RESUMO
The implementation of the national 'Getting It Right First Time' was assessed by interviewing six surgeons involved at various levels in surgical site infection (SSI) audit. The positive impacts were to create new professional collaboration, improve stakeholder engagement, and increase the profile of SSIs. One particular knowledge gap highlighted was that some participants had been unaware until that point of the criteria for diagnosing an SSI. The quality of data collected was felt to be poor due to methodological flaws. The audit was described as highly time-consuming and unsustainable if leaning on junior surgeons, without protected time and designated responsibility.
Assuntos
Cirurgiões/psicologia , Infecção da Ferida Cirúrgica , Humanos , Pesquisa QualitativaRESUMO
BACKGROUND: The rise in antimicrobial resistance has highlighted the importance of surgical site infection (SSI) prevention with effective surveillance strategies playing a key role in improving patient safety. AIM: To map national needs and priorities for SSI surveillance against current national surveillance activity. METHODS: This study analysed SSI surveillance in National Health Service (NHS) hospitals in England covering 23 surgical procedures. Data collected were: (i) annual number of procedures, (ii) SSI rates from national reports, (iii) national reporting requirement (mandatory, voluntary, not offered), (iv) priority ranking from a survey of 84 English NHS hospitals, (v) excess length of stay and costs from the literature. The relationships between estimated SSI burden, national surveillance activity, and hospital-reported priorities were explored with descriptive and univariate analyses. FINDINGS: Among the 23 surgical categories analysed, top priority ranking by hospitals was associated only with current surveillance (r = 0.76, P < 0.01) and mandatory reporting (33% vs 8 and 4%, P = 0.04). Percentage of hospitals undertaking surveillance, mandatory reporting, and the selection of priorities did not match SSI burden. Large bowel surgery (LBS, voluntary) and caesarean section (not offered) were the two highest contributors of total SSIs per annum, with 39,000 (38%) and 17,000 (16%) respectively, while the four orthopaedic categories (all mandatory) contributed 5000 (5%). LBS also had the highest associated costs (£119 million per annum). CONCLUSION: Current surveillance and future priorities were not associated with SSI rate, volume, or cost to hospitals. The two highest contributors of SSIs and related costs have no (caesarean section) or limited (LBS) coverage by national surveillance.
Assuntos
Monitoramento Epidemiológico , Controle de Infecções/métodos , Infecção da Ferida Cirúrgica/epidemiologia , Infecção da Ferida Cirúrgica/prevenção & controle , Inglaterra/epidemiologia , Humanos , Controle de Infecções/tendências , Prevalência , Inquéritos e QuestionáriosRESUMO
This multi-centre study assessed operating room (OR) staff compliance with clothing regulations and traffic flow during surgical procedures. Of 1615 surgical attires audited, 56% respected the eight clothing measures. Lack of compliance was mainly due to inappropriate wearing of jewellery (26%) and head coverage (25%). In 212 procedures observed, a median of five people [interquartile range (IQR) 4-6] were present at the time of incision. The median frequency of entries to/exits from the OR was 10.6/h (IQR 6-29) (range 0-93). Reasons for entries to/exits from the OR were mainly to obtain materials required in the OR (N=364, 44.5%). ORs with low compliance with clothing regulations tended to have higher traffic flows, although the difference was not significant (P=0.12).
Assuntos
Atitude do Pessoal de Saúde , Vestuário , Fidelidade a Diretrizes , Controle de Infecções/métodos , Procedimentos Cirúrgicos Operatórios , Humanos , Salas CirúrgicasRESUMO
INTRODUCTION: High sensitivity assays for cardiac troponin (cTn) have reduced time to diagnosis of myocardial infarction (MI) but at costs to diagnostic specificity. We hypothesised that measurement of an upstream open reading frame peptide (uORF) from the human cTnT gene (TnTuORF) might improve cTn specificity in MI patients. METHODS: A novel immunoassay to TnTuORF was developed and used to document circulating concentrations in normal healthy volunteers (n=150); assess potential trans-organ secretion in patients undergoing cardiac catheterisation (n=16); characterise temporal TnTuORF concentrations during ST-elevation MI (STEMI, n=4) and assess the potential of TnTuORF to assist the diagnosis and prognosis of MI in patients presenting with chest pain suspicious of ACS (n=502). Plasma immunoreactive TnTuORF was characterised on reverse phase and size exclusion HPLC. RESULTS: In normal volunteers and suspected acute coronary syndrome (ACS) patients, TnTuORF had no relationship with TnI or TnT. Trans-organ venous sampling suggested TnTuORF secretion is not exclusively cardiac based. In STEMI patients, TnTuORF concentrations decreased for up to 12h after onset. In suspected ACS patients, TnTuORF could not diagnose MI (ROC AUC=0.446, P=0.117) but could diagnose cardiac disorders other than MI (AUC=0.79, P<0.001). CONCLUSION: This is the first evidence for a circulating uORF peptide. TnTuORF does not appear to aid the diagnosis of MI but further studies to assess its potential in cardiovascular disease are required.
