Morphological and Tissue Characterization of Culprit Lesions in Patients with ST-Segment Elevation Myocardial Infarction After Thrombolytic Therapy. Analysis with Grayscale Intravascular Ultrasound and iMAP^TM Technology

Background:

Currently, there is a great debate about the pathophysiology of acute myocardial infarction and tissue composition and morphology of lesions responsible for ischemic events. However, few studies have investigated the applicability of tissue characterization using iMAP^TM technology in these patients. We evaluated patients with ST-segment elevation myocardial infarction after thrombolytic therapy with grayscale intravascular ultrasound and iMAP^TM technology to describe the tissue composition of the culprit lesions.

Methods:

Twenty-five ST-segment elevation myocardial infarction patients with successful reperfusion had the three major epicardial coronary arteries evaluated by grayscale intravascular ultrasound and iMAP^TM technology.

Results:

Mean age was 51 ± 11.5 years with a prevalence of males (72%). The artery most often involved was the right coronary artery (48%). Intravascular ultrasound showed that the culprit lesions were long (mean extension 31.0 ± 17.2 mm) with a high percent of plaque volume (58.5 ± 5.1%). At the point of highest obstruction (minimal luminal area), the plaque burden was 82.5 ± 7.5%. Furthermore, the mean remodeling index was 1.4 ± 1.0, indicating positive remodeling. iMAP^TM analysis of the lesion and minimal luminal area showed a prevalence of fibrotic and necrotic components when compared to other components.

Conclusions:

In ST-segment elevation myocardial infarction patients, the culprit lesion showed a prevalence of positive arterial remodeling and the necrotic core component in the composition of the culprit plaque corroborating in vivo the main pathophysiology of acute atherosclerotic disease.

Myocardial infarction; Plaque, atherosclerotic; Thrombolytic therapy; Ultrasonography