First Patient Implanted with Medtronic’s MRI-Friendly ICD System

The first U.S. implant of Medtronic Inc.’s Evera MRI SureScan implantable cardioverter defibrillator (ICD) system recently was performed. It is estimated that as many as 63 percent of ICD patients will need an MRI (medical resonance imaging) within 10 years of receiving a device, according to figures cited by Minneapolis, Minn.-based Medtronic. Because no ICD system has yet been approved for MRI-conditional use by the U.S. Food and Drug Administration (FDA), patients with devices have been contraindicated from receiving MRI scans; this is because of the potential interactions between the MRI, ICD function and patient safety.

The procedure follows FDA approval of the company’s investigational device exemption application and pivotal clinical trial protocol. According to the company, Evera MRI is the first ICD system to be evaluated in the United States that allows for MRI scans positioned on any region of the body. The first device was successfully implanted at Marquette General Hospital in Marquette, Mich., as part of Medtronic’s randomized, global pivotal clinical trial that will enroll up to 275 patients at approximately 45 centers. The Evera MRI ICD system currently is available only for investigational use in the United States.

“ICD patients in the U.S. are frequently denied access to MRI, and results from this clinical trial may give us the evidence needed to make MRI standard,” said Michael R. Gold, M.D., Ph.D., Michael E. Assay professor of medicine and director of cardiology at the Medical University of South Carolina and principal investigator in the study. “We are optimistic about the possibilities that may be ahead for ICD patients. Adding an ICD that would allow patients to have full-body access to MRI would be a significant breakthrough for this patient population.”

Evera MRI is designed to better fit inside the body, with a contoured shape and thin, smooth edges that increase patient comfort by reducing skin pressure by 30 percent. In addition, patients in the study implanted with Evera MRI will receive the company’s Sprint Quattro Secure family of ICD leads.

Evera MRI includes SmartShock 2.0, a shock reduction algorithm that is designed to enable the device to better differentiate between dangerous and harmless heart rhythms. While the majority of shocks delivered are necessary to treat potentially fatal arrhythmias, studies estimate that approximately 20 percent of patients with implantable defibrillators may experience inappropriate shocks in response to a benign arrhythmia or electrical noise sensed by the device. According to Medtronic officials, SmartShock technology has shown to help eliminate these inappropriate shocks, and delivers a 98 percent inappropriate shock free rate at one year.

“Our goal with the Evera MRI system is to give patients the most unrestricted access to MRI scans, and ultimately allow them to get the diagnostic answers they need,” said Marshall Stanton, M.D., vice president and general manager of the tachycardia business at Medtronic.