Recurrent Cardiovascular Events Despite Antiplatelet Therapy in a Patient with Polycythemia Vera and Accelerated Platelet Turnover

Outcomes of Patients With Myeloproliferative Neoplasms Admitted With Myocardial Infarction: Insights From National Inpatient Sample

Background

Myeloproliferative neoplasms (MPNs) are hematopoietic stem cell neoplasms with a high risk of thrombosis, including acute myocardial infarction (AMI). However, outcomes after AMI have not been thoroughly characterized.

Objectives

The purpose of this study was to characterize outcomes after AMI in patients with MPNs compared with patients without MPNs.

Methods

Patients with a primary admission of AMI from January 2006 to December 2018 were identified using the National Inpatient Sample. Outcomes of interest included in-hospital death or cardiac arrest (CA) and major bleeding. Propensity score weighting was used to compare outcomes between MPN and non-MPN groups.

Results

A total of 1,644,304 unweighted admissions for AMI were included; of these admissions, 5,374 (0.3%) were patients with MPNs. After propensity score weighting, patients with MPNs had a lower risk of in-hospital death or CA (OR: 0.83; 95% CI: 0.82-0.84) but a higher risk of major bleeding (OR: 1.29; 95% CI: 1.28-1.30) compared with non-MPN patients. There was a decreasing temporal rate of in-hospital death or CA and bleeding in patients without MPNs (Ptrend < 0.001 for both). However, there was an increasing temporal rate of in-hospital death or CA (Ptrend < 0.001) and a stable rate of major bleeding (Ptrend = 0.48) in patients with MPNs.

Conclusions

Among patients hospitalized with AMI, patients with MPNs have a lower risk of in-hospital death or CA compared with patients without MPNs, although they have a higher risk of bleeding. More investigation is needed in order to improve post-AMI bleeding outcomes in patients with MPN.

Acute Myocardial Infarction Followed by Cerebral Hemorrhagic Infarction in Polycythemia Vera: Case Report and Literature Review

A 60-year-old man presented to our emergency room with severe chest pain. Based on the electrocardiogram and elevated serum troponin T levels, acute coronary syndrome was suspected. Coronary angiography revealed total occlusion of the middle of the left anterior descending coronary artery. However, blood cell count abnormalities were not of concern. Twelve days later, the patient developed hemorrhagic infarction in the right parieto-occipital lobe. Acute coronary syndrome and cerebral hemorrhagic infarction were primarily caused by thrombus formation due to polycythemia vera (PV), based on the presence of increased blood consistency on admission. PV was diagnosed after bone marrow biopsy and genetic testing. The patient was treated with descending cell and antiplatelet therapy. Our case highlights the importance of the urgent identification of PV. When acute myocardial infarction occurs in patients with no significant risk factors for cardiovascular disease, blood routine abnormalities should be paid close attention to. If PV was diagnosed as early as possible, thrombotic and hemorrhagic complications could be prevented in the early stages.

Ischemic stroke as a presenting manifestation of polycythemia vera: a narrative review

Polycythemia vera (PV) is a myeloproliferative disorder associated with an increased risk of cerebrovascular diseases. In this narrative review, we aimed to analyze the relationships between acute ischemic stroke and PV. We conducted a PubMed/Medline and Web of Sciences Database search using MeSH major terms. We found 75 articles and finally considered 12 case reports and 11 cohort studies. The ischemic stroke resulted as the first manifestation of PV in up to 16.2% of cases; the cumulative rate of cerebrovascular events was up to 5.5 per 100 persons per year and stroke accounted for 8.8% of all PV-related deaths; age, mutations, and a previous history of thrombosis were the main risk factors. The best approach to reduce stroke recurrence risk is unclear, even if some evidence suggests a potential role of lowering hematocrit below 45%. Ischemic stroke represents one of the most common PV manifestations but, despite their relationship, patients with both diseases have a very heterogeneous clinical course and management. PV-related strokes often remain underdiagnosed, especially for the low prevalence of PV. An early diagnosis could lead to prompt treatment with phlebotomy, cytoreduction, and low-dose aspirin to decrease the risk of recurrences. Clinicians should be aware of PV as a risk factor for stroke when approaching the differential diagnosis of cryptogenic strokes. An early diagnosis could positively influence patients' management and clinical outcomes. Further studies are required to evaluate the role of PV treatments in the prevention of cerebrovascular disease.

