Case Presentation:

This is a 51‐year‐old man with no significant medical history who presented to an outside hospital with a 1‐day complaint of sudden‐onset left‐sided chest pain radiating to the left shoulder, associated with diaphoresis and shortness of breath that developed while working out at home. The initial electrocardiogram showed acute ST‐segment elevations in leads 1, aVL, and V2 through V6, and serum troponin level was 9.03 ng/mL. The patient was then transferred to our hospital where he underwent emergent coronary angiography that showed total occlusion of the proximal and distal left anterior descending (LAD) coronary artery with very large thrombus burden. He was treated with thrombectomy and intracoronary abciximab and also had 2 drug‐eluting stents placed in the LAD. The initial laboratory evaluation was also notable for a platelet count of 1.15 million/ microL. His serum troponin peak level was 161 ng/mL. He continued to have persistent thrombocytosis and subsequently underwent a bone marrow biopsy that showed a hypercellular marrow with increased megakaryocytes and thrombocytosis, leading to the diagnosis of essential thrombocytosis (ET). He was discharged from the hospital on his fourth day postadmission on anti‐platelet agents and was followed up by a hematologist as an outpatient. Analysis for the JAK‐2 mutation was negative; however, the patient continued to have persistently elevated platelet counts (>900,000/μL 1 month after presentation) and treatment with hydroxyurea was initiated. The patient tolerated treatment well and to this day has had no further episodes of chest pain.


Essential thrombocytosis (ET) is a myeloproliferative disorder in the same class as polycythemia vera and reactive thrombocytosis. The disease can manifest clinically with vaso‐occlusive events anywhere in the body. Acute myocardial infarction is a rare and sometimes fatal clinical manifestation of ET. When coronary occlusion does occur, patients usually have one or more coronary risk factors (hyperlipidemia, smoking, etc.), although that was not the case with our patient. Molecular analysis has shown an association between ET and mutations in the JAK‐2 pathway in about 60% of cases. Although our patient was negative for a JAK‐2 mutation, his bone marrow biopsy supported the diagnosis of ET. Treatment is generally warranted only if patients meet the criteria for the high‐risk category which includes age older than 60 years or a prior history of thrombosis. Common treatment modalities include hydroxyurea or anagrelide.


The purpose of this case report is to highlight the importance of early detection of ET. In rare instances, this disease can present with life‐threatening cardiac complications in previously asymptomatic patients with or without known risk factors for coronary atherosclerosis. Patients who are considered high risk should undergo treatment to avoid potentially fatal complications.