Objectives: The goal of this study was to assess the incidence, clinical correlates, and angiographic appearance of ruptured atherosclerotic plaques detected in saphenous vein grafts (SVGs).
Background: Ruptured atherosclerotic plaques in native coronary arteries but not in SVGs have been well described with intravascular ultrasound (IVUS).
Methods: We reviewed 791 pre-intervention IVUS SVG studies and identified 95 ruptured plaques in 76 SVGs in 73 patients. Standard clinical, angiographic, and IVUS measurements were collected and/or measured. Ruptured plaques were compared with nonruptured plaques in 276 randomly selected patients.
Results: The IVUS-detected ruptured plaques had angiographically complex morphology (95%) with ulceration (79%), intimal flap (71%), and sometimes aneurysm formation (14%). Compared with control SVG lesions, ruptured plaques occurred more often in patients with acute coronary syndromes, in older SVGs (12.3 +/- 5.0 years vs. 8.6 +/- 5.2 years, p < 0.001), and in patients with hypercholesterolemia (92% vs. 81%, p = 0.021) and hypertension (78% vs. 63%, p = 0.015). Multiple ruptured plaques were identified in 22 patients in 19 grafts, more often in diabetic patients (55% vs. 29%, p = 0.054). A tear in the fibrous cap could be identified in 59% of plaques; in 70% it occurred at the shoulder of the plaque and in 30% at the center of the plaque. The IVUS features of ruptured plaques included positive remodeling in 71%, which was more common than in control plaques (40%, p < 0.001).
Conclusions: Ruptured atherosclerotic plaques occur in old SVGs with an incidence of 9.7%. These lesions have a complex angiographic appearance and positive remodeling characteristics. This is similar to ruptured plaques in native arteries.