FAVOR II Europe-Japan Study Examines Sensitivity and Specificity of QFR
October 31, 2017—Findings from the FAVOR II Europe-Japan study were presented at TCT 2017, the 29th annual Transcatheter Cardiovascular Therapeutics scientific symposium being held October 30 to November 2 in Denver, Colorado.
As summarized in the TCT announcement, the prospective, observational, investigator-initiated study was performed at 11 hospitals in Europe and Japan from March 2017 to October 2017. The primary endpoint was sensitivity and specificity of quantitative flow ratio (QFR) compared to two-dimensional quantitative coronary angiography (2D-QCA), with fractional flow reserve (FFR) as reference standard.
The study found that QFR had higher sensitivity (88% vs 46%; P < .001) and specificity (88% vs 77%; P < .001) compared to 2D-QCA. Key secondary endpoints of feasibility of QFR, which was defined as the fraction of vessels with successful FFR measurements where in-procedure QFR is computed, was 97% (n = 373) and time to QFR was 4.8 minutes (interquartile range, 3.5–6.0 min) compared to 7 minutes for FFR (interquartile range, 5.0–10.0 min; P < .001).
Jelmer Westra, MS, research fellow at Aarhus University Hospital in Aarhus, Denmark, commented in the TCT announcement, “QFR showed superior sensitivity and specificity for detection of functional significant lesions in comparison with 2D-QCA using FFR as reference standard. In addition, in-procedure QFR computation was feasible and was computed within the time of standard FFR measurements. Still, randomized trials are needed to determine if a QFR-based diagnostic strategy provides noninferior clinical outcomes compared to pressure wire–based strategies.”