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1.
Eur Heart J ; 43(14): 1416-1424, 2022 04 06.
Artigo em Inglês | MEDLINE | ID: mdl-34910136

RESUMO

AIMS: REVEAL was the first randomized controlled trial to demonstrate that adding cholesteryl ester transfer protein inhibitor therapy to intensive statin therapy reduced the risk of major coronary events. We now report results from extended follow-up beyond the scheduled study treatment period. METHODS AND RESULTS: A total of 30 449 adults with prior atherosclerotic vascular disease were randomly allocated to anacetrapib 100 mg daily or matching placebo, in addition to open-label atorvastatin therapy. After stopping the randomly allocated treatment, 26 129 survivors entered a post-trial follow-up period, blind to their original treatment allocation. The primary outcome was first post-randomization major coronary event (i.e. coronary death, myocardial infarction, or coronary revascularization) during the in-trial and post-trial treatment periods, with analysis by intention-to-treat. Allocation to anacetrapib conferred a 9% [95% confidence interval (CI) 3-15%; P = 0.004] proportional reduction in the incidence of major coronary events during the study treatment period (median 4.1 years). During extended follow-up (median 2.2 years), there was a further 20% (95% CI 10-29%; P < 0.001) reduction. Overall, there was a 12% (95% CI 7-17%, P < 0.001) proportional reduction in major coronary events during the overall follow-up period (median 6.3 years), corresponding to a 1.8% (95% CI 1.0-2.6%) absolute reduction. There were no significant effects on non-vascular mortality, site-specific cancer, or other serious adverse events. Morbidity follow-up was obtained for 25 784 (99%) participants. CONCLUSION: The beneficial effects of anacetrapib on major coronary events increased with longer follow-up, and no adverse effects emerged on non-vascular mortality or morbidity. These findings illustrate the importance of sufficiently long treatment and follow-up duration in randomized trials of lipid-modifying agents to assess their full benefits and potential harms. TRIAL REGISTRATION: International Standard Randomized Controlled Trial Number (ISRCTN) 48678192; ClinicalTrials.gov No. NCT01252953; EudraCT No. 2010-023467-18.


Assuntos
Aterosclerose , Infarto do Miocárdio , Oxazolidinonas , Adulto , Aterosclerose/tratamento farmacológico , Atorvastatina/uso terapêutico , Método Duplo-Cego , Humanos , Infarto do Miocárdio/tratamento farmacológico , Oxazolidinonas/efeitos adversos , Resultado do Tratamento
2.
Clin Trials ; 15(1_suppl): 5-12, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29452517

RESUMO

The Clinical Trials Transformation Initiative reflects on 10 years of working to improve the quality and efficiency of clinical trials. This article highlights many of the Clinical Trials Transformation Initiative's accomplishments and offers examples of the impact that the Clinical Trials Transformation Initiative has had on the clinical trials enterprise. After conducting more than 25 projects and issuing recommendations for specific strategies to improve the design and execution of clinical trials, some common themes and lessons learned have emerged. Lessons include the importance of engaging many stakeholders, advanced planning to address critical issues, discontinuation of non-value added practices, and new opportunities presented by technology. Through its work, the Clinical Trials Transformation Initiative has also derived some operational best practices for conducting collaborative, multi-stakeholder projects covering project selection, project team dynamics and execution, and multi-stakeholder meetings and team discussions. Through these initiatives, the Clinical Trials Transformation Initiative has helped move the needle toward needed change in the clinical trials enterprise that has directly impacted stakeholders and patients alike.


