Functional assessment of coronary artery lesions with fractional flow reserve (FFR) or instant wave-free ratio (IFR) have shown improvement of most symptoms and clinical outcomes of patients with stable CAD. However, these tools recommended by the current guidelines increase procedure complexity, risk and cost.
This is why the angiographic quantitative flow ratio-guided coronary intervention (QFR) has been created and validated, with good and accurate reproducibility with FFR. With the FAVOR III China has shown at one year improved clinical results after PCI when using QFR vs using conventional angiography.
The aim of this study was to determine whether the benefit of QFR persists at 2 years, particularly in patients where QFR changed revascularization strategy.
Primary end point (PFP) was major adverse cardiovascular events (MACE) defined as all cause death, AMI, or ischemia driven revascularization. Secondary end point included MACE with no periprocedural AMI, procedure duration, amount of contrast, change of PCI strategy and cost effectiveness.
3825 patients were randomized: 1913 to the QFR guided group and 1912 to the angiography guided group. Mean age was 62. The most frequent presentation was unstable angina (58%). Mean SYNTAX score was 9.5. The revascularization strategy was changed in 23% of patients in the QFR group and 6% in the conventional angiography group (p=0.0001) due to deferring treatment in those originally planned for PCI (19.6% vs. 5.2%, respectively, P<0.0001) and unplanned PCI in those not planned to receive it (4.4% vs 1.5% respectively, p<0.0001).
Read also: Patients with INOCA in the ISCHEMIA Trial.
Primary end point at 2 years was 8.5% in the QFR vs 12.5% in the conventional angiography group (HR 0.66, 95% CI 0.54-0.81; P<0.0001), at the expense of a lower rate of AMI (p=0.0002) and lower rate of clinical guided revascularization (p=0.02) in the QFR. MACE rate with no periprocedural AMI was also lower in the QFR (5.8% vs 8.8%, p=0.0004).
Patients whose intervention strategy was modified saw higher relative reduction of MACE, with better outcomes in patients with lesions differed because of QFR outcomes.
Conclusion
QFR guided lesion selection improved clinical outcomes at 2 years vs. Conventional angiography. The benefit was more pronounced in patients whose revascularization strategy was changed according to QFR.
Dr. Andrés Rodríguez.
Member of the Editorial Board of SOLACI.org.
Original Title: Angiographic Quantitative Flow Ratio-Guided Coronary Intervention: Two-Year Outcomes of the FAVOR III China Trial.
Reference: Lei Song, MD, et al Journal of the American College of Cardiology (2022).
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