Wearable Heart Monitor Increases Diagnoses of Common Heart Rhythm Disorder By 50%

Atrial fibrillation (AF) is the most common heart rhythm disorder globally, affecting over 40 million individuals. Symptoms may include palpitations, shortness of breath, fatigue, and disrupted sleep. However, AF often goes undetected as many individuals do not exhibit any symptoms and the condition can be episodic, complicating diagnosis efforts. Those diagnosed with AF are at a significantly increased risk of stroke, up to five times greater than those without, and are commonly prescribed anticoagulants to mitigate this risk. Recent studies have indicated that brief, one-time screenings for AF yield no substantial increase in diagnosis rates, whereas prolonged screening efforts have noted heightened detection, especially of paroxysmal AF, which is characterized by intermittent disturbances. Now, newly presented research at ESC Congress 2024 suggests that utilizing a wearable heart monitor for a two-week period can detect AF in older adults but does not reduce the risk of strokes.

The GUARD-AF trial, initiated in December 2019 by Duke University Medical Center (Durham, NC, USAl), involved 11,905 participants from 149 primary care locations across the US. This study tested whether continuous monitoring with the Zio XT ECG patch from iRhythm Technologies (San Francisco, CA, USA), which records heart rhythm over 14 days, could identify undiagnosed AF in older adults and thereby reduce stroke rates compared to usual care practices. The study randomly assigned 5,952 participants to the screening group and 5,953 to receive usual care, with a median participant age of 75 and 57% being female. Of those in the screening group, 5,684 (96%) returned usable ECG data. The researchers followed up on clinical outcomes using Medicare claims and Kaiser Permanente data.

After an average follow-up of 15 months, the incidence of stroke was slightly higher in the screening group compared to the usual care group (37 vs. 34), while bleeding events were fewer (52 vs. 60). Diagnoses of AF and the initiation of oral anticoagulant treatments were more frequent in the screening group than in the usual care group (5% [284 patients] vs. 3.3% [196] and 4.2% [239] vs. 2.8% [167], respectively). The researchers pointed out that the early termination of the trial due to the COVID-19 pandemic means these findings do not conclusively demonstrate that screening for AF can reduce stroke hospitalizations.

“Our study showed a 52% increase in the number of cases of atrial fibrillation diagnosed over a maximum of 2.5 years of follow-up, an increase in the initiation of oral anticoagulants with no increase in rates of hospitalization for bleeding, and no significant reduction in the rate of hospitalizations for all stroke compared with usual care,” said lead author Professor Renato Lopes, Duke University Medical Center. “Despite being the largest study using a 14-day, patch-based continuous ECG monitor as the screening strategy, our results should not be considered conclusive due to the early termination of the study and lower than expected number of clinical events. Further studies with longer follow-up and including participants at higher risk for stroke are needed to establish the true potential of AF screening in reducing rates of strokes.”

Related Links:
Duke University Medical Center 
iRhythm Technologies