New quantitative flow ratio method tops FFR in diagnosing heart blockages
A team of international researchers showed that quantitative flow ratio (QFR) was feasible for testing coronary artery stenosis, and more accurate compared to traditional wire-based fractional flow reserve (FFR), according to a study published online March 19 in Circulation: Cardiovascular Imaging.
Currently, guidelines recommend an FFR-based approach to assess obstruction-mediated ischemia, but factors such as the need for drug-induced hyperemia, prolonged procedure time and an unfavorable reimbursement system for this strategy have prompted desire for a new method.
A previous study, cited by the authors, evaluated the optimal approach for QFR computation which demonstrated favorable results. The group applied this method to their WIFI II (Wire-Free Functional Imaging II) study, which is expressed as QFR.
QFR is a computation of FFR based on a 3D reconstruction of the stenotic vessel rendered from two angiographic projections combined with contrast flow frame count.
In this study, FFR was measured in 292 lesions from 191 patients. QFR was computed in 240 of 255 lesions. QFR correctly classified 83 percent of lesions using FFR with cutoff at 0.80 as reference standard.
The QFR approach achieved a 77 percent sensitivity, 86 percent specificity, 75 percent negative predictive value and 87 percent positive predictive value, according to corresponding author Jelmer Westra, with the Department of Cardiology, at Aarhus University Hospital in Denmark and colleagues.
“Functional lesion evaluation by QFR measurement is feasible and shows good agreement and diagnostic accuracy compared with FFR in patients with intermediate stenosis,” wrote Westra et al. “QFR may emerge as a safe and cost-reducing diagnostic modality potentially improving the utilization of physiological guided decision-making.”
Matt joined Chicago’s TriMed team in 2018 covering all areas of health imaging after two years reporting on the hospital field. He holds a bachelor’s in English from UIC, and enjoys a good cup of coffee and an interesting documentary.