Does screening for undiagnosed afib lower stroke risk?

Among individuals ≥70 years of age seen in primary care practice, screening for afib using a 14-day continuous ECG monitor didn’t reduce stroke hospitalizations. Authors caution that event rates were low and the trial didn’t enroll the planned sample size.

The prospective, parallel-group, randomized GUARD-AF trial began enrollment across 149 primary care sites across the U.S. in December 2019. Participants were randomized 1:1 to screening or usual care. Primary efficacy outcome was hospitalization due to all-cause stroke, while the primary safety outcome was bleeding.

The COVID-19 pandemic led to premature termination of enrollment, with 11,905 participants (median age, 75 years; 56.6% female) in the intention-to-treat population. Median follow-up was 15.3 months. Risk of stroke in the screening group was 0.7% vs. 0.6% in the usual-care group (hazard ratio [HR], 1.10; 95% CI, 0.69-1.75). Risk of bleeding was 1.0% in the screening group vs. 1.1% in the usual care group (HR, 0.87; 95% CI, 0.60-1.26). Afib was diagnosed in 5% of the screening group vs. 3.3% of the usual-care group. The rate of initiation of oral anticoagulation after randomization was higher in the screening vs. usual-care group (4.2% vs. 2.8%).

Source:

Lopes RD, et al. (2024, September 1). J Am Coll Cardiol. Effect of Screening for Undiagnosed Atrial Fibrillation on Stroke Prevention. https://pubmed.ncbi.nlm.nih.gov/39230544/