Abstract 14338: Prevalence, Associations and Outcomes of Double Orifice and Parachute Mitral Valve

Abstract

Background: The incidence of congenital mitral valve disease is 0.4%; Double Orifice Mitral Valve (DOMV) and Parachute Mitral Valve (PMV) are two morphologic pathologies that may result in mitral valve dysfunction. The objectives of this study are 1) To describe valve function and progression and 2) To define factors contributing to disease progression. Methods: Retrospective database review. Fyler codes for DOMV, PMV and text search was performed. Echocardiographic images, echo reports, and chart review were used to identify mitral regurgitation (MR), mitral stenosis (MS), morphology, and associated lesions. Results: 39 patients with DOMV and 76 patients with PMV were identified. In the DOMV cohort, 51% were male, median age at diagnosis was 0.17 years (IQR 0.01, 3.88); median follow-up of 5.92 years (IQR 0.46, 10.22). In the PMV cohort, 44% were male, median age at diagnosis at was 0.01 years (IQR 0, 0.34); median follow-up of 2.56 years (IQR 0.25, 9.55). 41% of DOMV and 23% of patients with PMV had normal valve function at initial visit. DOMV was associated with MR (p=0.04), and PMV with MS (p<0.0001). 23% of patients in the PMV cohort had progressive MS compared to 5% of patients in the DOMV cohort (p<0.0001). There was no significant difference in MR progression between both groups (p=0.02). Papillary muscle (PM) morphology was evaluated in 37 (excluding canals) of 76 patients in the PMV cohort. 5 had true PMV (single PM), 32 had variant PMV with two PM groups of which 62.5% had dominant posterior medial PM. 67% of those with posterior medial PM dominance had progressive MS irrespective of association with Shone’s complex. The anterolateral PM muscle group dominant PMV were not associated with Shone’s complex and progressive MS. Conclusion: DOMV are more likely to have MR while PMV are more likely to have MS. DOMV has non progressive MR and MS. Posterior medial PM dominance in PMV is more likely to have progressive MS.