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

Newswise – ORLANDO – November 4, 2021 – The FAVOR III China trial found that screening lesions for percutaneous coronary intervention (PCI) using non-invasive physiological quantitative flow ratio (QFR) measurement improved PCI outcomes compared to standard strategy guided by angiography.

The results were reported today at TCT 2021, the 33e Cardiovascular Research Foundation (CRF) Annual Scientific Symposium. TCT is the world’s first 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 calculations from the angiogram, allows online estimation of fractional flow reserve (FFR) without the use of a wire pressure or pharmacological agents to induce hyperemia. Previous studies have demonstrated the feasibility and accuracy of online QFR assessment in assessing the hemodynamic significance of coronary stenosis compared to pressure wire FFR measurement. FAVOR III China was a multicenter, investigator-initiated, blinded, randomized, sham-controlled trial that compared QFR and angiography for lesion screening and monitored results for one year after treatment. procedure.

Patients with stable or unstable angina pectoris or those having more than 72 hours after a myocardial infarction who had at least one lesion with a stenosis of diameter between 50% and 90% in a coronary artery with a vessel diameter of reference 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 a 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 male, 33.9% were diabetic, 63.5% had acute coronary syndrome, and 54.0% had multivascular disease.

All patients, post-cath lab physicians, and research staff were blind to treatment allocation. Participants in both arms underwent a pre-defined 10-minute time limit for actual or notional QFR calculation before PCI. Target vessels to be treated with standard angiographic 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 all-cause death, myocardial infarction or ischemia-induced revascularization, was 5.8% for the group guided by QFR against 8.8% for the group. PCI group guided by angiography (HR 0.65, 95% CI: 0.51-0.83, p = 0.0004). The major secondary endpoint (MACE rate at one year, excluding perioperative myocardial infarction) was 3.1% for the group guided by QFR versus 4.8% for the group guided by angiography (HR 0.64, 95% CI: 0.46-0.89, p = 0.0073).

“A QFR-guided vessel and lesion selection strategy improved clinical outcome at one year compared to standard angiography advice in patients undergoing PCI, due to both fewer procedural complications and superior outcomes long-term. Said Bo Xu, MBBS, director of catheterization laboratories at Fuwai Hospital in Beijing, China. “The simplicity and safety of QFR compared to physiological wire measurements should facilitate the adoption of physiological injury assessment in routine clinical practice. “

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

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

Martin E. Berry