Efficiency of Thyroid Function Test in the Prediction of Atrial Fibrillation Following Open Heart Surgery.

OBJECTIVE: To analyse the efficiency of thyroid function tests (thyroid stimulating hormone, thyroxine and tri-iodothyronine) on prediction of postoperative atrial fibrillation. STUDY DESIGN: Meta-analysis. Place of Study: Siyami Ersek Chest and Cardiovascular Surgery Education and Research Hospital, Istanbul, Turkey. METHODOLOGY: Literature review was carried out in PubMed, Science Direct and Ovid Database. No date limitations was applied. Trials, which evaluated the preoperative levels of thyroid stimulating hormone, thyroxine and tri-iodothyronine in cardiac surgery patients, were included. Only the articles in English language were reviewed. We evaluated the results with fix or random effect models according to the presence of heterogeneity (I2 >25%). RESULTS: Five hundred and forty-seven articles were obtained after screening of databases. After checking over the titles and abstracts, five trials were included which covered 380 patients and complied with inclusion criteria. According to results of analysis, there was no significant relationship between postoperative atrial fibrillation and thyroid stimulating hormone (SMD: 0.38, 95%CI -0.46-1.23, p=0.375), and also thyroxine (SMD: 0.006, 95% CI -0.29-0.30, p=0.966). However, tri-iodothyronine (SMD: -1.06, 95% CI -2.08- -0.03, p=0.04) was correlated with development of atrial fibrillation. Heterogeneity was observed in three parameters (I2; for TSH: 92.45%, for T3: 93.08% and for T4: 31.78%). CONCLUSION: Preoperative levels of tri-iodothyronine was an effective parameter for predicting postoperative atrial fibrillation after cardiac surgery, but there was a need of larger trials for eliminating heterogeneity for all of the parameters of thyroid function tests. Key Words: Cardiac surgery, Atrial fibrillation, Thyroid stimulating hormone, Thyroxine, Tri-iodothyronine.