An intravascular ultrasound classification of angiographic coronary arteryaneurysms

The purpose of this study was to use intravascular ultrasound IVUS to clari fy the morphology of coronary aneurysms diagnosed by angiography. Seventy-s even consecutive patients with an aneurysmal dilatation in a native coronar y artery diagnosed by angiography (defined as a lesion lumen diameter 25% l arger than reference) were evaluated by IVUS. IVUS true aneurysms were defi ned as having an intact vessel wall and a maximum lumen area 50% larger tha n proximal reference. IVUS pseudoaneurysms had a loss of vessel wall integr ity and damage to adventitia or perivascular tissue. Complex plaques were l esions with ruptured plaque or spontaneous or unhealed dissection. Aneurysm al dilatation and reference segments were assessed using standard IVUS quan titative techniques. Twenty-one lesions (27%) were classified as true aneur ysms, 3 (4%) were classified as pseudoaneurysms, 12 (16%) were complex plaq ues, and the other 41 (530%) were normal arterial segments adjacent to grea ter than or equal to 1 stenosis. The maximum lumen area within the aneurysm al segment was largest for pseudoaneurysm (35.1 +/- 10.4 mm(2)), 22.1 +/- 9 .9 mm(2) for true aneurysm, and similar for complex plaques (11.2 +/- 3.5 m m(2)) and normal segments with adjacent stenoses (13.8 +/- 6.4 mm(2)): anal ysis of variance, p < 0.0001. Only one third of angiographically diagnosed aneurysms had the IVUS appearance of a true or pseudoaneurysm. instead, mos t angiographically diagnosed aneurysms had the morphology of complex plaque s or normal segments with adjacent stenoses. (C) 2001 by Excerpta Medica, I nc.