MitraClip G4 device safe and effective in reducing mitral regurgitation at one year: EXPAND G4 study

The researchers observed durable reductions in MR severity to ≤1+ in more than 90% of patients and concomitant improvements in quality of life and functional status. The findings were presented at TCT 2023 and subsequently published online in JACC: Cardiovascular Interventions on October 24, 2023.

The fourth-generation M-TEER device (Abbott) introduced an independent leaflet grasping, an improved clip deployment sequence, and 2 wider clip sizes to tailor the treatment of patients with mitral regurgitation for a broad range of anatomies. Previous studies have already demonstrated the 30-day safety and effectiveness of the fourth-generation M-TEER device.

Ralph Stephan von Bardeleben, Department of Cardiology, University Medical Center of Mainz, Mainz, Germany, and colleagues aimed to evaluate 1-year outcomes in a contemporary, real-world cohort of subjects treated with the MitraClip G4 system.

EXPAND G4 is an ongoing multicenter, prospective, international, single-arm study that enrolled patients with primary and secondary MR. One-year outcomes were heart failure hospitalization, MR severity (echocardiographic core laboratory assessed), functional capacity (NYHA functional class), MR severity (echocardiographic core laboratory assessed), and quality of life (Kansas City Cardiomyopathy Questionnaire). From 2020 to 2022, a total of 1,164 subjects underwent M-TEER.

The study revealed the following findings:

• At 1 year, there was a durable reduction in MR to mild or less in 92.6% and to none or trace in 44.2%.
• Few subjects had major adverse events through 1 year (<2% for myocardial infarction, surgical reintervention, or single-leaflet device attachment).
• The 1-year Kaplan-Meier estimates for all-cause mortality and heart failure hospitalization were 12.3% and 16.9%.
• Significant improvements in functional capacity (NYHA functional class I or II in 82%) and quality of life (18.5-point Kansas City Cardiomyopathy Questionnaire overall summary score improvement) were observed.

"Our findings showed that treatment with a fourth-generation M-TEER device led to durable 1-year MR reduction to ≤1+ in 93% of the patients and the lowest 1-year rates of heart failure hospitalization (HFH) and all-cause mortality in an M-TEER study to date," the researchers wrote. "These benefits were accompanied by improved quality of life and functional capacity."

"The durable long-term outcomes support the continued improvement of M-TEER therapy in achieving higher standards in MR reduction and clinical outcomes that should drive future development of M-TEER therapy," they concluded.

Reference:

von Bardeleben RS, Mahoney P, Morse MA, et al. 1-year outcomes with fourth-generation mitral valve transcatheter edge-to-edge repair from the EXPAND G4 study. J Am Coll Cardiol Intv. 2023;Epub ahead of print.