MitraClip confers mitral regurgitation reduction in two trials
Patients with HF and moderate to severe mitral regurgitation who underwent transcatheter mitral valve repair had a greater reduction of mitral regurgitation at 30 days compared with guideline-directed medical therapy, according to an analysis of the COAPT trial presented at EuroPCR.
In addition, next-generation versions of the valve (MitraClip NTR and XTR, Abbott) were safe and effective in treating patients with the same condition who underwent transcatheter mitral valve repair, according to data from the EXPAND trial presented at the same meeting.
As Cardiology Today’s Intervention previously reported, 2-year data found that the transcatheter device (MitraClip, Abbott) reduced the risk for HF hospitalization and mortality and improved exercise tolerance and quality of life compared with medical therapy.
In this analysis of the trial, Saibal Kar, MD, FACC, interventional cardiologist and director of interventional cardiac research at Cedars-Sinai, and colleagues evaluated the impact and durability of the degree of residual mitral regurgitation at 30 days on long-term functional and clinical outcomes in patients assigned the transcatheter device with guideline-directed medical therapy (n = 302) or guideline-directed medical therapy alone (n = 312).
In a pooled analysis, HF hospitalization or all-cause mortality at 24 months occurred in 73.5% of patients with a mitral regurgitation grade of 3+/4+ at 30 days, 49.8% of those with a mitral regurgitation grade of 2+ at 30 days and 38.6% of patients with a mitral regurgitation grade of 0/1+ at 30 days. When patients with a grade of 0/1+ were compared with those with a grade of 3+/4+, the HR of having HF hospitalization or all-cause mortality was 0.38 (95% CI, 0.29-0.5). The HRs of these events were 0.5 in grade 2+ vs. grade 3+/4+ (95% CI, 0.36-0.68) and 0.76 in grade 0/1+ vs. grade 2+ (95% CI, 0.54-1.07).
When patients were stratified by the treatment they were assigned to, fewer patients assigned the transcatheter device with guideline-directed medical therapy who had a mitral regurgitation grade of 0/1+ or 2+ at 30 days were hospitalized for HF or had all-cause death at 24 months compared with those assigned guideline-directed medical therapy alone with the same degree of mitral regurgitation. The rate of these events was similar in both groups of patients with grade 3+/4+ mitral regurgitation at 30 days.
The cumulative rate of HF hospitalizations at 24 months was higher in patients with grade 3+/4+ mitral regurgitation at 30 days compared with those with grade 0/1+ and grade 2+ mitral regurgitation (P for interaction = .72). This was also observed for the cumulative rate of all-cause mortality (P for interaction = .55).
At 12 months, more patients with grade 0/1+ and grade 2+ mitral regurgitation had improvements in Kansas City Cardiomyopathy Questionnaire (KCCQ) scores at 12 months compared with those with grade 3+/4+ mitral regurgitation. Patients assigned the transcatheter device with guideline-directed medical therapy with grade 0/1+ and grade 2+ mitral regurgitation had more improvements in these scores compared with those assigned guideline-directed medical therapy alone with the same severity of mitral regurgitation (P for interaction = .71).
In patients with less than grade 1+ mitral regurgitation at 30 days, there were fewer patients with worsening severity at 12 and 24 months in the transcatheter device with guideline-directed medical therapy group vs. guideline-directed medical therapy alone group. This was also observed in patients with residual mitral regurgitation of grade 2+ at 30 days.
“This finding suggests that the greater reduction of [mitral regurgitation] with the MitraClip compared with [guideline-directed medical therapy] alone underlies the observed clinical benefits from the MitraClip,” Kar said during the presentation.
In another trial, Jörg Hausleiter, MD, of Ludwig-Maximilians Universität München in Munich, and colleagues assessed clinical outcomes related to a third-generation transcatheter device in 500 patients (mean age, 78 years; 56% men) with symptomatic mitral regurgitation of grade 3+.
Compared with the previous version of the transcatheter device, the next-generation version increases coaptation surface area, steering precision, ease of use and deliverability, in addition to an expansion in the range of mitral valve anatomies treatable with the system and a reduction in clip rate and device time, according to the presentation.
Patients were followed up at 30 days, 6 months and 12 months for outcomes of interest including procedure time, device use, major adverse events, NYHA classification, mitral regurgitation reduction and KCCQ assessment.
The implant rate was 99.2% and 94% had acute procedural success. The length of stay in the hospital for the index procedure was 6.3 days. Of the devices included in this study, the NTR was used in 41% of patients, the XTR was used in 43% of and both were used in 16%.
At 30 days, all-cause death occurred in 2.8% of patients, 1.4% had nonelective CV surgery for device-related complications and 0.4% had stroke. MI did not occur within this time period.
Regarding adverse events, 3.4% had single leaflet device attachment, which was mainly associated with more complex anatomy, according to the presentation. Most of these events occurred during the first cases.
“These data indicate a learning curve with the new system,” Hausleiter said during the presentation. “There was a significant reduction in the occurrence of [single leaflet device attachments] after the first five cases.”
The number of patients with mitral regurgitation of grade 0/1+ increased from zero at baseline to 74% at discharge, which then decreased to 66% at 30 days. A mitral regurgitation grade of 2+ was seen in zero patients at baseline, 22% at discharge and 28% at 30 days.
There were improvements in both NYHA classification and KCCQ assessment from baseline to 30 days.
“The data continue to support the safety and efficacy of the next-generation MitraClip device,” Hausleiter said during the presentation. – by Darlene Dobkowski
Hausleiter J, et al. Trials and registries: Tricuspid and mitral valve repair. Presented at: EuroPCR; May 21-24, 2019; Paris.
Kar S, et al. Hot line and trial update. Presented at: EuroPCR; May 21-24, 2019; Paris.
Disclosures: The COAPT trial was funded by Abbott. The EXPAND trial was sponsored by Abbott Medical Devices. Hausleiter reports he received research support and speaker honoraria from Abbott Vascular and Edwards Lifesciences. Kar reports he received grant/research support from Abbott Vascular, Boston Scientific, Edwards Lifesciences and Gore Medical; consulting fees/honoraria from Abbott Vascular, Boston Scientific and Gore Medical; and other financial benefit from Valcare.