Optical Coherence Tomography-Based Functional Stenosis Assessment: FUSION-A Prospective Multicenter Trial

Area of Science:

• Cardiovascular Imaging
• Interventional Cardiology
• Medical Device Technology

Background:

• Percutaneous coronary intervention (PCI) guidance often relies on intravascular imaging or intracoronary physiology, but rarely both.
• Virtual flow reserve (VFR) is an optical coherence tomography (OCT)-based model estimating fractional flow reserve (FFR) to assess coronary lesion significance.

Purpose of the Study:

• To validate the accuracy of OCT-derived VFR in assessing intermediate coronary artery stenoses.
• To compare VFR performance against invasive FFR as the gold standard.

Main Methods:

• The FUSION study was a multicenter, prospective, observational trial comparing OCT-derived VFR with invasive FFR.
• VFR was calculated using a 3D lumen morphology-based flow model from OCT data.
• Patients with 40%-90% angiographic stenosis underwent both OCT and FFR assessments, with VFR analysis blinded to site investigators.

Main Results:

• The analysis included 266 vessels from 224 patients across 25 US centers.
• OCT-derived VFR demonstrated an overall accuracy of 82.0%, sensitivity of 80.4%, and specificity of 82.9% compared to invasive FFR (cutoff ≤0.80).
• The study met prespecified performance goals for both sensitivity (71.6%) and specificity (76.6%), with an area under the curve of 0.88.

Conclusions:

• OCT-derived VFR is a sensitive and specific method for predicting invasive FFR values.
• Combining high-resolution intravascular imaging with imaging-derived physiology offers potential synergistic benefits for guiding PCI.