Geometric Models in Left Main Coronary Bifurcation: Mathematical Accuracy and Clinical Limits in the Era of Intravascular Imaging

The geometry of coronary bifurcations plays a fundamental role in the pathophysiology of atherosclerosis and in the planning of percutaneous coronary intervention. Among these structures, the bifurcation of the left main coronary artery (LMCA) assumes singular relevance, not only due to the large myocardial territory it irrigates, but also due to the complex interaction between hemodynamic forces, vascular remodeling, and the progression of atherosclerotic disease. In this context, geometric models that estimate the diameter of the main vessel from the dimensions of the distal branches have been proposed as auxiliary tools for vessel sizing and for optimizing interventional strategies. However, studies systematically comparing these models with intravascular imaging tools, which are more precise in measuring coronary arteries, are lacking.^–

Garzon et al. evaluated the reliability of the Murray, Finet, and Huo-Kassab models in estimating the dimensions of the LMCA bifurcation in arteries with moderate atherosclerosis, using quantitative coronary angiography (QCA) and Intravascular ultrasound (IVUS) as reference methods.The authors demonstrated that the Murray and Huo-Kassab models exhibit greater accuracy and precision compared to the Finet model, with the Murray model performing particularly better when IVUS is used as the reference standard. These findings are consistent with the theoretical robustness of models based on fluid dynamics principles and energy optimization, in contrast to the Finet model, which is empirically derived from angiographic fractal geometry.^–

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