The safety profile of transcatheter edge-to-edge repair (TEER) of the mitral valve for degenerative mitral regurgitation (MR) was excellent, with a high rate of successful TEER that increased over 8 years in an older patient population, according to an analysis of the real-world Society of Thoracic Surgeons (STS)/American College of Cardiology (ACC) Transcatheter Valve Therapy (TVT) Registry.

Raj R. Makkar, MD, of Cedars-Sinai Medical Center, Los Angeles, reported these findings during a Featured Clinical Research presentation Sunday at the ACC Scientific Sessions 2023 in New Orleans.

TEER of the mitral valve is approved by the U.S. Food and Drug Administration for degenerative MR in patients with high surgical risk, but the contemporary, real-world outcomes of TEER in degenerative MR are not currently known.

Therefore, Makkar and colleagues evaluated the trends and procedural and clinical outcomes of TEER in degenerative MR using the STS/ACC TVT Registry.

The current analysis included 19,088 non-emergent TEERs performed with the MitraClip device (Abbott) for moderate-to-severe or severe degenerative MR. These procedures were performed between January 2014 and June 2022.

The primary endpoint was MR success, defined as post-TEER residual MR of moderate or less and the absence of severe stenosis, which was defined as mean mitral gradient <10 mmHg. Secondary endpoints included death, heart failure rehospitalization and mitral valve reintervention in the hospital and at 30 days and 1 year, and death and heart-failure rehospitalization based on residual MR and mitral valve gradients.

At baseline, the patients’ median age was 82 years (interquartile range [IQR]: 76-86), nearly half (49%) were female, and their median STS risk score was 4.57% (IQR: 2.8% to 7.4%). Medical history included stroke in 9.8%, chronic lung disease in 31.9%, the need for home oxygen in 10.3%, heart failure within the 2 weeks prior to TEER in 77.0%, atrial fibrillation or flutter in 60.1%, and coronary artery disease in 47.0%.

Baseline echocardiography showed that most patients (82.2%) had severe degenerative MR and 17.8% had moderate-to-severe MR. Most (80.2%) had leaflet prolapse, with the most common location being posterior (46.0%), and 62.7% had leaflet flail, with the most common location again being posterior (49.3%).

In-hospital event rates were low: 1.1% of patients died, 1.1% underwent unplanned cardiac surgery or intervention, 0.72% had a stroke or transient ischemic attack (TIA), and 0.34% had a new requirement for dialysis.

At 30 days, 2.7% of patients had died, 2.6% had been rehospitalized for heart failure, 1.7% underwent unplanned cardiac surgery or intervention, 1.4% had a stroke or TIA, and 0.51% had a new requirement for dialysis.

Echocardiography showed that the rate of moderate or less MR severity was 97.6% post-procedure, 97.4% at discharge and 95.3% at 30 days. The rate of mild or less MR severity was 77.5% post-procedure, 77.4% at discharge and 65.7% at 30 days.

Nearly all patients had a mean mitral valve gradient <10 mmHg post-procedure (99.1%), and this was largely sustained at discharge (97.1%) and 30 days (96.5%).

Most patients met the primary MR success endpoint of moderate or less MR and mean mitral gradient <10 mmHg: 95.2% post-procedure, 93.0% at discharge and 89.0% at 30 days.

“Our analysis showed that in an older patient population with limited therapeutic options, transcatheter-based mitral valve repair was safe and was effective in reducing valve leakage from severe to moderate or less in almost 90% of patients,” Makkar said in a news release announcing the results.

The annualized rate of MR success rose from 81.5% in 2015 to 92.2% in 2022.

At 1 year post-procedure, patients whose TEER was successful had a significantly lower mortality rate than those whose procedure was not successful (14.0% vs. 26.7%; adjusted hazard ratio [HR]: 0.49, 95% confidence interval [CI]: 0.42-0.56; p<0.001).

The same was true at 1 year for heart-failure readmission (successful 8.4% vs. unsuccessful 16.9%; adjusted HR: 0.47, 95% CI: 0.41-0.54; p<0.001) and mitral valve reintervention (successful 2.1% vs. unsuccessful 13.5%; adjusted HR: 0.15, 95% CI: 0.12-0.19; p<0.001).

The 1-year death rate was highest in patients with an unsuccessful procedure (26.7%), and the rate was significantly lower in patients with residual mild or less MR and gradient <10 mmHg than in patients with residual moderate or less MR and gradient <10 mmHg (adjusted HR: 0.73, 95% CI: 0.66-0.82; p<0.001).

Again, a similar pattern was shown in 1-year heart-failure readmission, with an unsuccessful procedure yielding the highest rate (16.9%) and mild or less MR and gradient <10 mmHg showing a significantly lower rate than that of moderate or less MR and gradient <10 mmHg (adjusted HR: 0.68, 95% CI: 0.60-0.78; p<0.001).

Study limitations include that the STS/ACC TVT Registry includes site-reported data with no echocardiographic core laboratory or independent adjudication of clinical events, incomplete echocardiographic and clinical follow-up, lack of a comparator arm and follow-up being limited to 1 year.

These results suggest that TEER with the MitraClip is safe and effective in patients with degenerative MR who are at elevated risk for surgery, Makkar said.

He added that the goal of TEER for degenerative MR should be to achieve mild or less MR without creating significant mitral stenosis.