Tissue Characteristics of Residual Lesion in Patients With Acute Coronary Syndrome Caused by Plaque Rupture Versus Plaque Erosion: A Single-center, Retrospective, Observational Study

Abstract

PurposePatients with acute coronary syndrome (ACS), frequently caused by plaque rupture (PR), often have vulnerable plaques in residual and culprit lesions. However, whether this occurs in patients with plaque erosion (PE) as well is unknown. Therefore, we compared the tissue characteristics of residual lesions in patients with PE and those with PR.MethodsThe data of 88 patients with ACS who underwent both optimal coherence tomography (OCT) and intravascular ultrasound (IVUS) were retrospectively analyzed. Based on plaque morphology of the culprit lesions identified using OCT, patients were classified into PE and PR groups. The tissue characteristics of residual lesions evaluated using integrated backscatter IVUS were compared between the two groups after percutaneous coronary intervention. ResultsPatients were classified into the PE group (n=23) and PR group (n=35). The PE group had a significantly lower percent lipid volume and a higher percent fibrous volume than those of the PR group (35.0±17.8% vs. 49.2±13.4%, p<0.001; 63.2±17.1% vs. 50.3±13.1%, p=0.002, respectively). Receiver operating characteristic curve analysis revealed that the percent lipid volume in the residual lesions was a significant discriminant factor in estimating the plaque morphology of the culprit lesion (optimal cut-off value, <43.5%; sensitivity and specificity values were 73.9% and 68.6%, respectively).ConclusionsPatients with PE had a significantly lower percent lipid volume and a significantly higher percent fibrous volume in the residual lesions than in those with PR, suggesting that the nature of coronary plaques in patients with PE is different from that in patients with PR.