A new approach to spot and measure the extent of artery blockages may supplant angiography as the go-to technique for treating advanced coronary artery disease, according to data presented Thursday at the Transcatheter Cardiovascular Therapeutics Conference in Orlando.
Quantitative flow ratio (QFR) relies on 3D artery reconstruction and blood flow measurements to help doctors decide which arteries to stent during percutaneous coronary intervention. Mount Sinai researchers found QFR prevented a number of unnecessary stents and spotted more obstructive lesions that would have otherwise been overlooked.
This is the first study to investigate QFR and its associated outcomes, which may push physicians to use it as an alternative to angiography or pressure wires, Gregg W. Stone, MD, director of Academic Affairs at Mount Sinai Health System, said Nov. 4.
“For the first time, we have clinical validation that lesion selection with this method improves outcomes for patients with coronary artery disease undergoing stent treatment,” Stone, senior author of the study, added. “By avoiding the time, complications, and extra resources required to measure lesion severity using a pressure wire, this simpler technique should serve to greatly expand the use of physiology in patients undergoing cardiac catheterization procedures.”
For the multi-center, randomized trial, the team assessed 3,825 patients who underwent PCI between December 2018 and January 2020. Participants either suffered a heart attack 72 hours before treatment or had at least one coronary artery with one or more blockages deemed 50-90% narrowed. Half the patients received standard angiography-guided PCI while the others underwent QFR-guided treatment
Doctors using QFR opted not to treat 375 vessels originally targeted for PCI, while those using angiography skipped 100. Conversely, providers treated 85 vessels in the QFR group that weren’t originally set to be treated, compared to 28 in the angiography cohort.
Those decisions produced lower one-year heart attack rates among QFR patients compared to angiography (65 vs. 109 patients) and a smaller chance of requiring additional PCI (38 vs. 59) with similar survival.
Finally, QFR-guided procedures reduced the proportion of patients who had died, suffered a heart attack or needed additional stenting by 35% at the one-year mark.
“Based on these findings, following regulatory approval I would anticipate QFR to be widely adopted by interventional cardiologists to improve outcomes for their patients.” Stone said.
The full study was also published Thursday in The Lancet.