Quantitative flow ratio-based outcomes in patients undergoing transcatheter aortic valve implantation quaestio study

The role of aortic valve area in the quantitative flow ratio-fractional flow reserve discrepancy in patients with coronary artery disease and severe aortic stenosis

Introduction

The accuracy of fractional flow reserve (FFR) and quantitative flow ratio (QFR) in assessing coronary artery disease in severe aortic stenosis (AS) patients may be affected by the severity of AS.

Aim

We investigated the relationship between aortic valve area (AVA) and the diagnostic performance of QFR in this context.

Material and methods

We analyzed 416 intermediate coronary lesions in 221 severe AS patients using FFR and QFR, categorizing them based on AVA into two groups: AVA < 0.5 cm2 and AVA ≥ 0.5 cm2.

Results

In all, 47 (21.2%) patients had an AVA < 0.5 cm2. The median FFR and QFR values were comparable between groups, with a high agreement rate: interclass coefficient of 0.96 (95% CI: 0.94 to 0.97) for AVA < 0.5 cm2 and 0.97 (95% CI: 0.97 to 0.98) for AVA ≥ 0.5 cm2. Concordance in detecting significant ischemia was 96.3% for AVA ≥ 0.5 cm2 but dropped to 86.5% for AVA < 0.5 cm2, with discrepancies mainly in cases where FFR was negative and QFR positive. Multivariable analysis showed AVA and %DS as independent predictors of discordance; AVA ≥ 0.5 cm2 had an OR of 0.229 (95% CI: 0.095 to 0.548; p < 0.001), and each 1% increase in %DS increased the odds by 1.070 (95% CI: 1.034 to 1.107; p < 0.001).

Conclusions

In severe AS, QFR closely correlates with FFR. However, patients with AVA < 0.5 cm2 might exhibit a higher incidence of false-positive ischemia detection by QFR.

Consensus document on the clinical application of invasive functional coronary angiography from the Japanese Association of Cardiovascular Intervention and Therapeutics

Invasive functional coronary angiography (FCA), an angiography-derived physiological index of the functional significance of coronary obstruction, is a novel physiological assessment tool for coronary obstruction that does not require the utilization of a pressure wire. This technology enables operators to rapidly evaluate the functional relevance of coronary stenoses during and even after angiography while reducing the burden of cost and complication risks related to the pressure wire. FCA can be used for treatment decision-making for revascularization, strategy planning for percutaneous coronary intervention, and procedure optimization. Currently, various software-computing FCAs are available worldwide, with unique features in their computation algorithms and functions. With the emerging application of this novel technology in various clinical scenarios, the Japanese Association of Cardiovascular Intervention and Therapeutics task force was created to outline expert consensus on the clinical use of FCA. This consensus document advocates optimal clinical applications of FCA according to currently available evidence while summarizing the concept, history, limitations, and future perspectives of FCA along with globally available software.