AMALFI reported a 6.8% new AFib diagnosis rate with a single 14-day Zio long-term continuous monitoring patch, compared to 5.4% on usual care over 2.5 years (ratio 1.26; 95% CI 1.02–1.57; p=0.03) in 5,040 UK primary care patients aged 65 and older at moderate to high stroke risk. Median time to diagnosis was 103 days with screening versus 530 days with usual care. Exposure to oral anticoagulation averaged 1.63 months in the intervention arm versus 1.14 months in the control arm (difference, 0.49 months; 95% CI, 0.24–0.75; p < 0.001). The intervention achieved a median wear time of 13.9 days with 98.8% analyzable time in an elderly, comorbidity-heavy population. The core development is Oxford’s randomized AMALFI trial, presented at ESC 2025 and published in JAMA, which demonstrates that a one-off, home-applied Zio XT patch, combined with usual care, modestly increases AFib detection and accelerates diagnosis compared with usual care alone. The study was conducted entirely remotely: participants were identified through automated primary care EHR queries across 27 practices, devices were mailed for self-application, and returns were managed by mail with central analysis. The trial was not powered for clinical outcomes, such as stroke; however, it demonstrates that at-scale AFib screening via mail-out LTCM is operationally feasible and can help move patients onto anticoagulation earlier. Strategically, these data serve as a validation step for home-based cardiac monitoring within population health workflows, rather than specialty-led diagnostics. For iRhythm, the result supports a service model centered on primary care initiation, EHR targeting, and centralized interpretation in a market that emphasizes prevention and community care. The signal is incremental in absolute terms, and the absence of outcome reductions keeps the long-running screening debate alive. Nonetheless, the durable effect from a single baseline monitor over 2.5 years suggests a pragmatic entry point for health systems wary of continuous or repeat screening burdens. The trial also showcases a fully site-less design with high adherence in patients aged 75 and older, countering the assumption that remote-only workflows falter in older cohorts. Implications will be felt across stakeholders. For sponsors and CROs, AMALFI is a template for EHR-driven identification, remote consent and fulfillment, and centralized readouts that compress cycle times and reduce site overhead — but shift complexity to logistics, data operations, and safety follow-up. Primary care networks gain a workable pathway to capture silent AFib without clinic visits. However, practices will need protocols for initiating anticoagulation, managing bleed risk, and follow-up of incidental arrhythmias. Device vendors face a clearer bar: not simply diagnostic yield, but proof of scalable deployment that integrates with primary care systems. For regulators and payers, particularly NHS England and NICE, the modest absolute detection lift must be weighed against program costs, downstream anticoagulation exposure, potential overdiagnosis, and health equity considerations related to mail-based access. Research sites should note the continued migration of specific cardiovascular diagnostics into decentralized models that bypass traditional site infrastructure. Next, watch for health-economic analyses tied to AMALFI and whether NICE moves toward guidance on targeted AFib screening using LTCM from primary care. Key uncertainties include clinical outcomes, bleeding rates, and net clinical benefit, as well as repeat screening cadence and digital inclusion. Operationally, the questions are whether EHR registries can sustain accurate targeting at scale, whether centralized interpretation capacity keeps pace, and how procurement frameworks balance device, analysis, and workflow costs. Replication in non-UK settings and stratified analyses to refine who benefits most will determine whether this becomes a commissioned service or remains an adjunct diagnostic.
Jon Napitupulu is Director of Media Relations at The Clinical Trial Vanguard. Jon, a computer data scientist, focuses on the latest clinical trial industry news and trends.
