GOTHENBURG, Sweden -- Percutaneous mitral valve repair appears to benefit patients at high surgical risk, a case-control analysis within the EVEREST II trial suggested.
High-risk patients who received the MitraClip device saw a substantial survival advantage compared with a matched group of high-risk patients who largely remained on medical management, Olaf Franzen, MD, of the University Clinic of Hamburg, Germany, and colleagues found.
One-year survival rates were 77.5% with the clip in functional mitral regurgitation and 72% in degenerative cases but 55.3% among the concurrent controls (P=0.0047 and 0.0924, respectively), the group reported here at the European Society of Cardiology's Heart Failure Congress.
Action Points
- Note that this study was published as an abstract and presented at a conference. These data and conclusions should be considered to be preliminary until published in a peer-reviewed journal.
- Explain that percutaneous mitral valve repair appears to benefit patients at high surgical risk compared with medical management, suggested by a case-control analysis within the EVEREST II trial.
- Note that NYHA heart failure class, quality of life, and rates of re-hospitalization for heart failure improved significantly in the MitraClip-treated patients at one year.
The percutaneous approach also improved left ventricular volumes, functional class, quality of life, and heart failure hospitalization rates.
However, this hypothesis-generating data should not inform clinical practice yet, warned study discussant Andrew Clark, MD, of the University of Hull in Kingston-upon-Hull, U.K.
"We simply don't know that the MitraClip is better than doing nothing in this group of patients," he cautioned attendees at the late-breaking clinical trial session.
Franzen also cautioned against overinterpreting the results, calling for validation in a prospective clinical trial.
"We have encouraging data," he said. "I think for patients in need there is already something out there, but we certainly need trials to prove that."
Clinicians in Europe have had commercial access to the MitraClip since 2008, despite a recent recall regarding the delivery system. The device is not approved in the U.S.
The pivotal EVEREST II trial, designed to support an application for FDA approval, initially showed dramatic benefits with the clip in patients with significant symptomatic mitral regurgitation compared with surgery. One and two year follow up, though, favored surgery for efficacy and showed none of the initial advantage in mortality with the clip.
Franzen's group pooled 211 patients with at least one year of follow up from high risk cohorts treated through the EVEREST program.
Controls comprised 36 patients with 3+ or 4+ mitral regurgitation screened for EVEREST II. The controls also met the same high surgical risk criteria of 12% or higher surgical risk, based on the Society of Thoracic Surgeons risk calculator or by surgeon estimate based on pre-specified comorbidities. These patients were not enrolled in EVEREST II because of mitral valve anatomy or patient preference.
These controls received standard of care managment through one year, which meant 86% got medical management alone and 14% had mitral valve surgery despite their high risk.
By comparison in the clip-treated cohort, 98.6% of those with functional mitral regurgitation and 96.5% of those with degenerative mitral regurgitation remained free of surgery at one year.
Mitral regurgitation grade dropped to 2+ or less for 80% to 82% of the MitraClip recipients at one year. Their left ventricular volumes improved significantly compared with baseline for end diastole in both functional and degenerative groups and for end systole in the functional regurgitation group (all P<0.0001).
New York Heart Association functional class climbed to I or II for 78% of functional cases and for 86% of degenerative cases treated with the percutaneous valve procedure by one year (P<0.0001 and P=0.0013 versus baseline, respectively).
Quality of life measured on the SF-36 climbed significantly compared with baseline in MitraClip-treated patients for both the physical and mental components with increases ranging from 4 to 7 points.
Rehospitalization for heart failure dropped in the year after the clip procedure compared with the prior year by 44% in the functional mitral regurgitation group and by 55% in the degenerative group (P=0.0004 and 0.006, respectively).
Major adverse events at 30 days in the high surgical risk cohort treated through the EVEREST program occurred in 20.8% of functional and 17.7% of degenerative mitral regurgitation patients overall, or in 10.7% and 6.5% excluding transfusions.
Disclosures
Franzen reported being an advisory board member and speaker for Abbott.
Clark reported having no conflicts of interests to disclose.
Primary Source
Heart Failure Congress
Source Reference: Franzen O, et al "EVEREST high surgical risk cohort: Comparison of outcomes in functional and degenerative mitral regurgitation: Results through 1 year" HFC 2011.