NOBLE trial-is it time to revise the guidelines?

The Nordic-Baltic-British left main revascularization trial (NOBLE) is a prospective, randomized, multicentre, non-inferiority trial comparing percutaneous coronary angioplasty (PCI) with coronary artery bypass grafting (CABG) for revascularization of patients with unprotected left main coronary artery (LMCA) stenosis. The primary outcome was a combined endpoint of all-cause mortality, stroke, non-procedural myocardial infarction and repeat revascularization. CABG was found to be superior to PCI with respect to the 5-year MACCE rates (28% vs. 19%) with a hazard ratio (HR) of 1.58 (95% CI 1.24-2.01). All-cause mortality rates were similar, but PCI was associated with increased occurrence of non-procedural myocardial infarction (p = 0.0002) and repeat revascularization (p = 0.0009). There was no difference in the stroke rates (p = 0.11) at 5 years. Currently, European Society of Cardiology and the European Association for Cardio-Thoracic Surgery (ESC/EACTS) guidelines on myocardial revascularization assign a class 1A recommendation to PCI in patients with unprotected LMCA stenosis with a SYNTAX score < 23. The findings of the NOBLE trial challenge this premise.