Coronary microvascular dysfunction due to essential thrombocythemia and policythemia vera: the missing piece in the puzzle of their increased cardiovascular risk?

Thrombotic and hemorrhagic events in 2016 World Health Organization-defined Philadelphia-negative myeloproliferative neoplasm

BACKGROUND/AIMS

Recent changes in the diagnostic criteria for myeloproliferative neoplasms (MPNs) and increasing patient numbers necessitate updating of the data on vascular events in patients with such disorders.

METHODS

In this single-center study, thrombotic and hemorrhagic events were retrospectively analyzed in patients diagnosed with essential thrombocythemia (ET), polycythemia vera (PV) prefibrotic/early primary myelofibrosis (pre-PMF), or PMF, based on the 2016 World Health Organization diagnostic criteria.

RESULTS

Of a total of 335 consecutive patients (139 ET, 42 pre-PMF, 124 PV, and 30 PMF patients; 192 males and 143 females) of median age 64 years (range, 15 to 91), 112 (33.4%) experienced a total of 126 thrombotic events before diagnosis, at the time of diagnosis, or during follow-up over a median of 4.6 years (range, 0.1 to 26.5). Cerebrovascular thrombosis (18.8%) was the most common initial event, followed by coronary heart disease (10.1%) and splanchnic (1.5%) and peripheral thrombosis (1.5%). Arterial thrombosis was more common than venous thrombosis (31.3% vs. 2.1%, respectively; p = 0.001). Thrombosis was most frequent in PV patients (39.5%), followed by patients with pre-PMF (38.1%), ET (30.9%), and PMF (13.3%). Of the 112 patients who experienced thromboses, 53 (47%) and 39 (33.9%) had thrombotic events before and at the time of MPN diagnosis, respectively. Twenty-seven patients (8.1%) experienced 29 hemorrhagic events, of which gastrointestinal bleeding (n = 20) was the most common.

CONCLUSION

Most thrombotic events occurred before or at the time of diagnosis, and the prevalence of arterial thrombosis was markedly higher than that of venous thrombosis in patients with MPN.

The Assessment of the Platelet Function During the Acute Phase of ST-segment Elevation Myocardial Infarction in Essential Thrombocythemia

We encountered a case of ST-segment elevation myocardial infarction (STEMI) as the first clinical manifestation of essential thrombocythemia (ET). Platelet function tests revealed high thrombogenicity during primary percutaneous coronary intervention compared with general cardiovascular patients, whereas the platelet function two weeks after admission was effectively suppressed by dual antiplatelet therapy. The patient, who lacked cytoreduction, suffered from recurrent STEMI because of poor compliance with antiplatelet drugs. The risk of acute coronary occlusion may be high during the acute phase of STEMI in ET patients because of high thrombogenicity. Insufficient antiplatelet therapy and no cytoreduction are also risk factors for recurrent coronary events.

Vascular target organ damage in patients with Philadelphia negative myeloproliferative syndrome: A propensity score analysis

PURPOSE

To assess whether subjects with Philadelphia negative myeloproliferative neoplasms (Ph-MPNs) show differences in the presence of vascular, cardiac or renal target organ damage (TOD) and other vascular function parameters as compared to individuals without this condition.

METHODS

An observational study was conducted. Fifty-seven subjects diagnosed with Ph-MPNs used as cases and 114 subjects without Ph-MPNs as controls. We matched the subjects with and without Ph-MPNs using the propensity scores in a 1:2 ratio using the variables gender, type 2 diabetes mellitus, high blood pressure, hyperlipidaemia and smoking. Vascular, cardiac and renal TOD were established according to the criteria of the European Society of Hypertension and Cardiology guidelines. Arterial stiffness was also assessed using the cardio-ankle vascular index (CAVI).

