The DECISION-QFR study was presented by Taku Asano, MD, St. Luke's International Hospital, Tokyo, Japan, at the Congress of the European Association of Percutaneous Coronary Interventions (EuroPCR) 2022, being held this week in Paris.
"The QFR approach may enhance the practicability of physiology-guided decision-making for the optimal revascularization," he concluded.
Asano explained that patient risk assessment considering coronary anatomy and its physiologic significance, which is represented by the functional SYNTAX score calculated by FFR measurement, demonstrates better capability in predicting outcomes after revascularization in patients with multivessel disease compared to one considering only anatomy. However, an FFR measurement requires an invasive procedure that has a risk of vessel injury and excess procedure time due to pressure-wire manipulation and is uncomfortable for the patient.
The new QFR approach, which is an FFR simulation based on angiographic images, allows estimation of the functional SYNTAX score without use of a pressure wire.
The current DECISION QFR study aimed to investigate the feasibility of using QFR as the physiologic information in a heart team discussion determining an optimal revascularisation strategy for patients with multivessel disease.
For the prospective, randomized trial, 260 patients with multivessel coronary disease were evaluated both with FFR and QFR.
Subsequently, two different heart teams were randomly assigned to make a decision on the type of treatment, either percutaneous coronary intervention (PCI), coronary artery bypass grafting (CABG) or equipoise between these approaches, based either on QFR or FFR. Members of the heart team in the QFR group were blinded to the FFR values, and vice versa.
Results showed a substantial agreement in terms of treatment recommendations (PCI/equipoise vs CABG), with a Cohen's K of 0.73 (95% CI, 0.62 – 0.83).
The agreement between FFR and QFR for treatment recommendation reached 91.5% at a patient level, whereas at a vessel level, it reached 86.1% and 88% for PCI and CABG, respectively.
"Functional SYNTAX score and SYNTAX score II 2020 derived from QFR yielded an almost perfect agreement with the scores derived from FFR," Asano said.
Also, procedure time for performing QFR was significantly shorter than for FFR.
Commenting on the study, the moderator of the EuroPCR session at which it was presented, Alexandra Lansky, MD, professor of medicine at Yale School of Medicine, said this was a well-conducted study designed to assess whether clinical decision-making can be reliably based on angiographically derived QFR.
"They demonstrated moderate correlation of QFR compared to the gold standard FFR. While it is not perfect, there was excellent correlation of the QFR derived Functional Syntax Score and the Syntax II score compared to invasive FFR," Lansky told theheart.org | Medscape Cardiology.
"Ultimately, there was 91% agreement in the decision to refer patients to CABG or equipoise between CABG and multivessel PCI and 86% agreement for PCI," she added.
"In general, when integrated with clinical factors and presentation, QFR provides reliable guidance for clinical decision making of the revascularization strategy compared to FFR; the benefit of QFR is the wide applicability based on a simple diagnostic angiogram and it can be done in less time and without the invasive approach of FFR," Lansky concluded.
Also commenting on the study, Giuseppe di Gioia, MD, University Federico II, Naples, Italy, co-moderator of the EuroPCR session, said: "This study further reinforces the good results obtained with QFR evaluation and expands its application to patients with multivessel disease."
Regarding its use in clinical practice, di Gioia added, "The possibility of investigating microcirculation by also estimating the index of microcirculatory resistance is a valuable addition to an already interesting tool and will be crucial to investigate possible INOCA (ischemia with no obstructive coronary arteries)."
The DECISION-QFR study was a Japanese investigator-initiated trial funded by National Grants-in-Aid for Scientific Research. Asano reports no relevant financial relationships.
Congress of the European Association of Percutaneous Coronary Interventions (EuroPCR) 2022: Presented May 17, 2022