Tricuspid annulus disjunction in patients with genetically tested Marfan Syndrom and Mitral annular disjunction

Background: Mitral annular disjunction (MAD) has recently gained interest in research and clinical practice. Tricuspid annulus disjunction (TAD) is a structural abnormality characterised by a separation between the right atrial wall and the tricuspid valve hinge point and has been described in association with MAD. Yet, its clinical relevance remains unclear. Marfan syndrome (MFS) is a connective tissue disorder in which MAD is present in about 50 percent of cases. Yet, the association of MFS and TAD is unkown.

Methods: In a single centre retrospective analysis of 59 patients with genetically tested Marfan Syndrom we used cardiac magnetic resonance (CMR) to screen for the existence of MAD and TAD. We further compared our patient collective with the general population and a collective of non-syndromic patients with MAD diagnosed by cardiac magnetic resonance (CMR).

Results: In 59 patients with genetically tested Marfan Syndrom 51 patients showed MAD (mean cm) of which 23 patients (45.1%) had additional TAD (mean 3.79 mm). The prevalence of TAD did not differ significantly between patients with MFS and those without. Neither was an increased prevalence of TAD observed, when comparing MFS patients to the general population.

Furthermore, TAD was not associated with a higher incidence of malignant cardiac arrythmias or tricuspid valve prolapse.

Conclusion: In this large collective of patients with genetically tested marfan syndrome TAD was shown to be a relatively common anatomical finding in cardiac magnetic resonance. However, the observation of TAD seemed to be independent of MFS and the prevalence of TAD was not significantly elevated when compared to the general population. Additionally, TAD was not associated with malignant cardiac arrhythmia or tricuspid valve prolapse. These findings suggest that isolated TAD may have limited clinical relevance, though further studies are needed to confirm its prognostic significance in broader patient populations.

TAD in a 46 year marfan syndrom patient with MAD. Anatomical depication for comparison (Henle J. Handbuch der systematischen Anatomie des Menschen. Vol 3, Part 1. Germany: Vieweg; 1876:14–20.)