Correlation between morphologic characteristics and local temperature differences in culprit lesions of patients with symptomatic coronary artery disease

Objectives The purpose of this study was to investigate the possible correlation between morphologic and functional characteristics of culprit lesions (CL) in patients with acute coronary syndromes (ACS) and chronic stable angina (CSA). Background Intravascular ultrasound (IVUS) provides morphologic assessment and intracoronary thermography (ICT) evaluates the local inflammatory activation of CL. Methods Eighty-one consecutive patients, 48 with ACS and 33 with CSA, were enrolled. Ratio of lesion to reference external elastic membrane area, indicated by IVUS, was defined as positive remodeling index (pRi) (>= 1) or negative remodeling index (nRi) (<1). We also investigated the existence of ruptured plaque (rp) in the CL. By ICT temperature difference (Delta T) between the CL and the proximal vessel wall was measured. Results Patients with ACS had greater remodeling index than patients with CSA (1.15 +/- 0.18 vs. 0.90 +/- 0.12; p < 0.01), as well as increased Delta T (0.08 +/- 0.03 degrees C vs. 0.04 +/- 0.02 degrees C; p < 0.01). Patients with pRi had higher Delta T than patients with nRi (0.07 +/- 0.03 degrees C vs. 0.04 +/- 0.02 degrees C; p < 0.001). In patients with nRi there was no difference in AT between ACS and CSA (p = 0.22). Patients with rp had increased Delta T compared with patients without rp (0.09 +/- 0.03 degrees C vs. 0.05 +/- 0.02 degrees C; p < 0.01). Multivariate analysis showed that Delta T was independently correlated with the presence of rp, pRi, and ACS. Conclusions The present study showed that culprit lesions with plaque rupture and positive arterial remodeling have increased thermal heterogeneity, although in certain patients a discrepancy between morphogic and functional characteristics was observed. A combination of morphologic and functional examination may offer additional diagnostic and prognostic information.