Mitral Valve Surgery for Functional Regurgitation: Insights into Heart Failure and Readmission

Background: Functional mitral regurgitation (FMR) is a significant burden among our increasingly elderly population. Mitral valve repair (MVr) is the preferred surgical treatment of FMR despite limited evidence supporting its efficacy. Mitral valve replacement (MVR) is the alternative procedure typically reserved for patients who are at higher risk or refractory to MVr. The present study aims to determine which of the two procedures is more effective in the surgical treatment of FMR. Methods: 344 charts of FMR patients who received either MVr (n = 263) or MVR (n = 81) from 2004-2016 at our institution were reviewed. Treatment efficacy was assessed based on heart failure (HF)-readmission and survival rates within 5 years from discharge. Propensity score approach with inverse probability weighting and Cox regression models were employed to evaluate procedural impact on survival and rehospitalizations, respectively. Follow-up echocardiographic data from the original cohort was assessed for differences in metrics between procedural groups at >6 months (MVr: n = 75; MVR: n = 23) and 1 year (MVr: n = 75; MVR: n = 18) post-op. Results: MVR patients had a lower risk of being readmitted for HF within 5 years compared to the MVr group (HR-adj (95% CI): 0.60 (0.41 - 0.88), p = 0.008). MVR patients also had a higher overall risk of death (HR-adj (95% CI): 1.82 (1.05 - 3.16), p = 0.034) but this was border-line significantly different at 5 years cut-off (p = 0.057). Conclusions: Higher HF readmission in MVr patients than in sicker, higher surgical-risk MVR patients reflects the inadequacy of MVr to treat FMR. Novel approaches to MVR may be necessary to adequately manage FMR.