Abstract 4215: Intravascular Ultrasound Evaluation of Both the Left Anterior Descending and Left Circumflex Branches After Left Main Bifurcation Stenting
Background: Distal left main (LM) bifurcation stenting is still a challenge for interventional cardiologists.
Methods: Pre- and post-intervention IVUS of both the LAD and LCX as well as of the distal LM was performed in 57 pts (male: 48, mean age: 61±12 yrs) undergoing LM bifurcation stenting. The LM bifurcation was divided into 3 segments (distal LM, LAD and LCX). Minimal lumen CSA site at 3 segments, distal LM, LAD and LCX ostium dimension were evaluated respectively and compared between pre- and post-intervention measurements.
Results: A single stent cross-over technique was used in 28 pts, and 2 stents in 29 pts (crush-stenting in 25 pts, T-stenting in 3 pts, and culotte technique in 1 pt). Overall, 72 sirolimous eluting stents and 14 paclitaxel eluting stents were implanted. All 57 LM bifurcation stenting procedures were finished with final kissing balloon inflations. At 6-month follow-up, major adverse cardiac event (MACE) rate was 14.5%; there were 2 cardiac deaths and 1 stent thrombosis. Target lesion revascularization rate was 10.9 %. Follow-up angiography was performed in 45 pts (78.9%). The binary angiographic restenosis rate was 28.9%, mostly (13/16) located at the LCX ostium. Pts treated with 2 stents had a smaller pre-intervention ostial LCX minimum lumen area (MLA) than the 1-stent cross-over group (4.1mm2 vs 6.0mm2, P=0.001).Post-intervention IVUS showed that two-thirds of the MLAs were located at the LCX ostium. Multivariate analysis showed the post-intervention ostial LCX MLA was the strongest predictor of angiographic restenosis at the LCX ostium (OR 0.33, 95%CI [0.16, 0.69], p=0.003). In particular, for the 1 stent cross-over group, a post-intervention ostial LCX MLA ≥4 mm2 was associated with a restenosis rate of 5.9% while an MLA <4mm2 was associated with a restenosis rate of 50% (p=0.04). For the 2- stent group, a post-intervention ostial LCX MLA ≥5.5 mm2 was associated with a restenosis rate of 15.4% vs an MLA of <5.5 mm2 that was associated with a restenosis rate of 66.7% (p=0.026).
The final ostial LCX MLA was the only predictor of restenosis after LM bifurcation stenting irrespective of the technique: 1 or 2 stents.
IVUS may help to assure an optimum lumen at the site of the ostium of the LCX.