Abstract 14184: Patients With Coronary Artery Disease and Bilateral Carotid Inflammation Show Higher One Year Rate of Cardiovascular Events

Abstract

Background: Inflammation is an essential characteristic of vulnerable atherosclerotic plaque. Although its prognostic value during invasive assessment has been documented, the clinical significance of its routine evaluation is still under dispute. Microwave radiometry (MWR) allows the rapid, in vivo, noninvasive assessment of the internal temperature of carotid arteries, reflecting local inflammation. The aim of the present study was to evaluate the prognostic role of carotid atherosclerotic plaque temperatures in patients with documented coronary artery disease (CAD). Methods: Consecutive patients with significant CAD as documented by coronary angiography were included in the study. All patients underwent evaluation of both carotid arteries by 1) ultrasound and 2) microwave radiometry (MWR). During ultrasound study maximum carotid plaque thickness was assessed in all carotids. Temperature difference (ΔT) by MWR was defined as maximal temperature along the carotid artery minus minimum. ΔT ≥0.90°C was assigned as high ΔT. Major cardiovascular event (MACE) was defined as death, stroke, myocardial infarction or revascularization. All patients were followed-up clinically for one year. Results: In total 192 patients were included in the study. At baseline thirty patients (15.6%) had high ΔT temperatures (≥0.90°C) in both carotid arteries. Max plaque thickness was slightly higher in this group (2.75±1.34 vs 2.27±1.03, p=0.07). MACE was 23.3% in the group with bilateral high ΔT and 4.3% in non-high ΔT group (p<0.001). By multivariate logistic regression analysis, ΔT was an independent predictor for MACE, when adjusted for sex, age contemporary risk factors, number of vessels with significant stenosis and maximum carotid plaque thickness (OR: 6.10, 95% CI 1.56-23.80, p=0.001). In Kaplan-Meier plots patients with bilateral high ΔT showed higher event and mortality rates, compared with patients in non-high ΔT group (log-rank p=0.001 for both comparisons). Conclusion: The presence of bilateral high carotid artery temperatures as assessed by MWR has implications in short term prognosis of patients with CAD. A long term study is warranted to establish the prognostic impact of MWR in this high-risk population.