HRS: MagnaSafe provides promising preliminary results
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The multicenter study is designed to determine the risks of 1.5T MRI in 1,500 patients with pacemakers and ICDs undergoing a clinically indicated non-thoracic MRI scan.
The goal is to provide ordering physicians with MRI risk information that they can share with patients who have an implanted device, Robert J. Russo, MD, PhD, director of Scripps Health in La Jolla, Calif., told Cardiovascular Business.
Prior to scanning, devices were interrogated using a standardized protocol. Patients who did not depend on the devices had functions de-activated; dependent patients had devices programmed to an asynchronous pacing model. Tachyarrhythmia therapies were disabled in non-pacemaker-dependent ICD patients.
The researchers analyzed 454 scans acquired at 12 sites between April 2009 and November 2011, including 340 pacemakers, 114 ICDs and 875 leads.
Four episodes of rhythm abnormalities occurred, according to Russo. Three were observed in patients with an established history of atrial fibrillation. The fourth episode persisted for less than 48 hours and did not require any intervention, Russo said.
The trial continues to accrue sites and patients, Russo noted.
Although Medicare coverage of MRI scans of patients with implanted devices is limited to those enrolled in prospective trials, Russo said, “With appropriate screening and pre- and post-scan programming, it looks like we can safely scan almost every [pacemaker and ICD patient] who requires a clinically indicated MRI exam.”
After 525 exams, only one exam, an MRI study of the left shoulder in a patient with an implanted left-side device, has been technically inadequate, he said.