Wearable Continuous ECG Monitor Effectively Detects AF in Older Adults With Hypertension

A wearable continuous electrocardiogram (cECG)-based screening intervention increased atrial fibrillation (AF) detection 10-fold among older patients with hypertension and prompted anticoagulation in most cases, according to the results of a study in JAMA Cardiology.

The multicenter, randomized clinical trial included 856 patients aged 75 years or older with hypertension and without known AF from April 5, 2015, to March 26, 2019, from 48 primary care practices. More than half of the overall group were women (n=487, 56.9%), the mean (SD) age was 80.0 (4.0) years, and 94% were White.

The control group (n=422) received standard care, which included pulse check and heart auscultation by a physician at baseline and 6 months. The screening group (n=434) received an adhesive cECG patch monitor worn for 2 weeks at baseline and 3 months, in addition to standard care, as well as an automated home blood pressure (BP) device with oscillometric AF screening capability to use twice daily during the cECG monitoring periods.

In the intention-to-screen analysis, the primary outcome was AF detected by cECG monitoring or clinically within 6 months. In the screening group, the cECG monitor was worn at baseline by 423 participants (97.5%) and at 6 months by 344 individuals (79.3%). Additionally, 412 of 434 participants (94.9%) used the BP monitor for a median of 27.4 days.

In the primary analysis, AF was detected in 23 of 434 participants (5.3%) in the screening group compared with 2 of 422 (0.5%) in the control group (relative risk [RR], 11.2; 95% CI, 2.7-47.1; P =.001; absolute difference, 4.8%; 95% CI, 2.6%-7.0%; P <.001; number needed to screen, 21).

Among the participants with cECG-detected AF, the median total time in AF was 6.3 hours (interquartile range [IQR], 4.2-14.0 hours; range, 1.3 hours-28 days), and the median duration of the longest AF episode was 5.7 hours (IQR, 2.9-12.9 hours). Anticoagulation was initiated in 15 of 20 patients (75.0%) with cECG-detected AF. By 6 months, anticoagulant therapy for any indication was prescribed for 18 of 434 patients (4.1%) in the screening group and 4 of 422 (0.9%) in the control group (RR, 4.4; 95% CI, 1.5-12.8; P =.007; absolute difference, 3.2%; 95% CI, 1.1%-5.3%; P =.003).

Twice-daily AF screening with the home BP monitor had a sensitivity of 35.0% (95% CI, 15.4%-59.2%), specificity of 81.0% (95% CI, 76.7%-84.8%), positive predictive value of 8.9% (95% CI, 4.9%-15.5%), and negative predictive value of 95.9% (95% CI, 94.5%-97.0%).

The main limitation of the trial is that it was underpowered to detect differences in clinical outcomes, noted the study authors. In addition, the follow-up duration was short and a lead-time bias effect cannot be excluded.

“This randomized clinical trial provides evidence that a wearable continuous ECG strategy is well tolerated and effective for early detection of AF in older primary care patients, often leading to oral anticoagulant treatment with the potential to avert future strokes,” the investigators concluded. “Intermittent oscillometric screening with a BP monitor is an inferior strategy for detecting paroxysmal AF. Future studies need to determine the effect of AF screening on clinical outcomes.”

Disclosures: Some of the authors reported affiliations with pharmaceutical companies. Please see the original reference for a full list of authors’ disclosures.

Reference

Gladstone DJ, Wachter R, Schmalstieg-Bahr K, et al. Screening for atrial fibrillation in the older population: a randomized clinical trial. JAMA Cardiol. Published online February 24, 2021. doi:10.1001/jamacardio.2021.0038