Computed tomography angiographic examination of coronary sinus morphometry and spatial orientation: a guide for cardiac resynchronization therapy procedures.

BACKGROUND: This study aimed to characterize the morphometric features and three-dimensional spatial orientation of the coronary sinus ostium (CSO) within the right atrium using computed tomography angiography, and to identify demographic and anatomical determinants of CSO level. MATERIALS AND METHODS: A total of 300 individuals (147 women and 153 men; mean age, 50.27 ± 10.39 years) who underwent coronary computed tomography angiography (CTA) were included in this retrospective cross-sectional study. Morphometric parameters included the proximal and distal coronary sinus diameters, CSO diameter, CSO-right atrial floor distance (CSO level), mean left ventricular wall thickness, septal wall thickness, proximal diameters of four major coronary arteries, and axial, coronal, and sagittal spatial angles of the CSO. RESULTS: All coronary artery diameters and both ventricular wall-thickness measures were significantly greater in men. Coronary sinus and CSO diameters increased with age, whereas CSO level decreased (r = -0.221, p < 0.001). The CSO formed angles of 65.15° ± 11.08°, 33.51° ± 17.95°, and 32.58° ± 17.47° with the axial, coronal, and sagittal planes, respectively, with no significant sex differences. In multivariable logistic regression analysis, male sex was independently associated with a higher CSO level, whereas older age, greater septal wall thickness, larger CSO diameter, and a larger sagittal angle were associated with a lower CSO level; mean left ventricular (LV) free-wall thickness (anterior and lateral) was not an independent predictor. CONCLUSIONS: Selected coronary sinus and cardiac morphometric parameters exhibited sex-related differences, while coronary sinus and CSO diameters increased progressively with age. The three-dimensional spatial orientation of the CSO within the right atrium appears to be a sex-independent anatomical parameter.Preoperative CTA may contribute to a better understanding of coronary sinus anatomy and, in selected cases, may facilitate procedural planning for coronary sinus-based cardiac interventions.