UM Study Shows MR Scans Do Not Harm Patients with ICD Devices
A study by Miller School researchers of patients with implantable cardioverter defibrillator (ICD) devices has demonstrated that even multiple cardiac magnetic resonance (MR) scans did not adversely affect the health of the patient or function of the devices.These findings have important clinical implications, since most patients with ICD and other cardiac devices such as pacemakers have been instructed never to have an MR scan because of concerns about possible device damage.
For the study, which was published in the August issue of the journal Heart, 10 patients who were enrolled in a research study of cardiac stem cell therapy and who had an ICD device each underwent three cardiac MR scans over a period of a year. The devices were evaluated before and after each MR scan and no significant changes in device measurements or function were identified. The patients were followed for up to two years after initial MR scanning without clinical adverse events related to the MR scans.
The findings are important because device and MR manufacturers, as well as the Food and Drug Administration, have advised against magnetic resonance imaging in patients with ICDs or pacemakers in order to avoid possible device damage. MR scans of the brain, heart, spine, and other body regions can provide crucial information for clinical diagnosis and management, and it has been estimated that patients with cardiac devices have a 50 to 75 percent likelihood of having an indication for MR scanning over the lifetime of their devices.
Previous research studies have addressed the safety of single MR scans in device patients, but until the Miller School study, the safety of multiple MR imaging procedures among such patients had not been reported. Multiple scans being a more stringent test of the safety of devices in the MR environment, these results provide evidence that MR scans of device patients may be safely performed in appropriate clinical situations. The authors advise that such scanning should only be performed in medical centers, such as the University of Miami Hospital, that have experience in these specialized procedures.
“These findings are very important for the clinical management of heart patients with implantable devices who need sophisticated cardiac imaging,” said Joshua Hare, M.D., Louis Lemberg Professor of Medicine and director of the Interdisciplinary Stem Cell Institute, the senior author of the study.
Other members of the Miller School team contributing to the study were M. Juhani Junttila, M.D., cardiology fellow; Joel E. Fishman, M.D., Ph.D., associate professor of radiology; Gustavo A. Lopera, M.D., assistant professor of medicine; Pradip M. Pattany, Ph.D., research associate professor of radiology; Barry H. Trachtenberg, M.D., cardiology fellow; Darcy L. Velazquez, R.N., B.S.N., research manager at the Interdisciplinary Stem Cell Institute; and Adam R. Williams, M.D.; Cristina Sanina, M.D.; and Jacques Mather, M.D., postdoctoral associates at the Institute.