Key Points
- While transcatheter edge-to-edge repair (TEER) is FDA approved for treatment of degenerative mitral regurgitation (MR) in patients at high surgical risk, outcomes in this population are not well described.
- This study used registry data to report clinical endpoints including mortality and procedure success over time for patients undergoing TEER for degenerative MR in the United States.
- The safety profile of MitraClip for degenerative MR was excellent despite advanced age (82 years) and significant comorbidities Succesful repair was achieved in 89% of the patients.
TEER is an FDA approved therapy for patients with degenerative MR at high surgical risk, but the outcomes of these patients in real-world settings are not well described.
On March 5, 2023, Dr. Raj Makkar of Cedars-Sinai Medical Center presented the Safety and Efficacy of Transcatheter Edge-to-Edge Mitral Repair In Degenerative Mitral Regurgitation: An Analysis Of The STS/ACC TVT Registry.
The purpose of this study was to describe the trends, procedural outcome, and clinical outcomes for treating degenerative MR with TEER in the real world using the STS/ACC TVT registry, a national database which captures all patients undergoing this procedure in the United States. After excluding patients with ischemic cardiomyopathy, prior surgical mitral valve intervention, cardiogenic shock, mechanical ventilatory support and active endocarditis, as well as those with missing data in the registry, moderate or less degenerative MR prior to the procedure, no clear degenerative etiology, and mitral leaflet calcification or posterior leaflet tethering, a total of 19,088 patients undergoing non-emergent TEER for at least moderate to severe “pure” degenerative MR were included. The primary end point was procedural success, defined as residual MR graded moderate or less and a mean mitral gradient of less than 10mmHg. Secondary end points included overall death, heart failure hospitalization (HFH), and mitral valve reintervention at 30 days and 1 year, as well as the risk of death and HFH based on residual MR and mitral valve gradients.
The median age was 82 years, with a median STS score of 4.57% and LVEF of 58%. The majority of patients (82.2%) had severe MR with an average mitral valve area of 4.00 and mean gradient of 2.00 pre-procedure; 80.2% had leaflet prolapse and 62.7% had flail leaflet. Common comorbidities included atrial fibrillation, coronary artery disease, and recent heart failure within the past two weeks prior to procedure.
They found that the in-hospital and 30 day mortality rates were 1.1% and 2.7% respectively. In- hospital rates of cardiac surgery or intervention, stroke, and new dialysis were 1.1%, 0.72% and 0.34% respectively. At 30 days, rates of HFH, unplanned cardiac surgery or intervention, stroke or TIA, and new dialysis were 2.6%, 1.7%, 1.4% and 0.51% respectively. At 30 days 95.3% of patients had MR severity less than or equal to moderate and 96.5% had a mean mitral valve gradient less than 10 mmHg. Overall, the primary endpoint of procedural success was achieved in 89.0% of patients at 30 days, and these success rates significantly increased over time. Dr. Makar hypothesized that this is due to improved operator and institutional experience as well as advances in 3D echocardiographic technology and availability. At one year was mortality significantly higher among patients who had an unsuccessful procedure (26.7% vs 14.0%, adjusted HR 0.49 CI 0.42-0.56, p<0.001), as was heart failure readmission (16.9% vs 8.4%, HR 0.47 CI 0.41-0.54, p<0.001), and need for mitral valve reintervention (13.5% vs 2.1%, CI 0.12-0.19, p <0.001). When stratified according to procedural success, 1 year mortality from lowest to highest was among those with mild MR/no MS, moderate MR/No MS, mild MR/Mild-Mod MS, Mod MR/Mild-Mod MS, and greater than moderate MR/greater than moderate MS, respectively.
As it used real world registry data provided by sites, this study was limited by the lack of an independent echocardiographic core laboratory or clinical event adjudication. There are no surgical or medical management comparator arms. Clinical follow up was not complete for all patients, with the risk of bias for those lacking data; furthermore, only one year outcomes were reported.
A successful repair as defined by this study was achieved by nearly 90% of patients and was associated with better clinical outcomes, and the rates of successful repair increased significantly over the study period. In conclusion, according to Dr. Makar, “transcatheter mitral valve repair with the MitraClip device is a safe and effective treatment for degenerative MR patients who are at elevated risk for surgery. The goal…should be to achieve mild or less residual MR without creating significant mitral stenosis.”
