Management of Moderate Eccentric Proximal Left Main Coronary Artery Lesions

Diagnostic Evaluation

For intermediate left main coronary artery lesions (40-70% stenosis), FFR (Fractional Flow Reserve) or iFR are recommended before any intervention to determine hemodynamic significance, as only stenoses >90% predict hemodynamic relevance with high accuracy, according to the European Heart Journal 2
The European Society of Cardiology recommends that for stenoses between 50-70%, only about 35% are hemodynamically significant, highlighting the need for functional assessment 1
IVUS (intravascular ultrasound) can demonstrate true lumen dimensions and improve the evaluation of eccentric lesions, as suggested by the European Heart Journal 3

The European Heart Journal suggests that for lesions of the left main coronary artery, especially in stable patients, discussion by the Heart Team is mandatory before any ad hoc intervention, considering patient profile, coronary anatomy, SYNTAX score, left ventricular function, and surgical risk 2, 3
For low-complexity left main coronary artery lesions (SYNTAX ≤22), percutaneous coronary intervention (PCI) is an equivalent alternative to coronary artery bypass grafting (CABG), with non-inferior survival and less invasiveness, as recommended by the European Heart Journal 2
CABG is the preferred mode of revascularization over PCI for left main coronary artery disease, given the lower risk of spontaneous myocardial infarction and need for repeat revascularization, according to the European Heart Journal 2

The American College of Cardiology recommends that all patients require antiplatelet therapy (aspirin), high-intensity statins to stabilize plaques, modification of risk factors (hypertension, diabetes, smoking cessation), and ACE inhibitors/ARBs if there is left ventricular dysfunction, regardless of the revascularization strategy chosen 1

Eccentric left main coronary artery lesions present specific technical challenges, including a higher risk of dissection during intervention, difficulty in achieving optimal stent apposition, and the need for IVUS to guide the procedure, as noted by the European Heart Journal and Praxis Medical Insights 3, 4
The American Heart Association suggests that PCI is contraindicated (Class III) in patients with significant left main coronary artery disease who are candidates for CABG, especially if there is high anatomical complexity 5