60 research outputs found

    Platelet Function in Patients with Diabetes Mellitus: From a Theoretical to a Practical Perspective

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    Patients with diabetes mellitus have an increased prevalence of vascular disease. Pathologic thrombosis associated with atherosclerotic plaque rupture is a major cause of morbidity and mortality. Platelets are intimately involved in the initiation and propagation of thrombosis. Evidence suggests that platelets from patients with type 2 diabetes have increased reactivity and baseline activation compared to healthy controls. We review the pathophysiology of platelet hyperreactivity in DM patients and its implications in clinical practice, with particular focus on acute coronary syndromes, percutaneous coronary intervention, and novel antiplatelet agents

    Risk Factors for Nonplatelet Thromboxane Generation After Coronary Artery Bypass Graft Surgery

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    BACKGROUND: Persistent thromboxane (TX) generation while receiving aspirin therapy is associated with an increased risk of cardiovascular events. The Reduction in Graft Occlusion Rates (RIGOR) study found that aspirin-insensitive TXA2 generation, indicated by elevated urine 11-dehydro-TXB2 (UTXB2) 6 months after coronary artery bypass graft surgery, was a potent risk factor for vein graft thrombosis and originated predominantly from nonplatelet sources. Our goal was to identify risks factors for nonplatelet TXA2 generation. METHODS AND RESULTS: Multivariable modeling was performed by using clinical and laboratory variables obtained from 260 RIGOR subjects with verified aspirin-mediated inhibition of platelet TXA2 generation. The strongest variable associated with UTXB2 6 months after surgery, accounting for 47.2% of the modeled effect, was urine 8-iso-prostaglandin (PG)F2alpha, an arachidonic acid metabolite generated nonenzymatically by oxidative stress (standardized coefficient 0.442, P \u3c 0.001). Age, sex, race, lipid therapy, creatinine, left ventricular ejection fraction, and aspirin dose were also significantly associated with UTXB2 (P \u3c 0.03), although they accounted for only 4.8% to 10.2% of the modeled effect. Urine 8-iso-PGF2alpha correlated with risk of vein graft occlusion (odds ratio 1.67, P=0.001) but was not independent of UTXB2. In vitro studies revealed that endothelial cells generate TXA2 in response to oxidative stress and direct exposure to 8-iso-PGF2alpha. CONCLUSIONS: Oxidative stress-induced formation of 8-iso-PGF2alpha is strongly associated with nonplatelet thromboxane formation and early vein graft thrombosis after coronary artery bypass graft surgery. The endothelium is potentially an important source of oxidative stress-induced thromboxane generation. These findings suggest therapies that reduce oxidative stress could be useful in reducing cardiovascular risks associated with aspirin-insensitive thromboxane generation

    Differential Impact of Serial Measurement of Nonplatelet Thromboxane Generation on Long-Term Outcome After Cardiac Surgery.

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    BACKGROUND: Systemic thromboxane generation, not suppressible by standard aspirin therapy and likely arising from nonplatelet sources, increases the risk of atherothrombosis and death in patients with cardiovascular disease. In the RIGOR (Reduction in Graft Occlusion Rates) study, greater nonplatelet thromboxane generation occurred early compared with late after coronary artery bypass graft surgery, although only the latter correlated with graft failure. We hypothesize that a similar differential association exists between nonplatelet thromboxane generation and long-term clinical outcome. METHODS AND RESULTS: Five-year outcome data were analyzed for 290 RIGOR subjects taking aspirin with suppressed platelet thromboxane generation. Multivariable modeling was performed to define the relative predictive value of the urine thromboxane metabolite, 11-dehydrothromboxane B CONCLUSIONS: Long-term nonplatelet thromboxane generation after coronary artery bypass graft surgery is a novel risk factor for 5-year adverse outcome, including death. In contrast, nonplatelet thromboxane generation in the early postoperative period appears to be driven predominantly by inflammation and did not independently predict long-term clinical outcome

    A randomized, double-blind, placebo-controlled trial of Ad5FGF-4 gene therapy and its effect on myocardial perfusion in patients with stable angina

