Acute ST-segment Elevation Myocardial Infarction as the First Manifestation of Essential Thrombocytosis

Acute myocardial infarction in myeloproliferative neoplasms

Myeloproliferative neoplasms (MPNs) are a heterogeneous group of hematologic malignancies characterized by an abnormal proliferation of cells of the myeloid lineage. Affected individuals are at increased risk for cardiovascular and thrombotic events. Myocardial infarction (MI) may be one of the earliest clinical manifestations of MPNs or may be a thrombotic complication that develops during the natural course of the disease. In the present review, we examine the epidemiology, pathogenesis, clinical presentation, and management of MI in MPNs based on the available literature. Moreover, we review potential biomarkers that could mediate the MI-MPNs crosstalk, from classical biochemical tests, e.g., lactate dehydrogenase, creatine kinase and troponins, to pro-inflammatory cytokines, oxidative stress markers, and clonal hematopoiesis.

Myocardial Infarction as an Initial Presentation of Essential Thrombocythemia With Calreticulin (CALR) Mutation (None Type 1, None Type 2)

Essential thrombocythemia (ET) is one of the classical Philadelphia-negative myeloproliferative neoplasms with different mutations that can be associated with it, like Janus kinase 2 (JAK2), myeloproliferative leukemia protein (MPL), and Calreticulin (CALR) (types 1 and 2). However, there is a lack in the literature concerning other types of CALR mutations and their clinical significance and prognosis. Here we report a 42-year-old male with type 2 diabetes who presented with an inferior ST-elevation myocardial infarction and thrombocytosis. The diagnosis of ET with CALR (neither type 1 nor type 2) was confirmed, which suggests the pathognomonic feature of this mutation.

Acute Limb Ischemia in the Young: A Rare Case of Essential Thrombocytosis

Acute limb ischemia (ALI) is rarely observed in young populations. The hypercoagulable state is a notable cause of ALI other than artery disease progression and cardiac embolization. A hypercoagulable state occurs in essential thrombocytosis because of the overproduction of hematopoietic cells secondary to the mutation of the JAK2, CALR, or MPL genes. We report a rare case of a 37-year-old woman presenting with Rutherford IIA ALI in the left lower extremity. Laboratory data revealed she had a platelet count reaching up to 1.38 mil/μL, with other blood profiles being normal. A JAK2 mutation examination was later performed and proved positive. After careful management with catheter-directed thrombolysis, surgical thrombectomy, and cytoreductive therapy using hydroxyurea, the symptoms subsided and eventually restored the patient to physical activity in less than one month.

Could there be a relation between Steven-Johnson syndrome and ST-segment elevation myocardial infarction?

Steven-Johnson syndrome (SJS) is a rare but serious mucocutaneous reaction to medications. We present a rare case of SJS developing after antibiotic administration for a lower respiratory tract infection and whose inpatient course was complicated with an acute ST-segment elevation myocardial infarction (MI). The laboratory findings revealed thrombocytosis which was possibly reactive and explained the underlying pathophysiology of the thrombus formation seen in the coronary artery. Stenting and aspiration of thrombus was performed. This case illustrates a possibly rare association between SJS and MI.