Morphometric Assessment for Functional Evaluation of Coronary Stenosis With Intravascular Ultrasound and Ultrasonic Flow Ratio in Vessels With a Single Stenosis

The ultrasonic flow ratio (UFR) can identify the functional severity of coronary stenosis, but it is unclear whether it can improve the diagnostic accuracy of intravascular ultrasound (IVUS) in determining coronary stenosis hemodynamics in vessels with a single stenosis. This study investigated the diagnostic performance of IVUS‐derived parameters in identifying functionally significant coronary stenosis in a vessel with a single stenosis.

Seventy vessels with a single stenosis in 68 patients were analyzed. All vessels underwent IVUS and determination of the Murray law‐based quantitative flow ratio (μQFR). IVUS images were used to determine the UFR. The correlation between UFR and μQFR was assessed using Spearman's method, Bland–Altman plots, and receiver operating characteristic (ROC) analysis. Risk factors were determined using univariate logistic regression analysis and multivariate stepwise logistic regression analysis.

UFR showed a good correlation with μQFR (r = 0.87, p < 0.001). With μQFR as the reference, the diagnostic accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of UFR were 98.57%, 95.24%, 100.00%, 100.00%, and 98.00%, respectively. With UFR/μQFR concordance, lesion length, minimal lumen diameter, and diameter stenosis in quantitative coronary angiography (QCA), minimal lumen area, plaque burden, and plaque volume in IVUS showed good diagnostic efficiency in determining the functional significance of coronary stenosis in a vessel with single stenosis. Multiple logistic regression models, including lesion length and diameter stenosis in QCA, and minimal lumen area in IVUS, provided superior predictive efficacy for physiologically significant ischemia.

UFR has a good correlation with μQFR. Without fractional flow reserve and μQFR, IVUS‐derived parameters and QCA derived parameters have relevant diagnostic efficiency in identifying the hemodynamic significance of coronary stenosis in a vessel with single stenosis.