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Prevalence and prognostic significance of device-detected subclinical atrial fibrillation in patients with heart failure and reduced ejection fraction

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posted on 2020-04-02, 09:58 authored by Rosita Zakeri, John M Morgan, Patrick Phillips, Sue Kitt, G Andre Ng, Janet M McComb, Simon Williams, David J Wright, Jaswinder S Gill, Alison Seed, Klaus K Witte, Martin R Cowie, REM-HF Investigators
BACKGROUND: Cardiac implanted electronic devices (CIEDs) can detect short durations of previously unrecognised atrial fibrillation (AF). The prognostic significance of device-detected subclinical AF, in the context of contemporary heart failure (HF) therapy, is unclear. METHODS: Amongst patients enrolled in the Remote Monitoring in HF with implanted devices (REM-HF) trial, three categories were defined based on total AF duration in the first year of follow-up: no AF, subclinical AF (≥6 min to ≤24 h), and AF >24 h. All-cause mortality, stroke, and cardiovascular hospitalisation were assessed. RESULTS: 1561 patients (94.6%) had rhythm data: 71 (4.6%) had subclinical AF (median of 4 episodes, total duration 3.1 h) and 279 (17.9%) had AF >24 h. During 2.8 ± 0.8 years' follow-up, 39 (2.5%) patients had a stroke. Stroke rate was highest amongst patients with subclinical AF (2.0 per 100-person years) versus no AF or AF >24 h (0.8 and 1.0 per 100-person years, respectively). In the overall cohort, AF >24 h was not an independent predictor of stroke. However, amongst patients with no history of AF (n = 932), new-onset subclinical AF conferred a three-fold higher stroke risk (adjusted HR 3.35, 95%CI 1.15-9.77, p = 0.027). AF >24 h was associated with more frequent emergency cardiovascular hospitalisation (adjusted HR 1.46, 95%CI 1.19-1.79, p < 0.0005). Neither AF classification was associated with mortality. CONCLUSIONS: In patients with HF and a CIED, subclinical AF was infrequent but, as a new finding, was associated with an increased risk of stroke. Anticoagulation remains an important consideration in this population, particularly when the clinical profile indicates a high stroke risk.


This work was supported by the British Heart Foundation (grant 28479) and Boston Scientific Ltd. (Arden Hills, St Paul MN, USA), Medtronic Ltd. (Minneapolis, MN, USA), and St. Jude Medical (Minneapolis, MN, USA).



International Journal of Cardiology, 2020, in press

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Leicester Biomedical Research Centre


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