The third-generation MitraClip devices, NTR and XTR, resulted in improved reduction of mitral regurgitation (MR) compared to earlier-generation devices, and patients also reported improved functional status and quality of life, according to study results presented Friday at the TCT Connect virtual conference.
Saibal Kar, MD, of Los Robles Medical Center, Thousand Oaks, California, presented results of the Global EXPAND study. It was a prospective, multicenter, international, single-arm study that enrolled 1,041 patients with MR severity ≥3+ , both primary and secondary, at 57 centers in the U.S. and Europe between April 2018 and May 2019.
The study’s aim was to evaluate real-world clinical outcomes in patients treated with the third-generation MitraClip NTR and XTR systems (Abbott).
The key outcome measures were MR severity, procedural outcomes and major adverse events (MAE); survival and heart failure hospitalization; and quality of life (Kansas City Cardiovascular Questionnaire [KCCQ] score) and functional assessment (New York Heart Association [NYHA] class).
Data were adjudicated by an echocardiographic core laboratory, clinical events committee and independent physician committee.
The study patients’ mean age was 77.3±9.7 years and 55% were men. The mean Society of Thoracic Surgeons Predicted Risk of Mortality score was 6.3% ± 6.3% for mitral valve repair and 8.0% ± 6.4% for mitral valve replacement.
As adjudicated by the echo core lab, at baseline, 56% of patients had MR 3+ or 4+ under U.S. guidelines. This improved to 2.2% at 30 days, and the improvement was largely sustained at 1 year (2.0%). Mild or trace MR (0+) was achieved in 25.7% of patients at 30 days and 18.9% at 1 year, MR ≤1+ was achieved in 88.8% at 30 days and 89.2% at 1 year, and MR ≤2+ was achieved in 97.8% at 30 days and 97.3% at 1 year.
Breaking down the results by etiology, of patients with primary MR, 66.4% had MR 3+ at baseline, and this improved to 2.7% at 30 days and 4.9% at 1 year. At 30 days, 87% of primary MR patients had MR ≤1+, and this was largely sustained at 1 year (84.5%). Turning to secondary MR, at 30 days, 90.1% had MR ≤1%, and this rate actually further improved to 93% at 1 year.
Regarding functional assessment, 78.5% of the entire study cohort had NYHA class III or IV heart failure, and this improved to 19.9% at 30 days and 19.7% at 1 year. Mean KCCQ score improved from 47 at baseline to 67 at 30 days and 70.2 at 1 year.
At 1 year, the entire study cohort had a 14.9% all-cause mortality rate. This was lower in patients with primary MR (12.%) and higher in those with secondary MR (17.7%). The rates of other adverse events were as follows: MI, 1.2%; stroke, 1.7%; single-leaflet device attachment, 1.7%; leaflet injury, 0.4%; mitral valve stenosis, 0.5%; and mitral valve reintervention, 1.9%.
The results show that transcatheter mitral valve repair with the third-generation MitraClip devices achieve MR ≤1% more often than with prior generations, and that this improvement is maintained at 1 year. This significant reduction in MR was associated with sustained improvements in quality of life and heart failure symptoms at 1 year.
Finally, Kar said during a press conference announcing the results, the additional of an additional clip size, XTR, and improvements in the device’s delivery system resulted in a greater reduction in MR without an increase in adverse events.
The study received funding from Abbott.