Coronary plaque rupture is associated with carotid thermal heterogeneity in patients presenting with acute myocardial infarction
Authors: Bounas P , Synetos A , Karanasos A , Papanikolaou A , Drakopoulou M , Latsios G , Trantalis G , Olympios C , Tousoulis D , Toutouzas K 
Published: November 2020

Abstract

Introduction
Vulnerable plaques of the coronary arteries, share common characteristics such as the thin cap fibrous cap, that make the prone to rupture in the presence of stimulus such as shear stress or inflammation. Optical coherence tomography (OCT) is an imaging method, by which the fibrous cap and the presence of plaque rupture can be accurately in vivo visualized. Recent studies have shown an association between increased carotid temperature heterogeneity (ΔT) detected by microwave radiometry (MWR) and cardiovascular events.

Purpose
To evaluate the impact of carotid temperature heterogeneity on the culprit plaque morphology on patients presenting with acute myocardial infarction.

Method
A total of 37 patients undergoing percutaneous coronary intervention (PCI) for an acute myocardial infarction who had an identifiable de novo culprit lesion in a native coronary artery, were enrolled in this study. All patients underwent PCI and Optical Coherence Study (OCT) within 12 hours since symptom onset. The culprit lesion of the angiogram was clearly identified by a combination of ECG, wall motion abnormalities seen in cardiac ultrasound, and coronary angiogram. The OCT study was performed using the LightLab OCT wire, and acquired images were analyzed by 2 independent investigators using previously validated criteria for OCT plaque characterization. After the completion of the PCI all patients underwent MWR of both carotid arteries and ΔT was defined as maximal temperature detected along each carotid artery minus minimum.

Results
Thirty four patients with acute myocardial infarction 21 with STEMI (61.76%) and 13 (38.23%) with NSTEMI were included in the study. STEMI patients had more ruptured plaques compared to NSTEMI patients (71.41 versus 38.46%, p=0.053). Thin cap fibroatheroma (TCFA) was present in 31 patients (91.1%), while all ruptured plaques had a TCFA compared to 11 TCFA (78.57%) observed in plaques that had no rupture (p=0.03). HsCRP was significantly increased in ruptured plaques compared to non ruptured ones (14.41±4.02 versus 9.9±2,5, p&lt;0.005). Mean ΔT was significantly increased in ruptured plaques compared to no ruptured ones (1.01±0.31 versus 0.51±0.14°C, p&lt;0.005), as well as in plaques with TCFA compared to those without a TCFA (0.82±0.37 versus 0.60±0.05°C, p=0.001). In the multivariate analysis, STEMI, hsCRP, and ΔT were entered from which hsCRP (OR 1.51; 95% CI 0.99–2.28; P=0.051) and ΔT ((OR for 0.1°C increase 3.40; 95% CI 1.29–8.96; P=0.013) remained in the final model, with ΔT being the only variable independently associated with the presence of rupture.

Conclusions
Carotid thermal heterogeneity is associated with the presence of plaque rupture in patients with acute myocardial infarction. Further studies are needed in order to assess the possible prognostic impact of carotid ΔT on such population.

Funding Acknowledgement
Type of funding source: None