Acute Myocardial Infarction in a Patient with Essential Thrombocythemia Treated with Glycoprotein Ilb/Illa Inhibitor

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.

Essential thrombocythemia with non-ST-segment elevation myocardial infarction as the first manifestation: A case report

BACKGROUND

We report a case of essential thrombocythemia (ET) in a 44-year-old male who exhibited non-ST-segment-elevation myocardial infarction (NSTEMI) as the first manifestation without known cardiovascular risk factors (CVRFs). For the first time, we reported a left main trifurcation lesion in NSTEMI caused by ET, including continuous stenosis lesions from the left main to the ostial left anterior descending (LAD) artery and an obvious thrombotic lesion in the ostial and proximal left circumflex (LCX) artery. There was 60% diffuse stenosis in the left main (LM) that extended to the ostial LAD, thrombosis of the ostial LAD and proximal LCX, and 90% stenosis in the proximal LCX. During the operation, thrombus aspiration was performed, but no obvious thrombus was aspirated. Performing the kissing balloon technique (KBT) in the LCX and LM unexpectedly increased the narrowness of the LAD. Then, the single-stent crossover technique, final kissing balloon technique and proximal optimization technique (POT) were performed. On the second day after percutaneous coronary intervention (PCI), the number of platelets (PLTs) still increased significantly to as high as 696 × 10⁹/L. The bone marrow biopsy done later, together with JAK2 (exon 14) V617F mutation, confirms the diagnosis of ET. Hydroxyurea was administered to inhibit bone marrow proliferation to control the number of PLTs.

CASE SUMMARY

A 44-year-old male patient went to a local hospital for treatment for intermittent chest pain occurring over 8 h. The examination at the local hospital revealed elevated cTnI and significantly elevated platelet. Then, he was diagnosed with acute myocardial infarction and transferred to our hospital for emergency interventional treatment by ambulance. During the operation, thrombus aspiration, the single-stent crossover technique, final kissing balloon technique and POT were performed. Dual antiplatelet therapy comprising aspirin and ticagrelor was used after PCI. Evidence of mutated JAK2 V617F and bone marrow biopsy shown the onset of ET. Together with JAK2 (exon 14) V617F mutation, ET was diagnosed according to the World Health Organization (WHO) diagnostic criteria, and the patient was placed on hydroxyurea. During the one-year postoperative period, repeated examinations showed a slight increase in PLTs, but the patient no longer had chest tightness, chest pain or bleeding or developed new thromboembolisms.

CONCLUSION

Routine physical examinations and screenings are conducive to the early detection of ET, and the risk for thrombosis should be assessed. Then, active antiplatelet therapy and myelosuppression therapy should be used for high-risk ET patients.

Essential thrombocytemia and acute coronary syndrome: clinical profile and association with other thromboembolic events

BACKGROUND

The existence of a relationship between essential thrombocytemia (ET) and acute coronary syndromes (ACS) has been suggested.

METHOD

Data from eleven consecutive patients admitted with ET in the cardiology department were reviewed.

RESULTS

Nine patients (82%) presented with ACS and two with bradycardia. Patients with ACS had a mean age of 67+/-11 years. Risk factors, especially hypertension (6, 66.7%), and smoking (6, 66.7%) were frequent. Average platelet count was 509 778+/-282 126/mm3. Significant coronary lesions were found in five of six patients studied with coronary angiography. During hospitalization, a patient suffered a thrombotic stroke, a massive pulmonary embolism, and partial aortic thrombosis. Another patient had a transient ischemic attack. Discharge treatments were aspirin (78%), clopidogrel (56%), acenocumarol (33%), hydroxyurea (56%) and anagrelide (44%). Three patients (27%) had thromboembolic events during follow-up (median 1.6 years), 2 patients had coronary events and 1 patient had venous thrombosis. There were neither significant haemorrhages nor deaths.

CONCLUSIONS

Patients with ET and ACS have similar profiles to those of traditional ACS with frequent risk factors and significant coronary artery disease. Association with other thrombotic events can be seen during admission and follow-up while haemorrhagic complications seem to be rare.