Answer: F. There is currently no evidence to support anticoagulation in this setting; focus on rate control with a beta-blocker and treating the underlying cause of the presenting rhythm.
The patient in the scenario above is presenting with thyrotoxicosis/thyroid storm. His Burch-Watofsky Point Scale (BWPS) score is 95, which is highly suggestive of thyroid storm.1 Furthermore, his thyroid stimulating hormone (TSH) level is markedly low, suggesting marked hyperthyroidism. His electrocardiogram reveals atrial fibrillation (AF) with a rapid ventricular response.
Up to 15% of patients presenting with thyroid storm will present with AF, which can complicate the clinical presentation by precipitating heart failure. The correlation between AF and thromboembolism independent of other risk factors remains controversial.2 In 2006, the American College of Cardiology (ACC) in its executive summary guideline for the management of AF suggested that thyrotoxicosis was an independent risk factor for thromboembolism in patients presenting with AF and that those patients should receive anticoagulation therapy during a thyroid crisis.3
However, in 2008, recognizing the paucity of data to support that recommendation, the American College of Chest Physicians recommended that anticoagulation management be guided by CHA2DS2-VASC scores.4 In 2014, the ACC released a joint guideline with the American Heart Association and the Heart Rhythm Society stating that thyrotoxicosis was not independently associated with higher embolic risk for stroke and that anticoagulation should be guided by CHA2DS2-VASC risk factors.2
In this patient, the CHA2DS2-VASC score is 0. Therefore, no evidence exists at this time to support initiation of anticoagulation. Treatment should be aimed at re-establishing a euthyroid state, which often results in restoration of sinus rhythm.2 Cardioversion and anti-arrhythmics often fail to restore sinus rhythm during thyroid storm and thus are not routinely recommended. Beta-blockers or nondihydropyridine calcium-channel blockers are highly effective in this setting and are recommended for rate control.2
- Burch HB, Wartofsky L. Life-threatening thyrotoxicosis. Thyroid storm. Endocrinol Metab Clin North Am. 1993;22(2):263-277.
- January CT, Wann LS, Alpert JS, et al; for the American College of Cardiology/American Heart Association Task Force on Practice Guidelines. 2014 AHA/ACC/HRS guideline for the management of patients with atrial fibrillation: a report of the American College of Cardiology/American Heart Associate Task Force on Practice Guidelines and the Heart Rhythm Society. J Am Coll Cardiol. 2014;64(21):e1-e76.
- European Heart Rhythm Association, Heart Rhythm Society, Fuster V, et al. ACC/AHA/ESC 2006 guidelines for the management of patients with atrial fibrillation–executive summary: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines and the European Society of Cardiology Committee for Practice Guidelines (Writing Committee to Revise the 2001 Guidelines for the Management of Patients With Atrial Fibrillation). J Am Coll Cardiol. 2006;48(4):854-906.
- Singer DE, Alberts GW, Dalen JE, et al. Antithrombotic therapy in atrial fibrillation: American College of Chest Physicians evidence-based clinical practice guideline (8th edition). Chest. 2008;133(6):546S-592S.