768-3 Yellow Plaques and Vessel Morphology Prior to Coronary Intervention. A Study Using Intracoronary Angioscopy

Angioscopy provides a direct and chromatic visualization of the intimal surface of the coronary arteries, providing an opportunity to assess in-vivo the characteristics of the culprit lesion in stable and unstable syndromes. We performed angioscopy in 78 patients prior to coronary interventions. Twenty five had stable angina (SAP), 36 unstable angina (UAP) defined as classes IIB and IIIB of the Braunwald classification, and 17 patients had post-infarction angina (Braunwald IIIC) (POST-MI). The parameters evaluated in the stenotic segment were: 1) lumen shape: round or elliptical vs complex (COMPlEX). 2) intimal surface: ulcerated (UlC) vs non-ulcerated. 3) presence of yellow plaque (YEL). 4) presence of red thrombi (THR). A THR score was derived from THR morphology: single mural (1 point), multiple mural (2), protruding (3), occlusive (4). and then multiplied by the extent of segments with THR (proximal, mid and distal lesion). Angiography was used to classify lesions as unstable or stables according to a modified Ambrose classification. Results An angiographic unstable lesion was present in 44%, 39% and 41% of the lesions, respectively in SAP, UAP and POST-MI with a predictive value for an angioscopic complex lesion of 0.63. Angioscopy SAP UAP POST-MI p value COMPLEX 5 (20%)*¥ 14 (39%)* 11 (65%)¥ <0.05*¥ ULC 3 (12%)*¥ 17 (47%)* 9 (53%)¥ <0.05*¥ Red Thrombus 4 (16%)*¥ 25 (69%)* 14 (82%)¥ <0.05*¥ THR score 3.25±2.22 496±329 586±466 ns Yellow plaque 18 (72%) 22 (66%) 12 (71%) ns Thrombotic burden was higher, whenever a yellow plaque was present near a THR (THR score 3.08±2.07, YEL present vs. 5.87±3.93, no YEL, p<0.05). Conclusions Vessel ulceration and thrombosis is frequently found in UAP and POST-MI, but is poorly predicted by angiography. Yellow plaques are present in the majority of the patients and when ruptured they are associated with a larger thrombus formation. This may partially explain the benefits of anti-lipid therapy.