Objective: To explore the correlation between incidence of atrial fibrillation (AF) and thyroid dysfunction.
Methods: Patients with stable angina pectoris with thyroid function test results hospitalized at Fuwai Hospital from 2011 Jan to 2011 Dec were included in this analysis (n = 2 541). General clinical data and related biochemical parameters were analyzed. We divided patients into 5 subgroups according to TSH levels: <0.55 mIU/L (n = 105), 0.55-2.49 mIU/L (n = 1599), 2.50-4.77 mIU/L (n = 621), 4.78-9.99 mIU/L (n = 180), >10.00 mIU/L (n = 36).
Results: A total of 157 patients were diagnosed with AF (6.8%). (1) Compare to stable angina pectoris patients without AF, stable angina pectoris patients with AF have older age (P < 0.001), higher proportion of female (P = 0.04), uric acid (P < 0.001), NT-proBNP (P = 0.001), larger left atrial diameter (P < 0.001), left ventricular end diastolic diameter (P < 0.001) and lower LVEF (P = 0.038), FT3(P = 0.002), TT3 (P < 0.001). (2) When TSH levels were less than 0.55,0.55-2.49, 2.50-4.77, 4.78-9.99 mIU/L and greater than 10.00 mIU/L, the incidence of AF were 7.6% (8/105) , 5.7% (91/1 599), 7.9% (49/621), 9.4% (17/180) and 22.2% (8/36), respectively. Both a high and a low TSH level were associated with an increased incidence of AF. After adjustment for common risk factor (age, gender and so on) , stepwise multiple logistic regression analysis revealed that TSH levels were significantly related with the incidence of AF. Compared to patients with TSH 0.55-2.49 mIU/L, the adjusted odds ratio of AF for TSH < 0.55, 2.50-4.77, 4.78-9.99, >10.00 mIU/L were 1.37 (95%CI 0.65-2.90, P = 0.415), 1.42 (95CI 0.99-2.04, P = 0.057), 1.73 (95%CI 1.01-2.97, P = 0.048), 4.74 (95%CI 2.10-10.69, P < 0.001), respectively.
Conclusion: Our results show that incidence of AF increases in proportion to TSH level in patients with stable angina pectoris.