Assuntos
Ensaios Clínicos como Assunto/normas , Melhoria de Qualidade/normas , Ensaios Clínicos como Assunto/ética , Comportamento Cooperativo , Confiabilidade dos Dados , Humanos , Participação do Paciente , Segurança do Paciente/normas , Seleção de Pacientes , Estados Unidos , United States Food and Drug Administration
3.
BMC Nephrol ; 18(1): 147, 2017 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-28460629

RESUMO

BACKGROUND: Reducing LDL cholesterol (LDL-C) with statin-based therapy reduces the risk of major atherosclerotic events among patients with chronic kidney disease (CKD), with no evidence of an excess risk of cancer or death from any non-vascular cause. However, non-randomized data have suggested that statin therapy may have effects (both adverse and beneficial) on particular non-vascular conditions that do not cause death. METHODS: The Study of Heart and Renal Protection (SHARP) randomized patients with CKD to simvastatin 20 mg plus ezetimibe 10 mg (simvastatin/ezetimibe) daily versus matching placebo. Participants were followed up at least 6 monthly and all post-randomization serious adverse events (SAEs) were recorded. This supplementary analysis reports the effects of treatment on non-vascular SAEs, overall, by system of disease, by baseline characteristics, and by duration of follow-up. RESULTS: During a median of 4.9 years follow-up, similar numbers of participants in the two groups experienced at least one non-vascular SAE (3551 [76.4%] simvastatin/ezetimibe vs 3537 [76.6%] placebo; risk ratio [RR] 0.99, 95% confidence interval [CI] 0.95-1.04). There was no good evidence of any significant effect of simvastatin/ezetimibe on SAEs attributed to any particular nonvascular disease system (of 43 comparisons, only 3 yielded an uncorrected p value < 0.05, of which the smallest was p = 0.02). The relative risk of any nonvascular SAE did not vary significantly among particular prognostic subgroups or by duration of follow-up. CONCLUSIONS: In the SHARP trial, allocation to simvastatin/ezetimibe combination therapy was not associated with any significant non-vascular hazard. TRIALS REGISTRATION: SHARP was retrospectively registered after the first participant was enrolled in 2003 at ISRCTN (ISRCTN54137607 on 31 January 2005: http://www.isrctn.com/ISRCTN54137607) and ClinicalTrials.gov (NCT00125593 on 29 July 2005: https://clinicaltrials.gov/ct2/show/NCT00125593).


Assuntos
LDL-Colesterol/sangue , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/mortalidade , Inibidores de Hidroximetilglutaril-CoA Redutases/administração & dosagem , Hipercolesterolemia/mortalidade , Hipercolesterolemia/prevenção & controle , Insuficiência Renal Crônica/mortalidade , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticolesterolemiantes/administração & dosagem , Causalidade , Comorbidade , Feminino , Humanos , Hipercolesterolemia/sangue , Incidência , Internacionalidade , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Taxa de Sobrevida , Resultado do Tratamento
4.
Am Heart J ; 187: 182-190, 2017 05.
Artigo em Inglês | MEDLINE | ID: mdl-28454801

RESUMO

Patients with prior vascular disease remain at high risk for cardiovascular events despite intensive statin-based treatment. Inhibition of cholesteryl ester transfer protein by anacetrapib reduces low-density lipoprotein (LDL) cholesterol by around 25% to 40% and more than doubles high-density lipoprotein (HDL) cholesterol. However, it is not known if these apparently favorable lipid changes translate into reductions in cardiovascular events. METHODS: The REVEAL study is a randomized, double-blind, placebo-controlled clinical trial that is assessing the efficacy and safety of adding anacetrapib to effective LDL-lowering treatment with atorvastatin for an average of at least 4years among patients with preexisting atherosclerotic vascular disease. The primary assessment is an intention-to-treat comparison among all randomized participants of the effects of allocation to anacetrapib on major coronary events (defined as the occurrence of coronary death, myocardial infarction, or coronary revascularization). RESULTS: Between August 2011 and October 2013, 30,449 individuals in Europe, North America, and China were randomized to receive anacetrapib 100mg daily or matching placebo. Mean (SD) age was 67 (8) years, 84% were male, 88% had a history of coronary heart disease, 22% had cerebrovascular disease, and 37% had diabetes mellitus. At the randomization visit (after at least 8weeks on a protocol-defined atorvastatin regimen), mean plasma LDL cholesterol was 61 (15) mg/dL and HDL cholesterol was 40 (10) mg/dL. INTERPRETATION: The REVEAL trial will provide a robust evaluation of the clinical efficacy and safety of adding anacetrapib to an effective statin regimen. Results are anticipated in 2017.


