The prevalence of coronary sinus and left circumflex artery overlap in relation to the mitral valve

Objectives: Characterize where the circumflex artery crosses between the coronary sinus and mitral valve in order to minimize the occurrence of coronary compression during percutaneous indirect mitral valve interventions.

Background: Treatment of mitral valve regurgitation using an indirect percutaneous approach via access through the coronary sinus remains under active research and development. Characterization of anatomical locations where the circumflex artery crosses between the coronary sinus and mitral valve is important for mitigation of serious ischemic complications.

Methods: Magnetic resonance images were obtained for 65 perfusion-fixed human hearts. Three-dimensional reconstructions of anatomical orientations of the coronary sinus, circumflex artery, and mitral valve annulus were generated. The prevalence and location of sites where the circumflex artery coursed between the coronary sinus and mitral valve were assessed.

Results: The circumflex artery coursed between the coronary sinus and mitral valve in 88% of specimens. Overlaps between the circumflex artery and coronary sinus were less prevalent more proximal to the coronary sinus ostium. The coronary sinus did not lie in the same plane as the mitral annulus in roughly 20% of the hearts.

Conclusion: The prevalence of circumflex overlap between the coronary sinus and mitral valve was common across the sample size. The large variability in anatomy confirms the value of imaging individual patient cardiac anatomy prior to performing indirect percutaneous mitral valve annuloplasty to avoid impairment to the circumflex artery. This novel database can be utilized in the development of additional cardiac therapies that require access to the coronary sinus, such as therapeutic ablations.