Validation of virtual fractional flow reserve pullback curves.

Area of Science:

• Cardiovascular medicine
• Interventional cardiology
• Medical imaging analysis

Background:

• Angiography-derived fractional flow reserve (FFR) has demonstrated high diagnostic accuracy.
• Virtual FFR pullback curves, a novel application, require validation against traditional wire-based FFR methods.

Purpose of the Study:

• To validate virtual FFR pullback curves against wire-based FFR pullbacks.
• To assess the clinical utility of virtual FFR pullbacks using patient-reported outcomes.

Main Methods:

• A pooled analysis of two prospective studies involving patients with significant coronary artery disease (CAD).
• Comparison of virtual and wire-based FFR pullbacks for characterizing CAD as focal or diffuse.
• Quantitative analysis using pullback pressure gradient (PPG) and visual assessment.
• Patient-reported outcomes using the Seattle Angina Questionnaire (SAQ) post-percutaneous coronary intervention (PCI).

Main Results:

• Analysis included 298 patients (300 vessels) with both virtual and wire-based pullbacks.
• Fair agreement was observed in visual assessment of CAD patterns (Cohen's Kappa: 0.31).
• Mean PPG values showed strong correlation (r=0.68) between virtual and wire-based methods.
• Patients with high virtual PPG reported significantly better angina frequency post-PCI.

Conclusions:

• Virtual FFR pullback curves exhibit moderate agreement with wire-based FFR pullbacks.
• Virtual FFR PPG is a valuable tool for characterizing CAD and predicting angina improvement after PCI.