Assuntos
Anticolesterolemiantes/uso terapêutico , Atorvastatina/uso terapêutico , Doença das Coronárias/prevenção & controle , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Oxazolidinonas/uso terapêutico , Idoso , Anticolesterolemiantes/efeitos adversos , HDL-Colesterol/sangue , HDL-Colesterol/efeitos dos fármacos , LDL-Colesterol/sangue , LDL-Colesterol/efeitos dos fármacos , Método Duplo-Cego , Quimioterapia Combinada , Feminino , Humanos , Análise de Intenção de Tratamento , Masculino , Pessoa de Meia-Idade , Oxazolidinonas/efeitos adversos , Projetos de Pesquisa
5.
J Intern Med ; 268(2): 145-54, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20337853

RESUMO

OBJECTIVE: To assess the relevance of cystatin C, as a marker of mild-to-moderate renal impairment, for vascular and nonvascular mortality in older people. DESIGN: Prospective cohort study. SETTING: Re-survey in 1997 to 1998 of survivors in the 1970 Whitehall study of London civil servants. SUBJECTS: Five thousand three hundred and seventy-one men (mean age at resurvey: 77 years) who took part in the resurvey and had plasma cystatin C concentration measured. MAIN OUTCOME MEASURES: Cause-specific mortality over subsequent 11 years (1997 to 2008). METHODS: Cox regression was used to estimate the associations of cystatin C with vascular and nonvascular mortality, before and after adjustment for prior disease and other risk factors (including lifetime blood pressure). RESULTS: During an 11.0-year follow-up period, there were 1171 deaths from vascular causes [26 per 1000 per year (py)] and 1615 deaths from nonvascular causes (36 per 1000 py). Compared with men with cystatin C in the bottom fifth of the distribution, men in the top 10th had about two-fold higher mortality rates from vascular and nonvascular mortality (fully adjusted P both <0.001) even after adjustment for prior disease and all measured confounders, including lifetime blood pressure. The fully adjusted relative risks per 50% higher cystatin C concentrations were 1.66 [95% CI 1.48 to 1.85] for vascular mortality, 1.92 [95% CI 1.66 to 2.22] for ischaemic heart disease mortality and 1.46 [95% CI 1.31 to 1.61] for nonvascular mortality. CONCLUSIONS: In older men, plasma concentration of cystatin C, probably as a marker of mild renal disease, is a strong independent predictor of both vascular and nonvascular mortality.


Assuntos
Cistatina C/sangue , Mortalidade , Adulto , Idoso , Envelhecimento/sangue , Biomarcadores/sangue , Doenças Cardiovasculares/mortalidade , Métodos Epidemiológicos , Humanos , Nefropatias/mortalidade , Londres/epidemiologia , Masculino , Pessoa de Meia-Idade , Prognóstico
6.
J Clin Pharm Ther ; 29(3): 263-6, 2004 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15153088

RESUMO

Medical students need to have a sound theoretical knowledge of pharmacology and a training in the practical aspects of therapeutics in order to prescribe effectively, safely and rationally when they qualify. Students have traditionally sat written exams and the practical aspects have been largely ignored. At the University of Birmingham we set up an objective structured clinical examination (OSCE) style examination to test the practical aspects of therapeutics. Over the last 2 years, 434 students have been examined in this way to determine competency in various clinical skills including, for example prescription writing, the drawing up and giving of injections, setting up nebulizers, and patient counselling about drug effects. Over that time we found the therapeutics OSCE to be feasible and useful. It has demonstrated serious practical deficiencies that were not apparent from written examinations in some students' ability to prescribe and administer drugs. Since its introduction, performance in the OSCE has improved. Whether this will result in safer and more effective prescribing in the preregistration house officer year has not been formally evaluated but it appears that they approach this aspect of patient care with greater confidence than graduates from other schools.


