Early lumen diameter loss after percutaneous transluminal coronary angioplasty is related to coronary plaque burden: a role for viscous plaque properties in early lumen diameter loss.

OBJECTIVES: We tested the hypothesis that lumen diameter loss within 1 h after percutaneous transluminal coronary angioplasty is related to plaque volume parameters.
BACKGROUND: Early lumen diameter loss after coronary balloon angioplasty may predict restenosis and may paradoxically decrease late lumen diameter loss. Viscous properties of the vessel wall, as would be determined by tissue volume and composition, may be involved in early lumen diameter loss.
METHODS: Early lumen diameter loss was measured with quantitative coronary angiography as the loss in lesion lumen diameter (significant loss 0.4 mm) occurring between 5 min and a median of 40 min after successful coronary balloon angioplasty in 68 patients. Thirty-nine patients were evaluated with intravascular ultrasound at the narrowest lumen cross-section of the dilated lesion, 29 patients formed a control group without intravascular ultrasound imaging. We tested the relation between intravascular ultrasound parameters and early lumen diameter loss.
RESULTS: Early lumen diameter loss of > or = 0.4 mm was present in eight patients (12%), decreasing lumen diameter from 2.26 +/- 0.36 mm to 1.73 +/- 0.43 mm. There was no difference in the frequency of early lumen diameter loss between the groups with or without intravascular ultrasound imaging. Univariate intravascular ultrasound determinants of early lumen diameter loss were media bounded area (p = 0.01), maximal plaque thickness (p = 0.02), eccentricity index (p = 0.03) and the presence of hard lesions (p = 0.02).
CONCLUSION: Early lumen diameter loss in the first hour after successful coronary balloon angioplasty occurs in a small proportion of patients. It is related to hard lesion type, maximal plaque thickness and eccentricity index, favoring a role for viscous plaque properties in early lumen diameter loss.