In patients with untreated thyrotoxicosis, atrial fibrillation was not a significant independent risk factor for cerebrovascular events (p=0.17), whereas age was an important risk factor (p<0.005).
Cohort (n=610)
Is atrial fibrillation an independent risk factor for cerebrovascular events in patients with thyrotoxicosis?
In patients with thyrotoxicosis, atrial fibrillation may not be an independent risk factor for stroke, questioning the routine use of prophylactic anticoagulation in this specific population.
p-value: p=0.17
Chronic atrial fibrillation is associated with an increased risk of stroke. In elderly patients with thyrotoxicosis, atrial fibrillation is frequently encountered, and the true risk of cerebrovascular events in these patients is controversial. We retrospectively studied 610 patients with initially untreated thyrotoxicosis, 91 (14.9%) of whom had atrial fibrillation, with the highest frequency in the elderly patients. The risk of cerebrovascular events, with special attention to the first year after the diagnosis of thyrotoxicosis, was calculated using logistic regression methods with age, sex, and atrial fibrillation as independent variables. Only age was an important risk factor (p less than 0.005), whereas sex and atrial fibrillation were not significant (p = 0.09 and p = 0.17, respectively) as independent risk factors. This is contrary to other studies of patients with thyrotoxic atrial fibrillation, and the need for further clarification of this issue is clear. From our study the indication for prophylactic treatment with anticoagulants for prevention of stroke in thyrotoxic atrial fibrillation seems doubtful, especially as no controlled studies of such treatment in patients with atrial fibrillation are currently available.
Petersen et al. (1988) conducted a cohort in Thyrotoxicosis (n=610). Atrial fibrillation vs. No atrial fibrillation was evaluated on Cerebrovascular events (p=0.17). In patients with untreated thyrotoxicosis, atrial fibrillation was not a significant independent risk factor for cerebrovascular events (p=0.17), whereas age was an important risk factor (p<0.005).