Quantitative flow ratio (QFR)-guided lesion selection improved 2-year clinical outcomes for percutaneous coronary intervention (PCI) compared with standard angiography guidance, according to new data from the FAVOR III China trial.
The benefits were most pronounced among patients in whom QFR assessment altered the planned revascularization strategy, noted the research team, led by Lei Song, MD, from the Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing.
Findings from the multicenter, randomized, sham-controlled trial, were reported Monday at Transcatheter Cardiovascular Therapeutics (TCT) 2022 in Boston and published simultaneously online in the Journal of the American College of Cardiology.
Speaking during a prerecorded presentation shown at TCT 2022, Song cited previous data from the FAVOR III China trial that showed QFR-based lesion selection improved 1-year clinical outcomes compared with conventional angiographic guidance for PCI, but noted that it had been uncertain whether the gains seen in 1-year data would be preserved, increase or diminish over time.
“We herein report the 2-year results from the FAVOR III China trial,” he said.
Song said the new study was aimed at determining whether the benefits of QFR guidance persist at 2 years, and particularly whether benefits were sustained for patients in whom QFR changed the revascularization strategy.
As part of the FAVOR III trial, 3,825 patients were randomized to a QFR-guided strategy (PCI performed only if QFR ≤0.80) or a standard angiography-guided strategy at 26 hospitals in China.
Adult patients with stable or unstable angina or those ≥72 hours post-myocardial infarction (MI) in whom PCI was planned based on standard angiography guidance were considered for enrollment. Angiographic inclusion criteria required at least one lesion with a percentage diameter stenosis of 50% to 90% in a coronary artery with ≥2.5 mm reference vessel diameter by visual assessment by the local site investigators, the researcher noted.
Patients were not eligible if they had severe heart failure, severe chronic kidney disease (estimated glomerular filtration rate <45 ml/kg/1.73 m2), allergy to contrast or study medications, pregnancy, or life expectancy <1 year, he said.
Major adverse cardiac events (MACE) – a composite of all-cause death, MI, or ischemia-driven revascularization (IDR) – occurring within 2 years were analyzed in the intention-to-treat population.
New findings from 2-yeat follow up report that MACE occurred in 161/1913 (8.5%) patients in the QFR-guided group and in 237/1912 (12.5%) patients in the angiography-guided group (hazard ratio [HR] 0.66, 95% confidence interval [CI] 0.54-0.81, P<0.0001).
Song noted that this was driven by fewer MIs (4.0% vs. 6.8%, HR 0.58, 95% CI 0.44-0.77, P=0.0002) and IDRs (4.2% vs. 5.8%; HR 0.71, 95% CI 0.53-0.95, P=0.02) in the QFR-guided group.
Landmark analysis also showed consistent results within the first year and between 1-2 years (P-interaction=0.99), he said, adding that although the 2-year MACE rate was lower in the QFR-guided group in both patients with and without revascularization strategy changes, the extent of outcome improvement was greater (P-interaction=0.009) among those patients in whom the pre-planned PCI strategy was modified by QFR.
“A QFR-guided strategy of lesion selection for PCI improved 2-year clinical outcomes compared with standard angiography guidance, with incrementally increasing benefits over time,” said Song.
“The reductions in MACE were most pronounced in patients in whom QFR assessment directed changes in the pre-PCI revascularization plan and in whom a QFR-concordant PCI strategy was performed.”
The study received funding from the National Clinical Research Center for Cardiovascular Diseases at Fuwai Hospital, Beijing Municipal Science and Technology Commission, and National High Level Hospital Clinical Research Funding. Pulse Medical (Shanghai, China) provided the QFR system and software at no charge for the study.
Song L, Xu B, Tu S, et al. Angiographic Quantitative Flow Ratio-Guided Coronary Intervention: Two-Year Outcomes of the FAVOR III China Trial. J Am Coll Cardiol 2022 Sep 19 (Article in press).
Image Credit: Jason Wermers/CRTonline.org