Three-dimensional intravascular ultrasound evaluation of carina and plaque shift at the distal left main coronary artery bifurcation after treatment with a one-stent cross-over technique.

Abstract

OBJECTIVE: To assess the geometrical changes in the distal left main coronary artery (LMCA), left anterior descending (LAD), and left circumflex (LCX) that occur after a distal LMCA lesion is treated using a one-stent cross-over strategy. BACKGROUND: Morphological changes after stent implantation into distal LMCA lesions are not fully understood. METHODS: We used pre- and postintervention three-dimensional intravascular ultrasound of both the LAD and LCX as well as of the LMCA to evaluate distal LMCA lesions after a 1-stent cross-over strategy. In 38 distal LMCA bifurcation lesions, cross-sectional measurements were performed every 1 mm over a 5-mm segment in the LAD and LCX distal to the carina and over the entire LMCA proximal to the carina. RESULTS: The increase in lumen volume correlated with the increase in external elastic membrane volumes: R = 0.917, P < 0.001, in the LMCA and R = 0.785, P < 0.001, in the LAD with no decrease in plaque volume except at the distal end of the LMCA (P = 0.081) and at the LAD carina (P = 0.11). The LCX lumen area decreased significantly at the LCX carina from 5.9 ± 2.0 mm(2) to 5.3 ± 1.9 mm(2) (P < 0.01); however, the response was variable from a 4.0 mm(2) decrease to a 1.8 mm(2) increase in lumen area. While the change in LCX lumen area at the carina correlated with the change in vessel area (R = 0.791, P < 0.001), there was also a small increase in plaque area at the LCX carina from 6.4 ± 2.9 mm(2) to 6.8 ± 2.9 mm(2) (P < 0.01). CONCLUSIONS: LMCA bifurcation lumen changes after cross-over single-stent implantation were determined primarily by conformational changes in vessel geometry.