Reviewer: Dr. Erdi Babayiğit

Name of the Study: Heart Team decision-making based on angiography-derived FFR: DECISION QFR

Published Congress: EuroPCR 2022

Background: Functional SYNTAX Score (FSS) assessment has shown that physiological assessment is better than anatomical assessment alone in predicting clinical outcomes in patients with multivessel disease to be revascularized. Quantitative flow reserve (QFR) is a simulation of FFR based on angiographic images, facilitating the evaluation of FSS without the need for a pressure wire or pharmacological hyperemia.

Objectives: The DECISION QFR study investigated the feasibility of the QFR in terms of providing physiological information to the cardiac team in deciding the optimal revascularization strategy in patients with multivessel disease.

Methods: The DECISION QFR study is a prospective, randomized clinical trial conducted at 10 different centers in Japan, involving 260 patients with 2 or 3 vessel disease including proximal LAD lesion and with chronic coronary syndromes eligible for revascularization. Patients were evaluated by two different heart teams consisting of interventional cardiologist and cardiac surgeon. Both teams evaluated anatomical SYNTAX score, functional SYNTAX score created with either QFR or FFR, and FSS-based SYNTAX II 2020 scoring in terms of percutaneous intervention or coronary artery bypass graft operation. The primary endpoint of the study was the decision-making situation in which both heart teams agreed as “CABG only” or “equipoise (CABG or PCI) or PCI only”, and decision agreement was evaluate by the Cohen’ ?. index. (? >0.60: substantial agreement). The secondary endpoints were agreement in vessel to be treated and mean procedural times.

Results: Among the patients who met the inclusion criteria in the study, the mean age of 248 patients was 70.9 (± 10.2), 48.4% had diabetes, 41.9% had the 2-vessel disease, and 58.1% had the 3-vessel disease. The mean anatomical SYNTAX score of the patients was 20.9 ± 9.3.
The correlation between QFR and FFR was high. (Pearson R=0.68). 91.5% agreement was observed between the tertiles of FSS evaluated according to QFR (FSSQFR) and FSS evaluated according to FFR (FSSFFR). (intraclass correlation coefficient (ICC) = 0.94 [0.93-0.95]). There was also a high rate of agreement between the QFR and FFR groups in the SYNTAX II 2020 scoring system, which evaluates the 10-year mortality after PCI (ICC = 0.998 [0.998-0.999]).
Cohen’s kappa value was 0.73 as “significant agreement” in the agreement of treatment recommendations.
As a secondary endpoint, the rate of agreement at vessel level to be treated or not with PCI or CABG recommendation was 86.1% in the PCI group and 88.0% in the CABG group, according to the QFR and FFR. (Cohen’s Kappa value for both: 0.72)
The other secondary endpoint, mean total procedure time was shorter in the QFR group than in the FFR group. (p =0.035 for total, p<0.001 for prespecified angiographic protocol)

Conclusion: In patients with multivessel disease, QFR-based scoring versus FFR-based scoring showed substantial agreement in treatment decision making by the cardiac team. There was an almost perfect agreement between the QFR-based SYNTAX and SYNTAX II 2020 scores and the FFR-based scores. Considering the prospective angiography times, QFR has a shorter procedure time compared to FFR.

Interpretations:  In addition to the anatomical SYNTAX score, functional SYNTAX scores provide more information to the cardiac team in terms of clinical outcomes in the decision-making process in multi-vessel patients. Among the handicaps of FFR in functional scoring are possible vessel damage by the pressure wire and an increase in the duration of the procedure. Compared to the FFR, the QFR does not require additional manipulation and has a shorter time in the angiography plan and is more advantageous, besides, it shows clinical compatibility in decision making with FFR. The easy applicability of the QFR may increase the applicability of physiology guidance for optimal revascularization in clinical decision making.