ObjectiveTo analyze the thyroid hormone levels in patients with acute type A aortic dissection (ATAAD) and assess its clinical significance.MethodsWe included 88 patients with ATAAD who underwent surgical treatment in Beijing Anzhen Hospital between January 2018 and August 2018. Meanwhile, we extracted 187 blood samples of healthy people from our laboratory (Beijing Lab for Cardiovascular Precision Medicine, Beijing, China) as control group. Examining preoperative thyroid hormone levels and perioperative serum creatine for patients and examining thyroid hormone levels for healthy people. Based on difference in thyroid hormone levels between patients and healthy people, we divide patients into abnormal thyroid hormone groups and control groups, analyzing the relationship between thyroid hormone levels and variance of postoperative serum creatinine.ResultsPatients with ATAAD have lower total triiodothyronine (TT3), thyrotropin (TSH), free triiodothyronine (FT3) and higher free thyroxine (FT4) levels than healthy people (respectively, P<0.001, P<0.001, P<0.001 and P<0.001). What’s more, patients with ATAAD who had low TT3 before operation had higher elevation of postoperative serum creatinine and rate of acute kidney injury(P=0.019).CONCLUSIONSPatients with ATAAD have different thyroid hormone levels than healthy people, preoperative TT3 is associated with elevation of postoperative serum creatinine and occurrence of acute kidney injury. Thyroid function measurement should be a routine preoperative examination in patients with ATAAD.