Successive development of ischemic stroke and hemorrhagic stroke in a patient with essential thrombocythemia: a case report

Patients with essential thrombocythemia (ET) can experience hemorrhagic or ischemic vascular events. The prevention of these complications is challenging, and the overall risk of vascular events caused by ET is often overlooked. A 34-year-old man was admitted for a 10-day history of weakness and numbness in his right limbs. He had been diagnosed with ET in 2008 but had stopped receiving treatment half a year before admission. Physical examination showed a superficial sense of disturbance in the right limbs and decreased muscle strength in the right upper and lower limbs (4/5). His platelet count (459 × 10⁹/L) was elevated. Magnetic resonance imaging showed acute watershed infarction, and he was treated successfully. However, he was readmitted for headache and left limb weakness 14 months later. A head computed tomography scan revealed spontaneous subdural hemorrhage. He underwent subdural hematoma removal and decompressive craniectomy. Surgery and pathological investigation revealed no venous sinus thrombosis or vascular malformation. His condition improved, and he exhibited a stable condition 1 year after discharge. Successive development of ischemic stroke and spontaneous subdural hemorrhage is rare in a patient with ET. This case suggests that ET is not only a risk factor for stroke but can also cause highly heterogeneous strokes.

Platelet Function and Turnover in Essential Thrombocythemia: A Systematic Review

Essential thrombocythemia (ET) is a myeloproliferative neoplasm characterized by increased platelet counts. ET has an incidence of 0.6 to 2.5 per 100,000 per year in Europe and North America. The disease is characterized by an increased thromboembolic risk, possibly caused by increased platelet counts. Furthermore, increased platelet function and/or increased platelet turnover may play a role. We aimed to explore: (1) whether platelet function and platelet turnover are increased in ET patients compared with healthy controls, and (2) whether these parameters are associated with increased thromboembolic risk and, therefore, may support decision-making on treatment in ET patients. We performed a systematic literature search on March 20, 2020 in Embase and PubMed following the Preferred Reporting Items for Systematic and Meta-Analysis (PRISMA) guidelines. In total, 1,923 articles were identified, 38 of which were included according to prespecified inclusion and exclusion criteria. Among the 38 studies, platelet activation (CD36 and CD62P) was investigated in 18 studies and was found to be increased in 12 of these. Platelet aggregation was investigated in 21 studies and was reported to be reduced in 20 of them. Platelet turnover (immature platelet count and mean platelet volume) was investigated in five studies with inconclusive results. No parameters were reported to predict the risk of thromboembolic events. In conclusion, platelet activation was increased in ET patients, but platelet aggregation was reduced. Future studies exploring markers of thromboembolic risk in ET patients are warranted.

Recurrent Stroke in a Ghanaian Patient With Polycythemia

BACKGROUND

Polycythemia is a rare but important preventable cause of stroke with potential for recurrence when not identified and appropriately managed.

CASE PRESENTATION

This is a case of a 55-year-old Ghanaian who presented to our tertiary facility after a 2-month delay with a history of sudden onset of right-sided hemiparesis and expressive aphasia. He had suffered a previous stroke with left hemiparesis 2 years previously where hypertension and polycythemia were identified and treatment initiated. However, patient defaulted treatment for 18 months prior to the onset of recurrent stroke. A cranial CT scan revealed chronic right and subacute left middle cerebral artery territorial infarcts. Presenting hematocrit was 71%. Treatments initiated included high dose hydroxyurea, venesections, and dual antiplatelet therapy of Aspirin and Clopidogrel. He has since been discharged and remains stable under follow-up with moderate functional deficits- Modified Rankin score of 3/6 and the hematocrit of 54% at 3 months postdischarge.

CONCLUSIONS

Default of therapy for polycythemia is associated with a profound risk of recurrent strokes requiring patient education and support to prevent the devastating consequence of this modifiable but rare cause of stroke. This case report highlights the challenges of instituting secondary prevention for stroke in resource-limited settings.