Two-Year Outcomes Presented From FAVOR III China Trial of QFR-Guided Lesion Selection for PCI

September 19, 2022—Results presented from the FAVOR III China trial found that quantitative flow ratio (QFR) guidance for lesion selection for percutaneous coronary intervention (PCI) improved 2-year clinical outcomes compared with standard angiography guidance. The benefits of QFR, which enables online estimation of fractional flow reserve (FFR) without the use of a pressure wire or pharmacologic agents to induce hyperemia, were most pronounced among patients in whom QFR assessment altered the planned revascularization strategy.

The FAVOR III China findings were reported at TCT 2022, the 34th annual Transcatheter Cardiovascular Therapeutics scientific symposium of the Cardiovascular Research Foundation held September 16-19 in Boston, Massachusetts. The study was published online ahead of print by Lei Song, MD, et al in the Journal of the American College of Cardiology.

Dr. Song is Professor of Interventional Cardiology, Fuwai Hospital, National Center for Cardiovascular Disease, Chinese Academy of Medical Sciences and Peking Union Medical College in Beijing, China.

The study received support from the National Clinical Research Center for Cardiovascular Diseases, Fuwai Hospital, Beijing Municipal Science and Technology Commission, and National High Level Hospital Clinical Research Funding. Pulse Medical Imaging Technology (Shanghai) Co., Ltd, provided the QFR system and software for the study at no charge.

FAVOR III China was an investigator-initiated, multicenter, sham-controlled blinded randomized trial that compared QFR guidance with standard angiography guidance for lesion selection and monitored outcomes post procedure. Previously, the pivotal FAVOR III China trial demonstrated that lesion selection for PCI using QFR guidance improved 1-year clinical outcomes compared with conventional angiographic guidance.

As summarized in the TCT press release, the data, which encompassed 3,825 randomized patients, demonstrated the following:

• The 2-year major adverse cardiac events (MACE; a composite of all-cause death, myocardial infarction [MI], or ischemia-driven revascularization [IDR]), occurred in 8.5% of patients in the QFR-guided group versus 12.5% of patients in the angiography-guided group (hazard ratio [HR], 0.66; 95% CI, 0.54-0.81; P < .0001).
• The MACE difference was driven by fewer MIs (4.0% vs 6.8%; HR, 0.58; 95% CI, 0.44-0.77; P = .0002) and fewer IDRs (4.2% vs 5.8%; HR, 0.71; 95% CI, 0.53-0.95; P = .02) in the QFR-guided group.

The results were consistent within the first year and between 1 to 2 years (P = .99 for interaction), noted the investigators.

Compared with the prerandomization-intended lesion selection based on angiography guidance, the revascularization strategy was changed after randomization in 445 (23.3%) patients in the QFR-guided group and 119 (6.2%) patients in the angiography-guided group (P < .0001).

The change was because of treatment deferral of at least one vessel originally intended for PCI (19.6% and 5.2%, respectively; P < .0001) and unplanned PCI of at least one vessel not originally intended to be treated (4.4% and 1.5%, respectively; P < .0001).

Additionally, the investigators reported that PCI was performed less frequently, fewer stents and less contrast were used, and the residual SYNTAX score was lower in the QFR-guided group compared with the angiography-guided group in those patients who had the PCI strategy changed.

The TCT press release advised that although the MACE rate at 2 years was lower with QFR guidance both in patients in whom the preplanned PCI revascularization strategy changed (HR, 0.34; 95% CI, 0.21-0.55) and those in whom it did not change (HR, 0.70; 95% CI, 0.56-0.88) after randomization, those with strategy changes had a greater relative reduction in MACE (P = .009 for interaction), driven by better outcomes in patients in whom vessels that had been intended to be treated were deferred after QFR assessment.

Patients with pre-PCI QFR-concordant versus nonconcordant treatment had a lower risk of 2-year MACE (8.8% vs 17.2%; P < .0001) and MACE excluding periprocedural MI (6.1% vs 11.9%; P < .0001). This benefit of QFR-concordant treatment was present in both patients randomized to QFR guidance and angiography guidance.

Dr. Song commented in the TCT press release, “Two-year outcomes of a QFR-guided vessel and lesion selection strategy showed that the benefits of QFR guidance continued to accrue over time compared with standard angiography guidance in patients undergoing PCI. Improvement was greatest among patients in whom the PCI strategy was modified by QFR as well as those who had QFR-concordant PCI.”

In conclusion, Dr Song advised, “Longer-term follow-up is needed to determine whether the 2-year benefits of QFR guidance for PCI lesion selection are preserved, increase, or diminish over time.”