Acute Myocardial Infarction as Initial Manifestation of Acute Myeloid Leukemia: A Rare Manifestation of Leukostasis.

Leukostasis is a medical emergency caused by compromise of tissue perfusion secondary to hyperleukocytosis in acute myeloid leukemia (AML). Typically it affects lungs and brain, with cardiac involvement being exceedingly rare. We present a case of AML presenting as acute coronary syndrome secondary to leukostasis-induced myocardial ischemia. A 43-year-old morbidly obese gentleman presented with typical anginal chest pain. On examination, he was diaphoretic and in acute distress secondary to pain. EKG revealed ST elevation in lead I and aVL and PR depressions in precordial leads. Troponin peaked at 5.55 ng/mL. Echocardiogram showed normal left ventricle function with no wall motion abnormality. Blood work was notable for white blood cell (WBC) count of 185,200 cells/μL with 81% blasts. Coronary angiogram revealed no obstruction. Emergent leukapheresis and hydroxyurea were initiated. WBC count decreased to 48,200 cells/ μL and angina resolved after leukapheresis. With diagnosis of AML, he received 7+3 induction chemotherapy with cytarabine and idarubicin, followed by re-induction and consolidation chemotherapy. He subsequently underwent allogenic bone marrow transplantation and achieved complete remission. Hyperleukocytosis in AML can cause leukostasis, characterized by evidence of tissue ischemia. Coronary vasculature accounts for 6% of cases with leukostasis. This can manifest as myocardial infarction. Emergent and timely initiation of leukapheresis can potentially lead to a complete resolution of microvascular occlusion.