The MitraClip system is a catheter-based therapy intended to reduce mitral regurgitation (MR). This less-invasive mitral valve repair therapy is adapted from the open surgical double-orifice technique, and increases the options for select MR patients, may reduce the symptoms of heart failure (HF), and may improve quality of life.

The system consists of three major subsystems:

• A Steerable Guide Catheter
• A Clip Delivery System
• The MitraClip device (implant)

The MitraClip device is attached directly to the mitral valve, without opening the patient's chest. To access the mitral valve, the Guide Catheter is inserted into the femoral vein to reach the heart. Using the catheter, the Clip Delivery System delivers and deploys the MitraClip device. The procedure is performed under general anesthesia without the use of a heart-lung machine, and post-procedure recovery is typically one to three days.

As the world's first percutaneous mitral valve repair system, the MitraClip system received CE mark approval in 2008.

Mitral Regurgitation

Mitral regurgitation (MR) is the most common type of heart valve insufficiency in the United States; Approximately 4 million people have significant mitral valve insufficiency, with an annual incidence of 250,000¹. Approximately 50,000 of these patients undergo surgery each year in the United States. Prevalence and incidence are similar in Europe, where it's the second most common type of heart valve disease². The disease affects millions of people worldwide.

Mitral regurgitation occurs when the leaflets (or flaps) of the heart's mitral valve do not close properly and leak. The mitral valve is a one-way valve that separates the left atrium (a chamber in the heart which collects blood from the lungs) from the left ventricle (a chamber in the heart which pumps blood to the rest of the body). During pumping, the leak in the mitral valve causes blood to flow backwards (MR) into the left atrium, thereby decreasing blood flow to the body. To maintain blood flow to the body and compensate for the MR, the left ventricle must pump harder. Backflow due to MR places an extra burden on the left ventricle and lungs. Eventually, this burden can cause other problems such as:

• Stroke
• Sudden death
• Irregular heartbeat
• Increasing damage to the heart muscle (Progressive myocardial injury)
• Inability to maintain adequate circulation of blood (Congestive heart failure)

Double-orifice Technique

Since the early 1990's, the double-orifice technique has been increasingly used in the treatment of mitral regurgitation. Pioneered in Italy by Dr. Ottavio Alfieri, the technique involves suturing together the two leaflets of the mitral valve. The valve continues to open on both sides of the suture, allowing blood flow through the valve from the left atrium to left ventricle, while assuring proper valve closure when blood is pumped from the left ventricle to the rest of the body.

Well over 1,500 procedures using the double-orifice technique have been reported in peer-reviewed clinical literature with up to 15 years of follow-up.³

As the world's first percutaneous valve repair system, the MitraClip system received CE mark approval in 2008.

Studies 

ACCESS Europe
REALISM
EVEREST II
EVEREST I

ACCESS Europe

ACCESS Europe is a post market observational study of the MitraClip system to gather information regarding health economics and clinical care in Europe. Patients will be evaluated at baseline through 12 months after enrollment. Two concurrent groups of (a) medically managed heart failure patients with MR and (b) patients who have undergone mitral valve surgery for MR will be followed and evaluated primarily from a health economic perspective. Up to 300 MitraClip therapy patients will be enrolled and up to 100 patients will be enrolled in each of the concurrent groups.

REALISM

The REALISM study is a prospective, multi-center, continued access registry of the EVEREST II study to collect new information regarding treatment of MR with the MitraClip system. Patients will undergo 30-day, 6-month and 12-month clinical follow-up and yearly thereafter for 5 years. The study will consist of two arms: a high risk arm and a non-high risk arm. Up to 120 of the non-high risk patients with NYHA functional Class III or IV will be entered into a functional capacity sub-study where patients will complete a six-minute walk test. This study is based in the United States and is currently enrolling.

EVEREST II

EVEREST II is a US clinical study being conducted to assess the safety and efficacy (or effectiveness) of the MitraClip system for patients diagnosed with Grade 3 (moderate to severe) or Grade 4 (severe) MR. Study participants are required to have a number of follow-up visits and evaluations including ultrasound studies over the course of at least a 24-month period following treatment. EVEREST II consists of a randomized arm and a High Risk Registry arm.

EVEREST II Randomized Arm

Enrollment in this arm was successfully completed in September 2008. Initiated in 2005, this study arm compares the MitraClip procedure to the current standard of care, mitral valve surgery. To ensure unbiased results, participants were randomly assigned to either the MitraClip procedure or to surgery, in a "two-to-one" ratio. This means that 2 out of 3 trial participants underwent the MitraClip procedure and 1 out of 3 trial participants underwent mitral valve surgery.

EVEREST II High Risk Registry Arm

Enrollment in the High Risk Registry arm was successfully completed in January of 2008. Initiated in 2007, this study arm was designed to evaluate the safety and efficacy of the MitraClip device in patients who are considered to have a high risk of not surviving surgery.

1. Pedrazzini, GB, et al. Swiss Med Wkly, 2010. 140(3-4):36-43.
     Nkomo VT, et al. Lancet, 2006. 368:1005-11.
     Iung B, et al. Eur Heart J, 2003. 24:1231-43.
2. STS U.S. Cardiac Surgery Database. Mitral Valve Repair and Replacement Patients: Incidence of Complications Summary. 2008. www.sts.org.
3. Maisano, F., et al. Eur J Cardiothorac Surg, 2000. 17(3):p.201-5.
     Maisano, F., et al. Eur J Cardiothorac Surg, 1998. 13(3):p. 240-5; discussion 245-6.
     Umana, J.P., et al. Ann Thorac Surg, 1998. 66(5):p. 1640-6.
     Alfieri, O. and Maisano, F. J Card Surg, 1999. 14(6):p. 468-70.