A Medical Device Daily
Evalve (Menlo Park, California) reported the release of data at last week's scientific sessions of the American College of Cardiology (ACC; Washington) that it said demonstrate that successful reduction of mitral regurgitation (MR) can be maintained for up to 36 months following treatment with the company's MitraClip device. Results at 12 months also show significant reverse left ventricular (LV) remodeling, indicating improved LV function.
New Endovascular Valve Edge-to-Edge REpair Study (EVEREST) registry data presented by Ted Feldman, MD, director of the cardiac catheterization lab at Evanston Northwestern Healthcare (Evanston, Illinois), based on echocardiographic core laboratory assessment at the University of California San Francisco, directed by Elyse Foster, MD, showed that at 12 months, patients who were successfully treated with a MitraClip device had statistically significant reverse LV remodeling. Additionally, 86% of patients were free from mitral valve surgery and 97% of patients had improved or stable NYHA Class, with 93% in Class I or II.
Importantly, ongoing durability was confirmed: all patients who had successful MR reduction at 12 months remained surgery-free with MR 2+ or less at two years.
Feldman, EVEREST II co-principal investigator, said "The EVEREST trial, the only trial of its kind in the world, is now also studying the use of the MitraClip device in patients at higher risk for surgical mortality."
"With over 200 MitraClip devices implanted to date, we are gaining experience and our ability to reduce mitral regurgitation is increasing. The MitraClip device provides a minimally invasive option to reduce mitral regurgitation that still allows the patient to undergo a first surgical repair later if needed," added Donald Glower, MD, professor of cardiovascular surgery at Duke University Medical Center and Co-Principal Investigator of EVEREST II.
Evalve is currently conducting the pivotal EVEREST II clinical research study evaluating the safety and efficacy of the MitraClip device vs. surgical mitral valve repair or replacement. The study will enroll 279 patients at up to 42 sites in the U.S. and Canada; the company anticipates complete enrollment by the end of 2007. Patients are randomized 2:1 to receive the MitraClip device. The company plans to file a PMA application in the U.S once all patients are followed for one year and to seek CE-marking in late 2007.
In other ACC news:
• Data were released from the bridge-to-transplantation (BTT) arm of the HeartMate II pivotal trial that demonstrate that the device, made by Thoratec (Pleasanton, California), provides mechanical circulatory BTT support for heart failure patients, and that these patients experience a lower number of adverse events and an improved quality of life while being supported by the device.
The data were presented by Leslie Miller. MD, of Washington Hospital Medical Center/Georgetown University (Washington). The trial enrolled 133 patients at 26 centers from March 2005 through May 2006, and the data reflected follow-up through the end of December 2006. Thoratec completed its premarket approval filing seeking approval for the BTT indication at the end of 2006.
Miller reported that 100 patients, or 75% of the cohort, met the trial's primary endpoint, which was cardiac transplantation or survival at 180 days while remaining eligible for transplantation. The 25% (33) who did not meet the primary endpoint included 25 who died while being supported on the device. There were no reported mechanical pump failures.
The data showed that the trial met or exceeded the objectives for the secondary endpoints, including frequency of adverse events, improved functional status and enhanced quality of life.
"The outcomes of this study demonstrate that the HeartMate II not only provides reliable, long-term circulatory support, but also improves the quality of life for these patients," Miller said. "As the first continuous flow circulatory support device to complete a U.S. trial, we are pleased with the outcomes and look forward to completing the other arm of the study that involves a larger cohort of patients who are not eligible for transplantation," he added.
The mean support duration for patients in the BTT trial was 169 days, with one patient supported by the device for 600 days, or 20 months. The patients ranged in age from 18 to 69.
• Cambridge Heart (Bedford, Massachusetts) reported the presentation of a multi-center, prospective study assessing the utility of Microvolt T-Wave Alternans (MTWA), using the CH2000 or Heartwave system, in predicting risk of sudden death among patients with non-ischemic cardiomyopathy.
The Prognostic Value of T-Wave ALternans in Patients with Heart FAilure Due to Nonischemic Cardiomyopathy (ALPHA) study enrolled 446 patients with NYHA Class II or III non-ischemic cardiomyopathy and LF ejection fraction (LVEF) less than or equal to 40%.
On the primary endpoint (cardiac death and life-threatening arrhythmias) an abnormal MTWA test had a Hazard Ratio of 4.01 (p=0.002), or four times the risk than a normal MTWA test. The 12-month negative predictive value of the test was reported to be 98.7%, indicating that patients with a negative test result are at very low risk of sudden cardiac death. For patients with LVEF less than 35%, the Hazard Ratio and negative predictive value were 4.28 (p=0.004) and 99%, respectively.