Abstract

Background: Coronary artery diseases are the leading cause of death worldwide. Stenting or angioplasty of coronary arteries as interventional management requires knowledge about the morphology of the coronary tree, including luminal diameters.

Objective: This work aimed to study the diameters of the left main coronary artery and its branches measured by QCA in relation to the diameters derived by Finet’s law.

Methods: This was a cross-sectional, retrospective, hospital-based study. The number of angiograms used was 357. The diameters of the left main coronary artery (LM₁), left anterior interventricular artery (LAD₁), and left circumflex artery (LCx₁) were measured by QCA. The diameter of LM₁ was measured by 5 mm before its termination, and the diameters of LAD₁ and LCx₁ were obtained by 5 mm from their origins. Finet’s law was used to calculate the diameters of LM2, LAD₂ and LCx₂ using the QCA measurements.

Results: The mean age of participants was 53.3±8.8 years. Female patients represented 58.9%. The mean diameter of the left main coronary using QCA was 3.75±0.85 mm, and the diameter calculated using Finet’s law was 3.89±0.80 mm. The diameters of LAD₁ and LCx₁ were larger than those calculated with Finet’s law. The Z-test showed a significant difference between the diameter of the LM₁ calculated by Finet’s law; both diameters were positively associated. The diameters of LAD₁ and LAD₂ showed a non-significant correlation (r = 0.0653, P = 0.259526) and a negative correlation between LCx₁ and LCX₂ (r = -0.2659, P = 0.00001). The Z-test showed a significant difference in the diameter of LAD and LCx measured by QCA and Finet’s law.

Conclusion: An association was found between the diameter of LM measured by QCA and calculated with Finet’s law; the diameter calculated by Finet’s law was larger. The diameters of LAD and LCx measured by QCA were larger than those calculated by Finet’s law. A positive correlation existed between the diameters measured by QCA and Finet’s law, and they had significant differences. Finet’s law can assist in the selection of stent size. Despite the literature about Finet’s law, generalising its use requires more studies on different ethnicities.