Arrhythmias and conduction disturbances
Detection of Previously Undiagnosed Atrial Fibrillation in Patients With Stroke Risk Factors and Usefulness of Continuous Monitoring in Primary Stroke Prevention

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The detection of undiagnosed atrial tachycardia/atrial fibrillation (AT/AF) among patients with stroke risk factors could be useful for primary stroke prevention. We analyzed newly detected AT/AF (NDAF) using continuous monitoring in patients with stroke risk factors but without previous stroke or evidence of AT/AF. NDAF (AT/AF >5 minutes on any day) was determined in patients with implantable cardiac rhythm devices and ≥1 stroke risk factors (congestive heart failure, hypertension, age ≥75 years, or diabetes). All devices were capable of continuously monitoring the daily cumulative time in AT/AF. Of 1,368 eligible patients, NDAF was identified in 416 (30%) during a follow-up of 1.1 ± 0.7 years and was unrelated to the CHADS2 score (congestive heart failure, hypertension [blood pressure consistently >140/90 mm Hg or hypertension treated with medication], age ≥75 years, diabetes mellitus, previous stroke or transient ischemic attack). The presence of AT/AF >6 hours on ≥1 day increased significantly with increased CHADS2 scores and was present in 158 (54%) of 294 patients with NDAF and a CHADS2 score of ≥2. NDAF was sporadic, and 78% of patients with a CHADS2 score of ≥2 with NDAF experienced AT/AF on <10% of the follow-up days. The median interval to NDAF detection in these higher risk patients was 72 days (interquartile range 13 to 177). In conclusion, continuous monitoring identified NDAF in 30% of patients with stroke risk factors. In patients with NDAF, AT/AF occurred sporadically, highlighting the difficulty in detecting paroxysmal AT/AF using traditional monitoring methods. However, AT/AF also persisted for >6 hours on ≥1 days in most patients with NDAF and multiple stroke risk factors. Whether patients with CHADS2 risk factors but without a history of AF might benefit from implantable monitors for the selection and administration of anticoagulation for primary stroke prevention merits additional investigation.

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Methods

The present analysis was based on a subset of patients who were enrolled in the TRENDS study. The design8 and primary results9, 10 of the TRENDS study have been previously published. In brief, TRENDS was a prospective, observational study that enrolled patients who had recently received a pacemaker, implantable cardioverter defibrillator, or cardiac resynchronization therapy device for a class I-II indication and who also had ≥1 of the following stroke risk factors: congestive heart failure,

Results

We enrolled 2,813 patients from 116 centers in the TRENDS study. The patients with previous stroke or TIA (n = 353), an absence of CHADS2 stroke risk factors (n = 60), a documented history of AF (n = 480), warfarin and/or antiarrhythmic drug use (n = 380), or device data unavailable (n = 172) were excluded from the present analysis (Figure 1). The remaining 1,368 patients were the focus of the present analysis and were followed up for a mean of 1.1 ± 0.7 years. Of the 1,368 patients, 416 (30%,

Discussion

To our knowledge, this is the first study to quantify the incidence of NDAF using a variety of continuous monitoring devices in patients with known risk factors for stroke. The detection of AT/AF in these patients could influence decisions regarding anticoagulation and/or treatment of rhythm control. We found NDAF in a significant proportion of patients (31%) with multiple stroke risk factors during a mean follow-up of 1.1 years. Most patients with NDAF and elevated stroke risk factors also

References (24)

  • A.M. Gillis et al.

    Beneficial effects of statin therapy for prevention of atrial fibrillation following DDDR pacemaker implantation

    Eur Heart J

    (2008)
  • T.V. Glotzer et al.

    Rationale and design of a prospective study of the clinical significance of atrial arrhythmias detected by implanted device diagnostics: the TRENDS study

    J Interv Card Electrophysiol

    (2006)
  • Cited by (0)

    This study was funded by Medtronic, Inc. (Minneapolis, Minnesota).

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