Background: Intravascular Ultrasound (IVUS) is a supportive tool for coronary angiography in evaluating intermediate coronary lesions. However, old cut-off value of 4mm2 of IVUS Minimal Lumen Area (MLA) has been proved very low diagnosic accuracy. Objective: We aimed to assess a new cut-off value of IVUS MLA and its diagnostic performance to predict ischemia, using fractional flow reserve (FFR) as gold standard. Methods: Denovo Intermediate lesions were evaluated with both IVUS and FFR. A total of 32 lesions were enrolled into the study. Results: Thirty two patients, who had denovo intermediate lesions distributing at prox-mid segment of RCA (31.3%), LAD (59.4%) and LCx (6.2%), were enrolled into this study, with average age: 63.97±11.59 (years), male: 71.9% and female: 28.1%, mean diameter stenosis: 50.68% ± 8.83 and mean reference diameter: 2.99 mm ± 0.61mm. IVUS MLA (r = 0.386, p < 0.014) correlated with FFR. The stenotic diameter (r = -0.159, p < 0.192), the length (r = -0.052, p = 0.389) and the plaque volume (r = -0.105, p = 0.284) didn’t well correlate with FFR. Best cut-off value (BCV) of IVUS MLA to define the functional significance (FFR ≤0.8) was 2.55 mm2 (AUC 0.776; 95% CI 0.607-0.946) with sensitivity and specitivity were 66.7% and 88.2% respectively.
Conclusion: In this study, an IVUS MLA of 2.55 mm2 was the BCV to define the functional significance of denovo intermediate coronary stenosis. However, when IVUS MLA is used to determine the functional significance, both the lesion diameter and length should be considered.
Key words: intermediate lesion, intravascular ultrasound (IVUS), Fractional Flow Reserve (FFR)
Role of fractional flow reserve in guiding intervention for borderline coronary lesions
