Afib Screening Expands With Mail-In Heart Patch Monitors
Remote trial in the U.K. shows feasibility of mass screening for hidden atrial fibrillation but raises questions about cost and clinical impact
Topline
The AMALFI trial found that mailing ECG patch monitors to older adults at moderate to high stroke risk led to more atrial fibrillation (Afib) diagnoses compared to usual care, highlighting a scalable approach to remote screening. However, whether this strategy reduces strokes or is cost-effective remains uncertain.
Study Details
The AMALFI randomized clinical trial, conducted in the U.K. and presented at the European Society of Cardiology 2025 meeting, investigated whether sending wearable ECG patch monitors by mail could uncover previously undiagnosed Afib in high-risk adults. Afib is a leading cause of stroke, but widespread screening is not yet standard practice due to limited evidence of benefit versus risk.
Researchers invited over 22,000 individuals identified through primary care records. About 5,000 participants, aged 65 or older and with elevated CHA2DS2-VASc scores, were enrolled. None had a prior diagnosis of Afib or atrial flutter.
Methodology
Participants were randomly assigned to either receive a mail-in Zio XT ECG patch for 14 days of continuous monitoring or to continue usual care. General practitioners managed findings according to routine clinical practice. The trial followed participants for 2.5 years, assessing new Afib diagnosis, use of anticoagulation, and stroke outcomes.
Key Findings
Increased detection: Afib was recorded in 4.2% of patch users during monitoring. After 2.5 years, Afib was documented in 6.8% of the screened group versus 5.4% of the usual-care group.
Earlier diagnosis: Afib was detected a median of 103 days into follow-up with patches, compared with 530 days for usual care.
Treatment impact: Anticoagulant use was slightly higher in the screened group (1.63 vs 1.14 months of exposure), but stroke rates were similar (2.7% vs 2.5%).
Low-burden Afib: More than half of detected cases involved very low Afib burden (<10% of monitoring time), raising debate about whether anticoagulation is always warranted.
Implications for Practice
For patients, the trial demonstrates that hidden Afib can be detected with a simple, non-invasive device delivered and returned by mail. This may provide peace of mind to older adults at higher risk of stroke, especially those without easy access to in-person cardiac monitoring.
For clinicians, the results suggest that remote Afib screening is feasible, scalable, and could be incorporated into primary care workflows with minimal disruption. Yet, the uncertain benefit on stroke prevention, the challenge of managing low-burden Afib, and the cost of large-scale adoption remain barriers. Importantly, the findings emerged in the U.K.’s universal healthcare system and may not directly translate to other healthcare settings.
Long-term follow-up and health economic analyses from AMALFI will be key in determining whether population-wide Afib screening should become routine practice.