The 3-year results of the prospective mSTOPS study support the clinical value of early screening for atrial fibrillation (AF) and targeted detection in moderate-risk populations.

Prof. Steven Steinhubl (Scripps Research Translational Institute, USA) presented the awaited 3-year results of the mSTOPS study of prospective screening for AF [1]. The study involved 5,214 eligible individuals identified through claims data to have risk factors for AF but who had not been previously diagnosed. Via a web-based platform, 1,738 individuals were enrolled to undergo either immediate or delayed active ECG monitoring at home for up to 4 weeks with a Zio XT patch monitor (2-week monitoring periods spaced 4 months apart). Each monitored participant was matched with 2 non-monitored participants with similar stroke-risk CHA2DS2-VASc scores as controls. The study looked at the time to first diagnosis of AF and its clinical consequences, especially with regard to stroke, for the active monitoring cohort as well as the cohort undergoing usual care. Participants have been followed for 3 years at the time of this presentation.

After 3 years of monitoring, AF was newly diagnosed in 11.4% of those actively monitored with Zio versus only 7.7% of the control group (a statistically significant 48% improvement). The trial found that the incidence rate of a cardiac event (i.e. stroke, myocardial infarction, systemic embolism, or death) was 8.4 per 100 person-years in people diagnosed with AF who underwent active monitoring, compared with the control group incidence rate of 13.8 per 100 person-years. Active monitoring also led to statistically fewer hospitalizations for bleeding, the primary safety endpoint for the study (incidence rate of 0.32 per 100 person-years vs 0.71 per 100 person-years). Active monitoring also led to fewer total hospitalizations (12.9 vs 18.9 per 100 person-years).

Prof. Steinhubl concluded: “The 3-year results support the clinical value of early screening and targeted detection in moderate-risk populations. The study validates continued research into how to best monitor high-risk populations and confirms the value in discovering ways we can detect previously undiagnosed AF. It underscores the value of detecting AF as soon as possible to produce better patient outcomes.”

  1. Steinhubl S, et al. 3-Year Clinical Outcomes in a Nationwide, Randomized, Pragmatic Clinical Trial of Atrial Fibrillation Screening — Mhealth Screening to Prevent Strokes (mstops) — mSToPS. LBS.06, Virtual AHA Scientific Sessions 2020, 13-17 Nov.