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Introduction The relationship of venous thromboembolism (VTE) with platelet reactivity is unclear. Platelet function plays a key role in arterial thrombosis. Evidence suggests antiplatelet agents also effects in reducing VTE. Our aim is to describe the role of baseline platelet function in development of VTE in the community-based Framingham Heart Study (FHS) cohort. Materials and methods Participants in the Framingham Offspring cohort fifth examination and Omni cohort first examination were eligible. We used light transmission aggregometry to measure platelet aggregation in response to collagen and a range of ADP and epinephrine doses. The study population consisted of 2831 participants [average age 54.3 years; 57% female]. Results and conclusions During a median follow-up of 20.4 years, we observed 138 incident VTE events. In age-, sex- and cohort-adjusted analysis an increase in collagen lag time was associated with increased risk for incident VTE (HR 1.01 [1.00–1.02]; p = 0.049). Increased maximal aggregation to low dose epinephrine (1.0 μM) was associated with lower VTE risk (HR 0.84 [0.71–0.99]; p = 0.042]). However, additional multivariable analyses attenuated the collagen-VTE and epinephrine-VTE associations to trends, primarily due to adjustment for baseline body mass index (BMI), a VTE risk factor and potential modifier of platelet function. Secondary analyses considering varying follow-up periods, cancer incidence and interim aspirin use did not dramatically affect the collagen and epinephrine trends observed. Baseline platelet aggregability was only weakly associated with incident VTE, and in a paradoxical direction, in a community-based population. Other markers of platelet function and hemostasis could prove to be more useful predictors. [ABSTRACT FROM AUTHOR]

Background &objectives Venous and arterial thrombosis share common pathophysiology. Multiple biomarkers reflecting various biological pathways can predict arterial thrombosis. We studied whether this approach could identify persons at risk of first venous thromboembolism (VTE). [ABSTRACT FROM AUTHOR]

Background Reports of the crude incidence of venous thromboembolism (VTE) in Western countries vary widely. Data regarding risk factors, incidence and recurrence of VTE from deeply-phenotyped community-based cohort studies are needed. Objectives To study the incidence, associated mortality, and predisposing factors of VTE in the prospective, longitudinal community-based Framingham Heart Study. Patients/Methods The study sample consisted of the Framingham Heart Study Original, Offspring, Third Generation, and Omni cohorts (N = 9754). Incidence rates (IR) were standardized to the 2000 US population. Cox proportional hazards regression models were used to study risk factor associations. Results During 1995–2014 (total follow-up time 104,091 person-years [median 9.8 (range 0–20) years]), 297 incident VTE events were observed. Age-adjusted IR of VTE was 20.3/10,000 (95% CI 17.9–22.6). Of the events 120 (40%) were pulmonary embolism (PE) and 177 (60%) were deep venous thrombosis (DVT); 29% were unprovoked, 40% provoked, and 31% cancer-related. Cancer-related VTE was associated with high mortality at 30 days (24.2%), 1 year (66.3%), and 5 years (75.6%). In multivariable models, age and obesity, but no other traditional cardiovascular risk factors, were significantly associated with VTE (hazard ratio [HR] per 10-year increase in age 1.69, 95% CI 1.48–1.92; HR for obesity (BMI ≥ 30 kg/m 2 ) 1.88, 95% CI 1.44–2.45). Conclusions We provide data on the epidemiology of VTE. VTE is associated with significant mortality, and prognosis after cancer-related VTE is particularly poor. Traditional cardiovascular risk factors beyond age and obesity are not associated with VTE. [ABSTRACT FROM AUTHOR]

Abstract: Introduction: CHADS2 and CHA2DS2-VASc scores are used to estimate thromboembolic risk in atrial fibrillation (AF). HAS-BLED is recommended for bleeding risk prediction. Their value in predicting the outcome of AF patients after percutaneous coronary intervention (PCI) is unknown. Thus, our aim was to assess whether these simple risk scores are useful in predicting outcome in these patients. Materials and Methods: AFCAS is an observational, multicenter, prospective registry including patients (n=929) with AF referred for PCI. Primary study endpoints were 1) all cause mortality; 2) major adverse events (all-cause mortality, myocardial infarction, repeat revascularization, stent thrombosis, transient ischemic attack, stroke or other arterial thromboembolism; MACCE); and 3) bleeding at 12 months follow-up. CHADS2 and CHA2DS2-VASc scores and a modified HAS-BLED (mHAS-BLED) score (omitting labile INR and liver function) were calculated. Results: Patients were distributed as follows: CHADS2 low 29.5%, intermediate 55.2%, high 15.3%; CHA2DS2-VASc low 9.6%, intermediate 46.0%, high 44.5%. A high CHA2DS2−VASc score was predictive of all-cause mortality (p=0.02), whereas CHADS2 was not. High CHA2DS2-VASc score predicted MACCE (HR 2.24, 95%CI 1.21-4.17, p=0.01), as did a high CHADS2 score (HR 1.60, 95%CI 1.05-2.45, p=0.029). Their predictive performance was only modest (C indexes 0.56-0.57). CHADS2 or CHA2DS2-VASc scores were not associated with bleeding. High mHAS-BLED scores (≥3) were not associated with any of the study outcomes. Conclusions: High CHA2DS2-VASc score was the best predictor of thrombotic outcomes after PCI in a high risk AF population. High mHAS-BLED score was not predictive of bleeding events. More accurate, simple risk scores are needed. [Copyright &y& Elsevier]