Assuntos
Currículo/tendências , Avaliação Educacional/métodos , Farmacologia Clínica/educação , Competência Clínica/normas , Prescrições de Medicamentos/normas , Avaliação Educacional/normas , Humanos , Conhecimento , Estudantes de Medicina , Ensino/métodos , Materiais de Ensino/normas , Fatores de Tempo , Reino Unido
7.
J Clin Pharm Ther ; 27(4): 233-42, 2002 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-12174024

RESUMO

This paper reviews the role of beta-blockers in the prevention of cardiovascular morbidity and mortality in patients with diabetes mellitus. There is good evidence from randomized controlled trials that beta-blockers, in particular the lipophilic agents, substantially reduce cardiovascular mortality and morbidity. However, hitherto beta-blockers have been underused in diabetic patients, perhaps because of perceived risks of beta-blocker therapy. Reappraisal of the evidence suggests that the traditional reluctance to use beta-blockers in this group is based on fears of adverse effects that are largely unfounded.


Assuntos
Antagonistas Adrenérgicos beta/uso terapêutico , Doença das Coronárias/etiologia , Doença das Coronárias/prevenção & controle , Complicações do Diabetes , Antagonistas Adrenérgicos beta/farmacologia , Morte Súbita Cardíaca , Humanos , Padrões de Prática Médica , Estudos Prospectivos
8.
J Hum Hypertens ; 16(5): 333-6, 2002 May.
Artigo em Inglês | MEDLINE | ID: mdl-12082494

RESUMO

Malignant hypertension (MHT) is a rare and severe form of hypertension characterised by arteriolar necrosis and severe vascular damage, leading to stroke, myocardial infarction and death. We hypothesised that in addition to endothelial damage, MHT may be associated with increased oxidative stress. Lipid hydroperoxides (LHP, an index of oxidative damage) and plasma von Willebrand factor (vWf, an index of endothelial damage/dysfunction) were measured in 16 patients with MHT and compared with 16 non-malignant essential hypertensives and 32 normotensive controls. vWf was greater in MHT (mean 117 iU/dL) than in non-malignant hypertensives (97 iU/dL) or normotensive controls (100 iU/dL) (ANOVA P = 0.017). However, although LHP were greater in MHT (mean 10.6 micromol/L) than in normotensives (4.5 micromol/L, P < 0.001), the levels in MHT were similar to those in non-malignant hypertension (12.3 micromol/L). In conclusion endothelial damage (raised vWf) was more evident in MHT compared with both normotensive controls and with non-malignant hypertension, whilst oxidative stress (raised LHP) was increased to a similar extent in both hypertension groups when compared with normotensive controls. These observations raise the possibility abnormal oxidative stress is probably not the mechanism responsible for the endothelial damage seen in malignant phase hypertension.


Assuntos
Hipertensão Maligna/metabolismo , Hipertensão/metabolismo , Estresse Oxidativo , Análise de Variância , Endotélio Vascular/fisiopatologia , Feminino , Humanos , Peróxidos Lipídicos/metabolismo , Masculino , Pessoa de Meia-Idade , Fator de von Willebrand/metabolismo
9.
QJM ; 95(3): 165-71, 2002 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11865172

RESUMO

BACKGROUND: Low-density lipoprotein (LDL) consists of a heterogeneous group of particles of varying size and electrophoretic mobility. A predominance of small, more mobile particles is a risk factor for cardiovascular disease. AIM: To investigate the hypothesis that untreated patients with essential hypertension in the absence of vascular disease may exhibit abnormalities of LDL subfractions. SETTING: Specialist hypertension clinic. DESIGN: Cross-sectional study. METHODS: Following disc polyacrylamide gel electrophoresis, the mean (LDL locus) and heterogeneity (LDL spread) of mobility was recorded in 41 patients (mean age 52.6 years, 24 men) presenting with untreated essential hypertension (in the absence of vascular disease or diabetes mellitus) and in 45 healthy controls (age 56.9 years, 22 men) recruited from primary-care lists. RESULTS: Although there were no significant differences in total, low- or high-density lipoprotein cholesterol concentrations, LDL locus was significantly greater in the hypertensive group: mean (95%CI) 36.7 (35.7-37.6) vs. 34.8 (34.1-35.5), p=0.002. LDL locus was significantly elevated even in hypertensives with triglyceride concentrations below the median (<1.25 mmol/l). LDL spread was also greater in the hypertensive group, but not significantly: 5.6 (5.2-6.0) vs. 5.5 (5.3-5.8), p=0.10. DISCUSSION: Hypertensive patients have a preponderance of smaller LDL subfractions. This dyslipidaemia is not readily detected by conventional lipid assays.


