Graz Study on the Risk of Atrial Fibrillation "GRAF"

Active, not recruiting

Phase 4 Results N/A

Trial Description

Atrial fibrillation (AF) is the most common clinical arrhythmia. AF is associated with increased risk for stroke due to blood clots formed in the fibrillating atria. Some patient characteristics increase the likelyhood of AF and at the same time the risk of stroke when AF has developed. To reduce the risk of stroke, anticoagulation therapy is recommended in patients with AF and risk factors (such as high blood pressure, diabetes, vessel disease). However, occasional (paroxysmal) AF may occur without symptoms and remain undetected, leaving patients at risk.
Aim of the prospective randomized study is to compare two management strategies for patients at increased risk for AF but without a known history of AF. Patients are seen regularly (monthly, then quarterly) for follow-up (incl. ECG recording and blood sample). One group of patients additionally receives a subcutaneous implantation of a loop recorder for continuous rhythm monitoring, while the control group remains on standard follow-up. Observation period is one year (optional extension for 3 years). The time to first diagnosis of AF is compared between groups, blood samples are analyzed for potential biomarkers of AF.



  • Medtronic Reveal XT implantable loop recorder Device
    Intervention Desc: subcutaneous implantation
    ARM 1: Kind: Experimental
    Label: loop recorder
    Description: patients will be implanted with a subcutaneous loop recorder and have regular follow-ups

Trial Design

  • Allocation: Randomized
  • Masking: Open Label
  • Purpose: Diagnostic
  • Endpoint: Efficacy Study
  • Intervention: Parallel Assignment


Type Measure Time Frame Safety Issue
Primary Time to first diagnosis of atrial fibrillation 12 months No
Secondary Time to change in therapy based on the diagnosis of atrial fibrillation Baseline (0 months), 1,2,3,4,5,6,9 and 12 months No
Secondary Hospitalizations 12 months No
Secondary Change in NTproBNP serum level associated with occurrence of atrial fibrillation Baseline (0 months), 1,2,3,4,5,6,9 and 12 months No
Secondary Death 12 months No
Secondary Stroke 12 months No