Detection of Plaque Neovascularization by Optical Coherence Tomography: Ex Vivo Feasibility Study and In Vivo Observation in Patients With Angina Pectoris.

OBJECTIVES

The purposes of this study were: (1) to assess the feasibility of optical coherence tomography (OCT) for detecting neovascularization; and (2) to clarify the impact of plaque neovascularization on coronary vessel behavior over time.

BACKGROUND

Plaque neovascularization may be related to plaque vulnerability.

METHODS

In an ex vivo study, a total of 55 coronary plaques from 31 human cadavers were examined by OCT. Plaque neovascularization was diagnosed based on the presence or absence of microchannels (MCs) by OCT. In an in vivo study, we explored 83 major coronary arteries from 42 patients with angina pectoris. A total of 56 coronary plaques were selected from non-culprit (non-stented) lesions with plaque burden >40% by intravascular ultrasound (IVUS). These plaques were classified into two groups based on the presence or absence of MC by OCT.

RESULTS

In the ex vivo study, the sensitivity and specificity of OCT to detect plaque neovascularization were 52% and 68%, respectively. In the in vivo study, MC was detected in 25 plaques (44.6%). High-density lipoprotein cholesterol was significantly lower in the MC group vs the non-MC group (42.7 ± 7.8 mg/dL vs 51.6 ± 14.4 mg/dL; P=.02). Percent change in lumen volume index (VI) in the MC group was significantly greater vs the non-MC group (P=.01). Percent change in lumen VI correlated significantly with percent change in external elastic membrane VI (P=.01).

CONCLUSIONS

OCT was feasible for detecting neovascularization of coronary plaques. Serial OCT examinations revealed that coronary plaques with neovascularization showed greater luminal narrowing as a result of inadequate adaptive vessel remodeling.