A volumetric intracoronary ultrasonographic study of coronary bifurcation lesions

To evaluate the plaque distribution and composition pattern in the left main coronary artery (LMCA) disease using intracoronary ultrasound.

Intravascular ultrasound data of 50 patients from the January 2010 to December 2015 with significant LMCA bifurcation lesions, with angiographic diameter stenosis >50%, and requiring revascularization, were evaluated. Plaque burden and percentage of necrotic core (% NC) at the minimal lumen area site and maximal % NC site were measured in different segments. The segments that were included in the study are as follows: segment 1: proximal LMCA, segment 2: left anterior descending (LAD) ostium, segment 3: left circumflex branch (LCX) ostium, segment 4: proximal LAD, segment 5: proximal LCX. According to its relationship with the bifurcation ridge, the blood vessel wall was divided into the contralateral bifurcation ridge blood vessel wall and bifurcation ridge blood vessel wall.

Plaque burden results showed that the plaque eccentricity index of segment 2 and segment 3 was significantly higher than that of the other segments at sites of the minimal lumen area and maximal % NC with a statistically significant difference (p<0.05). Plaque eccentricity index of contralateral bifurcation ridge was significantly higher than that of the bifurcation ridge, and the difference was statistically significant (p<0.05). Analysis of plaque composition showed the fibrous tissue percentage of segment 2 and segment 3 was significantly higher than the other segments that at the sites of minimal lumen area and the maximal % NC site. The fibrous percentage of the contralateral bifurcation ridge was significantly lower than that of the bifurcation ridge.

Intravascular ultrasound is an effective way for detecting the distribution and composition of the atherosclerotic plaque at the left main coronary artery bifurcation and is of great significance to adjuvant interventional therapy.