RESULTS

Mean age was 63.50±11.70 and 62.90±8.32 years in subjects with and without Ph-MPNs, 32 females (56%) in the first group and 62 (54%) in the second. Subjects with Ph-MPNs have a higher percentage of carotid injury than subjects without Ph-MPNs (35.1% vs. 21.1%) and higher albumin/creatinine ratio. In the logistic regression analysis, subjects with Ph-MPNs had an OR=2.382 (IC95% 1.066-5.323) for carotid injury versus those without haematological disease.

CONCLUSIONS

Subjects with Ph-MPNs have twice the risk of by carotid injury than those without haematological disease.

The JAK-STAT pathway: an emerging target for cardiovascular disease in rheumatoid arthritis and myeloproliferative neoplasms

Inflammation contributes centrally to cardiovascular diseases, and anti-inflammatory treatments can reduce cardiovascular events. The JAK-STAT pathway is an emerging target in inflammation, mainly in rheumatoid arthritis (RA) and chronic myeloproliferative neoplasms (MPNs), disorders that heighten cardiovascular risk. The aim of this study was to review the international literature on the relationship between dysregulation of the JAK-STAT pathway in RA/MPNs and cardiovascular risk and on the potential cardiovascular effects of JAK-STAT inhibitors. The JAK-STAT pathway sustains inflammatory and thrombotic events in autoimmune disorders such as RA and MPNs. Here, an imbalance exists between pro- and anti-inflammatory cytokines [increased levels of interleukin (IL)-6, IL-1-β, tumour necrosis factor-α, decreased levels of IL-10] and the over-expression of some prothrombotic proteins, such as protein kinase Cε, on the surface of activated platelets. This pathway also operates in atherosclerotic cardiovascular disease. JAK-STAT inhibitors may reduce cardiovascular events and related deaths in such conditions, but the potential of these agents requires more studies, especially with regard to cardiovascular safety, and particularly for potential prothrombotic effects. JAK-STAT inhibitors merit consideration to curb heightened cardiovascular risk in patients with RA and MPNs, with rigorous assessment of the potential benefits and risks.

Assessment of the conjunctival microcirculation in adult patients with cyanotic congenital heart disease compared to healthy controls

PURPOSE

Congenital heart disease (CHD) is the most common live birth defect and a proportion of these patients have chronic hypoxia. Chronic hypoxia leads to secondary erythrocytosis resulting in microvascular dysfunction and increased thrombosis risk. The conjunctival microcirculation is easily accessible for imaging and quantitative assessment. It has not previously been studied in adult CHD patients with cyanosis (CCHD).

METHODS

We assessed the conjunctival microcirculation and compared CCHD patients and matched healthy controls to determine if there were differences in measured microcirculatory parameters. We acquired images using an iPhone 6s and slit-lamp biomicroscope. Parameters measured included diameter, axial velocity, wall shear rate and blood volume flow. The axial velocity was estimated by applying the 1D + T continuous wavelet transform (CWT). Results are for all vessels as they were not sub-classified into arterioles or venules.

RESULTS

11 CCHD patients and 14 healthy controls were recruited to the study. CCHD patients were markedly more hypoxic compared to the healthy controls (84% vs 98%, p = 0.001). A total of 736 vessels (292 vs 444) were suitable for analysis. Mean microvessel diameter (D) did not significantly differ between the CCHD patients and controls (20.4 ± 2.7 μm vs 20.2 ± 2.6 μm, p = 0.86). Axial velocity (Va) was lower in the CCHD patients (0.47 ± 0.06 mm/s vs 0.53 ± 0.05 mm/s, p = 0.03). Blood volume flow (Q) was lower for CCHD patients (121 ± 30pl/s vs 145 ± 50pl/s, p = 0.65) with the greatest differences observed in vessels >22 μm diameter (216 ± 121pl/s vs 258 ± 154pl/s, p = 0.001). Wall shear rate (WSR) was significantly lower for the CCHD group (153 ± 27 s^-1 vs 174 ± 22 s^-1, p = 0.04).

CONCLUSIONS

This iPhone and slit-lamp combination assessment of conjunctival vessels found lower axial velocity, wall shear rate and in the largest vessel group, lower blood volume flow in chronically hypoxic patients with congenital heart disease. With further study this assessment method may have utility in the evaluation of patients with chronic hypoxia.