Assuntos
Hipertensão/sangue , Lipoproteínas LDL/sangue , Estudos Transversais , Feminino , Humanos , Lipídeos/sangue , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Triglicerídeos/sangue
10.
Am J Kidney Dis ; 38(3): 537-46, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11532686

RESUMO

Patients with chronic renal impairment (CRI) are at greatly increased risk for premature vascular disease; however, little is known about its evolution. This paper describes a cohort of patients with CRI and reports study design, baseline demographic and biochemical data, and comparisons with two contemporaneous age- and sex-matched control groups, one with established coronary artery disease and the other without overt vascular disease. Among 369 individuals (median age, 63 years; range, 18 to 88 years; 67% men) with CRI, 34% had a history of vascular disease and 21% had electrocardiographic left ventricular hypertrophy (LVH). Even in those with mild renal impairment (serum creatinine < 2.1 mg/dL), approximately one third had vascular disease and 12% had LVH. A history of hypertension was present in 76% of the CRI group, but as compared with controls, systolic and diastolic blood pressures were not elevated. Low-density lipoprotein (LDL) cholesterol concentration also was not elevated, but CRI was associated with elevated serum triglyceride and plasma homocysteine levels and reduced high-density lipoprotein (HDL) cholesterol, hemoglobin, and serum albumin concentrations. Across the spectrum of CRI, more severe renal dysfunction was associated with lower levels of diastolic blood pressure, LDL and HDL cholesterol, albumin, and hemoglobin, but increased levels of plasma homocysteine. This cross-sectional analysis shows that vascular disease is common in individuals with mild CRI attending a nephrology program and also suggests trends in the levels of a number of potential vascular risk factors with respect to severity of renal dysfunction. These results will be further quantified in a prospective biennial follow-up.


Assuntos
Doenças Cardiovasculares/etiologia , Falência Renal Crônica/complicações , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores/sangue , Pressão Sanguínea , Doenças Cardiovasculares/sangue , Doenças Cardiovasculares/epidemiologia , Transtornos Cerebrovasculares/sangue , Transtornos Cerebrovasculares/epidemiologia , Transtornos Cerebrovasculares/etiologia , HDL-Colesterol/sangue , Estudos de Coortes , Doença das Coronárias/sangue , Doença das Coronárias/epidemiologia , Doença das Coronárias/etiologia , Creatinina/sangue , Estudos Transversais , Diabetes Mellitus/epidemiologia , Feminino , Hemoglobina A/análise , Homocisteína/sangue , Humanos , Hipertrofia Ventricular Esquerda/sangue , Hipertrofia Ventricular Esquerda/epidemiologia , Hipertrofia Ventricular Esquerda/etiologia , Falência Renal Crônica/sangue , Masculino , Pessoa de Meia-Idade , Estado Nutricional , Doenças Vasculares Periféricas/sangue , Doenças Vasculares Periféricas/epidemiologia , Doenças Vasculares Periféricas/etiologia , Prevalência , Estudos Prospectivos
11.
J Am Coll Cardiol ; 37(7): 1858-63, 2001 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-11401123

