GENETIC DETERMINANTS OF THROMBOSIS.

Venous thromboembolism (VTE) is a major cause of morbidity and mortality in the United States. VTE is caused by genetic and acquired conditions, but the genetic variants that increase the risk of VTE are not fully characterized. Recent genome-wide association studies (GWAS) have discovered novel genetic loci linked to VTE.

Effect of the P-Selectin Inhibitor Crizanlizumab on Survival Free of Organ Support in Patients Hospitalized for COVID-19: A Randomized Controlled Trial.

Background: COVID-19 has been associated with endothelial injury, resultant microvascular inflammation and thrombosis. Activated endothelial cells release and express P-selectin and von Willebrand factor, both of which are elevated in severe COVID-19 and may be implicated in the disease pathophysiology. We hypothesized that crizanlizumab, a humanized monoclonal antibody to P-selectin, would reduce morbidity and death in patients hospitalized for COVID-19.

Dyslipidemia.

Dyslipidemia is an important risk factor for coronary artery disease and stroke. All persons with dyslipidemia should be advised to focus on lifestyle interventions, including regular aerobic exercise, a healthy diet, maintenance of a healthy weight, and abstinence from smoking. In addition to lifestyle interventions, lipid-lowering therapy should be considered for persons at moderate to high risk for atherosclerotic cardiovascular disease based on validated risk equations.

Cardiac pericytes mediate the remodeling response to myocardial infarction.

Despite the prevalence of pericytes in the microvasculature of the heart, their role during ischemia-induced remodeling remains unclear. We used multiple lineage-tracing mouse models and found that pericytes migrated to the injury site and expressed profibrotic genes, coinciding with increased vessel leakage after myocardial infarction (MI). Single-cell RNA-Seq of cardiac pericytes at various time points after MI revealed the temporally regulated induction of genes related to vascular permeability, extracellular matrix production, basement membrane degradation, and TGF-β signaling.

High risk oral contraceptive hormones do not directly enhance endothelial cell procoagulant activity in vitro.

Background: Oral contraceptive (OC) use increases venous thromboembolism risk 2-5-fold. Procoagulant changes can be detected in plasma from OC users even without thrombosis, but cellular mechanisms that provoke thrombosis have not been identified. Endothelial cell (EC) dysfunction is thought to initiate venous thromboembolism.

Markers of endothelial cell activation are associated with the severity of pulmonary disease in COVID-19.

Severe coronavirus disease-19 (COVID-19) is characterized by vascular inflammation and thrombosis. We and others have proposed that the inflammatory response to coronavirus infection activates endothelial cells, leading to endothelial release of pro-thrombotic proteins. These mediators can trigger obstruction of the pulmonary microvasculature, leading to worsening oxygenation, acute respiratory distress syndrome, and death.

Platelet olfactory receptor activation limits platelet reactivity and growth of aortic aneurysms.

As blood transitions from steady laminar flow (S-flow) in healthy arteries to disturbed flow (D-flow) in aneurysmal arteries, platelets are subjected to external forces. Biomechanical platelet activation is incompletely understood and is a potential mechanism behind antiplatelet medication resistance. Although it has been demonstrated that antiplatelet drugs suppress the growth of abdominal aortic aneurysms (AAA) in patients, we found that a certain degree of platelet reactivity persisted in spite of aspirin therapy, urging us to consider additional antiplatelet therapeutic targets.

Effect of Crizanlizumab, a P-Selectin Inhibitor, in COVID-19: A Placebo-Controlled, Randomized Trial.

COVID-19 is characterized by vascular inflammation and thrombosis, including elevations in P-selectin, a mediator of inflammation released by endothelial cells. We tested the effect of P-selectin inhibition on biomarkers of thrombosis and inflammation in patients with COVID-19. Hospitalized patients with moderate COVID-19 were randomly assigned to receive either placebo or crizanlizumab, a P-selectin inhibitor, in a double-blind fashion.

Estrogen activates endothelial exocytosis.

Estrogen therapy is used to treat patients with post-menopausal symptoms, such as hot flashes and dyspareunia. Estrogen therapy also decreases the risk of fractures from osteoporosis in post-menopausal women. However, estrogen increases the risk of venous thromboembolic events, such as pulmonary embolism, but the pathways through which estrogen increase the risk of thromboembolism is unknown.

Myocardial Injury in Severe COVID-19 Compared With Non-COVID-19 Acute Respiratory Distress Syndrome.

Background: Knowledge gaps remain in the epidemiology and clinical implications of myocardial injury in coronavirus disease 2019 (COVID-19). We aimed to determine the prevalence and outcomes of myocardial injury in severe COVID-19 compared with acute respiratory distress syndrome (ARDS) unrelated to COVID-19.

Methods: We included intubated patients with COVID-19 from 5 hospitals between March 15 and June 11, 2020, with troponin levels assessed.

Do-Not-Resuscitate Status and Risk-Standardized Mortality and Readmission Rates Following Acute Myocardial Infarction.

Background Important administrative-based measures of hospital quality, including those used by Centers for Medicare and Medicaid Services, may not adequately account for patient illness and social factors that vary between hospitals and can strongly affect outcomes. Do-not-resuscitate (DNR) order on admission (within the first 24 hours) is one such factor that may reflect higher preadmission illness burden as well as patients' desire for less-intense therapeutic interventions and has been shown to vary widely between hospitals. We sought to evaluate how accounting for early DNR affected hospital quality measures for acute myocardial infarction.

Acetylcholine Inhibits Platelet Activation.

Platelets are key mediators of thrombosis. Many agonists of platelet activation are known, but fewer endogenous inhibitors of platelets, such as prostacyclin and nitric oxide (NO), have been identified. Acetylcholinesterase inhibitors, such as donepezil, can cause bleeding in patients, but the underlying mechanisms are not well understood.

Impact of non-cardiovascular disease burden on thirty-day hospital readmission in heart failure patients.

Background: Little is known about the impact of non-cardiovascular disease (CVD) burden on 30- -day readmission in heart failure (HF) patients. The aim of the study was to assess the role of non-CVD burden on 30-day readmission in HF patients. \ METHODS: We analyzed the effect of non-CVD burden by frequency of ICD-9 code categories on readmis-sions of patients discharged with a primary diagnosis of HF.

New vascular insights into premature aging.

Hutchinson-Gilford progeria syndrome (HGPS) is a fatal disease characterized by premature aging in which young children fail to thrive and adolescents die from myocardial infarction or stroke. The pathogenesis of HGPS is studied intensively because the mechanisms of premature aging may lead to a better understanding of normal aging. In this issue of the JCI, Osmanagic-Myers and colleagues identify the cellular mechanisms that lead to vascular abnormalities and death in children with HGPS.