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    AbstractObjectivesThe primary objective of this study was to determine whether intracoronary administration of the adenoviral gene for fibroblast growth factor (Ad5FGF-4) can improve myocardial perfusion compared with placebo.BackgroundAnimal studies and observational clinical studies have shown improvement in perfusion of the ischemic myocardium using genes encoding angiogenic growth factors; however, randomized, double-blind data in humans are lacking.MethodsWe performed a randomized, double-blind, placebo-controlled trial of intracoronary injection of 1010adenoviral particles containing a gene encoding fibroblast growth factor (Ad5FGF-4) to determine the effect on myocardial perfusion. Fifty-two patients with stable angina and reversible ischemia comprising >9% of the left ventricle on adenosine single-photon emission computed tomography (SPECT) imaging were randomized to gene therapy (n = 35) or placebo (n = 17). Clinical follow-up was performed, and 51 (98%) patients underwent a second adenosine SPECT scan after 8 weeks.ResultsOverall (n = 52), the mean total perfusion defect size at baseline was 32.4% of the left ventricle, with 20% reversible ischemia and 12.5% scar. At eight weeks, Ad5FGF-4 injection resulted in a significant reduction of ischemic defect size (4.2% absolute, 21% relative; p < 0.001) and placebo-treated patients had no improvement (p = 0.32). Although the change in reversible perfusion defect size between Ad5FGF-4 and placebo was not significant (4.2% vs. 1.6%, p = 0.14), when a single outlier was excluded a significant difference was observed (4.2% vs. 0.8%, p < 0.05). Ad5FGF-4 was well tolerated and did not result in any permanent adverse sequelae.ConclusionsIntracoronary injection of Ad5FGF-4 showed an encouraging trend for improved myocardial perfusion; however, further studies of therapeutic angiogenesis with Ad5FGF-4 will be necessary

    Patients\u27 Perceptions and Patient-Reported Outcomes in Progressive-Fibrosing Interstitial Lung Diseases

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    The effects of interstitial lung disease (ILD) create a significant burden on patients, unsettling almost every domain of their lives, disrupting their physical and emotional well-being and impairing their quality of life (QoL). Because many ILDs are incurable, and there are limited reliably-effective, life-prolonging treatment options available, the focus of many therapeutic interventions has been on improving or maintaining how patients with ILD feel and function, and by extension, their QoL. Such patient-centred outcomes are best assessed by patients themselves through tools that capture their perceptions, which inherently incorporate their values and judgements. These patient-reported outcome measures (PROs) can be used to assess an array of constructs affected by a disease or the interventions implemented to treat it. Here, we review the impact of ILD that may present with a progressive-fibrosing phenotype on patients\u27 lives and examine how PROs have been used to measure that impact and the effectiveness of therapeutic interventions

    Inhibition of transforming growth factor-β restores endothelial thromboresistance in vein grafts

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    BackgroundThrombosis is a major cause of the early failure of vein grafts (VGs) implanted during peripheral and coronary arterial bypass surgeries. Endothelial expression of thrombomodulin (TM), a key constituent of the protein C anticoagulant pathway, is markedly suppressed in VGs after implantation and contributes to local thrombus formation. While stretch-induced paracrine release of transforming growth factor-β (TGF-β) is known to negatively regulate TM expression in heart tissue, its role in regulating TM expression in VGs remains unknown.MethodsChanges in relative mRNA expression of major TGF-β isoforms were measured by quantitative polymerase chain reaction (qPCR) in cultured human saphenous vein smooth muscle cells (HSVSMCs) subjected to cyclic stretch. To determine the effects of paracrine release of TGF-β on endothelial TM mRNA expression, human saphenous vein endothelial cells (HSVECs) were co-cultured with stretched HSVSMCs in the presence of 1D11, a pan-neutralizing TGF-β antibody, or 13C4, an isotype-control antibody. Groups of rabbits were then administered 1D11 or 13C4 and underwent interpositional grafting of jugular vein segments into the carotid circulation. The effect of TGF-β inhibition on TM gene expression was measured by qPCR; protein C activating capacity and local thrombus formation were measured by in situ chromogenic substrate assays; and VG remodeling was assessed by digital morphometry.ResultsCyclic stretch induced TGF-β1 expression in HSVSMCs by 1.9 ± 0.2-fold (P < .001) without significant change in the expressions of TGF-β2 and TGF-β3. Paracrine release of TGF-β1 by stretched HSVSMCs inhibited TM expression in stationary HSVECs placed in co-culture by 57 ± 12% (P = .03), an effect that was abolished in the presence of 1D11. Similarly, TGF-β1 was the predominant isoform induced in rabbit VGs 7 days after implantation (3.5 ± 0.4-fold induction; P < .001). TGF-β1 protein expression localized predominantly to the developing neointima and coincided with marked suppression of endothelial TM expression (16% ± 2% of vein controls; P < .03), a reduction in situ activated protein C (APC)-generating capacity (53% ± 9% of vein controls; P = .001) and increased local thrombus formation (3.7 ± 0.8-fold increase over vein controls; P < .01). External stenting of VGs to limit vessel distension significantly reduced TGF-β1 induction and TM downregulation. Systemic administration of 1D11 also effectively prevented TM downregulation, preserved APC-generating capacity, and reduced local thrombus in rabbit VGs without observable effect on neointima formation and other morphometric parameters 6 weeks after implantation.ConclusionTM downregulation in VGs is mediated by paracrine release of TGF-β1 caused by pressure-induced vessel stretch. Systemic administration of an anti-TGF-β antibody effectively prevented TM downregulation and preserved local thromboresistance without negative effect on VG remodeling.Clinical RelevanceVein grafts (VGs) are commonly used conduits for coronary and peripheral arterial bypass surgeries. Thrombosis is a major cause of early VG failure. Trombomodulin (TM), a key component of the anticoagulant protein C pathway, is downregulated early after VG implantation and facilitates local thrombus formation. We found that paracrine release of transforming growth factor-β1 (TGF-β1), caused by pressure-induced stretch, was a potent negative regulator of TM in rabbit VGs. Administration of a neutralizing anti-TGF-β antibody effectively prevented TM downregulation and reduced local thrombus generation without adversely affecting long-term VG remodeling. This may represent a novel strategy to improve patency in patients undergoing arterial bypass procedures