RESUMO

OBJECTIVES: This study was designed to determine the effects of folic acid therapy on endothelial function in patients with coronary artery disease (CAD). BACKGROUND: Hyperhomocysteinemia, a risk factor for CAD, may cause atherosderosis by oxidative endothelial injury. Folic acid reduces plasma homocysteine, but the effect on adverse vascular events is unknown. METHODS: In a double-blind placebo-controlled trial, 90 patients (mean age [range] 63 [46 to 79] years, 79 men) with CAD were randomized to either folic acid 5 mg or placebo daily for 12 weeks. Endothelial function was assessed by measuring: 1) flow-mediated endothelium-dependent dilation (EDD) of the brachial artery; 2) combined serum nitrite/nitrate (NOx) concentrations and; 3) plasma von Willebrand factor (vWF) concentration. RESULTS: At the end of the study, plasma homocysteine was lower in the folic acid group compared with the placebo group (mean [95% confidence interval] 9.3 (8.5 to 10.1) vs. 12.3 [11.3 to 13.4] micromol/l, p < 0.001). Although there were no significant differences in EDD, serum NOx or plasma vWF between the two groups, there was a greater increase in EDD from baseline in the folic acid group compared to placebo (1.2 [0.7 to 1.8] vs. 0.4 [-0.3 to 1.1]%, p = 0.07). CONCLUSIONS: Folic acid reduced plasma homocysteine and was associated with a trend toward improved endothelial function in patients with CAD. The absence of an unequivocally positive result may have been due to inadequate sample size or chance. This reinforces the need for the results of large randomized controlled trials before the implementation of routine folic acid supplementation.


Assuntos
Doença das Coronárias/tratamento farmacológico , Doença das Coronárias/fisiopatologia , Endotélio Vascular/efeitos dos fármacos , Endotélio Vascular/fisiopatologia , Ácido Fólico/uso terapêutico , Homocisteína/sangue , Idoso , Doença das Coronárias/sangue , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Nitratos/sangue , Nitritos/sangue , Fluxo Sanguíneo Regional , Fator de von Willebrand/análise
12.
QJM ; 94(6): 327-32, 2001 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-11391031

RESUMO

Low-density lipoprotein (LDL) consists of a heterogeneous group of particles of differing size, density and electrophoretic mobility, smaller particles being more atherogenic. A high proportion of small LDL particles is an independent risk factor for cardiovascular disease. We hypothesized that patients with malignant phase hypertension (MHT), the most severe form of hypertension, would demonstrate a more atherogenic LDL subfraction profile than either non-malignant hypertension (NMHT) or normotensive controls. We compared 16 patients with MHT to 41 patients with untreated NMHT and 45 normotensive controls. LDL subfraction profile was measured by disc polyacrylamide gel electrophoresis using a validated scoring system to calculate the mean size (locus) and heterogeneity (spread) of LDL subfraction mobilities. A higher LDL locus indicates a greater proportion of small LDL subfractions. LDL cholesterol levels were similar in all three groups (p=0.23). High-density lipoprotein cholesterol (HDL-C) levels were significantly lower (p<0.001) and serum triglyceride concentrations significantly higher (p=0.02) in the MHT group, compared to normotensive controls. LDL locus was greater in the NMHT group than in the normotensive controls and intermediate in the MHT group (p=0.008). There was no significant difference in LDL spread (p=0.26). Serum triglyceride concentrations were not significantly higher after adjusting for confounding variables. MHT is associated with an abnormal lipid profile, characterized by low HDL-cholesterol concentration. This dyslipidaemia may be partly responsible for the vascular complications and the poor prognosis of these patients.


Assuntos
Hiperlipidemias/complicações , Hipertensão Maligna/complicações , Análise de Variância , Estudos de Casos e Controles , HDL-Colesterol/sangue , Eletroforese em Gel de Poliacrilamida , Feminino , Humanos , Hiperlipidemias/sangue , Hipertensão Maligna/sangue , Lipoproteínas LDL/sangue , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Triglicerídeos/sangue
14.
J Intern Med ; 248(4): 316-8, 2000 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11086642