Background: Renal impairment is a well-known risk factor for cardiovascular complications, but the effect of different stages of renal impairment on thrombotic/thromboembolic and bleeding complications in patients with atrial fibrillation (AF) undergoing percutaneous coronary intervention (PCI) remains largely unknown. We sought to evaluate the incidence and clinical impact of four stages of renal impairment in patients with AF undergoing PCI. Methods: We assessed renal function by estimated glomerular filtration rate (eGFR) and outcomes in 781 AF patients undergoing PCI by using the data from a prospective European multicenter registry. End-points included all-cause mortality, major adverse cardiac and cerebrovascular events (MACCE) and bleeding events at 12 months. Results: A total of 195 (25%) patients had normal renal function (eGFR ≥90 mL/min), 290 (37%) mild renal impairment (eGFR 60-89), 263 (34%) moderate renal impairment (eGFR 30–59) and 33 (4%) severe renal impairment (eGFR <30). Degree of renal impairment remained an independent predictor of mortality and MACCE in an adjusted a Cox regression model. Even patients with mild renal impairment had a higher risk of all-cause mortality (HR 2.25, 95%CI 1.02-4.98, p=0.04) and borderline risk for MACCE (HR 1.56, 95%CI 0.98- 2.50, p=0.06) compared to those with normal renal function. Conclusions: Renal impairment is common in patients with AF undergoing PCI and even mild renal impairment has an adverse prognostic effect in these patients requiring multiple antithrombotic medications. [ABSTRACT FROM AUTHOR]

The development of therapeutics depends on predictions of clinical activity from pre-clinical data. We have previously described SYNB1618, an engineered bacterial therapeutic (synthetic biotic) for the treatment of Phenylketonuria (PKU), a rare genetic disease that leads to accumulation of plasma phenylalanine (Phe) and severe neurological complications. SYNB1618 consumes Phe in preclinical models, healthy human volunteers, and PKU patients. However, it remains unclear to what extent Phe consumption by SYNB1618 in the gastrointestinal tract lowers plasma Phe levels in PKU patients. Here, we construct a mechanistic model that predicts SYNB1618 function in non-human primates and healthy subjects by combining in vitro simulations and prior knowledge of human physiology. In addition, we extend a model of plasma Phe kinetics in PKU patients, in order to estimate plasma Phe lowering by SYNB1618. This approach provides a framework that can be used more broadly to define the therapeutic potential of synthetic biotics. Mark Charbonneau et al. develop a mathematical model that describes the behavior of an engineered bacterial therapeutic, SYNB1618, in the human gastrointestinal tract and its effects on plasma phenylalanine (Phe) levels. This model enables the authors to predict plasma Phe lowering by SYNB1618 in patients with phenylketonuria. [ABSTRACT FROM AUTHOR]

INTRODUCTION: Ammonia levels are used to assess hepatic encephalopathy, but their levels are highly variable in clinical practice. METHODS: We studied factors associated with variation in ammonia values in cirrhotic patients without previous hepatic encephalopathy and healthy volunteers (HVs). RESULTS: Ammonia increased by 12% and 18% at 1 and 2 hour, respectively, after a protein meal in 64 cirrhotic patients (P < 0.001). In 237 HVs, ammonia levels varied significantly between sites (P < 0.0001). New site-specific ammonia upper limits based on HV levels using a strict analysis protocol differed from routinely used values. Correlation between paired fresh samples was high (r = 0.83) but modest between fresh and frozen samples (r = 0.62). DISCUSSION: Sample handling, processing, and protein intake impact ammonia levels across sites. [ABSTRACT FROM AUTHOR]

Alleles associated with lower levels of LDL cholesterol (LDL-C) have recently been associated with an increased risk of type 2 diabetes (T2D), highlighting the complex relationship between LDL-C and diabetes. This observation begs the question of whether LDL-C-raising alleles are associated with a decreased risk of T2D. This issue was recently addressed in a large familial hypercholesterolemia (FH) screening study, which reported a lower prevalence of self-reported diabetes in FH subjects than in age-matched relatives without FH. To extend this observation, we tested the association of FH with diabetes status and glycemia in a large Amish population enriched for the FH-associated APOB R3527Q variant that included 640 APOB R3527Q carriers and 4,683 noncarriers. Each copy of the R3527Q T allele was associated with a 74.9 mg/dL increase in LDL-C. There was little difference in T2D prevalence between subjects with (5.2%) and without (4.5%) the R3527Q allele (P = 0.23), and there was no association between R3527Q variant and impaired fasting glucose, fasting glucose or insulin, or oral glucose tolerance test-derived measures. Our data provide no evidence supporting an association between the APOB R3527Q variant and T2D or glycemia and highlight the asymmetry of the LDL-C-T2D relationship and/or the gene/variant-dependent specificity of the LDL-C-T2D association. [ABSTRACT FROM AUTHOR]