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Graz Study on the Risk of Atrial Fibrillation (GRAF)

This study is ongoing, but not recruiting participants.
Information provided by (Responsible Party):
Frank R Heinzel, MD, PhD, Medical University of Graz Identifier:
First received: October 23, 2011
Last updated: December 20, 2015
Last verified: December 2015

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.

Condition Intervention Phase
Atrial Fibrillation
Chronic Heart Failure
Vascular Disease
Device: Medtronic Reveal XT implantable loop recorder
Phase 4

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Open Label
Primary Purpose: Diagnostic
Official Title: Randomized Controlled Trial to Evaluate Implanted Event Recorders for the First Diagnosis of Atrial Fibrillation in High-risk Patients

Resource links provided by NLM:

Further study details as provided by Frank R Heinzel, MD, PhD, Medical University of Graz:

Primary Outcome Measures:
  • Time to first diagnosis of atrial fibrillation [ Time Frame: 12 months ]

Secondary Outcome Measures:
  • Time to change in therapy based on the diagnosis of atrial fibrillation [ Time Frame: Baseline (0 months), 1,2,3,4,5,6,9 and 12 months ]
  • Hospitalizations [ Time Frame: 12 months ]
  • Change in NTproBNP serum level associated with occurrence of atrial fibrillation [ Time Frame: Baseline (0 months), 1,2,3,4,5,6,9 and 12 months ]
  • Death [ Time Frame: 12 months ]
  • Stroke [ Time Frame: 12 months ]

Enrollment: 82
Study Start Date: November 2011
Estimated Study Completion Date: January 2016
Primary Completion Date: May 2015 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: loop recorder
patients will be implanted with a subcutaneous loop recorder and have regular follow-ups
Device: Medtronic Reveal XT implantable loop recorder
subcutaneous implantation
No Intervention: regular follow-up
patients will receive regular follow-ups with standard ECG


Ages Eligible for Study:   18 Years and older   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • CHA2DS2-VASc risk score >= 4*
  • 18 years or older

Exclusion Criteria:

  • known history of atrial fibrillation
  • implanted rhythm device
  • pre-existing indication for oral anticoagulation

(*)CHA2DS2-VASc: C - chronic heart failure (1 point); H - hypertension (1 point); A - age >= 75 years (2 points); D - diabetes (1 point); S - stroke (2 points); V - vascular disease (1 point); A - age >=65 and < 75 years (1 point); Sc - sex category (female) (1 point) ;

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Please refer to this study by its identifier: NCT01461434

LKH/Uniklinikum - Klinische Abteilung für Kardiologie
Graz, Austria, 8036
Sponsors and Collaborators
Medical University of Graz
  More Information

Responsible Party: Frank R Heinzel, MD, PhD, Associate Professor Frank R. Heinzel, MD, PhD, Medical University of Graz Identifier: NCT01461434     History of Changes
Other Study ID Numbers: GRAF-01-SCCT
Study First Received: October 23, 2011
Last Updated: December 20, 2015

Keywords provided by Frank R Heinzel, MD, PhD, Medical University of Graz:
atrial fibrillation
stroke prevention
implantable loop recorder

Additional relevant MeSH terms:
Heart Failure
Atrial Fibrillation
Vascular Diseases
Heart Diseases
Cardiovascular Diseases
Arrhythmias, Cardiac
Pathologic Processes processed this record on May 25, 2017