ECG patch monitoring identifies arrhythmias beyond AF: Apple Heart Study
Click Here to Manage Email Alerts
PHILADELPHIA — ECG patch monitoring after receiving an irregular pulse notification on the Apple Watch identified several arrhythmias beyond atrial fibrillation, according to a secondary analysis of the Apple Heart Study presented at the American Heart Association Scientific Sessions.
“Atrial fibrillation was the most common rhythm abnormality ... and frequent premature atrial contraction and atrial tachycardias were commonly associated with irregular tachograms and notifications,” Marco Valentin Perez, MD, associate professor of medicine (cardiovascular medicine) at Stanford University Medical Center, said during a presentation.
As Healio previously reported, of the 419,297 healthy participants who self-enrolled in the Apple Heart Study, 0.52% received an irregular pulse notification. Forty-four percent of those who received a notification went on to attend the first telehealth study visit. The ECG patch was mailed to 70% of participants (n = 658) and 68% returned their patch for analysis. Of 450 participants who received an ECG patch to wear at home, 34.8% had observed AF (97.5% CI, 27-43).
“The overall goal of the Apple Heart Study was to measure the ability of a smartwatch to use an application that identified atrial fibrillation,” Perez said during the presentation.
In this secondary analysis of 450 participants with completed ECG patches (23% women; 40% older than 65 years), 20 patients were contacted for AF findings at rates greater than 200 bpm (n = 18), pause for longer than 6 seconds (n = 1) and nonsustained ventricular tachycardia for longer than 6 seconds (n = 1), according to the new results.
Overall, 153 (34%) participants had AF for longer than 30 seconds. Among 297 participants who did not have AF, 74 (25%) had premature atrial contraction burden between 1% and 15%, and four (1.3%) participants had a burden greater than 15%, according to results presented here.
Three participants had high-grade atrioventricular block episodes that were linked to transient sinus slowing that lasted less than 4 seconds.
Two participants had premature ventricular contractions of at least 15%, and 11 participants (3.7%) had a nonsustained ventricular tachycardia episode for at least eight beats.
No complete heart block or second-degree heart block type 2 were recorded.
“What we do need is a better understanding of long-term implications and outcomes in these participants who don’t have atrial fibrillation, but might have another rhythm that might need attention,” Perez said during the presentation. – by Darlene Dobkowski
Reference:
Perez MV, et al. Late Breaking Trials in EP and LV Function. Presented at: American Heart Association Scientific Sessions; Nov. 16-18, 2019; Philadelphia.
Disclosures: The Apple Heart Study was sponsored by Apple. Perez reports he is an expert witness for Boehringer Ingelheim and received a research grant from Apple and NIH/NHLBI. Please see the abstract for all other authors’ relevant financial disclosures.
Perspective
Back to Top
Khaldoun G. Tarakji, MD, MPH
All of this information is helpful for us because with this wave of wearables and people who purchase these devices, we need to learn that any amount of information is a good addition to our knowledge about how to deal with the results and the outcome of all of these people recording from their devices.
To start with the Apple Heart Study, which is now published in The New England Journal of Medicine, showing that about 0.5% can get a notification and among those, 34% who received the ECG patch afterward confirmed AF.
Even at that stage, as a medical community, we’re concerned about a few things. Mainly the focus at that point was AF. What does this mean and is it going to lead to more intervention? At this point, we have a gap in knowledge of whether an intervention at this case or placing the patient on a blood thinner would lead to a different outcome. For the randomly picked-up asymptomatic AF, we have to highlight this.
This analysis adds another layer of information, but also another layer of concern. When you start getting notifications, that triggers more monitoring — and more monitoring can pick up more arrhythmias. That is something that we were concerned about even before. These types of arrhythmias that the ECG patch picked up irrespective of AF are what we encounter all the time. We do Holter monitoring, for example, even on a person who is asymptomatic and we pick up on these types of arrhythmias. We see slowing down of the heart rate, and especially those with advanced atrioventricular block that is associated with slowing of the sinus rate. That, a lot of time, is reflective of high vagal tone, which can happen at nighttime, for example.
Our biggest concern is not limited just to the AF, whether it’s going to lead to more management and more intervention. We still don’t have the evidence, but it can also lead to detection of more of the other types of arrhythmias that would be equally concerning that it might lead to more intervention that is not necessary. I’d like to see more data, but the types of arrhythmias that were picked up, these are things that we encounter on any type of monitor that we do routinely. It’s not unusual and it leads to a major intervention.
Click Here to Manage Email Alerts