Assuntos
Síndrome Coronariana Aguda/sangue , Síndrome Coronariana Aguda/diagnóstico , Fases de Leitura Aberta/fisiologia , Fragmentos de Peptídeos/sangue , Troponina T/sangue , Idoso , Idoso de 80 Anos ou mais , Biomarcadores/sangue , Feminino , Seguimentos , Humanos , Imunoensaio/métodos , Masculino , Pessoa de Meia-Idade , Fragmentos de Peptídeos/genética , Estudos Prospectivos , Troponina T/genéticaRESUMO
BACKGROUND/AIMS: We aimed to assess differences in patient management, and outcomes, of Australian and New Zealand patients admitted with a suspected or confirmed acute coronary syndrome (ACS). METHODS: We used comprehensive data from the binational Australia and New Zealand ACS 'SNAPSHOT' audit, acquired on individual patients admitted between 00.00 h on 14 May 2012 to 24.00 h on 27 May 2012. RESULTS: There were 4387 patient admissions, 3381 (77%) in Australia and 1006 (23%) in New Zealand; Australian patients were slightly younger (67 vs 69 years, P = 0.0044). Of the 2356 patients with confirmed ACS, Australian patients were at a lower cardiovascular risk with a lower median Global Registry Acute Coronary Events score (147 vs 154 P = 0.0008), but as likely to receive an invasive coronary angiogram (58% vs 54%, P = 0.082), or revascularisation with percutaneous coronary intervention (32% vs 31%, P = 0.92) or coronary artery bypass graft surgery (7.0% vs 5.6%, P = 0.32). Of the 1937 non-segment elevation myocardial infarction/unstable angina pectoris (NSTEMI/UAP) patients, Australian patients had a shorter time to angiography (46 h vs 67 h, P < 0.0001). However, at discharge, Australian NSTEMI/UAP survivors were less likely to receive aspirin (84% vs 89%, P = 0.0079, a second anti-platelet agent (57% vs 63%, P = 0.050) or a beta blocker (67% vs 77%, P = 0.0002). In-hospital death rates were not different (2.7% vs 3.2%, P = 0.55) between Australia and New Zealand. CONCLUSIONS: Overall more similarities were seen, than differences, in the management of suspected or confirmed ACS patients between Australia and New Zealand. However, in several management areas, both countries could improve the service delivery to this high-risk patient group.
Assuntos
Síndrome Coronariana Aguda/mortalidade , Angiografia Coronária/estatística & dados numéricos , Ponte de Artéria Coronária/mortalidade , Acessibilidade aos Serviços de Saúde/estatística & dados numéricos , Mortalidade Hospitalar , Síndrome Coronariana Aguda/diagnóstico , Síndrome Coronariana Aguda/terapia , Idoso , Austrália/epidemiologia , Ponte de Artéria Coronária/estatística & dados numéricos , Feminino , Humanos , Masculino , Auditoria Médica , Pessoa de Meia-Idade , Nova Zelândia/epidemiologia , Avaliação de Resultados em Cuidados de Saúde , Admissão do Paciente , Alta do Paciente , Taxa de SobrevidaRESUMO
BACKGROUND: There is a genetic contribution to the risk of ventricular arrhythmias in survivors of acute coronary syndromes (ACS). We wished to explore the role of 33 candidate single nucleotide polymorphisms (SNPs) in prolonged repolarization and sudden death in patients surviving ACS. METHODS: A total of 2,139 patients (1680 white ethnicity) surviving an admission for ACS were enrolled in the prospective Coronary Disease Cohort Study. Extensive clinical, echocardiographic, and neurohormonal data were collected for 12 months, and clinical events were recorded for a median of 5 years. Each SNP was assessed for association with sudden cardiac death (SCD)/cardiac arrest (CA) and prolonged repolarization at 3 time-points: index admission, 1 month, and 12 months postdischarge. RESULTS: One hundred six SCD/CA events occurred during follow-up (6.3%). Three SNPs from 3 genes (rs17779747 [KCNJ2], rs876188 [C14orf64], rs3864180 [GPC5]) were significantly associated with SCD/CA in multivariable models (after correction for multiple testing); the minor allele of rs17779747 with a decreased risk (hazard ratio [HR] 0.68 per copy of the minor allele, 95% CI 0.50-0.92, P = .012), and rs876188 and rs386418 with an increased risk (HR 1.52 [95% CI 1.10-2.09, P = .011] and HR 1.34 [95% CI 1.04-1.82, P = .023], respectively). At 12 months postdischarge, rs10494366 and rs12143842 (NOS1AP) were significant predictors of prolonged repolarization (HR 1.32 [95% CI 1.04-1.67, P = .022] and HR 1.30 [95% CI 1.01-1.66, P = .038], respectively), but not at earlier time-points. CONCLUSION: Three SNPs were associated with SCD/CA. Repolarization time was associated with variation in the NOS1AP gene. This study demonstrates a possible role for SNPs in risk stratification for arrhythmic events after ACS.
