Evaluation of guidewire artifact subtraction in quantitative and tissue analysis with intracoronary ultrasound and iMAPTM technology in patients presenting with acute coronary syndrome: an iWonder study subanalysis

Abstract

Background

Intravascular ultrasound (IVUS) is the most widely used ancillary method in Interventional Cardiology, and its analysis depends on standards for acquisition, measurement and interpretation of the images. By associating tissue characterization, the artifact caused by the guidewire may overestimate the percentage of necrotic core in certain lesions, leading to misclassification of fibroatheroma. In this paper we described quantitative and tissue analysis effects resulting from subtracting the effect of guidewire artifact on atherosclerotic lesions in patients with acute coronary syndrome.

Methods

Twenty-one patients with post-thrombolysis myocardial infarction were evaluated with grayscale IVUS and iMAP^TM technology, totaling 76 lesions.

Results

Grayscale IVUS showed that the lesions had a mean length of 21.01 ± 18.03 mm and revealed high plaque burden (52.07 ± 7.56%). The analysis by iMAP^TM demonstrated that, after subtracting the guidewire artifact, there was a reduction of all tissue (necrotic, calcific, lipid and fibrotic) components, but more markedly in necrotic core (mean difference: 3.59%). In addition, after artifact subtraction 12.4% of the lesions that initially exhibited a necrotic core ≥ 10% ceased to be classified as fibroatheroma.

Conclusions

An atheroma analysis by iMAP^TM technology showed that the guidewire artifact overestimated the tissue component of the necrotic core. This interference may change, in an erroneous and categorical way, the phenotypic characteristics of more stable and benign (fibrotic) lesions to potentially unstable lesions, for example, fibroatheromas, in a ratio of one out of ten patients.