Current LM Bifurcation Interventions
There are considerable data through registries and clinical trials that left main (LM) coronary artery intervention with percutaneous coronary intervention (PCI) is a safe procedure in elective cases. The EXCEL (Everolimus-Eluting Stents or Bypass Surgery for Left Main Coronary Artery Disease) and NOBLE (Percutaneous Coronary Angioplasty Versus Coronary Artery Bypass Grafting in Treatment of Unprotected Left Main Stenosis) trials with second-generation drug-eluting stents demonstrated low 30-day and long-term mortality. In the EXCEL trial, PCI was non-inferior to coronary artery bypass graft surgery at 3 years; in the NOBLE trial, coronary artery bypass graft surgery was superior to PCI at 5 years. The SYNTAX (Synergy Between Percutaneous Coronary Intervention With Taxus and Cardiac Surgery) score was not predictive of outcomes.
Given the considerable interest in LM PCI and the choice of multiple stenting techniques, it is important to provide guidance to the interventionalist in the current best practices. Eighty percent of LM stenosis is at the LM bifurcation, which increases the complexity of the intervention. Procedural mortality is low (<1.1%), and it is higher (<9%) in supported high-risk PCI. LM interventions are indicated for
- a lesion ≥70% diameter stenosis on angiography, or
- an intravascular ultrasound (IVUS) or optical coherence tomography (OCT) minimal luminal area ≤6 mm2, or
- a fractional flow reserve (FFR) ≥ 0.80.
A recent article by Rab et al.1 provides a confluence of ideas from thought leaders from Europe and China who have different approaches to LM bifurcation intervention. It emphasizes pre-procedural planning and risk assessment, and it guides the reader through an algorithmic approach (Figure 1) to PCI based on the involvement of the side branch (SB). A lesion is simple if the SB diameter stenosis is <70% with a lesion length <10 mm. A lesion is complex if the SB diameter stenosis is ≥70% with a lesion length >10 mm.
The majority of LM bifurcation lesions are simple, and the provisional single stent crossover approach from the LM to the left anterior descending artery is performed in 75% of cases. Because the LM is large in caliberaveraging 4.5 mm in diameter in most casesproximal optimization technique with a larger diameter balloon, 6-9 mm in length, is used with its distal marker just at the carina.
The manuscript details a step-by-step approach in the provisional technique, including conversion to the two-stent strategy of T-stenting and minimal protrusion (TAP) and Culotte techniques. For the complex lesion, the increasingly popular dedicated two-stent double kissing (DK) crush technique is described in detail.
Intracoronary imaging with IVUS or OCT is the final step and is strongly recommended to optimize the results of LM bifurcation PCI.
- Rab T, Sheiban I, Louvard Y, Sawaya FJ, Zhang JJ, Chen SL. Current Interventions for the Left Main Bifurcation. JACC Cardiovasc Interv 2017;10:849-65.
Clinical Topics: Cardiac Surgery, Invasive Cardiovascular Angiography and Intervention, Noninvasive Imaging, Atherosclerotic Disease (CAD/PAD), Aortic Surgery, Interventions and Coronary Artery Disease, Interventions and Imaging, Angiography, Nuclear Imaging
Keywords: Angiography, Angioplasty, Balloon, Coronary, Constriction, Pathologic, Coronary Artery Bypass, Coronary Artery Disease, Drug-Eluting Stents, Percutaneous Coronary Intervention, Registries, Risk Assessment, Stents, Taxus, Tomography, Optical Coherence
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