Risk of ischaemic stroke in thyrotoxic atrial fibrillation

Abstract

ObjectiveAtrial fibrillation (AF) is the most common cardiac complication of thyrotoxicosis and is strongly implicated in thromboembolic events. However, the incidence of stroke in thyrotoxic AF remains unclear. Herein, we aimed to investigate the risks of mortality and ischaemic stroke between patients with thyrotoxic AF and nonthyrotoxic AF.Designs and MethodsFrom Taiwan's National Health Insurance Research Database, 1868 patients with the concomitant diagnoses of AF and thyrotoxicosis identified between 2001 and 2010 were compared to 7472 patients with nonthyrotoxic AF using propensity score matching for age, sex and comorbidities.ResultsThere was no significant difference in either CHA2DS2‐VASc score or anticoagulant usage between the groups. Alternatively, the thyrotoxic group contained more β‐blocker/digoxin users, whereas the nonthyrotoxic group contained more statin users. Patients with thyrotoxic AF exhibited lower risks of all‐cause mortality (HR: 0.66, CI: 0.59‐0.73, P < .0001) and ischaemic stroke (HR: 0.73, CI: 0.64‐0.84, P < .0001) than those with nonthyrotoxic AF, especially thyrotoxic patients with CHA2DS2‐VASc scores ≥1. Comorbidities, including diabetes, hyperlipidaemia, hypertension and coronary artery disease, contributed to all‐cause mortality in patients with nonthyrotoxic AF; however, this effect was diminished in thyrotoxic AF.ConclusionsPatients with thyrotoxicosis and AF have a lower risk of stroke than patients with nonthyrotoxic AF. Treatment for thyrotoxicosis is also crucial as the prescription of anticoagulants based on CHA2DS2‐VASc scores.

Efficacy and safety of anticoagulation in thyrotoxic atrial fibrillation: a systematic review and meta-analysis

“…Forty-eight studies were retrieved for full-text screening and 39 studies were deemed ineligible. Nine studies (one RCT ( 14 ) and eight cohort studies ( 6 , 7 , 12 , 13 , 15 , 20 , 21 , 22 )) were included in the systematic review. Four cohort studies were included in the meta-analysis.…”

“…Three cohort studies ( 6 , 7 , 12 ) were judged to be at serious ROB. One cohort study ( 21 ) was judged to be at critical ROB. ROB of the observational studies is summarized in Fig.…”

“…The average age of participants was between 55 and 73 years. The youngest participants were 18 years old ( 15 , 21 ). Important baseline characteristics were statistically significantly different in some studies.…”

The Perfect Storm: A Case of Ischemic Stroke in the Setting of Thyroid Storm

“…Timely diagnosis of thyroid storm is challenging and is often missed due to non-specific symptoms, which reflect an increased metabolic state ( Ischemic stroke presenting with thyroid storm is a rare occurrence. Ischemic stroke can be both the cause and the effect of the thyroid storm [8,12]. Ischemic stroke as a result of thyroid storm has two possible mechanisms: atrial fibrillation and hypercoagulable state.…”

“…Moreover, there is evidence that beta antagonists can reduce adrenergic symptoms, which can minimize fevers, decrease convulsions, and improve psychotic symptoms [11]. When using beta antagonists, it is important to note that their half-life is shortened by circulating thyroid hormones [12]. Among the beta antagonists, propranolol is the most commonly utilized as it is non-selective and easy to administer both orally or intravenously [2,8,11].…”