Two Major Medtronic Cardiac Device Trials Get Rolling

Medtronic has kicked off two major cardiac device trials this month. The first is Miracle EF, a global clinical trial that is evaluating the effectiveness of cardiac resynchronization therapy pacemakers (CRT-Ps) in delaying the progression of heart failure in symptomatic patients with mildly reduced heart pumping function. The second is Reveal AF, which through continuous cardiac monitoring will evaluate the incidence of atrial fibrillation (AF) among patients suspected to be at a high-risk for the disease, and is aimed at identifying key patient predictors for detection of AF.

This month, Medtronic enrolled its first patient in Miracle EF. This large study will be the first to evaluate CRT-P in a widely underserved patient group—those who have a slightly reduced left ventricular ejection fraction (LVEF) in the range of 36 to 50 percent, which means that their hearts work somewhat more efficiently than heart failure patients who are currently indicated for implanted device therapy because of their lower LVEF.

The CRT-P devices used in Miracle EF are not approved by the U.S. Food and Drug Administration for the patient population being studied. Edward Schloss, M.D., FACC, performed the first implant at The Christ Hospital’s Lindner Research Center in Cincinnati, Ohio. The primary investigator for the site is Greg Egnaczyk, M.D., Ph.D., FACC.

“Previous studies have proven the real-world therapeutic benefits of CRT in treating mildly to severely symptomatic heart failure patients with moderately to severely reduced cardiac pumping capacity and electrical dyssynchrony,” said Professor Cecilia Linde, M.D., Ph.D., of Karolinska University Hospital in Stockholm, Sweden, and worldwide principal investigator in the trial. “Through this large global study we hope to further our research on the overall effectiveness of CRT-P by showing its benefit in treating patients with mild-to-moderate heart failure symptoms, but with milder impairment of heart pumping capacity than previously studied.”

The trial will take place at approximately 275 centers throughout the world in regions including the United States, Canada, Europe, Japan, and developing markets. The centers will enroll up to 2,300 patients who will each receive a Medtronic Consulta CRT-P in this prospective, double-blind, randomized controlled trial. The intention is that patients will be followed for at least two years or until the end of the study, which Medtronic estimates will take four to five years to complete. The effectiveness of the CRT-P in this patient population will be assessed using a composite endpoint of time to first event, defined as all-cause mortality or heart failure hospitalization.

“We are hopeful that, when completed, Miracle EF will influence clinical practice guidelines regarding the use of advanced cardiac resynchronization devices and potentially lead to another expanded indication for Medtronic CRT devices,” said David Steinhaus, M.D., vice president and general manager of heart failure, and medical director for the cardiac rhythm disease management business at Medtronic. “We look forward to the positive implications these findings could have on heart failure patients whose disease is less pronounced, yet who still experience symptoms and need advanced therapeutic solutions.”

Also this month, the first Reveal Insertable Cardiac Monitor (ICM) was implanted in a Reveal AF trial participant. The ICM is a thin device implanted just beneath the skin that continuously records heart activity. The trial will assess how often patients experience atrial fibrillation that lasts six minutes or more, a key measure in determining the incidence of AF in the trial. The trial also will evaluate how physicians manage these patients once atrial fibrillation has been diagnosed, and will identify how the disease can be detected in patients earlier in the continuum of care.

“As a cardiologist I am quite concerned about the risks and complications of atrial arrhythmias, especially thromboembolic complications of atrial fibrillation,” said Eugene Parent, M.D., attending cardiologist and director of echocardiography at the Bradenton Cardiology Center and Manatee Memorial Hospital in Bradenton, Fla. “Frequently these rhythm changes are difficult to detect. The Reveal AF study will use the Reveal ICM to detect undiagnosed atrial fibrillation in patients at high risk for thromboembolic complications and allow more effective and prompt treatment of these patients.”

In the study, 400 patients from approximately 60 centers in the United States and Europe will be implanted with a Reveal ICM. The Reveal device is hoped to transmit information from the patient’s heart via Medtronic’s CareLink network, thereby allowing physicians to review patient data remotely. Each patient will be followed for a minimum of 18 months to monitor for atrial fibrillation and have in-office visits every six months.

“Atrial fibrillation is the most common arrhythmia, and with a five-fold increase in the risk of stroke, the condition carries significant burdens for patients, as well as on the healthcare system,” said Pat Mackin, president of the cardiac rhythm disease management business and senior vice president at Medtronic. “Through this study, Medtronic intends to show the clinical value of ICMs in detecting atrial fibrillation so that early-stage therapeutic decisions can be made to improve each patient’s quality of life.”

Atrial Fibrillation is the most common heart arrhythmia affecting more than 3 million Americans and 7 million people worldwide. The disorder can be difficult to diagnose, as it can occur infrequently and patients may not experience symptoms during an episode. Reveal’s around-the-clock monitoring, in contrast with intermittent, external monitoring, can result in earlier and more reliable diagnosis, which can lead to faster treatment, claims Medtronic.

Medtronic provides medical devices in a range of market segments including cardiovascular. The company is headquartered in Minneapolis, Minn.