Coronary Bones

After out-of-hospital resuscitation, a 65-year-old hyperlipidemic patient with a history of smoking was brought to our hospital for early revascularization of an ST-segment– elevation myocardial infarction. Left ventricular function was found to be severely impaired with anterolateral akinesia by transthoracic echocardiography. Coronary angiography showed heavily calcified subtotal stenosis of the proximal left anterior descending and the left circumflex arteries. Immediate percutaneous coronary intervention was performed with stent placement in both affected vessels. Coronary blood flow was fully resorted, and the patient was referred to our intensive care unit. Experiencing severe brain damage despite early hypothermia treatment, the patient died 48 hours after percutaneous coronary intervention. Autopsy revealed a large acute anterolateral myocardial infarction including both papillary muscles. On histopathologic examination, cross-sections through the corresponding coronary arteries showed a large atheroma with negative remodeling, formation of mature lamellar bone including fatty bone marrow, and capillary neovascularization within the media of the vessel wall. Bone formation per se was not the main cause of lumen narrowing; however, it directly reflects late atheroma progression and plaque burden. No acute plaque rupture was found in the available cross-sections. The definite mechanism for the large myocardial infarction remains uncertain.