RESUMO

OBJECTIVE: To relate the changes in serum vitamin E, an essential antioxidant, to changes in fibrinogen, as well as indices of endothelial damage [as indicated by plasma markers, soluble thrombomodulin (sTM) and von Willebrand factor (vWf), and an index of platelet activation (soluble P selectin (sPsel)], in myocardial infarction treated with thrombolytic therapy. DESIGN AND SETTING: Prospective longitudinal pilot study in a teaching hospital Coronary Care Unit. SUBJECTS AND INTERVENTION: Seventeen patients (12 men: mean age (62 years +/- SD 11 years) admitted with acute myocardial infarction (AMI), who were given thrombolytic therapy, and 59 healthy controls. RESULTS: Baseline levels of fibrinogen (Mann-Whitney test, P = 0.0055) and vWf (P < 0.001) were significantly higher than controls, but sPsel, sTM or vitamin E levels were not significantly different. Following thrombolysis, as expected, median concentrations of plasma fibrinogen fell profoundly (Friedman ANOVA P < 0.001) so that after 45 min, levels were undetectable in 13 patients. At 24-h median fibrinogen concentration had recovered to approximately 30% of baseline (P < 0.01) and was still undetectable in three patients. Levels of vWf and sPsel increased steadily, reaching significance after three hours (both P < 0.05). However, levels of sTM rose immediately after thrombolysis, peaking between 1 and 3 h, and remained elevated at 24 h. These increases corresponded to a simultaneous early fall in serum vitamin E concentrations. CONCLUSION: The present pilot study demonstrates significant endothelial damage and platelet activation in association with increased oxidative stress following streptokinase therapy for AMI.


Assuntos
Endotélio Vascular/efeitos dos fármacos , Fibrinogênio/metabolismo , Fibrinolíticos/efeitos adversos , Infarto do Miocárdio/sangue , Infarto do Miocárdio/tratamento farmacológico , Selectina-P/sangue , Ativação Plaquetária/efeitos dos fármacos , Estreptoquinase/efeitos adversos , Trombomodulina/sangue , Vitamina E/sangue , Fator de von Willebrand/metabolismo , Idoso , Análise de Variância , Estudos de Casos e Controles , Feminino , Fibrinogênio/efeitos dos fármacos , Humanos , Masculino , Pessoa de Meia-Idade , Estresse Oxidativo/efeitos dos fármacos , Selectina-P/efeitos dos fármacos , Projetos Piloto , Estudos Prospectivos , Trombomodulina/efeitos dos fármacos , Fator de von Willebrand/efeitos dos fármacos
16.
Circulation ; 102(8): 871-5, 2000 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-10952955

RESUMO

BACKGROUND: Considerable evidence suggests that hyperhomocysteinemia is an independent vascular risk factor that promotes atherosclerosis by inducing endothelial dysfunction. Although folic acid reduces hyperhomocysteinemia, the effect on adverse vascular events is unknown. We hypothesized that in patients with chronic renal failure, a condition associated with both hyperhomocysteinemia and atherosclerosis, treatment with folic acid would improve endothelial function. METHODS AND RESULTS: In a prospective, double-blind protocol, 100 patients (mean age 62 years, 67 men) with predialysis chronic renal failure were randomized to 5 mg folic acid or placebo daily for 12 weeks. Endothelial function was assessed by measuring (1) endothelium-dependent dilation of the brachial artery, (2) combined serum nitrite/nitrate concentrations, and (3) plasma von Willebrand factor concentration. Baseline characteristics of the 2 groups were similar. At the end of the study, both serum and red cell folate concentrations were greater in the folic acid group than the placebo group [mean (95% CI) 39.0 (29.8 to 51.0) versus 7.7 (6.6 to 8.9) microg/L and 739 (613 to 891) versus 220 (184 to 262) microg/L, respectively; both P<0.001]. Despite a reduction in hyperhomocysteinemia in the folic acid group compared with the placebo group [15.1 (14.1 to 16.2) versus 20.1 (18.2 to 22.2) micromol/L; P<0.001], there were no significant differences in endothelium-dependent dilation, combined serum nitrite/nitrate concentrations, or plasma von Willebrand factor concentration between the 2 groups. CONCLUSIONS: High-dose folic acid lowers but fails to normalize hyperhomocysteinemia in patients with predialysis chronic renal failure. This was not accompanied by an improvement of endothelial function and suggests that treatment with folic acid may not reduce the burden of vascular disease in uremia.


