Smartphone-based ECG Screening Detects More Atrial Fibrillation than Usual Care in American Indian Adults

A new study found that mobile-based ECG screening for AF could improve health outcomes among American Indian adults who have historically endured greater health disparities.

A smartphone-based electrocardiogram (ECG) screening for atrial fibrillation (AF) was found to be feasible in American Indian tribal primary care clinics and detected more AF than usual care, according to a new study published today, April 21, 2021, in the Journal of the American Heart Association.

The study also found that more than half of those diagnosed with the arrhythmia were younger than age 65 years, the recommended age for screening.

“Single–time point screening for atrial fibrillation in tribal clinics has the potential to improve health outcomes among a large number of American Indian adults who have historically endured greater health disparities,” wrote authors in the open access journal of the American Heart Association (AHA).

Previous research has shown that American Indian adults have a higher risk of AF compared with all other racial and ethnic groups and a higher incidence of stroke than White and Black adults.

Study authors also noted that, as a population, American Indians have significantly higher rates of obesity, diabetes, and hypertension—all known risk factors for AF.

“We know the risk of atrial fibrillation is high in people who are from racial and ethnic groups, especially among American Indians, so we wanted to see if we could identify silent atrial fibrillation,” said lead author Stavros Stavrakis, MD, PhD, cardiologist, Heart Rhythm Institute of the University of Oklahoma Health Sciences Center, in an AHA press release. “Systemic screening among American Indians has never been done before, and the true rate of atrial fibrillation in this population is unknown.”

To examine the feasibility and effectiveness of a mobile-based AF screening, researchers enrolled 1019 American Indians aged ≥50 years (63% women) who received care at one of 4 tribal primary care clinics in the Absentee Shawnee Tribal Health System in Oklahoma between January 2019 to June 2020.

Study participants underwent a 30-second, single-lead ECG using the mobile device paired with a tablet at the clinic. Stavrakis and colleagues compared the ECG results of the screened participants to the results of a control group.

The control group consisted of 1267 American Indian adults, also aged ≥50 years, who were seen over the same time period at the same tribal clinics, but they did not receive the mobile-based ECG screening.

The results showed:

  • New AF was diagnosed in 15 out of 1019 (1.5%) patients screened vs 4 out of 1267 (0.3%) patients in the control group (mean difference, 1.2%; 95% confidence interval, 0.3%-2.2%, P=0.002).
  • Patients with newly diagnosed AF were slightly older than those in the control group who were not diagnosed with AF (61.4 years vs 65.9 years, respectively).
  • Of the 15 patients diagnosed with AF, 14 had a high risk of stroke (as measured by the CHA2DS2‐VASc score) and were referred to their primary care physician for initiation of anticoagulation.

“Our study shows that we have a very simple and accurate method to screen and diagnose atrial fibrillation that is easy to implement at tribal clinics,” said Stavrakis, who is also an associate professor of medicine at the University of Oklahoma College of Medicine, in the AHA press release. “This widely-available, low-cost approach has real potential to improve health outcomes among American Indians.”

The results also showed that about half of the patients with new screen-detected AF (8 of 15 patients) were aged <65 years. For this reason, the researchers noted that American Indian adults would benefit from AF screening before the recommended age of 65 years.

“In a targeted, high-risk population such as American Indians, our results showed screening at a younger age found many cases of atrial fibrillation that would have been missed following current age recommendations,” said Stavrakis in the press release. “We have the potential to improve outcomes in this population by initiating early treatment.”

One major limitation to the study is that it was not a randomized intervention, so the next step for researchers will be to do a randomized, controlled trial to get more “robust” data, added Stavrakis in the press release.