Progression of coronary calcium burden and carotid stiffness in patients with essential thrombocythemia associated with JAK2 V617F mutation

Relation of JAK2 V617F allele burden and coronary calcium score in patients with essential thrombocythemia

BACKGROUND

JAK2 V617F (JAK2) mutation is associated with clonal hemopoiesis in myeloproliferative neoplasms as well as with faster progression of cardiovascular diseases. Little is known about the relationship between allele burden and the degree of atherosclerotic alteration of coronary vasculature. We previously reported that carotid artery stiffness progressed faster in patients with JAK2 positive essential thromocythemia (ET) patients. After a four-year follow-up we investigated whether mutation burden of a JAK2 allele correlates with a higher coronary calcium score.

PATIENTS AND METHODS

Thirty-six patients with JAK2 positive ET and 38 healthy matched control subjects were examined twice within four years. At each visit clinical baseline characteristics and laboratory testing were performed, JAK2 mutation burden was determined, and coronary calcium was measured.

RESULTS

JAK2 allele burden decreased in 19 patients, did not change in 5 patients, and increased in 4 patients. The coronary calcium Agatston score increased slightly in both groups. Overall, there was no correlation between JAK2 allele burden and calcium burden of coronary arteries. However, in patients with the JAK2 mutation burden increase, the coronary calcium score increased as well.

CONCLUSIONS

The average JAK2 allele burden decreased in our patients with high-risk ET during the four-year period. However, in the small subgroup whose JAK2 mutation burden increased the Agatston coronary calcium score increased as well. This finding, which should be interpreted with caution and validated in a larger group, is in line with emerging evidence that JAK2 mutation accelerates atherosclerosis and can be regarded as a non-classical risk factor for cardiovascular disease.

Cardiovascular Risk in Philadelphia-Negative Myeloproliferative Neoplasms: Mechanisms and Implications-A Narrative Review

Myeloproliferative neoplasms (MPNs), encompassing disorders like polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (PMF), are characterized by clonal hematopoiesis without the Philadelphia chromosome. The JAK2 V617F mutation is prevalent in PV, ET, and PMF, while mutations in MPL and CALR also play significant roles. These conditions predispose patients to thrombotic events, with PMF exhibiting the lowest survival among MPNs. Chronic inflammation, driven by cytokine release from aberrant leukocytes and platelets, amplifies cardiovascular risk through various mechanisms, including atherosclerosis and vascular remodeling. Additionally, MPN-related complications like pulmonary hypertension and cardiac fibrosis contribute to cardiovascular morbidity and mortality. This review consolidates recent research on MPNs' cardiovascular implications, emphasizing thrombotic risk, chronic inflammation, and vascular stiffness. Understanding these associations is crucial for developing targeted therapies and improving outcomes in MPN patients.

Overview of dyslipidemia and metabolic syndrome in myeloproliferative neoplasms

Myeloproliferative neoplasms (MPNs) occur due to the abnormal proliferation of one or more terminal myeloid cell lines in peripheral blood. Subjects suffering from MPNs display a high burden of cardiovascular risk factors, and thrombotic events are often the cause of death in this population of patients. Herein, we provide a brief overview of dyslipidemia and metabolic syndrome and their epidemiology in MPNs and examine the common molecular mechanisms between dyslipidemia, metabolic syndrome, and MPNs, with a special focus on cardiovascular risk, atherosclerosis, and thrombotic events. Furthermore, we investigate the impact of dyslipidemia and metabolic syndrome on the occurrence and survival of thrombosis in MPN patients, as well as the management of dyslipidemia in MPNs, and the impact of MPN treatment on serum lipid concentrations, particularly as side/adverse effects reported in the context of clinical trials.

Higher platelet count, even within normal range, is associated with increased arterial stiffness in young and middle-aged adults

Background: Platelet counts and mean platelet volume (MPV) are related to cardiovascular disease, but a thorough investigation into the connection between increased arterial stiffness, MPV, and platelet counts is lacking. This study aimed to explore the association of platelet count and MPV with arterial stiffness in young and middle-aged adults.

Methods: A total of 2464 participants who underwent health checkups at National Cheng Kung University Hospital, Taiwan from November 2018 to December 2019 were included. We excluded participants aged <18 or >50 years; who are pregnant; on medication for dyslipidemia; with abnormal platelet count, incomplete data, and past history of hematologic disorders. We examined the association of platelet counts and MPV values with brachial-ankle pulse wave velocity (baPWV) levels and increased arterial stiffness.

Results: Platelet count was significantly higher in participants with increased arterial stiffness than in those without. The multiple linear regression model revealed that platelet counts were positively associated with baPWV levels (β = 1.88, 95% confidence interval (CI): 0.96 to 2.80). In the binary logistic regression analysis, subjects in the higher platelet counts quartiles had a higher risk of developing increased arterial stiffness (Q2 vs. Q1: odds ratio (OR): 1.54, 95% CI: 1.05 to 2.27; Q3 vs. Q1: OR: 1.57, 95% CI: 1.06 to 2.33; and Q4 vs. Q1: OR: 2.23, 95% CI: 1.50 to 3.30). In contrast, MPV levels were not associated with arterial stiffness.

