Limitations of angiography in the assessment of plaque distribution in coronary artery disease: A systematic study of target lesion eccentricity in 1446 lesions

Background Plaque distribution (eccentricity) may be a determinant of the success of transcatheter therapy, and certain devices may be better suited to treating severely eccentric lesions than others. However, no study has compared methods for assessing plaque distribution or systematically studied the validity of the angiographic assessment of plaque distribution. Methods and Results We studied 1446 native vessel target lesions in 1349 patients by intravascular ultrasound and coronary angiography. Angiographic and intravascular ultrasound criteria for lesion eccentricity were compared. Angiography showed that 795 of 1446 (55.0%) of target lesions were eccentric. When intravascular ultrasound was used, only 219 lesions (15.1%) had an are of normal arterial wall within the lesion (equivalent to the pathological definition of lesion eccentricity). When an eccentricity index of greater than or equal to 3.0 was used, intravascular ultrasound classified 659 lesions (45.6%) as eccentric. The concordance rates of classification were only 47.7% (versus lesions containing an are of normal arterial wall) and 53.8% (versus lesions with an ultrasound eccentricity index of greater than or equal to 3.0). More eccentric lesions had larger lumen cross-sectional areas, smaller plaque plus media and external elastic membrane cross-sectional areas, and smaller arcs of calcium, suggesting that they may represent less advanced atherosclerotic disease. Conclusions There was significant discordance between angiography and ultrasound in assessing plaque distribution. Angiography appeared to detect lesion eccentricity more often than intravascular ultrasound. Furthermore, markedly eccentric lesions, in which there is an are of normal vessel wall, were uncommon.