Measurement of the blood flow rate and velocity in coronary artery stenosis using intracoronary frequency domain optical coherence tomography: Validation against fractional flow reserve

Objectives: The main objective of this study was to assess the blood flow rate and velocity in coronary artery stenosis using intracoronary frequency domain optical coherence tomography (FD-OCT). A correlation between fractional flow reserve (FFR) and FD-OCT derived blood flow velocity is also included in this study. Methods & results: A total of 20 coronary stenoses in 15 patients were assessed consecutively by quantitative coronary angiography (QCA), FFR and FD-OCT. A percutaneous coronary intervention (PCI) optimization system was used in this study which combines wireless FFR measurement and FD-OCT imaging in one platform. Stenoses were labelled severe if FFR. ≤. 0.8. Blood flow rate and velocity in each stenosis segment were derived from the volumetric analysis of the FD-OCT pull back images. The FFR value was ≤. 0.80 in 5 stenoses (25%). The mean blood flow rate in severe coronary stenosis (. n=. 5) was 2.54. ±. 0.55. ml/s as compared to 4.81. ±. 1.95. ml/s in stenosis with FFR. >. 0.8 (. n=. 15). A good and significant correlation between FFR and FD-OCT blood flow velocity in coronary artery stenosis (. r=. 0.74, p<. 0.001) was found. Conclusion: The assessment of stenosis severity using FD-OCT derived blood flow rate and velocity has the ability to overcome many limitations of QCA and intravascular ultrasound (IVUS).