Assuntos
Síndrome Coronariana Aguda/complicações , Arritmias Cardíacas/genética , DNA/genética , Eletrocardiografia , Marcadores Genéticos , Predisposição Genética para Doença , Polimorfismo de Nucleotídeo Único , Síndrome Coronariana Aguda/genética , Síndrome Coronariana Aguda/metabolismo , Idoso , Arritmias Cardíacas/etiologia , Arritmias Cardíacas/metabolismo , Feminino , Seguimentos , Genótipo , Humanos , Masculino , Estudos Prospectivos , Fatores de RiscoRESUMO
AIMS: New Zealand's ageing population threatens the financial sustainability of our current model of health service delivery. The Canterbury Health, Ageing and Life Course (CHALICE) study aims to develop a comprehensive and flexible database of important determinants of health to inform new models. This paper describes the design, methodology, and first 300 participants of CHALICE. METHODS: Commencing August 2010, CHALICE is a multidisciplinary prospective random cohort study and biobank of 1,000 Canterbury adults aged 49-51 years at inception, stratified by self-identified Maori (n=200) and non-Maori (n=800) ethnicity. Assessment covers sociodemographic, physical, cognition, mental health, clinical history, family and social, cardiovascular, and lifestyle domains. Detailed follow-up assessment occurs every 5 years, with a brief postal follow-up assessment undertaken annually. RESULTS: For the first 300 participants (44 Maori, 256 non-Maori), the participation rate is 63.7%. Overall, 53.3% of participants are female, 75.3% are living in married or de facto relationships, and 19.0% have university degrees. These sociodemographic profiles are comparable with the 2006 Census, Canterbury region, 50-54 years age group percentages (50.7%, 77.2%, and 14.3%, respectively). CONCLUSIONS: CHALICE has been designed to provide quality data that will inform policy development and programme implementation across a broad spectrum of health indicators.
Assuntos
Envelhecimento , Nível de Saúde , Inquéritos Epidemiológicos , Envelhecimento/etnologia , Doença Crônica/etnologia , Feminino , Seguimentos , Comportamentos Relacionados com a Saúde , Conhecimentos, Atitudes e Prática em Saúde , Acessibilidade aos Serviços de Saúde , Disparidades nos Níveis de Saúde , Disparidades em Assistência à Saúde , Humanos , Estilo de Vida , Masculino , Pessoa de Meia-Idade , Havaiano Nativo ou Outro Ilhéu do Pacífico , Nova Zelândia , Estudos Prospectivos , Projetos de Pesquisa , Fatores SocioeconômicosRESUMO
The safety and efficacy of an implantable left atrial pressure (LAP) monitoring system is being evaluated in a clinical trial setting. Because the number of available specimens from the clinical trial for histopathology analysis is limited, it is beneficial to maximize the usage of each available specimen by relying on integrated microscopy techniques. The aim of this study is to demonstrate how a comprehensive pathology analysis of a single specimen may be reliably achieved using integrated microscopy techniques. Integrated microscopy techniques consisting of high-resolution gross digital photography followed by micro-computed tomography (micro-CT) scanning, low-vacuum scanning electron microscopy (LVSEM), and microground histology with special stains were applied to the same specimen. Integrated microscopy techniques were applied to eight human specimens. Micro-CT evaluation was beneficial for pinpointing the location and position of the device within the tissue, and for identifying any areas of interest or structural flaws that required additional examination. Usage of LVSEM was reliable in analyzing surface topography and cell type without destroying the integrity of the specimen. Following LVSEM, the specimen remained suitable for embedding in plastic and sectioning for light microscopy, using the positional data gathered from the micro-CT to intersect areas of interest in the slide. Finally, hematoxylin and eosin (H&E) and methylene blue staining was deployed on the slides with high-resolution results. The integration of multiple techniques on a single specimen maximized the usage of the limited number of available specimens from the clinical trial setting. Additionally, this integrated microscopic evaluation approach was found to have the added benefit of providing greater assurance of the derived conclusions because it was possible to cross-validate the results from multiple tests on the same specimen.
