A Medical Device Daily

Data presented at the American College of Cardiology's (Washington) 59th annual scientific session from the landmark EVEREST II (Endovascular Valve Edge-to-Edge REpair STudy) trial demonstrated that Abbott's (Abbott Park, Illinois) investigational MitraClip system met both its primary safety and effectiveness endpoints, which lead the company to suggest that the minimally invasive MitraClip procedure may be an important treatment option for patients with significant mitral regurgitation (MR). At one year, the MitraClip device demonstrated meaningful clinical benefits for patients with significant MR, including improvements in heart function, quality of life, and normal physical activity, and a decrease in cardiac symptoms. The EVEREST II trial is the first randomized trial of any minimally invasive mitral valve repair device compared to mitral valve surgery.

The MitraClip system includes a catheter-based device, which is delivered to the heart through a blood vessel in the leg (femoral vein). The MitraClip device is designed to reduce significant MR by clipping together the leaflets of the mitral valve (one of the four valves of the heart). MR is the most common type of heart valve insufficiency and occurs when the leaflets of the mitral valve do not close completely, causing blood to flow backwards and leak into the left atrium of the heart during the cardiac cycle. To maintain an adequate forward flow of blood throughout the body, the heart compensates by increasing the size of the left ventricle (main pumping chamber of the heart) to accommodate the increase in the volume of blood it is pumping.

“In the EVEREST II trial, the catheter-based system exhibited a highly favorable safety profile, while providing meaningful and sustained clinical benefits,“ said Ted Feldman, MD, director of the Cardiac Catheterization Laboratory at NorthShore University HealthSystem (Evanston, Illinois) and co-principal investigator of the EVEREST II trial. “The positive trial results validate my experience that the procedure is a valuable therapeutic option for select patients with mitral regurgitation. The therapy has the potential to transform the lives of thousands of patients, and enable some to go from bed rest to a more active lifestyle.“

Mitral regurgitation affects more than 8 million people in the U.S. and Europe and is currently managed with drugs or open heart surgery, depending on an individual patient's severity of MR and risk factors. Significant MR is a debilitating condition where the heart's ability to function continues to deteriorate over time, and may lead to irregular heartbeat, heart failure, stroke, heart attack or death.

The MitraClip system received the CE mark in March 2008, and is an investigational device in the U.S.

In other news from the ACC:

• Boston Scientific (Natick, Massachusetts) reported the completion of patient enrollment in the small vessel and long lesion trials of its PLATINUM clinical program. The trials are designed to compare the platinum chromium Promus Element Everolimus-Eluting Stent system to matched historical control groups of patients treated with the Taxus Express2 Paclitaxel-Eluting Stent system. “Data from clinical studies have shown that small vessels and long lesions each represent an estimated 10% of percutaneous coronary interventions,“ said Gregg Stone, MD, the principal investigator for the PLATINUM program.

“The availability of everolimus-based small vessel and long lesion stents will allow physicians greater flexibility in treating a broad range of complex coronary lesions. We look forward to the results of these important trials.“ The Promus is designed specifically for coronary stenting. The stent architecture and alloy combine to offer radial strength and flexibility. The stent architecture helps create consistent lesion coverage and drug distribution while improving deliverability, which is enhanced by an advanced catheter delivery system. The higher density alloy provides superior visibility and reduced recoil while permitting thinner struts compared to prior-generation stents, the company said.

• Iverson Genetic Diagnostics (Bothell, Washington) said they will conduct a WARFARIN clinical study to assess the efficacy of gene-based testing prior to initiating warfarin anticoagulation therapy to reduce the incidence of bleeding and thromboembolic events.

Researchers have identified two specific genes, VKORC1 and CYP2C9, that contribute up to 60% of individual variations in response to using warfarin. The WARFARIN Study will investigate that with identification of these genes, whether physicians will be able to administer the proper warfarin dosage for each patient and avoid major hemorrhagic and thromboembolic adverse events.

Warfarin is a commonly used anticoagulant that must be dosed properly to avoid bleeding complications from overdosing and ineffectiveness from under dosing. Currently, more than 2 million patients are prescribed warfarin in the United States each year, with 1%–5% experiencing a major bleeding event.