Background
Residual mitral regurgitation (MR) post transcatheter edge-to-edge repair (M-TEER) is a strong indicator of adverse events in patients with primary MR (PMR). While M-TEER generally improves MR, a subgroup continues to experience a substantial symptomatic burden, shown by New York Heart Association (NYHA) class III or IV status at discharge. Identifying predictive factors for these persistent symptoms can improve patient selection and post-procedure strategies. This study leverages data from the PRIME-MR registry to identify predictors of persistent symptom burden post M-TEER.
Methods
PRIME-MR is a retrospective, investigator-initiated registry including PMR patients who underwent M-TEER at 24 high-volume centers from 2009 to 2022. After excluding in complete cases, 888 patients were analyzed. Symptomatic status at discharge was classified as NYHA Class I/II or Class III/IV, with the latter indicating symptom persistance. The primary composite endpoint was all-cause mortality or rehospitalization.
Results
Among the 888 patients, 742 (83.6%) achieved NYHA Class I/II, while 146 (16.4%) remained in NYHA Class III/IV. Both groups were similar in age and sex distribution. However, those patients with persistent symptoms had higher initial NYHA classes (NYHA Class ≥III: 93.8% vs. 81.6%; p<0.001) and a shorter 6-minute walk distance (median 158 m [IQR 40, 270] vs. 252 m [137, 329]; p=0.006). Baseline MR severity (median EROA 0.4 cm² [0.3, 0.6]) did not differ ( p=0.81), but symptomatic patients had higher rates of mitral annular calcification (7.1% vs. 2.7%, p=0.023) and a smaller mitral valve orifice areas (4.0 cm² [3.1, 5.2] vs. 4.9 cm² [4.0, 5.8]; p=0.001). Moderate or greater residual MR at discharge was more frequent in symptomatic patients (56.6% vs. 28.9%; p<0.001) and linked to higher all-cause mortality or rehospitalization rates within 2 years (log-rank p<0.0001, Figure 1).
Conclusion
A distinct subset of patients undergoing M-TEER for primary MR does not experience symptomatic improvement at discharge, particularly those with mitral annular calcification and smaller mitral valve orifice areas. This subgroup was at significantly higher risk for mortality or rehospitalization. Tailored risk assessment and management strategies are crucial for improving outcomes in these high-risk patients.
