Medtronic (NYSE:MDT) announced today that a study using its continuous rhythm monitoring device showed AFib’s relationship with ischemic stroke.
Fridley, Minnesota-based Medtronic’s data covers 466,635 patients included in the Optum unidentified electronic health record (EHR) and Medtronic CareLink databases. Findings were published online in JAMA Cardiology, according to a news release.
Of the large population of patients, 891 who had Medtronic cardiovascular implantable electronic devices (CIEDs) capable of continuous rhythm monitoring sustained both an ischemic stroke and received 120 day of continuous monitoring prior to that stroke. The study defined AFib exposure as lasting 5.5 hours or more on any given day.
In total, 76.5% of those subjects had no AFib meeting the threshold over either 30-day period observed (1 to 30 days prior and 91 to 120 prior to the event), while 16% had at least one day with 5.5 hours or more of AFib in both periods and 7.4% had informative, discordant rhythm patterns (defined as those that had AFib exceeding 5.5 hours in only one period).
Among patients with CIEDs with informative, discordant rhythm patterns, having AFib of 5.5 hours or more raised the 30-day risk of ischemic stroke more than three-fold, while stroke risk was highest within five days of a 5.5-hour or more episode of AFib, then diminished rapidly thereafter. A temporal association between AFib and stroke was not seen in patients who were prescribed oral anticoagulants (OACs).
“As of late, there has been significant discussion surrounding the temporal relationship of AF episodes to stroke, as well as the use of continuous cardiac monitoring, specifically with ICMs, to detect clinically meaningful AF episodes that may lead to a stroke,” CMO of the Medtronic’s cardiovascular diagnostics and services business Dr. Rob Kowal said in the release. “This evidence highlights that patients are at highest risk for a stroke within five days of an AF episode that lasts five and a half hours or more. In addition to supporting the use of OACs in this patient population, this study also suggests the value of long-term cardiac monitoring to accurately detect these critical AF episodes.”