Hypothyroidism is associated with clinical outcomes in patients with acute myocardial infarction: subgroup analysis of China PEACE study

Purpose Thyroid dysfunction contributes to adverse events in several types of cardiovascular diseases. The aim of the present study is to determine whether thyroid status is associated with the prognosis of patients with acute myocardial infarction (AMI). Methods The present cohort arose from the China PEACE‑Prospective AMI study. Based on the evaluation of thyroid status, participants were divided into euthyroid, hypothyroid, and hyperthyroid groups. A total of 2569 AMI patients met the inclusion criteria of our present study. The primary outcomes were the 12-month composite cardiovascular endpoint (CCVE, a composite of all-cause death, myocardial infarction, revascularization, and heart failure) and the composite cardio-cerebral vascular endpoint (CCCVE, comprising CCVE and stroke). Results Of the entire cohort, 431 patients (16.8%) confirmed hypothyroid status and 102 (4.0%) were at hyperthyroid status. There were total 594 CCVEs (23.1%) and 687 CCCVEs (26.7%) in the general population. After adjusting conventional risk factors, AMI patients from the hypothyroid status group were at increased risk of the two composite endpoints, compared with euthyroid individuals (CCVE, HR:1.337, 95%CI: 1.097–1.630; CCCVE, HR:1.336, 95%CI: 1.111–1.607). However, no significant increased trends of the two composite endpoints could be observed in hyperthyroid group. Furthermore, hypothyroid status was also independently associated with a higher risk of revascularization (HR: 1.648, 95%CI: 1.047–2.595) and heart failure (HR: 1.382, 95%CI: 1.066–1.792). Conclusion Compared with euthyroid status, hypothyroid status has an independent predicting value for adverse cardiovascular events in AMI patients. Further investigations are required to illustrate whether treatment of thyroid dysfunction could improve the prognosis of AMI patients.