Case Report: Unusual persistent elevation of troponin I-systemic sclerosis masked by acute myocardial infarction

Myocardial infarction (MI) is a serious cardiovascular emergency that causes myocardial necrosis due to acute occlusion or spasm of a coronary artery leading to persistent ischemia and hypoxia; it is the major cause of death in patients with cardiovascular diseases worldwide. Systemic sclerosis (SSc) is a rare immune-mediated rheumatic disease characterized by fibrosis of skin and internal organs and vascular lesions. Although the survival in SSc has been improved in the past decades, the mortality rate remains high. Here we report a case of myocardial infarction combined with SSc and document the diagnostic and treatment process. A 55-year-old male patient underwent percutaneous coronary intervention (PCI) because of acute inferior MI, but a downtrend of cardiac troponin I (cTnI) was absent after operation. At 1 month later, the patient was readmitted for treatment due to residual vascular lesions, and the serum cTnI remained persistently high. After a thorough examination and histopathologic biopsy, the patient was ultimately diagnosed with a combination of SSc. Electrocardiograph, medical images, cardiac enzymes, and histopathological changes as well as coronary angiographic findings revealed the severity and complexity of the patient's condition. At 3 months after the second discharge, the follow-up data showed that the patient's condition improved significantly. This case may provide a novel perspective on the diagnosis and clinical management of this rare comorbidity.