Objectives: Mitral valve tenting parameters are indicators of left ventricular remodeling severity and may predict outcome in functional mitral regurgitation (FMR).  We hypothesized that indexing of mitral valve (MV) tenting area to BSA, to mitral annulus diameter or gender-adjusted analysis of tenting parameters may improve their prognostic value.

Methods: We identified retrospectively 240 consecutive FMR patients (mean age 68±10 years; males=135) from our institutional database who underwent isolated MV annuloplasty during a period of seven years (2010–2016). Using preoperative 2D transthoracic echocardiographic images, MV tenting parameters including tenting area, tenting height and annulus diameter were systematically assessed. Follow-up protocol consisted of chart review and structured clinical questionnaire. Primary study endpoint was the composite of death and adverse cardiac events (i.e., MV re-operation, CRT implantation, VAD implantation or heart transplantation). 

Results: Cox regression analysis identified BSA-indexed MV tenting area as an independent predictor of primary study endpoint (HR 1.9; 95%CI 1.1–3.5; p=0.02). After cut-off point analysis, BSA-indexed MV tenting area >1.35cm²/m²was also significantly associated with primary study outcome in the cox regression analysis (HR 2.3; 95% CI 1.3-4.0; p=0.003). Furthermore, Kaplan Meier analysis revealed significantly worse survival in patients with a BSA-indexed MV tenting area >1.35cm²/m²at baseline when compared to patients with BSA-indexed MV tenting area <1.35cm²/m²(p_(log-rank)=0.002) (Figure 1). Annulus-indexed MV tenting area showed only a tendency towards primary study endpoint prediction in the multivariate model (HR 2.8; 95%CI 0.6-12.6; p=0.17). Between female and male patients, BSA-indexed MV tenting area was similar (1.42±0.4cm²/m²vs. 1.45±0.4cm²/cm²; p=0.6) and gender was not associated with primary study outcome (HR 0.8;95%CI 0.5-1.4; p=0.5).

Conclusion: In our FMR cohort, BSA-indexed MV tenting area showed the strongest association with negative outcomes following isolated MV annuloplasty. Patients with BSA-indexed MV tenting area >1.35cm²/m²could potentially benefit from additional surgical maneuvers addressing left ventricular remodeling.