Background:
Mitral valve regurgitation (MR) is a common finding in heart failure patients. Transcatheter mitral valve repair (TMVR) is an established alternative for surgery in high-risk patients with proven prognostic benefit. However, evidence on the predictive value of symptomatic relief on long-term outcome is scarce.

Methods:
Patients consecutively treated with TMVR by isolated edge-to-edge repair from 06/2010-03/2018 (exclusion of combined forms) in our center were enrolled in a monocentric retrospective cohort study. Baseline, periprocedural and follow-up data were gathered. Symptoms were recorded by NYHA-class at baseline and after 1 month, 1 and 2 years follow-up. We performed Cox regression analyses to evaluate a potential impact of symptomatic improvement (dyspnea reduction by at least one NYHA class) on survival.  

Results:
Among the enrolled 627 patients (47.0% female, 57.4% functional MR; median follow-up period 462 days [IQR 142-945]; survival status available in 96.7%), relevant symptoms in kind of NYHA-classes III/IV were found in 89.0% before TMVR. 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.

A significant improvement compared to baseline was observed in 37.2% after 1 month (p<0.001), 36.6% at 1 year (p<0.001) and 50.0% at 2 years (p<0.001), without further significant changes over the follow-ups (when compared to 1-month data, see Figure 1). Overall, 74.5% of the initially symptomatic patients (NYHA III/IV at baseline) reported relief by the procedure at 1 month. While there was no significant difference in relevant baseline parameters between both groups (e. g., age, gender, Euroscore, etiology, most comorbidities, and blood values including BNP), the collective with symptomatic improvement had a better long-term survival (after 1 year: 89.1 vs 71.2%, p=0.001, after 2 years: 75.5 vs 58.7%, p=0.039, figure 2). By calculating cox regressions, symptomatic relief was identified as predictor for improved 1year (OR 5.21 [95% CI 2.39-11.34], p<0.001) and long-term survival (complete follow-up period up to 7 years, OR 2.08 [95%CI 1.35-3.20], p=0.01), even when adjusted for other risk factors with impact on prognosis.

Conclusion:
In patients with heart failure, transcatheter edge-to-edge mitral valve repair leads to symptomatic improvement in ¾ of the patients, which is associated with a significantly better long-term prognosis. Even when adjusting to other relevant co-factors, reduction of NYHA-grade at 30 days might serve as independent predictor for improved long-term survival.