Coronary artery dominance influences the distribution of calcified plaques in the coronary tree.

Background: Coronary artery dominance is determined by the coronary artery emitting the posterior descending artery. In the left dominant system, a greater proportion of coronary flow enters the left coronary artery, potentially influencing calcified plaque development in the left anterior descending artery (LAD).

Methods: This retrospective single-center cohort study analyzed patients who underwent computed tomography angiography from September 2006 to December 2022 at Harbor-UCLA in Los Angeles, California. Coronary artery calcium (CAC) was quantified for the three coronary vessels. The LAD calcium score was divided by the total calcium score to calculate the LAD calcium percentage, which was compared between left and right dominant coronary systems. Multivariable linear regression assessed the association between LAD calcium percentage and coronary dominance, adjusting for age, gender, BMI, hyperlipidemia, hypertension, family history of cardiovascular disease, and past smoking.

Results: Among 9560 subjects, 6766 with CAC greater than zero were enrolled. The average age was 64.8 ± 10.7 years: 68% were male, and 9% had left dominant coronary systems. The median CAC was 51 [0-352] in the right dominant and 49 [0-358] in the left dominant system (P = 0.73). Adjusted analysis revealed that individuals with left dominant coronary systems had a 10.1% higher (CI 7.5-12.8%, P < 0.001) LAD calcium percentage than those with right dominant systems.

Conclusion: Although coronary dominance does not influence overall plaque burden of atherosclerosis, it affects calcified plaque distribution. The left dominant system is associated with a higher proportion of calcified plaque in the LAD, potentially heightening the risk of adverse cardiovascular events.