Optimal Intravascular Ultrasound Criteria for Defining the Functional Significance of Intermediate Coronary Stenosis: An International Multicenter Study

Abstract

OBJECTIVE: We aimed to assess the ideal cut-off value of minimal lumen area (MLA)

by intravascular ultrasound (IVUS) and its diagnostic performance to predict

ischemia, using a large-scale, pooled analysis. METHODS: Eleven centers worldwide

were invited to provide their clinical, IVUS and fractional flow reserve (FFR)

data. A total of 881 lesions were enrolled. RESULTS: Angiographic % diameter

stenosis (r = -0.373, p < 0.0001) and IVUS MLA (r = 0.289, p < 0.0001) correlated

with FFR. Best cut-off value (BCV) of IVUS MLA to define the functional

significance (FFR <0.8) was 2.75 mm(2) (AUC 0.646, 95% CI 0.609-0.684). When the

diagnostic performance of IVUS MLA was tested according to the lesion location,

BCV could be found only in lesions in the proximal artery and the mid-left

anterior descending artery. Interestingly, Asians (n = 623) and Westerners (n =

258) showed different demographic and lesion characteristics as well as different

BCVs to define ischemia. The BCV for the proximal/mid-left anterior descending

artery lesions was 2.75 mm(2) (AUC 0.688, 95% CI 0.635-0.742) in Asians and 3.0

mm(2) (AUC 0.695, 95% CI 0.605-0.786) in Westerners. CONCLUSION: In this pooled

analysis, an IVUS MLA of 2.75 mm(2) was the BCV to define the functional

significance of intermediate coronary stenosis. However, when IVUS MLA is used to

determine the functional significance, both the lesion and patient

characteristics should be considered.