Combined use of OCT and IVUS in spontaneous coronary artery dissection.

SPONTANEOUS CORONARY ARTERY DISSECTION (SCAD) REPRESENTS A DIAGNOSTIC CHALLENGE (1,2). In this study, we used a combined imaging strategy, intravascular ultrasound (IVUS) and optical coherence tomography (OCT), in 8 patients with SCAD. The diagnosis of SCAD required the visualization of an intimomedial membrane with a double-lumen or intramural hematoma (Figs. 1, 2, and 3). Their mean age was 50 10 years, 6 patients were female, and all presented with acute coronary syndromes. Angiographically, all patients had diffuse lesions (38 23 mm), but only 1 showed a radiolucent flap. Both imaging techniques clearly depicted the true and false lumens (Figs. 1, 2, and 3). OCT was superior to IVUS in the identification of intimal ruptures and intraluminal thrombi (Table 1). OCT nicely depicted the false lumen/intramural hematoma, but its full extension could not be measured in some areas because of residual blood, shadowing, or insufficient penetration. On IVUS, the lumenintimal interface was not as sharply delineated, but this technique enabled a more complete vessel visualization with significantly longer assessment of the diseased segment and larger false lumen areas (Table 1). In 5 cases, IVUS unraveled a characteristic heterogeneous pattern within the false lumen (Fig. 3). In 2 patients, the dissecting membrane had blurred trailing edges on OCT, whereas IVUS revealed a characteristic 3-layered appearance overhanging a darker thrombosed false lumen (Fig. 2). After stenting (n 1⁄4 3), residual abluminal and distal hematomas were well detected with both techniques, but malapposed struts were more clearly visualized by OCT (Table 1). Our findings suggest that the combined use of OCT and IVUS provides valuable, unique, and complementary diagnostic insights on the pathophysiological substrate of SCAD.