    Patients\u27 perceptions and patient-reported outcomes in progressive-fibrosing interstitial lung diseases

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    The effects of interstitial lung disease (ILD) create a significant burden on patients, unsettling almost every domain of their lives, disrupting their physical and emotional well-being and impairing their quality of life (QoL). Because many ILDs are incurable, and there are limited reliably-effective, life-prolonging treatment options available, the focus of many therapeutic interventions has been on improving or maintaining how patients with ILD feel and function, and by extension, their QoL. Such patient-centred outcomes are best assessed by patients themselves through tools that capture their perceptions, which inherently incorporate their values and judgements. These patient-reported outcome measures (PROs) can be used to assess an array of constructs affected by a disease or the interventions implemented to treat it. Here, we review the impact of ILD that may present with a progressive-fibrosing phenotype on patients\u27 lives and examine how PROs have been used to measure that impact and the effectiveness of therapeutic interventions

    Patients\u27 Perceptions and Patient-Reported Outcomes in Progressive-Fibrosing Interstitial Lung Diseases

    Get PDF
    The effects of interstitial lung disease (ILD) create a significant burden on patients, unsettling almost every domain of their lives, disrupting their physical and emotional well-being and impairing their quality of life (QoL). Because many ILDs are incurable, and there are limited reliably-effective, life-prolonging treatment options available, the focus of many therapeutic interventions has been on improving or maintaining how patients with ILD feel and function, and by extension, their QoL. Such patient-centred outcomes are best assessed by patients themselves through tools that capture their perceptions, which inherently incorporate their values and judgements. These patient-reported outcome measures (PROs) can be used to assess an array of constructs affected by a disease or the interventions implemented to treat it. Here, we review the impact of ILD that may present with a progressive-fibrosing phenotype on patients\u27 lives and examine how PROs have been used to measure that impact and the effectiveness of therapeutic interventions

    PAR1 (Protease-Activated Receptor 1) Pepducin Therapy Targeting Myocardial Necrosis in Coronary Artery Disease and Acute Coronary Syndrome Patients Undergoing Cardiac Catheterization: A Randomized, Placebo-Controlled, Phase 2 Study

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    OBJECTIVE: Arterial thrombosis leading to ischemic injury worsens the prognosis of many patients with cardiovascular disease. PZ-128 is a first-in-class pepducin that reversibly inhibits PAR1 (protease-activated receptor 1) on platelets and other vascular cells by targeting the intracellular surface of the receptor. The TRIP-PCI (Thrombin Receptor Inhibitory Pepducin in Percutaneous Coronary Intervention) trial was conducted to assess the safety and efficacy of PZ-128 in patients undergoing cardiac catheterization with intent to perform percutaneous coronary intervention. Approach and Results: In this randomized, double-blind, placebo-controlled, phase 2 trial, 100 patients were randomly assigned (2:1) to receive PZ-128 (0.3 or 0.5 mg/kg), or placebo in a 2-hour infusion initiated just before the start of cardiac catheterization, on top of standard oral antiplatelet therapy. Rates of the primary end point of bleeding were not different between the combined PZ-128 doses (1.6%, 1/62) and placebo group (0%, 0/35). The secondary end points of major adverse coronary events at 30 and 90 days did not significantly differ but were numerically lower in the PZ-128 groups (0% and 2% in the PZ-128 groups, 6% and 6% with placebo, p=0.13, p=0.29, respectively). In the subgroup of patients with elevated baseline cardiac troponin I, the exploratory end point of 30-day major adverse coronary events + myocardial injury showed 83% events in the placebo group versus 31% events in the combined PZ-128 drug groups, an adjusted relative risk of 0.14 (95% CI, 0.02-0.75); P=0.02. CONCLUSIONS: In this first-in-patient experience, PZ-128 added to standard antiplatelet therapy appeared to be safe, well tolerated, and potentially reduced periprocedural myonecrosis, thus providing the basis for further clinical trials. Registration: URL: https://www.clinicaltrials.gov. Unique identifier: NCT02561000

