Evalve Two-Year Follow-up Data Demonstrates Preservation of Adequate Mitral Valve Area In Patients Treated with the Mitraclip® System
EVEREST Data Shows that the MitraClip® Therapy does not produce Clinically Significant Mitral Stenosis
MENLO PARK, Calif. December 4, 2008 -- Long-term data published in EuroIntervention showed that the expected decrease in Mitral Vale Area (MVA) after repair with the MitraClip® system to correct mitral regurgitation (MR) is not associated with clinically significant mitral stenosis. Additionally, with two years of follow-up, none of the patients treated with the MitraClip® system required surgery for mitral stenosis. At 12 months no important differences were reported between the use of one or two MitraClip® devices or based on the etiology of MR.
The analysis was conducted to assess diastolic mitral valve function after percutaneous repair. Echocardiographic measurements of MVA and mean trans-Mitral Valve Gradient (MVG) were made in 96 patients implanted with the MitraClip® device. Patients were followed for up to two years.
The MitraClip® system is the first commercially available medical device which provides a non-surgical mitral valve repair option for patients suffering from the effects of MR. The MitraClip® system is available commercially in Europe and is currently in late stage clinical trials in the United States.
MR affects millions of people worldwide and is the most common type of heart valve insufficiency in Europe and in the United States. The vast majority of patients with significant MR are untreated, which leaves their hearts affected by the chronic volume overload caused by MR, requiring the heart to work harder, and ultimately leading to heart failure.
"It is important to know that the encouraging results from use of the MitraClip® system were maintained at two years without mitral stenosis," said Howard C. Herrmann, M.D., director, Interventional Cardiology and Cardiac Catheterization Laboratories at the hospital of the University of Pennsylvania and lead author of the manuscript. "With these results, we have a growing body of evidence that MitraClip® therapy can be a good option for many patients in the right situation."
The MitraClip device creates a double orifice mitral valve by securing the leaflets to reduce MR in a replication of the surgical procedure pioneered by Ottavio Alfieri, MD. The resulting double orifice has an inherently smaller cross sectional area compared to the native mitral valve. In a preliminary study published in Catheterization and Cardiovascular Interventions in 2006, Dr. Herrmann and colleagues demonstrated a similar decrease in MVA using the MitraClip® system also without causing mitral stenosis. In the present analysis, these observations were extended to a larger study population with longer term follow up, and included patients who received more than one MitraClip® device and those with functional MR.
The study population for the present analysis included 107 patients with moderate-to-severe or severe MR who were enrolled in the EVEREST phase I registry (n=55) or subjects who were not randomized as part of the EVEREST II trial (n=52).
Baseline characteristics and hemodynamic measurements were analyzed for the 96 patients in the study population who received the MitraClip® device. All patients were either symptomatic (91 percent) or if asymptomatic had evidence of left ventricular dysfunction.
Transthoracic echocardiography was performed at baseline, pre-discharge, one year and two year follow-up and analyzed by an independent core echocardiographic laboratory at the University of California at San Francisco.
The mean MVA as measured by planimetry decreased from 6.0 +/- 1.3 cm at baseline to 3.6 +/-1.2 cm (p<0.05) at discharge. At 12 months MVA was 3.6 +/-1.2 cm (n= 59). The mean MVG increased from 1.7 +/- 0.9 mmHg at baseline to 4.1 +/-2.2 mmHg (p<0.05) at discharge. At 12 months MVG was 3.4 +/-1.6 mmHg (n=50). From discharge to 24 months, there were no significant changes in the mean MVA or MVG. There were no differences in mean MVA or MVG at 12 month follow up between patients who received one MitraClip® device (69 percent) and those receiving two MitraClip® devices (31 percent). Patients with functional MR had a slightly smaller mean MVA, both at baseline and at discharge, but did not differ from degenerative MR patients at later follow-up. These hemodynamic results are consistent with reports of surgical edge-to-edge repair which also have shown that diastolic mitral valve function is preserved.
"These longer-term results contribute to the existing body of clinical data regarding the performance of this first in class, less invasive treatment approach. We are pleased that Dr. Hermann and the coauthors have reported this important information so that it is available for physicians to discuss with their patients as they consider this non-surgical treatment option" said Ferolyn Powell, president and chief executive officer of Evalve.
About the MitraClip® Procedure
Percutaneous mitral repair with Evalve's MitraClip® system is performed by physicians in the catheterization laboratory. The heart beats normally during the procedure, and therefore does not require a heart-lung bypass machine. In addition to improving blood flow through the heart, the procedure may also relieve symptoms such as fatigue and shortness of breath that often affect patients with significant MR. After treatment, patients generally recover quickly. The MitraClip® therapy may improve quality of life and may help MR patients avoid or delay surgery, having preserved surgical options (valve repair or replacement) should surgery become necessary.
About Evalve, Inc.
Founded in 1999, Evalve, Inc. -headquartered in Menlo Park, California- has developed a proprietary system which enables percutaneous repair of cardiac valves. The company’s initial products are intended to reduce the risks, trauma and costs associated with current open, arrested heart surgical options. For more information about Evalve, Inc., and for an animated explanation of the procedure using the MitraClip® device, visit www.evalveinc.com. Evalve is the first portfolio company from the medical device company incubator, The Foundry (www.thefoundry.com).
The MitraClip® System is currently undergoing clinical evaluation in the United States and Canada.
MitraClip® and Evalve are registered trademarks of Evalve, Inc.