The following is a summary of “CAN 24H OF AMBULATORY ECG BE USED TO TRIAGE PATIENTS FOR EXTENDED MONITORING?,” published in the March 2023 issue of Cardiology by Johnson, et al.

Long-term monitoring for detecting atrial fibrillation (AF) is often limited due to economic and practical reasons. For a study, researchers sought to determine whether a 24-hour ECG (24h ECG) can be used to predict AF detection on extended cardiac monitoring.

All US patients aged 17-100 years who were monitored for 2-30 days using the PocketECG device (MEDICALgorithmics) in 2017 and did not have AF>30 seconds on the first day were included (n=18,220; mean age 64.4 years; 42.4% male). The population was randomly divided into equal training and testing datasets. A Lasso model was used to predict AF episodes ≥ 30s occurring on days 2-30.

The final model included the maximum heart rate, the number of premature atrial complexes (PACs), the fastest rate during PAC couplets and triplets, the fastest rate during premature ventricular couplets, and the number of ventricular tachycardia runs ≥4 beats. The discrimination was good overall (ROC statistic 0.7497, 95% CI 0.7336-0.7659) and among patients referred post-stroke/transient ischemic attack (ROC 0.7355, 95% CI 0.6494-0.8216) in the testing dataset. The inclusion of age and sex did not improve the model’s performance in the testing dataset. A model based only on age and sex had substantially poorer discrimination (ROC statistic 0.6542, 95% CI 0.6364-0.6720). The prevalence of observed AF in the testing dataset increased by a quintile of predicted risk: 0.4% in Q1, 2.7% in Q2, 6.2% in Q3, 11.4% in Q4, and 15.9% in Q5, in the overall population. The negative predictive value for AF in Q1 was 99.6%.

The study suggested that using data from a 24hECG can help avoid long-term monitoring for AF in 20% of a patient population, while an overall risk of 9% in the remaining 80% of the population warrants repeated or extended monitoring.

Source: jacc.org/doi/10.1016/S0735-1097%2823%2900459-X