Medtronic on Thursday announced that it is enrolling the first patients in its MIRACLE EF global clinical trial to evaluate the effectiveness of cardiac resynchronization therapy-pacemakers (CRT-Ps) in delaying the progression of heart failure in patients with mildly reduced heart pumping function. The study will be the first to evaluate CRT-P in what Medtronic calls a widely underserved patient group – those who have a slightly reduced left ventricular ejection fraction (LVEF) but whose hearts work a bit more efficiently than heart failure patients who are currently approved for the device. The CRT-P devices used in MIRACLE EF are not approved by the FDA for the patient population being studied. Dr. Edward Schloss performed the first implant at The Christ Hospital's Lindner Research Center in Cincinnati, Ohio. The primary investigator for the site is Dr. Greg Egnaczyk. "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 of Karolinska University Hospital in Stockholm, 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." Medtronic said that up to 2,300 patients at approximately 275 centers throughout the world – including in the United States, Canada, Europe, Japan and developing markets – will be enrolled in the trial. Patients will be followed for at least two years or until close of the study. The trial is expected to take four to five years to complete. "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, 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."