Coronary dissection in a patient with essential thrombocytosis.

A 50-year-old man was admitted to the hospital with left shoulder and arm discomfort. He had no recent history of change in his energy level, limitations to activity, exertional chest pain, or shortness of breath. He had cardiac risk factors, including a strong family history of pre-mature coronary artery disease and dyslipidemia. He had a syncopal episode in 2003 with a positive troponin I, but had a negative cardiac workup, including cardiac catheterization that showed luminal irregularities and no significant coronary artery disease. An echocardiogram was performed to rule out potential cardiac causes for shoulder pain and showed regional wall motion abnormalities. Follow-up cardiac catheterization revealed left anterior descending artery proximal and mid dissection and a long area of dissection in the first diagonal branch. Laboratory evaluation showed significant platelet elevation and positive JAK2 study. Ultrasound of the abdomen revealed moderate splenomegaly. The enlarged spleen, positive JAK2 study, and persistently elevated platelet count confirmed the diagnosis of essential thrombocythemia. Essential thrombocythemia can predispose individuals to vascular dysfunction and damage, which may contribute to coronary artery dissection. With this case, we propose that essential thrombocythemia should be excluded in the presence of coronary dissection and thrombocytosis.