Background:
Several studies have investigated factors influencing survival after transcatheter mitral valve repair (TMVR). Symptomatic and prognostic benefit by interventional edge-to-edge repair for mitral regurgitation (MR) in functional pathology (FMR) was proven. Female sex has been suggested to be associated with adverse outcome in cardio-surgical procedures and is factored in common risk scores accordingly. However, evidence on sex-specific differences regarding outcome after TMVR is sparse.

Methods:
We retrospectively analyzed the survival of patients successfully treated with isolated edge-to-edge repair of MR in the period between 06/2010 and 03/2018 (exclusion of combined forms of TMVR) in our center. Baseline, periprocedural and follow-up data were gathered. We performed survival analyses and cox regressions for both sexes.

Results:
Overall, 627 consecutive patients (47.0% females, 57.4% functional MR; median follow-up period 462 days [IQR 142-945 days]; survival status was available in 96.7%) were enrolled. Survival rates were 97.6% at discharge, 75.7% after 1, 54.5% after 3, 37.6% after 5 and 21.7% after 7 years. Male and female patients did not differ regarding estimated risk calculated by the Logistic Euroscore (at baseline: 25.0 [IQR 18.0/34.8] vs. 27.0 [18.4/40.1]%, p=0.093), distribution of MR-etiologies and most baseline parameters. Nevertheless, some differences were identified: in brief, women were older (79.9 [IQR 75.6/84.4] vs. 78.3 [72.9/83.4] years, p<0.001), were less often affected by coronary artery disease (53.1 vs. 75.0% p<0.001) and diabetes (23.7 vs. 31.3%, p=0.040) and the mean left ventricular function (44.5±12.9 vs. 38.9±13.4%, p<0.001) was higher in females than in males.

While no relevant differences were found for in-hospital (2.0 vs. 2.7%, p=0.613), 30 days (4.8 vs. 6.5%, p=0.473) and 1-year mortality (27.0 vs. 25.3%, p=0.675), the long-term survival was significantly better for female patients, especially in functional etiology (4-year survival in FMR 65.7 vs. 35.7%, p=0.006; Figure 1). Consecutively, while odds and hazard ratios did not indicate for gender-specific differences regarding in-hospital, 30-days and 1-year survival, female sex was associated with a lower risk for long-term mortality in the crude Cox-regression in our cohort (HR 0.68 [0.49-0.96], p=0.028 in the FMR subgroup).

Conclusion:
Our analysis suggests no adverse short- and mid-term prognosis for female gender in transcatheter Mitral Valve Edge-to-edge Repair for MR. In contrast and not indicated by Logistic Euroscore, female sex was associated with better long-term survival despite higher median age, which could partly be explained by a slightly more favorable cardiovascular risk profile.