The paradox of hypothyroidism: elevated cardiac biomarkers without coronary artery disease.

Summary: This case report describes a 55-year-old male with hypothyroidism who presented with chest pain, elevated cardiac biomarkers (creatine kinase-MB (CK-MB) and troponin T), and abnormal electrocardiogram (ECG), findings suggestive of acute coronary syndrome (ACS). Despite clinical suspicion of myocardial ischemia, coronary angiography revealed no significant coronary artery disease. Profound hypothyroidism, confirmed by markedly elevated thyroid-stimulating hormone (TSH) and anti-thyroid peroxidase antibodies, was identified as the underlying cause of the cardiac biomarker abnormalities. Treatment with thyroxine resulted in clinical improvement and normalization of cardiac markers. This case underscores the importance of considering hypothyroidism in the differential diagnosis of elevated cardiac enzymes and ischemic symptoms in the absence of coronary artery disease. Learning points: Hypothyroidism should be considered in patients presenting with ischemic symptoms and elevated cardiac biomarkers, in the absence of coronary artery disease. Elevated CK-MB and troponin in hypothyroidism may result from non-cardiac mechanisms, posing significant diagnostic challenges. Thyroid function tests should be routinely included in the diagnostic evaluation of patients with atypical presentations of myocardial injury. Timely diagnosis and management of hypothyroidism can help avoid misdiagnosis and unnecessary invasive interventions.