    Global burden of 369 diseases and injuries in 204 countries and territories, 1990–2019: a systematic analysis for the Global Burden of Disease Study 2019

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    Background: In an era of shifting global agendas and expanded emphasis on non-communicable diseases and injuries along with communicable diseases, sound evidence on trends by cause at the national level is essential. The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) provides a systematic scientific assessment of published, publicly available, and contributed data on incidence, prevalence, and mortality for a mutually exclusive and collectively exhaustive list of diseases and injuries. Methods: GBD estimates incidence, prevalence, mortality, years of life lost (YLLs), years lived with disability (YLDs), and disability-adjusted life-years (DALYs) due to 369 diseases and injuries, for two sexes, and for 204 countries and territories. Input data were extracted from censuses, household surveys, civil registration and vital statistics, disease registries, health service use, air pollution monitors, satellite imaging, disease notifications, and other sources. Cause-specific death rates and cause fractions were calculated using the Cause of Death Ensemble model and spatiotemporal Gaussian process regression. Cause-specific deaths were adjusted to match the total all-cause deaths calculated as part of the GBD population, fertility, and mortality estimates. Deaths were multiplied by standard life expectancy at each age to calculate YLLs. A Bayesian meta-regression modelling tool, DisMod-MR 2.1, was used to ensure consistency between incidence, prevalence, remission, excess mortality, and cause-specific mortality for most causes. Prevalence estimates were multiplied by disability weights for mutually exclusive sequelae of diseases and injuries to calculate YLDs. We considered results in the context of the Socio-demographic Index (SDI), a composite indicator of income per capita, years of schooling, and fertility rate in females younger than 25 years. Uncertainty intervals (UIs) were generated for every metric using the 25th and 975th ordered 1000 draw values of the posterior distribution. Findings: Global health has steadily improved over the past 30 years as measured by age-standardised DALY rates. After taking into account population growth and ageing, the absolute number of DALYs has remained stable. Since 2010, the pace of decline in global age-standardised DALY rates has accelerated in age groups younger than 50 years compared with the 1990–2010 time period, with the greatest annualised rate of decline occurring in the 0–9-year age group. Six infectious diseases were among the top ten causes of DALYs in children younger than 10 years in 2019: lower respiratory infections (ranked second), diarrhoeal diseases (third), malaria (fifth), meningitis (sixth), whooping cough (ninth), and sexually transmitted infections (which, in this age group, is fully accounted for by congenital syphilis; ranked tenth). In adolescents aged 10–24 years, three injury causes were among the top causes of DALYs: road injuries (ranked first), self-harm (third), and interpersonal violence (fifth). Five of the causes that were in the top ten for ages 10–24 years were also in the top ten in the 25–49-year age group: road injuries (ranked first), HIV/AIDS (second), low back pain (fourth), headache disorders (fifth), and depressive disorders (sixth). In 2019, ischaemic heart disease and stroke were the top-ranked causes of DALYs in both the 50–74-year and 75-years-and-older age groups. Since 1990, there has been a marked shift towards a greater proportion of burden due to YLDs from non-communicable diseases and injuries. In 2019, there were 11 countries where non-communicable disease and injury YLDs constituted more than half of all disease burden. Decreases in age-standardised DALY rates have accelerated over the past decade in countries at the lower end of the SDI range, while improvements have started to stagnate or even reverse in countries with higher SDI. Interpretation: As disability becomes an increasingly large component of disease burden and a larger component of health expenditure, greater research and developm nt investment is needed to identify new, more effective intervention strategies. With a rapidly ageing global population, the demands on health services to deal with disabling outcomes, which increase with age, will require policy makers to anticipate these changes. The mix of universal and more geographically specific influences on health reinforces the need for regular reporting on population health in detail and by underlying cause to help decision makers to identify success stories of disease control to emulate, as well as opportunities to improve. Funding: Bill & Melinda Gates Foundation. © 2020 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 licens
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