In the randomised AMALFI trial 5,040 individuals without a previous diagnosis of AF (≥65 years with a CHA2DS2VASc stroke risk score ≥3 for men or ≥4 for women) were randomised either to receive and return by postal mail an ECG patch monitor or to usual care (control).
At baseline, participants had a mean age of 78 years, 47 % were female and 19 % had a prior stroke or transient ischaemic attack. There was a modest increase in AF diagnosis at 2.5 years with the ECG patch. A post-randomisation primary care record of AF was present in 6.8% of individuals in the intervention arm and 5.4% in the control arm (ratio of proportions 1.26; 95%CI 1.02 to 1.57; p=0.03). Patchdetected AF burden was bimodally distributed, with 33% of cases having 100% burden (the entire monitoring period was spent in AF), while 55% had an AF burden <10%. At 2.5 years, mean exposure to oral anticoagulation was 1.63 months in the intervention arm and 1.14 months in the control arm (difference 0.50 months; 95%CI 0.24 to 0.75; p<0.0001). Stroke occurred in 2.7% of participants in the intervention arm and 2.5% in the control arm (event rate ratio 1.08; 95%CI 0.76 to 1.53).
Conclusion: Remote AF screening with an ECG patch monitor in older patients at moderate-to-high stroke risk leads to a modest increase in AF diagnosis and anticoagulation exposure. However, AF diagnosis unrelated to the patch occurred more commonly than anticipated, and over half of the patch-detected AF burden was low burden. Therefore, AF screening in this setting may have limited impact on stroke events.