Study Finds QFR-Guided Lesion Selection Leads to Better PCI Outcomes Compared with Conventional Angiography

ORLANDO – November 4, 2021 – The FAVOR III China trial found that lesion selection for percutaneous coronary intervention (PCI) using the non-invasively assessed physiologic measurement quantitative flow ratio (QFR) improved outcomes for PCI compared with a standard angiography-guided strategy.

Findings were reported today at TCT 2021, the 33^rd annual scientific symposium of the Cardiovascular Research Foundation (CRF). TCT is the world’s premier educational meeting specializing in interventional cardiovascular medicine. The study was also published simultaneously in The Lancet.

QFR, derived from three-dimensional coronary artery reconstruction and fluid dynamics computations from the angiogram, enables online estimation of fractional flow reserve (FFR) without the use of a pressure wire or pharmacological agents to induce hyperemia. Prior studies have demonstrated the feasibility and accuracy of online QFR assessment in assessing the hemodynamic significance of coronary stenoses compared with pressure wire-based FFR measurement. FAVOR III China was an investigator-initiated, multicenter, blinded, randomized, sham-controlled trial that compared QFR and angiography for lesion selection and monitored outcomes for one-year post procedure.

Patients with stable or unstable angina pectoris or those more than 72 hours post-myocardial infarction who had at least one lesion with a diameter stenosis between 50% and 90% in a coronary artery with a reference vessel diameter of at least 2.5 mm by visual assessment were randomized 1:1 to a QFR-guided strategy (PCI performed only if QFR ≤0.80) or an angiography-guided strategy (PCI based on standard visual angiographic assessment). Between December 2018 and January 2020, 3,825 participants at 26 sites were randomly assigned to QFR-guided PCI (n=1,913) or angiography-guided PCI (n=1,912). The mean age was 62.7 years, 70.6% were men, 33.9% had diabetes, 63.5% presented with an acute coronary syndrome, and 54.0% had multivessel diseases.

All patients, post-cath lab physicians, and research personnel were blinded to treatment allocation. Participants in both arms underwent a preset 10-minute delay for real or sham QFR calculation before PCI. The target vessels intended to be treated with standard angiography guidance were declared by operators and recorded prior to randomization.

The primary endpoint of the one-year rate of major adverse cardiac events (MACE), a composite of death from any cause, myocardial infarction, or ischemia-driven revascularization, was 5.8% for the QFR-guided group compared to 8.8% for the angiography-guided PCI group (HR 0.65, 95% CI: 0.51-0.83, p=0.0004). The major secondary endpoint (one-year rate of MACE, excluding periprocedural myocardial infarction) was 3.1% for the QFR-guided group versus 4.8% for the angiography-guided group (HR 0.64, 95% CI: 0.46-0.89, p=0.0073).

“A QFR-guided vessel and lesion selection strategy improved one-year clinical outcomes compared with standard angiography guidance in patients undergoing PCI, due both to fewer procedural complications and superior long-term results.” said Bo Xu, MBBS, Director, Catheterization Laboratories at Fuwai Hospital in Beijing, China. “The simplicity and safety of QFR compared with wire-based physiological measurements should facilitate the adoption of physiological lesion assessment into routine clinical practice.”

The study was funded by support from the Beijing Municipal Science and Technology Commission, Chinese Academy of Medical Sciences, and the National Clinical Research Center for Cardiovascular Diseases, Fuwai Hospital.

Dr. Xu reported grant/research support from Beijing Municipal Science and Technology Commission, Chinese Academy of Medical Sciences, and the National Clinical Research Center for Cardiovascular Diseases, Fuwai Hospital.