Atrial fibrillation and hyperthyroidism: relation between transoesophageal markers of a thrombogenic milieu and clinical risk factors for thromboembolism

UNLABELLED: Hyperthyroidism is a questionable risk factor for thromboembolism among patients with atrial fibrillation. OBJECTIVE: To correlate clinical risk factors for thromboembolism from a group of patients with atrial fibrillation related to hyperthyroidism with transoesophageal echocardiography (TOE) markers of a thrombogenic milieu. DESIGN: Clinical risk factors for thromboembolism, thyroid hormonal status, time since diagnosis of hyperthyroidism and TOE markers of a thrombogenic milieu were assessed in consecutive patients with atrial fibrillation related to hyperthyroidism. The following TOE parameters were assessed to define the presence of thrombogenic milieu: dense spontaneous echo contrast, thrombi or left atrial appendage blood flow velocities <0·20 m/s. Clinical risk factors for thromboembolism were based on CHADS(2) (Cardiac failure, Hypertension, Age, Diabetes and Stroke) classification. PATIENTS: This study included 31 consecutive patients aged between 18 and 65 years with atrial fibrillation related to hyperthyroidism scheduled for TOE. RESULTS: Thrombogenic milieu was present in 14 of 31 (45·2%) patients. The thyroid status could not predict the presence of a thrombogenic milieu. Despite low CHADS(2) score of 0/1, 6 of 13 (46·1%) patients had a thrombogenic milieu, whereas 10 of 18 (55·6%) patients with score ≥2 had none. The probability of having a thrombogenic milieu did not correlate with the number of clinical risk factors. CONCLUSION: Among patients younger than 65 years of age with atrial fibrillation related to hyperthyroidism, there is no association between clinical risk factors with TOE markers of a thrombogenic milieu. TOE adds useful information that may affect antithrombotic therapy guided by clinical risk classification.