Intermittent vs. Continuous Anticoagulation theRapy in patiEnts with Atrial Fibrillation (iCARE-AF): a randomized pilot study

  • Stavros StavrakisEmail author
  • Julie A. Stoner
  • Joel Kardokus
  • Paul J. Garabelli
  • Sunny S. Po
  • Ralph Lazzara



We hypothesized that intermittent anticoagulation based on daily rhythm monitoring using the novel oral anticoagulants (NOACs) is feasible and safe among patients with paroxysmal atrial fibrillation (AF).


Patients with paroxysmal AF and ≥1 risk factors for stroke were randomized to either intermittent or continuous anticoagulation. Those in the intermittent group were instructed to transmit a daily ECG using an iPhone-based rhythm monitoring device. If AF was detected, patients received one of the NOACs for 48 h–1 week. Patients who failed to transmit an ECG for three consecutive days or more than 7 days total were crossed over to continuous anticoagulation. Patients in the continuous group received one of the NOACs.


Fifty-eight patients were randomized to either intermittent (n = 29) or continuous anticoagulation (n = 29). Over a median follow-up of 20 months, 20 patients in the intermittent group failed to submit a daily ECG at least once (median three failed submissions). Four patients (14 %) crossed over to continuous anticoagulation due to failure to submit an ECG for three consecutive days. One stroke (continuous group) occurred during the study. Major bleeding occurred in two patients in the continuous and one patient in the intermittent group, after crossing over to continuous anticoagulation. In a prespecified per-protocol analysis, gastrointestinal bleeding was more frequent in the continuous group (16 vs. 0 %; p = 0.047).


Intermittent anticoagulation based on daily rhythm monitoring is feasible and may decrease bleeding in low-risk patients with paroxysmal AF. A larger trial, adequately powered to detect clinical outcomes, is warranted.


Atrial fibrillation Anticoagulation Remote monitoring Bleeding 



This study is funded by the American Heart Association no. 13CRP16860078 to Stavros Stavrakis and in part by the National Institutes of Health, National Institute of General Medical Sciences (no. U54GM104938), to the University of Oklahoma Health Sciences Center.

Compliance with ethical standards

Conflict of interest

The authors declare that they have no conflicts of interest.


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Copyright information

© Springer Science+Business Media New York 2016

Authors and Affiliations

  1. 1.Cardiovascular Section, Department of MedicineUniversity of Oklahoma Health Sciences CenterOklahoma CityUSA
  2. 2.Heart Rhythm InstituteUniversity of Oklahoma Health Sciences CenterOklahoma CityUSA
  3. 3.Department of Biostatistics and EpidemiologyUniversity of Oklahoma Health Sciences CenterOklahoma CityUSA

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