Medtronic Inc. has announced that the U.S. Food and Drug Administration (FDA) Circulatory System Devices Panel of the Medical Devices Advisory Committee has voted unanimously in favor of approval with conditions of the Revo MRI SureScan pacing system designed as MR Conditional, or safe for use in Magnetic Resonance Imaging (MRI) systems, under specified conditions. MRI procedures are not recommended in the U.S. for patients who currently have implanted pacemakers; if approved, Revo MRI has the potential to be the first FDA-approved pacing system designed for use in the MRI setting.

The FDA's Circulatory System Devices Panel, which met today, recommended Revo MRI for approval with conditions related to the planned post-market study, health care professional training and labeling to reflect MRI scans are to be conducted with the full Revo MRI SureScan Pacing System. The FDA will consider the panel's recommendation in its review of Revo MRI; however, it is not bound by its Advisory Committee's recommendations.

"MRI is critical in the diagnosis of many serious conditions; however, patients with current pacemakers most often do not have access to this vital technology," said Pat Mackin, President of the Cardiac Rhythm Disease Management business and Senior Vice President at Medtronic. "The result of today's panel brings Medtronic one step closer to helping address an important unmet patient need. We look forward to working with the FDA during the regulatory process so that we may provide certain pacemaker patients with access to MRI scans." 

The number of MRI scans performed increases each year, as does the number of people with implanted cardiac devices. In 2007, there were approximately 30 million MRI scans conducted in the U.S. and that number continues to grow. It is estimated that more than 200,000 patients annually in the U.S. have to forego an MRI scan because they have a pacemaker due to the risks involved, including interference with pacemaker operation, damage to system components, lead or pacemaker dislodgement, heating of the lead tips and unintended cardiac stimulation. MRI scans allow physicians to make a wide range of health diagnoses by viewing highly detailed images of internal organs, blood vessels, muscle, joints, tumors, areas of infection and more. 

The FDA panel reviewed safety and effectiveness data from a prospective, randomized multi center trial at 42 centers around the world featuring 464 implanted patients. Major inclusion criteria included standard Class I or II dual chamber pacemaker indication, which allowed for pacemaker-dependent patients. Patients were excluded if they had previously implanted medical devices or abandoned leads. Patients were randomized at implant to either receive an MRI or not to receive an MRI.

The primary endpoints evaluated were safety and effectiveness of the Revo MRI pacing system in the MRI environment. For safety, the MRI group was evaluated for MRI procedure-related complications through one month post MRI. The primary effectiveness endpoint tested equivalence between MRI versus control for atrial and ventricular pacing capture thresholds and atrial and ventricular sensed amplitudes through one month post MRI.