Patients who have undergone heart surgery appear to be at risk for atrial fibrillation (Afib) after being discharged home, even if they have not had Afib before, and may thus need monitoring, researchers advised.
Among patients who wore a 24-hour monitoring patch, Afib lasting at least 6 minutes was detected in 19.6% of patients compared with 1.7% of patients who received normal care during the 30 days they were followed (P<0.001), reported Subodh Verma, MD, PhD, of the University of Toronto in Canada.
“The number of patients needed to screen to detect atrial fibrillation in this cohort was six,” Verma said at a press conference at the virtual American Heart Association (AHA) meeting.
“In patients who have undergone cardiac surgery – isolated coronary artery bypass graft surgery, valve replacement, or the combination – and have an elevated risk of stroke with no history of preoperative or pre-discharge atrial fibrillation, a strategy of continuous rhythm monitoring unveiled a significant persistent burden of unrecognized and possibly actionable atrial fibrillation,” he said.
However, study discussant Ben Freedman, MBBS, PhD, of the Heart Research Institute in Sydney, Australia, cautioned that without studies that inform what to do with the information, the results are difficult to utilize.
“We find people who are being monitored and have these bouts of atrial fibrillation and they are put on anticoagulants without any evidence that it is doing any good,” he said. “If you really want to look for these people, we should be doing a large randomized multicenter controlled trial, if we could … Otherwise we are just finding out with not knowing what to do.”
Asked for his response, Verma told MedPage Today, “We are not creating patients, but we are trying to find ways to identify people who may be at higher risk who were otherwise not identified. Remember, these are patients who did not have preoperative or pre-discharge atrial fibrillation.
“This is a question that cardiologists grapple with,” Verma continued. “In a patient who is at high risk of stroke – the CHADS-VASc [congestive heart failure, hypertension, age, diabetes, previous stroke, vascular disease] score was 4 – for whom a surgeon would be happy to discharge, with the patient not on anticoagulation, does that risk of atrial fibrillation disappear or is there an ongoing persistent, occult risk of atrial fibrillation?”
“I think this is clinically meaningful because it is the first step to help underscore the fact that if you don’t have atrial fibrillation in the hospital after cardiac surgery, it doesn’t mean that you don’t have an ongoing risk of atrial fibrillation, and it also lays the foundation for the second part of the question, which is the need for doing a trial to see if anticoagulation is beneficial or not to reduce the risk of stroke,” Verma said.
“From a clinical standpoint, what this study tells me is that for my patients being discharged from the hospital who are not initiated on anticoagulation or have not had atrial fibrillation, I would have a low threshold to monitor these patients and to watch for periods of sustained unrecognized atrial fibrillation,” he noted.
While the incidence of Afib has been reported to be as high as 50% following heart-related surgery, most of those studies have looked at cases in the 3 to 5 days after surgery before the patient is discharged, and what happens after patients are sent home is not usually studied, Verna explained.
For the study, his team followed 336 patients treated at eight medical centers in Canada who were recovering from cardiac surgery. Participants did not have a history of Afib prior to surgery and were considered to be at risk for stroke based on factors including cardiac health, age, and medical history.
A total of 163 patients were assigned to receive 30 days of 24-hour, real-time, cardiac rhythm monitoring through an adhesive, patch-based monitor worn on the chest; the remaining 173 participants were assigned to the control group to receive 30 days of usual care, which did not involve planned cardiac rhythm testing/electrocardiogram assessment unless deemed medically necessary.
The study was funded by the Heart and Stroke Foundation of Canada with unrestricted grants from Bristol Myers Squibb (BMS), Pfizer, and Boehringer Ingelheim.
Verma disclosed relevant relationships with Abbott, Amgen, AstraZeneca, Bayer, Boehringer-Ingelheim, BMS, Eli Lilly, HLS Therapeutics, Janssen, Merck, Novartis, Novo Nordisk, Pfizer, PhaseBio, Sanofi and Valeant.
Freedman disclosed relevant relationships with Bayer, BMS/Pfizer, Daiichi-Sankyo, Omron, and AliveCor.