Physiologically Guided CABG Improves Outcomes in Valve Surgery Patients

Fresh research indicates that guiding coronary artery bypass grafting (CABG) with physiological assessments, specifically angiography-derived fractional flow reserve (Angio-FFR), significantly improves outcomes for patients undergoing valve surgery with concurrent coronary artery disease (CAD). This approach, compared to traditional angiography-guided CABG, reduces perioperative complications and may offer a more selective and effective method for surgical revascularization.

The FAVOR IV-QVAS Trial: A Landmark Study

The findings stem from the FAVOR IV-QVAS trial (NCT03977129), a pivotal randomized controlled trial conducted across 12 centers in China between 2019 and 2024. The study enrolled 793 patients scheduled for primary valve surgery who presented with at least one coronary stenosis of 50% or greater in a major epicardial vessel suitable for grafting . Participants were randomly assigned to either Angio-FFR–guided CABG or conventional coronary angiography (CAG)-guided CABG.

How Angio-FFR Guided the Procedure

In the Angio-FFR–guided CABG group, grafts were performed only on vessels ≥1.5 mm with ≥50% stenosis and an Angio-FFR ≤0.80. This means that bypasses were only created for areas of the artery where blood flow was significantly restricted, as determined by the Angio-FFR assessment. The conventional CAG-guided CABG group, however, underwent bypass grafting for all angiographic stenoses ≥50% .

Key Findings and Benefits

The FAVOR IV-QVAS trial demonstrated a substantial reduction in perioperative complications – nearly halved – in the Angio-FFR–guided CABG group compared to the conventional approach . The primary endpoint, a composite of all-cause death, non-fatal myocardial infarction, non-fatal stroke, unplanned coronary revascularization, and new renal failure requiring dialysis, was evaluated 30 days post-surgery.

• Reduced Complications: Angio-FFR guidance led to fewer perioperative complications.
• Selective Revascularization: AI-powered physiologic guidance allowed for a reduction in the number of grafts performed without compromising the completeness of revascularization .
• First Randomized Evidence: The trial provides the first randomized evidence supporting physiology-based surgical revascularization .

Understanding Angio-FFR and its Role in CABG

Fractional flow reserve (FFR) is a measurement of blood flow through a coronary artery. Angio-FFR builds upon this by deriving FFR information directly from coronary angiography images, eliminating the require for invasive pressure wire measurements . This allows surgeons to assess the functional significance of coronary artery blockages and determine which lesions truly require bypass grafting.

Implications for Future Practice

The results of the FAVOR IV-QVAS trial suggest a shift towards a more personalized and physiologically guided approach to CABG in patients undergoing valve surgery. By selectively revascularizing only those areas with significant blood flow limitations, surgeons can potentially minimize the risks associated with unnecessary grafting and improve overall patient outcomes. Further research is ongoing to refine the application of Angio-FFR and explore its benefits in other patient populations.

Previous Research on FFR-Guided CABG

Prior studies, such as one from 2013 by Toth et al., have also indicated that FFR-guided CABG can reduce the number of graft anastomoses and the on-pump surgery rate. Bypass graft patency at 3 years was shown to be higher with FFR-guided compared to angiography-guided CABG .