Two real-world European studies of Abbott’s minimally invasive MitraClip® device demonstrate positive outcomes for patients with MR

Abbott today announced publication of positive outcomes from two European post-approval studies of the first-in-class catheter-based MitraClip® therapy for the treatment of mitral regurgitation (MR). Results from ACCESS-EU, a European prospective study that enrolled 567 patients at 14 sites, have been published in the Journal of the American College of Cardiology. In addition, findings of the investigator-sponsored German TRAnscatheter Mitral Valve Interventions (TRAMI) registry, which enrolled 1,064 patients at 20 German sites, were recently published in EuroIntervention.

Abbott’s MitraClip System, which received CE Mark in 2008 and is commercially available in Europe and other international markets, is an investigational device in the United States. The device is delivered to the heart through the femoral vein, a blood vessel in the leg, and is designed to reduce MR by clipping together a portion of the leaflets of the mitral valve to allow the heart to more efficiently pump blood.

Data from ACCESS-EU demonstrated that in real-world, post-approval experience in Europe, patients undergoing the MitraClip therapy are predominantly high surgical risk, elderly patients who are mainly affected by functional MR, a type of MR in which a damaged heart impairs the performance of a normal mitral valve. ACCESS-EU showed that in this patient population, the MitraClip procedure demonstrated low rates of hospital mortality and adverse events and provided significant improvements in day-to-day quality of life at one year following treatment.

“I am impressed by the excellent outcomes observed in real-world patients with the MitraClip therapy. The procedure proved safe and effective even in patients who are at high risk for complications from mitral valve surgery,” said Francesco Maisano, M.D., director of Transcatheter Valve Therapies at San Raffaele Hospital in Milan, Italy, lead author of the ACCESS-EU data publication and co-principal investigator of the study. “In my experience, the MitraClip therapy has a definite role for patients who are not candidates for surgery. I have treated many patients who have experienced a dramatic improvement in quality of life. Relief from the symptoms of mitral regurgitation has allowed many bedridden patients to return to normal day-to-day activities.”

“The data from these studies, which together evaluated more than 1,600 patients, add to the clinical evidence confirming positive results for treatment with MitraClip in high surgical risk patients suffering from the debilitating symptoms of significant mitral regurgitation,” said Charles A. Simonton, M.D., FACC, FSCAI, divisional vice president, Medical Affairs, and chief medical officer, Abbott Vascular. “The MitraClip device represents a true advance for these patients, who suffer from poor quality of life and have no satisfactory options to reduce their significant mitral regurgitation.”

Findings of the ACCESS-EU study showed:

Most patients currently treated in Europe are high surgical risk. The mean age was 74 years, with 45 percent of patients older than 75 years. Most patients had secondary or functional mitral regurgitation (FMR), a type of MR in which a damaged heart impairs the performance of a normal mitral valve; low ejection fraction (most 40 percent or lower); and presented with multiple comorbidities, including coronary artery disease (63 percent), hypertension (76 percent), atrial fibrillation (68 percent) and renal disease (42 percent).

An implant success rate of 99.6 percent.

No incidence of death or stroke during the MitraClip procedure and in the immediate post-operative period.

A majority of patients (91.2 percent) achieved MR reduction to MR grade of 2+ or less (on a scale of 1+ [mild MR] to 4+ [severe MR]) at discharge (p<0.0001).

At one year following the procedure, 78.9 percent of patients were free from MR severity of 2+ or more (p<0.0001), and 71.4 percent of patients were in NYHA Functional Class II or Class I compared to 15 percent at baseline (p<0.0001).

A large majority of patients (79.2 percent) were discharged to home rather than to a skilled nursing facility.

Significant improvements in quality of life. At one year, Six-Minute Walk Test results, which measure distance walked on a flat, hard surface in a six-minute period, improved by a mean of 59.5 meters (p<0.0001). Minnesota Living With Heart Failure results, which measure the effects of symptoms, functional limitations and psychological distress on an individual’s quality of life, improved by a mean 13.5 points (p<0.0001).

Results of the TRAMI registry showed similar benefits for the MitraClip therapy in both elderly and younger patients. To evaluate the influence of age, patients were divided into two subgroups: patients 76 years old and above, and patients younger than 76 years of age. The procedure proved to be safe in both groups. Hospital mortality was 2.9 percent in elderly patients and 2.8 percent in younger patients (p=0.96). Major adverse car­diovascular or cerebrovascular events (MACCE), defined as a com­posite endpoint of death, myocardial infarction or stroke, was 3.5 percent vs. 3.4 percent (p=0.93) respectively. The majority of patients – 81.8 percent of elderly patients and 86.2 percent of younger patients (p=0.06) – fully recovered from the MitraClip procedure and were discharged without the need for nursing care. There was substantial relief of heart failure symptoms for the majority of patients, with comparable proportions of patients in NYHA Functional Class II or Class I (69.5 percent and 61.4 percent, respectively; p=n.s.).

About Mitral Regurgitation

Mitral regurgitation (MR) is the most common type of heart valve insufficiency,1 affecting approximately one in 10 people aged 75 years and older. The condition occurs when the leaflets of the mitral valve do not close completely, causing blood to flow backward 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, the main pumping chamber of the heart. This requires the heart to work harder, and may ultimately lead to irregular heartbeats, stroke, heart attack or death. MR may also lead to heart failure, a potentially deadly condition that occurs when the heart is unable to pump sufficiently to distribute blood flow to meet the needs of the body.

About the MitraClip® Device

Abbott’s MitraClip therapy is designed to reduce MR and provide clinical and quality-of-life benefits for patients suffering from the debilitating symptoms of significant MR by clipping together a portion of the leaflets of the mitral valve. The device is delivered to the heart through the femoral vein, a blood vessel in the leg. The heart beats normally during the procedure, and a heart-lung bypass machine is not required. By reducing MR, the therapy may allow the heart to recover from overwork and improve function, potentially halting the progression of heart failure and enabling patients to live a higher-quality life.

The device received CE Mark in 2008 and is commercially available in approximately 30 countries, with more than 9,000 patients treated to date. The European Society of Cardiology (ESC) 2012 heart failure guidelines and the ESC/European Association for Cardio-Thoracic Surgery 2012 guidelines for the management of valvular heart disease specify the MitraClip device as a treatment option for high surgical risk patients with MR.

Reference

1. Nkomo VT, Gardin JM, Skelton TN, Gottdiener JS, Scott CG, Enriquez-Sarano M. Burden of valvular heart diseases: a population-based study. Lancet. 2006 Sep 16; 368(9540):1005-11.