Assuntos
Endotélio Vascular/efeitos dos fármacos , Ácido Fólico/uso terapêutico , Hematínicos/uso terapêutico , Homocisteína/sangue , Falência Renal Crônica/tratamento farmacológico , Idoso , Artéria Braquial/diagnóstico por imagem , Artéria Braquial/efeitos dos fármacos , Artéria Braquial/fisiopatologia , Método Duplo-Cego , Endotélio Vascular/fisiopatologia , Eritrócitos/metabolismo , Feminino , Ácido Fólico/sangue , Humanos , Falência Renal Crônica/sangue , Falência Renal Crônica/fisiopatologia , Masculino , Pessoa de Meia-Idade , Nitratos/sangue , Nitritos/sangue , Placebos , Estudos Prospectivos , Diálise Renal , Ultrassonografia , Vasodilatação/efeitos dos fármacos , Fator de von Willebrand/metabolismo
18.
Heart ; 83(2): 205-9, 2000 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-10648498

RESUMO

BACKGROUND: Endothelial dysfunction plays an important role in the development of atherosclerotic vascular disease, which is the leading cause of mortality in patients with chronic renal failure. OBJECTIVE: To examine the relation between predialysis renal failure and endothelial function. DESIGN: Two groups were studied: 80 patients with non-diabetic chronic renal failure and 26 healthy controls, with similar age and sex distributions. Two indices of endothelial function were assessed: high resolution ultrasonography to measure flow mediated endothelium dependent dilatation of the brachial artery following reactive hyperaemia, and plasma concentration of von Willebrand factor. Endothelium independent dilatation was also assessed following sublingual glyceryl trinitrate. The patients were divided into those with and without overt atherosclerotic vascular disease. RESULTS: Although patients with chronic renal failure had significantly impaired endothelium dependent dilatation compared with controls (median (interquartile range), 2.6% (0.7% to 4.8%) v 6.5% (4.8% to 8.3%); p < 0.001) and increased von Willebrand factor (254 (207 to 294) v 106 (87 to 138) iu/dl; p < 0.001), there was no difference between renal failure patients with and without atherosclerotic vascular disease. Within the chronic renal failure group, endothelium dependent dilatation and von Willebrand factor were similar in patients in the upper and lower quartiles of glomerular filtration rate (2.7% (0.7% to 6.7%) v 2.8% (1.1% to 5.0%); and 255 (205 to 291) v 254 (209 to 292) iu/dl, respectively). Endothelium independent dilatation did not differ between the renal failure or control groups and was also similar in patients with renal failure irrespective of the degree of renal failure or the presence of atherosclerotic vascular disease. CONCLUSIONS: Endothelial function is abnormal in chronic renal failure, even in patients with mild renal insufficiency and those without atherosclerotic vascular disease, suggesting that uraemia may directly promote the development of atherosclerosis early in the progression of chronic renal failure.


Assuntos
Arteriosclerose/fisiopatologia , Endotélio Vascular/fisiopatologia , Falência Renal Crônica/fisiopatologia , Arteriosclerose/sangue , Arteriosclerose/diagnóstico por imagem , Estudos de Casos e Controles , Endotélio Vascular/diagnóstico por imagem , Feminino , Humanos , Falência Renal Crônica/sangue , Falência Renal Crônica/diagnóstico por imagem , Masculino , Ultrassonografia , Fator de von Willebrand/análise
19.
Basic Res Cardiol ; 95 Suppl 1: I37-40, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-11192351

RESUMO

Sudden death is extremely common in patients suffering from cardiovascular diseases. At least one third of those with hypertension and probably about half of those who survive a myocardial infarction or suffer from cardiac failure who die in a clinical trial, die suddenly. Beta-blockers reduce the risk of sudden death in patients with cardiovascular disease, particularly in those who have had a myocardial infarction or heart failure. ACE inhibitors are perhaps less effective. Other cardiovascular drugs have not been shown to reduce the risk of sudden death.


Assuntos
Antagonistas Adrenérgicos beta/uso terapêutico , Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Morte Súbita Cardíaca/prevenção & controle , Humanos , Hipertensão/tratamento farmacológico , Infarto do Miocárdio/tratamento farmacológico
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