Cardiovascular Safety of Anagrelide Hydrochloride versus Hydroxyurea in Essential Thrombocythaemia

Essential thrombocythaemia (ET) is a rare myeloproliferative neoplasm. This multicentre, Phase 3b, randomised, open-label, non-inferiority study investigated the cardiac safety, efficacy and tolerability of first-line treatment with anagrelide or hydroxyurea in high-risk ET patients for up to 3 years. Eligible patients aged ≥ 18 years with a diagnosis of high-risk ET confirmed by bone marrow biopsy within 6 months of randomisation received anagrelide (n = 75) or hydroxyurea (n = 74), administered twice daily. Treatment dose for either compound was titrated to the lowest dose needed to achieve a response. Planned primary outcome measures were change in left ventricular ejection fraction from baseline over time and platelet count at Month 6. Planned secondary outcome measures were platelet count change from baseline at Months 3 and 36; percentage of patients with complete or partial response; time to complete or partial response; number of patients with thrombohaemorrhagic events; and changes in white blood cell count or red blood cell count over time. Neither treatment altered cardiac function. There were no significant differences in adverse events between treatment groups, and no reports of malignant transformation. The incidence of disease-related thrombotic or haemorrhagic events was numerically higher in anagrelide-treated patients. Both treatments controlled platelet counts at 6 months, with the majority of patients experiencing complete or partial responses. In conclusion, these results suggest that long-term treatment with anagrelide is not associated with adverse effects on cardiac function. This is one of the few studies using left ventricular ejection fraction assessment and central biopsy reading to confirm the diagnosis of ET.

Trial registration number: Clinicaltrials.gov NCT00202644

Vascular toxic effects of cancer therapies

Cancer therapies can lead to a broad spectrum of cardiovascular complications. Among these, cardiotoxicities remain of prime concern, but vascular toxicities have emerged as the second most common group. The range of cancer therapies with a vascular toxicity profile and the clinical spectrum of vascular toxic effects are quite broad. Historically, venous thromboembolism has received the greatest attention but, over the past decade, the arterial toxic effects, which can present as acute vasospasm, acute thrombosis and accelerated atherosclerosis, of cancer therapies have gained greater recognition. This Review focuses on these types of cancer therapy-related arterial toxicity, including their mechanisms, and provides an update on venous thromboembolism and pulmonary hypertension associated with cancer therapies. Recommendations for the screening, treatment and prevention of vascular toxic effects of cancer therapies are outlined in the context of available evidence and society guidelines and consensus statements. The shift towards greater awareness of the vascular toxic effects of cancer therapies has further unveiled the urgent needs in this area in terms of defining best clinical practices. Well-designed and well-conducted clinical studies and registries are needed to more precisely define the incidence rates, risk factors, primary and secondary modes of prevention, and best treatment modalities for vascular toxicities related to cancer therapies. These efforts should be complemented by preclinical studies to outline the pathophysiological concepts that can be translated into the clinic and to identify drugs with vascular toxicity potential even before their widespread clinical use.

What cardiologists should know about essential thrombocythemia and acute myocardial infarction: report of two cases and advanced heart failure therapies considerations

We present the cases of two young male patients aged 22 and 31 without prior medical history nor cardiovascular risk factors, who presented to the hospital with large anterior ST-elevation myocardial infarction (STEMI). Urgent coronary angiography revealed acute thrombotic occlusion of the proximal left anterior descending artery in both patients. Persistent thrombocytosis was noted and subsequent investigations led to the diagnosis of essential thrombocythemia (ET) with positive JAK2-V617F mutation. Myocardial infarction as a first clinical manifestation of ET is rare but must be considered in patients without cardiovascular risk factors who show persistent thrombocytosis. In young patients without risk factors, there may be great delays before the diagnosis of STEMI is made. Longer time to revascularization of extensive STEMI is associated with adverse outcomes and cardiogenic shock which can lead to advanced therapies like heart transplant and left ventricular assist device (LVAD). Considering the favorable long-term prognosis of patients with ET, advanced therapies may be a valuable option in the presence of severe left ventricular dysfunction.

