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Double the Trouble: Acute Coronary Syndrome and Ischemic Stroke in Polycythemia Vera

Magnetic resonance imaging (MRI) scan showing multifocal ischemic stroke. Diffusion-weighted imaging and T2 fluid-attenuated inversion recovery (FLAIR) images of brain MRI show multiple foci of diffusion restriction with FLAIR signal abnormality consistent with acute to early subacute infarcts. There was also an old lacunar infarct in left corona radiate and external capsule.

Magnetic resonance imaging (MRI) scan showing multifocal ischemic stroke. Diffusion-weighted imaging and T2 fluid-attenuated inversion recovery (FLAIR) images of brain MRI show multiple foci of diffusion restriction with FLAIR signal abnormality consistent with acute to early subacute infarcts. There was also an old lacunar infarct in left corona radiate and external capsule.

Vague symptoms turned out to be life-threatening conditions. A 50-year-old man with a history of polycythemia vera presented to the hospital with epigastric discomfort and clumsiness of the right hand for 5 days. Polycythemia vera was diagnosed 1 year prior, with good control of hematocrit by intermittent phlebotomy. He did not have any other medical history and was not taking any medications. He denied chest pain, shortness of breath, nausea, headache, vision change, or speech difficulty.

Assessment

On examination, he was in no acute distress and the vital signs were unremarkable except for increased heart rate of 119 beats per minute. Cardiovascular examination revealed regular rhythm with normal S1 and S2 sounds without murmur, rubs, or gallops. Lung fields were clear to auscultation. Laboratory investigation revealed white blood cell count of 33 × 109/L, hemoglobin of 13.5 g/dL, and platelet count of 1252 × 109/L. Noncontrast computed tomography of the head did not show intracranial hemorrhage. Troponin was elevated and electrocardiogram showed Q waves in the inferior leads and nonspecific ST-T changes. An echocardiogram showed inferior wall hypokinesis. Antiplatelet therapy was initiated with aspirin, prasugrel, and Integrilin (Merck & Co, Inc, Whitehouse Station, NJ) infusion, and troponin was trended daily. He was also initiated with hydroxyurea to reduce platelet count.

The patient reported worsening numbness and clumsiness in the right hand on day 5, and magnetic resonance imaging and magnetic resonance angiography were performed on day 7. The images showed multiple foci of cortical diffusion restriction with fluid-attenuated inversion recovery signal abnormality consistent with acute to early subacute infarcts in the bilateral frontal, parietal, and occipital lobes, and in the left cerebellum (Figure 1). The common, internal, and external carotid arteries were patent. Transesophageal echocardiogram did not demonstrate a cardiac source of emboli.

On day 10, blood count decreased to white blood cell count of 14.5 × 109/L and platelet of 669 × 109/L. Cardiac catheterization was deemed safe and he underwent coronary angiogram, which showed coronary artery disease without any obstructions.

Diagnosis

With electrocardiogram finding, elevated troponin and evidence of hypokinesis in echocardiogram, he was diagnosed with non-ST-segment elevation myocardial infarction on admission. He was also diagnosed with acute to subacute multifocal ischemic stroke from magnetic resonance imaging findings later during the hospital stay.

Polycythemia vera is one of the myeloproliferative neoplasms characterized by abnormal proliferation of hematopoietic stem cells.1 Thrombosis in polycythemia vera is not a rare event: the European Collaboration on Low-Dose Aspirin in Polycythemia Vera (ECLAP) study revealed that incidence of fatal, major and minor thrombosis was 5.5 events/100 persons per year, with myocardial infarction of 0.32 and stroke of 0.53 events/100 persons per year, respectively.2 His presentation was atypical for both myocardial infarction and ischemic stroke, and could have been missed easily. Notably, there is, to our knowledge, no report of simultaneous manifestation of these events during the course of polycythemia vera. The mechanism underlying the hemostatic imbalance in polycythemia vera is not completely understood. Clinical data have implicated that increased hematocrit, increased leukocytes, increased or activated platelets, and increased JAK2V617F allele burden are risk factors for thrombosis in polycythemia vera patients in addition to conventional risks.34567 However, the current consensus on criteria to stratify patients into high-risk category is age >60 years or with a history of thrombosis, or both. These patients are considered to benefit from cytoreduction in addition to phlebotomy, correction of cardiovascular risk factors, and low-dose aspirin.8 The treatment goal to reduce thrombotic events focuses on maintaining hematocrit <45% based on a randomized clinical trial.3 In our case, the patient fit in the low-risk category prior to the events and he was managed by phlebotomy. The hematocrit was well controlled at <45%; however, the platelet and white blood cell count were rising, with platelets exceeding 1000 × 109/L and white blood cell count >25 × 109/L (Figure 2), which, in retrospect, may have contributed to the thrombotic events.

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-Hitomi Hosoya, MD, PhD, Jeffrey J. Levine, DO, David H. Henry, MD, Sheldon Goldberg, MD

This article originally appeared in the June 2017 issue of The American Journal of Medicine.

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