1Universitäres Herz- und Gefäßzentrum Hamburg Klinik und Poliklinik für Kardiologie Hamburg, Deutschland; 2Universitäres Herz- und Gefäßzentrum Hamburg Klinik für Kardiologie Hamburg, Deutschland; 3Universitäres Herz- und Gefäßzentrum Hamburg Klinik und Poliklinik für Herz- und Gefäßchirurgie Hamburg, Deutschland; 4Universitäres Herz- und Gefäßzentrum Hamburg Allgemeine und Interventionelle Kardiologie Hamburg, Deutschland
Background
Relevant mitral regurgitation (MR) is associated with reduced quality of life and high mortality risk. Mitral transcatheter-edge-to-edge repair (M-TEER) is an alternative approach for surgery-ineligible patients with degenerative mitral regurgitation (DMR). Functional mitral regurgitation (FMR) requires a multimodal approach always including guideline-directed medical therapy (GDMT) before considering M-TEER. While the severity of residual MR (rMR) following M-TEER has a significant impact on long-term survival, the prognostic implications of recurrent MR (recMR) during follow-up, after an initially optimal postprocedural result, remain poorly understood.
Purpose
The aim of this retrospective, single-center analysis, was to investigate the prevalence of recMR (defined as worsening rMR during follow-up) and to assess its impact on outcomes in patients after M-TEER.
Methods
A total of n=461 patients underwent M-TEER between 2008 and 2021. Patients with rMR at discharge of ≤2+ and a median follow-up time of 5.96 (95%-CI 5.56-6.32) years were included. RecMR was defined as worsening of rMR by ≥1 grade at 6- or 12-months follow-up assessments. The primary endpoint was all-cause mortality. Additionally, predictors for recMR were analyzed.
Results
Among 461 patients (age 75.0 ± SD 9.1 years, 60.7% male, median STS score 3.6%, DMR 29.3%) 146 cases of recMR were observed (FMR: n=104/326 [31.9%] vs. DMR: n=42/135 [31.1%]). Regarding baseline characteristics, patients with recMR in the DMR subset had significantly higher systolic pulmonary artery pressure (sPAP) (median sPAP; 51 mmHg vs. 39 mmHg), while in the FMR subset, the left ventricular end-diastolic diameter (LVEDD) was significantly higher in patients with recMR (mean 67.2mm vs. 63.5mm).
A total of 212 patients (46.0%) died during follow-up. Kaplan-Meier 12-months landmark analysis showed significantly better survival in patients without recMR (p log rank=0.0088, Figure 1A). Univariable and multivariable Cox regression analysis (adjusted for age, LVEF≤30%, anemia, FMR, GFR<30ml/min, and atrial fibrillation) revealed a significant association of recMR with increased mortality rates (univariable: hazard ratio [HR]=1.45; 95%-confidence interval (CI) 1.10-1.91; p=0.0091; multivariable HR=1.43; 95%-CI: 1.06-1.93; p=0.019). Subgroup analysis indicated that the significant differences in primary endpoint outcomes, favoring patients without recMR, were primarily observed in the DMR subgroup (p log rank= 0.014, Figure 1B). The FMR subgroup did not show a statistically significant difference (p log rank= 0.11, Figure 1C). Furthermore, a backward selection regression analysis identified several predictors for recMR, including LVEDD, hyperlipidemia, mean mitral gradient and the number of clips.
Conclusion
RecMR appears to be an independent predictor of increased mortality risk, particularly in patients with DMR. In FMR patients, the underlying disease may affect the stability of results after M-TEER. Notably, patients with smaller anatomical configurations and calcification, who required a second clip during the procedure, experienced less likely recMR. Heart valve centers should consider using this information to guide follow-up strategies.
Figure 1: Kaplan-Meier 12 month landmark analysis for all-cause mortality according to recMR and non recMR following M-TEER. DMR = degenerative MR, FMR = functional MR, recMR = recurrent MR, M-TEER = mitral transcatheter edge-to-edge repair.