guiding revascularization since their values are based on a physiologic response to a flow‐limiting stenosis. Pd/Pa and FFR have comparable diagnostic correlation when compared with PET‐derived coronary flow reserve which is regarded as the noninvasive gold‐standard to define myocardial ischemia . Overall, the clinical implication of the mismatch between Pd/Pa and FFR is unclear.…”

“…While the CV benefit of FFR is robust and iFR, the same cannot be said of Pd/Pa . However, Pd/Pa appears to have nearly identical reproducibility to iFR which does have randomized outcomes data in two large trials “iFR‐SWEDEHEART” and “DEFINE‐FLAIR” totaling 4529 patients . Investigation has suggested that the overall stenosis severity and association with major adverse cardiovascular events may be similar for Pd/Pa and iFR in some patient populations .…”