Long-term results of mitral repair in patients with severe left ventricular dysfunction and secondary mitral regurgitation: does the technique matter?

OBJECTIVES

An isolated undersized annuloplasty was used to treat mitral regurgitation (MR) secondary to dilated cardiomyopathy (DCM) if the baseline coaptation depth (CD) was <1 cm. In the presence of significant tethering of the mitral leaflets (CD ≥1 cm), the edge-to-edge (EE) technique was combined with annuloplasty to improve the durability of the repair. The long-term results of this approach are unknown and represent the objective of this study.

METHODS

To obtain long-term outcome data, we included in the study population the first 105 consecutive patients with severe left ventricular dysfunction (ejection fraction 29 ± 6.6%) and secondary MR submitted to mitral valve repair. Forty patients underwent isolated undersized annuloplasty and 65 patients received the EE technique combined with annuloplasty. Preoperative and postoperative data were prospectively entered into a dedicated database. Clinical and echocardiographic follow-ups were performed in our institutional outpatient clinic.

RESULTS

Follow-up was 90% complete. The median follow-up time was 7.2 years (interquartile range 4.3;10.4). The longest follow-up time was 16.5 years. A comparative analysis between the annuloplasty group and the EE group was performed. Baseline LV dimensions and function were slightly worse in the EE group, but only the severity of tethering was significantly more pronounced than in the annuloplasty group. Hospital mortality (3 vs 2.5%, P = 1.0) and 10-year overall survival (42 ± 6.7 vs 55 ± 8.5%, P = 0.2) were not significantly different in the EE and annuloplasty group, respectively. Cumulative incidence functions of cardiac death were similar as well (at 10-years, 34.3 ± 8.1 vs 37.9 ± 6.4%, respectively, P = 0.4). At 10 years, cumulative incidence function of recurrence of MR ≥3+ was lower in the EE patients (10.3 ± 4.1 vs 30.8±8.0%, P = 0.01). Isolated annuloplasty [hazard ratio (HR) 4.84, 95% confidence interval (CI) 1.46-16.1, P = 0.01] and residual MR >1+ at hospital discharge (HR 5.25, 95% CI 2.00-13.8, P < 0.001) were significantly related to the development of MR ≥3. Failure of repair was associated with recurrence of New York Heart Association III or IV symptoms (P < 0.001).

CONCLUSIONS

In patients with end-stage DCM and secondary MR, the association of the EE technique to the undersized annuloplasty significantly decreases the rate of recurrent MR at long-term. This higher repair durability did not translate into a better long-term prognosis in this series.