AF Screening With a 14-Day ECG Monitor

Oct 16, 2024
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Authors:
Singer DE, Atlas SJ, Go AS, et al.
Citation:
Atrial Fibrillation Burden on a 14-Day ECG Monitor: Findings From the GUARD-AF Trial Screening Arm. JACC Clin Electrophysiol 2024;Oct 1:[Epublished].
Summary By:
Debabrata Mukherjee, MD, FACC

Quick Takes

  • This cohort study using 14-day patch ECG monitors found that 0.5% of participants had 100% AF and another 3.9% had paroxysmal AF.
  • Of note, most patients with paroxysmal AF had very low burden AF (i.e., a median of 0.46% time in AF and longest episodes of <40 minutes) and such a low burden of AF may not pose a substantial stroke risk.
  • Additional studies are indicated to clarify the relationship between different levels of AF burden (e.g., percent time in AF, length of longest episode), and risk of ischemic stroke.

Study Questions:

What is the frequency of atrial fibrillation (AF) and the distribution of AF burden found when screening individuals ≥70 years of age with a 14-day electrocardiograph monitor?

Methods:

The investigators report on a cohort study of the screening arm of a randomized AF screening trial (GUARD-AF) among those ≥70 years of age without a prior AF diagnosis (between 2019 and 2021). Screening was performed with a 14-day continuous electrocardiogram (ECG) patch monitor. The distributions of continuous indices of AF burden were described as mean ± standard deviation and medians (Q1-Q3). Frequencies and proportions of dichotomous variables were displayed. Differences in outcome proportions across patient subgroups were assessed using Pearson chi square test or Fisher exact test, as appropriate.

Results:

Analyzable patches were returned by 5,684 (95%) of screening arm participants; the median age was 75 years (Q1-Q3: 72-78 years), 57% were female, and the median CHA2DS2-VASc score was 3 (Q1-Q3: 2-4). AF was detected in 252 participants (4.4%); 29 (0.5%) patients had continuous AF and 223 (3.9%) had paroxysmal AF. Among those with paroxysmal AF, the average indices of AF burden were of low magnitude with right-skewed distributions. The median percent time in AF was 0.46% (Q1-Q3: 0.02%-2.48%), or 75 (Q1-Q3: 3-454) minutes, and the median longest episode was 38 (Q1-Q3: 2-245) minutes. The upper quartile threshold of 2.48% time in AF corresponded to 7.6 hours. Age >80 years was associated with screen-detected AF in the multivariable model (odds ratio, 1.46; 95% confidence interval, 1.06-2.02).

Conclusions:

The authors report that most AF detected in these older patients was very low burden.

Perspective:

This cohort study using 14-day patch ECG monitors in patients ≥70 years old found that 0.5% of participants had 100% AF and another 3.9% had paroxysmal AF. Of note, most patients with paroxysmal AF had very low burden AF (i.e., a median of 0.46% time in AF and longest episodes of <40 minutes) and such a low burden of AF may not pose a substantial stroke risk. Additional studies are indicated to clarify the relationship between different levels of AF burden (e.g., percent time in AF, length of longest episode) and risk of ischemic stroke. This may help guide the use of stroke-preventive interventions such as oral anticoagulant therapy in patients with screen-detected AF.

Clinical Topics: Arrhythmias and Clinical EP, Geriatric Cardiology, Atrial Fibrillation/Supraventricular Arrhythmias

Keywords: Atrial Fibrillation, Diagnostic Screening Programs, Electrocardiography, Geriatrics


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