Thumb-ECG Ambulant Screening for Atrial Fibrillation in Hyperthyroid Patients Treated With Radioiodine (TAMBOURINE)

This study is currently recruiting participants. (see Contacts and Locations)
Verified April 2015 by Karolinska Institutet
Information provided by (Responsible Party):
Peter Giesecke, M.D, Karolinska Institutet Identifier:
First received: September 13, 2013
Last updated: April 1, 2015
Last verified: April 2015

Background: Atrial fibrillation is a common heart rhythm disturbance affecting some 1-2% of the western population. It may cause symptoms such as irregular heartbeats, shortness of breath, and fatigue. It may also be asymptomatic (ie "silent atrial fibrillation). In some cases, atrial fibrillation is permanent whereas in others it is sporadic. Regardless of symptoms, there is an increased risk of stroke in some patients with this condition. Novel technologies are being developed to increase detection of silent atrial fibrillation, in order to find patients who might benefit from treatment with oral anticoagulants (blood-thinning medications) in order to reduce the risk of stroke. One of these technologies is thumb-ECG, a simple way for a patient to have his or her heart rhythm reliably analyzed at home.

Hyperthyroidism (sometimes referred to as "toxic goiter") is defined as an excessive production of thyroid hormone. It is known that hyperthyroidism may cause atrial fibrillation in about 8% of cases.

Objective: To provide thumb-ECG-monitors to hyperthyroid patients before and after treating their hormonal disturbance, in order to find episodes of silent atrial fibrillation.

Design: Prospective observational study.


  • Primary hypothesis: Silent atrial fibrillation is at least as common as overt atrial fibrillation in hyperthyroid patients.
  • Secondary hypothesis nr 1: Atrial fibrillation continues to be more prevalent compared to the normal population even after hyperthyroidism is treated.
  • Secondary hypothesis nr 2: The majority of patients with hyperthyroidism and atrial fibrillation are at increased risk of stroke and should be considered for treatment with oral anticoagulants.

Atrial Fibrillation

Study Type: Observational
Study Design: Observational Model: Cohort
Time Perspective: Prospective
Official Title: Thumb-ECG Ambulant Screening for Atrial Fibrillation in Hyperthyroid Patients Treated With Radioiodine

Resource links provided by NLM:

Further study details as provided by Karolinska Institutet:

Primary Outcome Measures:
  • Prevalence of asymptomatic (silent) atrial fibrillation in hyperthyroid patients [ Time Frame: Upon inclusion and 2 weeks onwards ] [ Designated as safety issue: No ]
    Upon inclusion, each patient will receive a thumb-ECG-monitor to take home. He/she will register his/her heart rhythm twice daily, and can also register at will upon symptoms. This will continue for 2 weeks, after which the monitor is returned.

Secondary Outcome Measures:
  • Prevalence of asymptomatic (silent) atrial fibrillation in patients treated for hyperthyroidism. [ Time Frame: Between 12 and 14 weeks after inclusion ] [ Designated as safety issue: No ]
    When a patient comes back to the policlinic after hyperthyroidism treatment (typically 3 months later), the same procedure is performed as upon inclusion. Thumb-ECG-monitoring is performed during a 2-week period.

  • Prevalence of risk factors for stroke in patients with atrial fibrillation [ Time Frame: Momentary (day 1, upon inclusion) ] [ Designated as safety issue: No ]
    Risk factors for stroke in atrial fibrillation according to the CHADS-VASc-scoring system.

Estimated Enrollment: 423
Study Start Date: February 2014
Estimated Study Completion Date: December 2017
Estimated Primary Completion Date: November 2017 (Final data collection date for primary outcome measure)
Hyperthyroid patients
Patients with hyperthyroidism admitted for treatment with radioiodine


Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No
Sampling Method:   Non-Probability Sample
Study Population
We will screen all patients residing in the extended region around Stockholm, Sweden who have been referred and admitted to the Radiumhemmet clinic for investigation (and usually treatment) with radioiodine.

Inclusion Criteria:

  • Patient is deemed suitable for radioiodine treatment
  • Patient has a thyreotropin (TSH) value below 0,1 mIU/L, measured less than 2 weeks before inclusion
  • Patient has a CHADS-VASc-score of 1 point or higher (excluding if 1 point is for female sex only)
  • Patient gives written consent to participate in study

Exclusion Criteria:

  • Patient has a previously known diagnosis of atrial fibrillation
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its identifier: NCT01945229

Contact: Peter Giesecke, M.D. +46 70 768 43 88

Radiumhemmet, Karolinska universitetssjukhuset Recruiting
Stockholm, Sweden, 17176
Contact: Camille Hilding, MD    +46 73 555 16 42   
Principal Investigator: Peter Giesecke, M.D.         
Sub-Investigator: Camille Hilding, M.D.         
Sponsors and Collaborators
Karolinska Institutet
Study Chair: Mårten Rosenqvist, Prof Karolinska Institutet
  More Information

Responsible Party: Peter Giesecke, M.D, M.D., specialist internal medicine, Karolinska Institutet Identifier: NCT01945229     History of Changes
Other Study ID Numbers: 3/9 B
Study First Received: September 13, 2013
Last Updated: April 1, 2015
Health Authority: Sweden: The National Board of Health and Welfare
Sweden: The Health and Social Care Inspectorate

Additional relevant MeSH terms:
Atrial Fibrillation
Arrhythmias, Cardiac
Cardiovascular Diseases
Endocrine System Diseases
Heart Diseases
Pathologic Processes
Thyroid Diseases processed this record on November 30, 2015