Prevalence and Clinical Implications of Tricuspid Valve Prolapse Based on Magnetic Resonance Diagnostic Criteria

Background: Tricuspid valve prolapse (TVP) is an uncertain diagnosis with unknown clinical significance because of a scarcity of published data. Objectives: In this study, cardiac magnetic resonance was used to: 1) propose diagnostic criteria for TVP; 2) evaluate the prevalence of TVP in patients with primary mitral regurgitation (MR); and 3) identify the clinical implications of TVP with regard to tricuspid regurgitation (TR). Methods: Forty-one healthy volunteers were analyzed to identify normal tricuspid leaflet displacement and propose criteria for TVP. A total of 465 consecutive patients with primary MR (263 with mitral valve prolapse [MVP] and 202 with nondegenerative mitral valve disease [non-MVP]) were phenotyped for the presence and clinical significance of TVP. Results: The proposed TVP criteria included right atrial displacement of ≥2 mm for the anterior and posterior tricuspid leaflets and ≥3 mm for the septal leaflet. Thirty-one (24%) subjects with single-leaflet MVP and 63 (47%) with bileaflet MVP met the proposed criteria for TVP. TVP was not evident in the non-MVP cohort. Patients with TVP were more likely to have severe MR (38.3% vs 18.9%; P < 0.001) and advanced TR (23.4% of patients with TVP demonstrated moderate or severe TR vs 6.2% of patients without TVP; P < 0.001), independent of right ventricular systolic function. Conclusions: TR in subjects with MVP should not be routinely considered functional, as TVP is a prevalent finding associated with MVP and more often associated with advanced TR compared with patients with primary MR without TVP. A comprehensive assessment of tricuspid anatomy should be an important component of the preoperative evaluation for mitral valve surgery.