Do we need antiplatelet therapy in thrombocytosis? Pro

Thrombocytosis (defined as platelets >450 × 109/l) has several aetiologies. After having excluded spurious thrombocytosis (e. g., due to microspherocytes, schistocytes, cryoglobulins, or bacteria), the differential diagnosis of true thrombocytosis encompasses secondary causes (as diverse as inflammation, infection, malignancy, iron deficiency, or asplenia), primary hereditary (rare forms of familial thrombocytosis) and primary acquired entities (either in the context of a myelodys-plastic syndrome or more frequently a myeloproliferative neoplasia). This manuscript addresses the following aspects: 1) diagnostic approach to thrombocytosis; 2) various mechanisms leading to a high platelet count; 3) potential of some of these mechanisms to modulate platelet function, producing hyper-reactive platelets and thus exerting a direct impact on the thrombotic risk; 4) indication of anti-thrombotic treatment in patients with thrombocytosis. There is a single prospective randomized clinical trial showing the benefit of acetyl-salicylic acid in polycythaemia vera. For other types of primary thrombocytosis and for secondary forms, treatment decisions have to be individualized according to the patient thrombotic and bleeding risks, taking into account the mechanism causing thrombocytosis. This manuscript discusses experimental and clinical data suggesting that besides patients with essential thrombocythaemia and other forms of primary thrombocytosis also those with thrombocytosis in the context of chronic inflammation, malignancy, or exposure to high altitude might benefit from anti-platelet treatment.

Coronary Microvascular Dysfunction - Epidemiology, Pathogenesis, Prognosis, Diagnosis, Risk Factors and Therapy

Angina has traditionally been thought to be caused by obstructive coronary artery disease (CAD). However, a substantial number of patients with angina are found to not have obstructive CAD when undergoing coronary angiography. A significant proportion of these patients have coronary microvascular dysfunction (CMD), characterized by heightened sensitivity to vasoconstrictor stimuli and limited microvascular vasodilator capacity. With the advent of non-invasive and invasive techniques, the coronary microvasculature has been more extensively studied in the past 2 decades. CMD has been identified as a cause of cardiac ischemia, in addition to traditional atherosclerotic disease and vasospastic disease. CMD can occur alone or in the presence obstructive CAD. CMD shares many similar risk factors with macrovascular CAD. Diagnosis is achieved through detection of an attenuated response of coronary blood flow in response to vasodilatory agents. Imaging modalities such as cardiovascular magnetic resonance, positron emission tomography, and transthoracic Doppler echocardiography have become more widely used, but have not yet completely replaced the traditional intracoronary vasoreactivity testing. Treatment of CMD starts with lifestyle modification and risk factor control. The use of traditional antianginal, antiatherosclerotic medications and some novel agents may be beneficial; however, clinical trials are needed to assess the efficacy of the pharmacologic and non-pharmacologic therapeutic modalities. In addition, studies with longer-term follow-up are needed to determine the prognostic benefits of these agents. We review the epidemiology, prognosis, pathogenesis, diagnosis, risk factors and current therapies for CMD.

Coronary Microvascular Function and Beyond: The Crosstalk between Hormones, Cytokines, and Neurotransmitters

Beyond its hemodynamic function, the heart also acts as a neuroendocrine and immunoregulatory organ. A dynamic communication between the heart and other organs takes place constantly to maintain cardiovascular homeostasis. The current understanding highlights the importance of the endocrine, immune, and nervous factors to fine-tune the crosstalk of the cardiovascular system with the entire body. Once disrupted, this complex interorgan communication may promote the onset and the progression of cardiovascular diseases. Thus, expanding our knowledge on how these factors influence the cardiovascular system can lead to novel therapeutic strategies to improve patient care. In the present paper, we review novel concepts on the role of endocrine, immune, and nervous factors in the modulation of microvascular coronary function.