Non-hyperaemic pressure ratios to guide percutaneous coronary intervention

Abstract

The use of fractional flow reserve (FFR) in guiding revascularisation improves patient outcomes and has been well-established in clinical guidelines. Despite this, the uptake of FFR has been limited, likely attributable to the perceived increase in procedural time and use of hyperaemic agents that can cause patient discomfort. This has led to the development of instantaneous wave-free ratio (iFR), an alternative non-hyperaemic pressure ratio (NHPR). Since its inception, the use of iFR has been supported by an increasing body of evidence and is now guideline recommended. More recently, other commercially available NHPRs including diastolic hyperaemia-free ratio and resting full-cycle ratio have emerged. Studies have demonstrated that these indices, in addition to mean distal coronary artery pressure to mean aortic pressure ratio, are mathematically analogous (with specific nuances) to iFR. Additionally, there is increasing data demonstrating the equivalent diagnostic performance of alternative NHPRs in comparison with iFR and FFR. These NHPRs are now integral within most current pressure wire systems and are commonly available in the catheter laboratory. It is therefore key to understand the fundamental differences and evidence for NHPRs to guide appropriate clinical decision-making.

Fractional Flow Reserve-Guided Coronary Revascularization: Evidence from Randomized and Non-Randomized Studies

“…In order to linearize the relationship between Q , Δ P , and R and to minimize the influence of the microcirculatory resistance, maximal coronary hyperemia must be achieved by using adenosine or papaverine infusion [ 36 , 37 ]. Although their discussion is beyond the purposes of this review, it should be noted that several other indexes have been created to perform the physiological evaluation of coronary lesions without the need for inducing maximal hyperemia [ 38 , 39 ]. Most of them have been validated using FFR as the gold-standard reference.…”

Culprit versus Complete Revascularization during the Initial Intervention in Patients with Acute Coronary Syndrome Using a Virtual Treatment Planning Tool: Results of a Single-Center Pilot Study

“…Whether simultaneous complete revascularization is superior to staged approaches for index PCI remains controversial due to the current ambiguous data, which suggest integrated and individualized approaches [ 12 , 13 , 14 , 15 ]. In this regard, myocardial ischemia evaluation has been highlighted [ 16 ], and physiology-guided coronary revascularization, including advanced invasive functional assessment tools, is of great clinical interest [ 17 , 18 ]. Instantaneous wave-free ratio co-registration software, with potential virtual PCI planning, is an option for optimizing the decision-making processes.…”

Hyperaemic and non-hyperaemic indices for functional assessment of coronary lesions in patients with severe aortic valve stenosis

“… 1 Moreover, in the VALIDATE-RFR study the sensitivity of both RFR and instantaneous wave-free ratio (iFR) were notably lower for the RCA. 5 Even though coronary perfusion is predominantly diastolic, the RCA perfuses in systole to a greater degree than the left coronary system, probably due to the thinner-walled right ventricle, which results in less systolic compression. 5 Furthermore, the RCA has a smaller diastolic suction wave.…”

“… 5 Even though coronary perfusion is predominantly diastolic, the RCA perfuses in systole to a greater degree than the left coronary system, probably due to the thinner-walled right ventricle, which results in less systolic compression. 5 Furthermore, the RCA has a smaller diastolic suction wave. 5 Subsequently, this variability of resting gradients in patients with AS mandates for cautious interpretation of the results provided, especially in the assessment of RCA lesions, as in this case.…”

“… 5 Furthermore, the RCA has a smaller diastolic suction wave. 5 Subsequently, this variability of resting gradients in patients with AS mandates for cautious interpretation of the results provided, especially in the assessment of RCA lesions, as in this case.…”