Left main coronary anatomy risk index: A donor body study

Coronary dominance is determined by the vessel that gives rise to the posterior descending artery; and these right-dominant, left-dominant, or codominant patterns influence ischemic risk and procedural strategy. Branching configuration and bifurcation angle of the LMCA may affect flow dynamics and plaque distribution, and stenosis or projection can complicate angiographic interpretation. We examined hearts from Midwestern donor bodies to evaluate coronary dominance, length, branching pattern, and bifurcation angle; and to characterize potential risk-related anatomical features using a newly developed index, Left Main Anatomy Risk Index (LMARI). Left ventricular wall thickness was measured as a separate assessment of myocardial hypertrophy. Multiple observers analyzed images, and interobserver agreement was assessed. Pearson correlation and analysis of variance were used to assess anatomic relationships. LMCA length was strongly associated with bifurcation angle (r = 0.78, p < 0.001) and was associated with branching pattern (p = 0.007), but was not associated with coronary dominance (p = 0.176). Most hearts fell within the LMARI-defined low-risk range (54, 90.0%). Among the 32 hearts assessed for left ventricular wall thickness, 20 (62.5%) met the anatomical criterion for hypertrophy. The LMARI is a novel exploratory index that seemed to provide a structured approach for summarizing LMCA morphology and assisting in identifying anatomical features that could pose risk during cardiac procedures. However, further multicenter studies incorporating clinical outcomes are needed to validate LMARI and determine its clinical utility across clinically diverse populations.