Background: Coronary vein grafts develop accelerated atherosclerosis after aortocoronary bypass surgery. Previous pathologic studies have suggested that the morphologic appearance of atherosclerotic lesions in saphenous vein grafts may have subtle differences compared with those of native coronary arteries and may be more prone to disruption and thrombus formation. However, a comparative in vivo assessment of the angioscopic morphology differences between these two types of vessels has not been reported previously. We compared the angioscopic lesion morphology of native coronary arteries and saphenous vein grafts in patients with unstable angina.
Methods and results: Percutaneous coronary angioscopy was performed in 60 consecutive patients with unstable angina. Plaque color, texture, friability, and the presence of atherosclerotic plaque ulceration or intracoronary thrombus were noted in the culprit lesion. The culprit lesion was located in native coronary arteries in 42 (70%) patients and in a saphenous vein graft in 18 (30%) patients. There were no significant differences in age, sex, and coronary risk factors including tobacco use, hypertension, hypercholesterolemia, or diabetes mellitus between the two populations. There were also no significant differences between the two groups in terms of plaque color, surface texture, or the incidence of complex plaque morphology (plaque ulceration and intracoronary thrombosis). Loosely adherent, friable plaque, detected by angioscopy, was absent in native coronary arteries and was present in 44% of the saphenous vein grafts (p < 0.0001).
Conclusions: The results of our angioscopic study indicate that other than a high incidence of plaque friability in vein grafts, the surface morphology of culprit lesions in unstable angina patients is quite similar for saphenous vein grafts and native coronary arteries.