Thumb-ECG Ambulant Screening for Atrial Fibrillation in Patients Treated for Hyperthyroidism (TAMBOURINE)

Atrial Fibrillation Clinical Trial

— TAMBOURINE  

Official title:

Thumb-ECG Ambulant Screening for Atrial Fibrillation in Patients Treated for Hyperthyroidism (TAMBOURINE)

Clinical Trial Details — Status: Terminated

Administrative data

• NCT number: NCT01945229
• Other study ID #: 3/9 B
• Status: Terminated
• Start date: February 2014
• Est. completion date: August 2020

Study information

• Verified date: September 2020
• Source: Karolinska Institutet
• Contact: n/a
• Is FDA regulated: No
• Study type: Observational

Clinical Trial Summary

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.

Hypotheses:

• 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.

Recruitment information / eligibility

• Status: Terminated
• Enrollment: 110
• Est. completion date: August 2020
• Est. primary completion date: August 2020
• Accepts healthy volunteers: No
• Gender: All
• Age group: N/A and older

Eligibility

Inclusion Criteria:

• Patient is deemed suitable for treatment with radioiodine or antithyroid drugs

• 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

Related Conditions & MeSH terms

• Atrial Fibrillation
• Hyperthyroidism

Locations

Country	Name	City	State
Sweden	Medicine Clinic, Sahlgrenska University Hospital	Gothemburg
Sweden	Endocrinology Clinik, Karolinska University Hospital	Stockholm
Sweden	Medicine Clinic, Danderyds Hospital	Stockholm

Sponsors (1)

Lead Sponsor	Collaborator
Karolinska Institutet

Country where clinical trial is conducted

Sweden, 

References & Publications (4)

Camm AJ, Lip GY, De Caterina R, Savelieva I, Atar D, Hohnloser SH, Hindricks G, Kirchhof P; ESC Committee for Practice Guidelines (CPG). 2012 focused update of the ESC Guidelines for the management of atrial fibrillation: an update of the 2010 ESC Guidelines for the management of atrial fibrillation. Developed with the special contribution of the European Heart Rhythm Association. Eur Heart J. 2012 Nov;33(21):2719-47. doi: 10.1093/eurheartj/ehs253. Epub 2012 Aug 24. Erratum in: Eur Heart J. 2013 Mar;34(10):790. Eur Heart J. 2013 Sep;34(36):2850-1. — View Citation

Frost L, Vestergaard P, Mosekilde L. Hyperthyroidism and risk of atrial fibrillation or flutter: a population-based study. Arch Intern Med. 2004 Aug 9-23;164(15):1675-8. Erratum in: Arch Intern Med. 2005 Feb 14;165(3):307. — View Citation

Metso S, Auvinen A, Salmi J, Huhtala H, Jaatinen P. Increased long-term cardiovascular morbidity among patients treated with radioactive iodine for hyperthyroidism. Clin Endocrinol (Oxf). 2008 Mar;68(3):450-7. Epub 2007 Oct 17. — View Citation

Osman F, Franklyn JA, Holder RL, Sheppard MC, Gammage MD. Cardiovascular manifestations of hyperthyroidism before and after antithyroid therapy: a matched case-control study. J Am Coll Cardiol. 2007 Jan 2;49(1):71-81. Epub 2006 Dec 13. — View Citation

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Prevalence of asymptomatic (silent) atrial fibrillation in hyperthyroid patients	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.	Upon inclusion and 2 weeks onwards
Secondary	Prevalence of asymptomatic (silent) atrial fibrillation in patients treated for hyperthyroidism.	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.	Between 12 and 14 weeks after inclusion
Secondary	Prevalence of risk factors for stroke in patients with atrial fibrillation	Risk factors for stroke in atrial fibrillation according to the CHADS-VASc-scoring system.	Momentary (day 1, upon inclusion)