Thumb-ECG Ambulant Screening for Atrial Fibrillation in Patients Treated for Hyperthyroidism (TAMBOURINE)
Study Details
Study Description
Brief 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.
| Condition or Disease | Intervention/Treatment | Phase |
|---|---|---|
|
|
Study Design
Arms and Interventions
| Arm | Intervention/Treatment |
|---|---|
| Hyperthyroid patients Patients with hyperthyroidism admitted for treatment with radioiodine or antithyroid drugs |
Outcome Measures
Primary Outcome Measures
- Prevalence of asymptomatic (silent) atrial fibrillation in hyperthyroid patients [Upon inclusion and 2 weeks onwards]
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. [Between 12 and 14 weeks after inclusion]
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 [Momentary (day 1, upon inclusion)]
Risk factors for stroke in atrial fibrillation according to the CHADS-VASc-scoring system.
Eligibility Criteria
Criteria
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
Contacts and Locations
Locations
| Site | City | State | Country | Postal Code | |
|---|---|---|---|---|---|
| 1 | Medicine Clinic, Sahlgrenska University Hospital | Gothemburg | Sweden | 41345 | |
| 2 | Endocrinology Clinik, Karolinska University Hospital | Stockholm | Sweden | 17176 | |
| 3 | Medicine Clinic, Danderyds Hospital | Stockholm | Sweden | 18288 |
Sponsors and Collaborators
- Karolinska Institutet
Investigators
- Study Chair: Mårten Rosenqvist, Prof, Karolinska Institutet
Study Documents (Full-Text)
None provided.More Information
Publications
- 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.
- 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.
- 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.
- 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.
- 3/9 B