An Unusual Presentation of ST Elevation Myocardial Infarction Complicated with Cardiogenic Shock Due to Myxedema Coma: A Case Report.

BACKGROUND Myxedema coma is an endocrine emergency with a high mortality rate, defined as a severe hypothyroidism leading to hypotension, bradycardia, decreased mental status, hyponatremia, hypoglycemia, and cardiogenic shock. Although hypothyroidism and cardiac disease has been interlinked, ST elevation myocardial infarction in the setting of myxedema coma have not been reported previously. CASE REPORT We report the case of a 70-year-old man who presented to the Emergency Department with chest pain and confusion. He also reported fatigue for the past week, which was progressively worsening. His past medical history was significant for renal cell carcinoma with metastatic bone disease being treated with chemotherapy (axitinib and pembrolizumab). In the Emergency Department, an ECG revealed inferior ST elevations. Shortly after presentation, the patient's blood pressure was decreasing, he became bradycardic (sinus), and his mental status was getting worse, so he was intubated for airway protection and was taken emergently for a cardiac catheterization, which failed to reveal an acute coronary occlusion. TSH was 60.6 mIU/L (0.465-4.680) mIU/ML, and free T4 0.3 ng/dL (0.8-2.2) ng/dL. The cardiac index was calculated to be 0.8 L/min/m² (normal range 2.6-4.2 L/min/m²), which confirmed cardiogenic shock due to myxedema coma. He was treated with levothyroxine (T4), liothyronine (T3), hydrocortisone, and multiple vasopressors but failed to respond and died 13 h after admission to the hospital. CONCLUSIONS Because of its rarity and high mortality, early diagnosis of myxedema coma and initiation of treatment by cardiologists requires a high level of suspicion, especially when patients with a history of hypothyroidism present with a cardiac complaint (ie, acute coronary syndrome, or bradycardia) that does not completely fit the clinical picture. It is of utmost importance for physicians to keep a wide differential diagnosis of other causes of ST elevation and/or persistent cardiogenic shock.