Feasibility of a novel radiofrequency signal analysis for in-vivo plaque characterization in humans: Comparison of plaque components between patients with and without acute coronary syndrome

BackgroundThe iMAP™ is a novel intravascular ultrasound (IVUS)-based technology to classify coronary plaque into 4 components. The aim of this study was to evaluate the feasibility of iMAP™ technology by comparing plaque characteristics in patients with and without acute coronary syndrome (ACS and non-ACS).Materials and methodsA total of 93 culprit lesions from 87 patients were analyzed using the iMAP™. Each plaque was classified into 4 components with a newly introduced parameter, confidence level (CL).ResultsiMAP™ analysis of the minimal lumen cross-sectional area (MLA) revealed that ACS lesions had significantly larger lipidic and necrotic areas than non-ACS lesions. Multivariate analysis revealed that the lipidic area at the MLA was an iMAP™ factor independently associated with ACS lesions (odds ratio − 1.5, p = 0.04). Based on receiver operating characteristic analysis with 4 different CL ranges, the lipidic area at the MLA with 25%-100% CL had the largest area under the curve (0.756), suggesting that 25%-100% is the best CL range for identifying ACS culprit lesions.ConclusionsThe feasibility of the novel iMAP™ IVUS system was shown in discriminating culprit lesions in patients with and without ACS. Analyzing with a CL of 25%-100% may be the best option for discriminating lesions.