A case of myocardial infarction caused by coronary vasospasm: efficacy of soluble lectin-like oxidized LDL receptor-1 for distinguishing between vasospasm and plaque rupture.

This case illustrates the benefits of using plasma levels of soluble lectin-like oxidized low-density lipoprotein receptor-1 (sLOX-1) to distinguish between myocardial injuries caused by coronary vasospasm or coronary plaque rupture. A 62-year-old woman with a history of dyslipidemia was admitted due to chest pain of 1 hour's duration. Electrocardiography demonstrated mild ST segment elevation in leads V1-6, and blood chemistry studies on admission showed a slight increase in the serum level of troponin T; therefore, acute myocardial infarction was diagnosed. However, the plasma level of sLOX-1, a marker of plaque rupture, did not increase during hospitalization. Coronary angiography demonstrated normal coronary arteries, and intracoronary acetylcholine infusion provoked coronary artery vasospasm. We could therefore diagnose myocardial injury caused by coronary vasospasm. We propose that the cause of myocardial injury cannot be predicted with electrocardiography and measurement of troponin T but can be clarified by measuring plasma levels of sLOX-1 in the early stage of acute coronary syndrome.