The third-generation MitraClip NTR/XTR transcatheter edge-to-edge repair (TEER) system resulted in significant reduction in mitral regurgitation (MR) in contemporary real-world practice, compared to earlier randomized controlled trials, according to new registry results.

Saibal Kar, MD, of Los Robles Regional Medical Center, Thousand Oaks, California, and colleagues reported these findings from the EXPAND (The MitraClip EXPAND Study of the Next Generation of MitraClip Devices) registry, in a manuscript published Monday online and in the March 13 issue of JACC: Cardiovascular Interventions.

EXPAND was a prospective, multicenter, international, post-market, observational single-arm study that enrolled patients with primary and secondary MR at 57 centers in the U.S., Europe and the Middle East. The patients were followed up from baseline through discharge, 30 days, and 12 months. Echocardiograms were analyzed by an independent core lab.

The study was sponsored by Abbott, the manufacturer of the MitraClip devices.

The study enrolled 1,041 subjects from April 2018 to March 2019, of whom 722 subjects (84%) successfully completed 12 months of follow-up. The average age was 77.3 ± 9.7 years, and 54.9% were male.

The Society of Thoracic Surgeons Predicted Risk of Mortality (STS-PROM) risk for repair was 6.3% ± 6.3% and replacement risk was 8.0% ± 6.4%, , and the Euro-SCORE II was 8.1 ± 8.0. The most common comorbidities were hypertension (82.9%) and atrial fibrillation (59.3%). More than half of the patients (53.7%) experienced a heart failure hospitalization in the prior 12 months. A total 78.6% of subjects had New York Heart Association (NYHA) functional class III/IV symptoms, 28.2% had prior cardiac surgeries, 35.7% had prior cardiac interventions.

The study demonstrated an implant success rate of 98.9% and 1.5 ± 0.6 clips implanted per subject. Significant MR improvement from baseline (MR ≥ 3+, 56.0%) to 30 days (MR ≤ 1+, 88.8%) was maintained through 1 year (MR ≤ 1, 89.2%). Most subjects with primary MR (84.5%) and secondary MR (93.0%) saw reduction in MR ≤1 at 1 year.

At 1-year, significant improvements in both NYHA functional class (NYHA I/II in 80.3% of subjects) and Kansas City Cardiomyopathy Questionnaire score (overall +21.6) were observed. The 1-year rate of heart failure hospitalization was 18.9% and all-cause mortality was 14.9%. The incidence of adverse clinical events was rare, with 1.7% of patients experiencing a single leaflet device attachment, and 1.9% of patients needing surgical mitral valve replacement in the first year.

These results were comparable or better than those shown in the COAPT (Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients With Functional Mitral Regurgitation) and EVEREST (Endovascular Valve Edge-to-Edge Repair) randomized controlled trials, both of which used prior-generation repair devices, the authors noted.

In an accompanying editorial, Benjamin Hibbert MD, PhD, of University of Ottawa Heart Institute, Ottawa, Ontario, and Mohamad Alkhouli, MD of Mayo Clinic School of Medicine, Rochester, Minnesota, lauded the authors for the study and stated that the EXPAND registry is an excellent example both in terms of the outcomes that can be achieved with modern TEER procedures and sets the standard for quality in observational research needed in structural heart disease field.

They further added that the largest contribution of this study may be to inspire further randomized trials to address the remaining uncertainties on the optimal treatment of primary MR.

In fact, Kar and colleagues noted that their findings did inspire a new randomized trial, MitraClip REPAIR MR study, which will compare TEER with the MitraClip to contemporary surgical repair for patients with degenerative MR at moderate surgical risk.

Sources:

Kar S, von Bardeleben RS, Rottbauer W, et al. Contemporary Outcomes Following Transcatheter Edge-to-Edge Repair: 1-Year Results From the EXPAND Study. JACC Cardiovasc Interv. 2023;16:589–602.

Hibbert B, Alkhouli M. Optimal Outcomes in Real-World Patients Treated With TEER: Reaching the Pinnacle. JACC Cardiovasc Interv. 2023;16:603–605.

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