Conclusions: Platelet count in midlife was positively associated with baPWV levels. Participants in higher platelet quartiles were at risk for increased arterial stiffness.

Coronary artery- and aortic valve calcifications in patients with Philadelphia-negative myeloproliferative neoplasms

BACKGROUND

Patients with the hematological cancers Philadelphia-negative Myeloproliferative Neoplasms (MPNs) have an increased risk of cardiovascular disease. However, whether MPNs have an increased burden of cardiac calcification has not been thoroughly investigated. Our aim is to investigate whether patients with MPNs have an increased burden of cardiac calcification that could help explain their increased risk of cardiovascular disease.

METHODS AND RESULTS

We recruited 161 patients (mean age 65 years, 52% men) with an MPN diagnosis between 2016 and 2018. Coronary artery calcium score (CACS) and aortic valve calcification (AVC) were measured by cardiac computer tomography, and detailed information on cardiovascular risk factors was recorded. MPNs were matched on age and sex, with 805 controls from the Copenhagen General Population Study. A CACS>400 was present in 26% of MPNs and 19% of controls (p = 0.031). AVC was present in 58% of MPNs and 34% of controls (p < 0.0001). After adjustment for cardiovascular risk factors, the odds ratio (OR) of a CACS>400 was 1.9 (95% CI 1.2-3.1, p = 0.008) in MPNs compared to controls, and the OR of AVC was 4.4 (95% CI 2.9-6.9, p < 0.0001) in MPNs compared to controls.

CONCLUSION

Patients with MPNs have a significantly higher prevalence of a CACS >400 and AVC, compared to controls from the general population. The association between MPN and a CACS>400 or AVC remains significant after adjustment for cardiovascular risk factors. These novel data support the hypothesis that MPNs have an increased burden of cardiac calcifications, independent of other cardiovascular risk factors.

Cardiovascular Disease in Myeloproliferative Neoplasms: JACC: CardioOncology State-of-the-Art Review

Myeloproliferative neoplasms are associated with increased risk for thrombotic complications. These conditions most commonly involve somatic mutations in genes that lead to constitutive activation of the Janus-associated kinase signaling pathway (eg, Janus kinase 2, calreticulin, myeloproliferative leukemia protein). Acquired gain-of-function mutations in these genes, particularly Janus kinase 2, can cause a spectrum of disorders, ranging from clonal hematopoiesis of indeterminate potential, a recently recognized age-related promoter of cardiovascular disease, to frank hematologic malignancy. Beyond thrombosis, patients with myeloproliferative neoplasms can develop other cardiovascular conditions, including heart failure and pulmonary hypertension. The authors review the pathophysiologic mechanisms of cardiovascular complications of myeloproliferative neoplasms, which involve inflammation, prothrombotic and profibrotic factors (including transforming growth factor-beta and lysyl oxidase), and abnormal function of circulating clones of mutated leukocytes and platelets from affected individuals. Anti-inflammatory therapies may provide cardiovascular benefit in patients with myeloproliferative neoplasms, a hypothesis that requires rigorous evaluation in clinical trials.

LPA Genotypes and Haplotypes Are Associated with Lipoprotein(a) Levels but Not Arterial Wall Properties in Stable Post-Coronary Event Patients with Very High Lipoprotein(a) Levels

Lipoprotein(a) [Lp(a)] levels are an independent risk factor for coronary artery disease (CAD). Two single-nucleotide polymorphisms (rs10455872, rs3798220) and number of KIV-2 repeats in the gene encoding Lp(a) (LPA) are associated with Lp(a) and CAD. Our aim was to investigate whether in patients with stable CAD and high Lp(a) levels these genetic variants are associated with increased Lp(a) and arterial wall properties. Blood samples underwent biochemical and genetic analyses. Ultrasound measurements for the functional and morphological properties of arterial wall were performed. Genotypes of rs10455872 and haplotypes AT and GT showed significant association with Lp(a) levels. Patients with GG showed significantly higher Lp(a) levels compared with those with AG genotype (2180 vs. 1391 mg/L, p = 0.045). Patients with no AT haplotype had significantly higher Lp(a) compared to carriers of one AT haplotype (2158 vs. 1478 mg/L, p = 0.023) or two AT haplotypes (2158 vs. 1487 mg/L, p = 0.044). There were no significant associations with the properties of the arterial wall. Lp(a) levels significantly correlated also with number of KIV-2 repeats (r = -0.601; p < 0.0001). In our patients, these two LPA polymorphisms and number of KIV-2 repeats are associated with Lp(a), but not arterial wall properties.