Thrombus and Plaque Erosion Characterized by Optical Coherence Tomography in Patients With Vasospastic Angina

Vasospastic angina (VSA) can result in endothelial damage and thrombus formation. The aim of this study was to evaluate the incidence of thrombus and plaque characteristics at coronary spasm segments compared with nonspasm segments by using optical coherence tomography (OCT) in patients with suspected VSA.

One hundred and eighty-three patients with suspected VSA were enrolled in this study. The ergonovine provocation test was performed in all patients for the diagnosis of VSA except in patients with spontaneous spasm. All target lesions were analyzed by OCT. Plaque erosion was defined as the presence of attached thrombus overlying an intact fibrous cap and visualized plaque on multiple adjacent OCT frames.

One hundred and nine spasm segments (93 patients) were compared with 55 nonspasm segments (39 patients). Thrombus was more frequently seen at spasm segments than at nonspasm segments (28.4% vs 7.3%; P = .026) and thrombus size was larger at spasm segments than at nonspasm segments (0.26 ± 0.50 mm² vs 0.04 ± 0.01 mm²; P = .023). Thin-cap fibroatheroma was more frequently seen at nonspasm segments than at spasm segments (16.4% vs 1.8%; P = .006). Plaque erosion was more prevalent at spasm segments than at nonspasm segments (25.7% vs 5.4%; P = .001).

Thrombus and plaque erosion were more common at spasm segments than at nonspasm segments assessed by OCT in patients with suspected VSA. These findings suggest the potential benefit and treatment role of antiplatelet therapy in vasospastic angina.