Percutaneous Coronary Intervention in Unprotected Left Main Stenosis: Medical Evidence from Randomized and Observational Studies

Abstract

Left main disease (LMD) is a stenosis of ≥50 %, and occurs in 3–5 % of patients, associated with multi-vessel coronary artery disease (CAD) in more than 75 %. With bare metal stents (BMS), left main stenting became more popular and the technique was used mainly in high risk patients such as acute myocardial infarction (AMI) or with contraindications for coronary artery bypass grafts (CABG). There was an initial low incidence of adverse events with this approach, but with concerns regarding restenosis-related events, drug eluting stents (DES) became the preferred option. Comparative studies with CABG and DES showed that both had similar mortality and incidence of MI but with higher recurrence of repeat revascularization procedures with DES. CABG had a higher stroke risk. Percutaneous Coronary intervention (PCI) should be a good option in most patients with LMD without bifurcation disease, in those with a small diameter circumflex artery and /or low or intermediate anatomic risk score. The latest European guidelines recommended PCI with DES implantation as a class I indication in certain subgroups of patients with LMD. On the other hand, CABG is still the “gold standard” and has remained a better option when the SYNTAX score is ≥33, with severe multi-vessel coronary disease, total occlusions of ≥2 major coronary epicardial vessels, severe calcifications or tortuosity, and in those with a contraindication to antiplatelet therapy.