AHA: Digital monitoring study finds high rates of hidden atrial fibrillation after heart surgery

AHA: Digital monitoring study finds high rates of hidden atrial fibrillation after heart surgery

While a potentially dangerous irregular heartbeat may not be detected immediately after cardiac surgery, it may develop in the month to follow—further raising a person’s chances of stroke and making the case for wider use of remote digital monitoring.

A group of Canadian researchers found that when high-risk patients wore a heart monitor patch 24 hours a day for the 30 days following a procedure, cases of afib were detected 10 times more often when compared to unmonitored patients who only attended their usual follow-up appointments.

This suggests that a high rate of cases may go unrecognized and untreated, especially in patients sent home with no prior history of afib, said Subodh Verma, a cardiac surgeon at the University of Toronto’s St. Michael’s Hospital and co-lead author of the late-breaking study presented virtually at the American Heart Association’s annual scientific sessions.

“The incidence of post-operative atrial fibrillation after discharge from cardiac surgery is not well defined,” Verma said. “Most studies are limited to the hospitalization phase only; studies beyond hospitalization are few.” 

The study—funded by the Heart and Stroke Foundation of Canada alongside grants from Bristol Myers Squibb, Pfizer and Boehringer Ingelheim—followed 336 patients at a higher risk for stroke as they recovered from cardiac surgery. 

They were randomly assigned to receive standard care or to wear an adhesive monitor on their chest: either Medtronic’s Seeq sensor or Icentia’s CardioSTAT patch. Participants in the control group only had an electrocardiogram or cardiac rhythm testing when it was deemed medically necessary. Both groups would later undergo two weeks of continuous monitoring about six to nine months following surgery. 

The patches detected cases of atrial fibrillation or atrial flutter lasting at least six minutes in almost 20% of patients in the monitoring group—and cases lasting more than six hours in nearly 9%—compared to about 2% of cases found through standard care.

“A significant risk of [post-operative atrial fibrillation] persists even in those patients without any preoperative or pre-discharge AF,” Verma said. “These data may help inform physicians about the importance of surveillance and vigilance in patients at high risk of stroke with respect to monitoring and prompt treatment for AF.”