RESUMO
This study examined renin-angiotensin-aldosterone (RAAS) system gene variants for associations with cardiovascular risk factors and outcomes in coronary heart disease. Coronary disease patients (n=1186) were genotyped for 21 single-nucleotide polymorphisms (SNPs) within angiotensinogen (AGT), angiotensin-converting enzyme (ACE), angiotensin-II type-1 receptor (AGTR1) and aldosterone synthase (CYP11B2). Associations with all-cause mortality and cardiovascular readmissions were assessed over a median of 3.0 years. The AGT M235T 'T' allele was associated with a younger age of clinical coronary disease onset (P=0.006), and the AGT rs2478545 minor allele was associated with lower circulating natriuretic peptides (P=0.0001-P=0.001) and E/E(1) (P=0.018). Minor alleles of AGT SNPs rs1926723 and rs11122576 were associated with more frequent history of renal disease (Pîº0.04) and type-2 diabetes (Pîº0.02), higher body mass index (Pîº0.02) and greater mortality (Pîº0.007). AGT rs11568054 minor allele carriers had more frequent history of renal disease (P=0.04) and higher plasma creatinine (P=0.033). AGT rs6687360 minor allele carriers exhibited worse survival (P=0.02). ACE rs4267385 was associated with older clinical coronary disease onset (P=0.008) and hypertension (P=0.013) onset, increased plasma creatinine (P=0.01), yet greater mortality (P=0.044). Less history of hypertension was observed with the AGTR1 rs12685977 minor allele (P=0.039). Genetic variation within the RAAS was associated with cardiovascular risk factors and accordingly poorer survival.
Assuntos
Doença da Artéria Coronariana/genética , Doença da Artéria Coronariana/mortalidade , Polimorfismo de Nucleotídeo Único , Sistema Renina-Angiotensina/genética , Idade de Início , Idoso , Angiotensinogênio/genética , Comorbidade , Doença da Artéria Coronariana/etnologia , Citocromo P-450 CYP11B2/genética , Feminino , Frequência do Gene , Predisposição Genética para Doença , Humanos , Hipertensão/genética , Hipertensão/mortalidade , Estimativa de Kaplan-Meier , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Nova Zelândia/epidemiologia , Razão de Chances , Peptidil Dipeptidase A/genética , Fenótipo , Prognóstico , Modelos de Riscos Proporcionais , Receptor Tipo 1 de Angiotensina/genética , Medição de Risco , Fatores de Risco , Fatores de TempoRESUMO
The aims of this study were to examine the relationships between CYP2D6 genotype and metoprolol dose, S- and R-metoprolol concentrations and clinical effects in patients with systolic heart failure. Data were obtained for 52 subjects, of which 27 had 2 functional alleles (24/27, CYP2D6*1/*1), 22 had 1 functional allele (18/22, CYP2D6*1/*4) and 3 had no functional alleles (CYP2D6*4/*4). Median dose-adjusted concentrations of S-metoprolol (active) were 6.3- and 3.2-fold higher in subjects with zero or one functional allele (P=0.016 and P=0.006), respectively, compared with subjects with two functional alleles. For the R-enantiomer (inactive), these concentrations were 10.7- and 3.7-fold higher (P=0.013 and P=0.003), respectively. Despite clear gene-concentration differences, no relationships between CYP2D6 genotype and dose or clinical effects could be shown. Although the number with no functional alleles was too small (n=3) to show effects, in patients with 1 functional allele other sources of variance are likely to be obscuring differences in clinical effects.
Assuntos
Antagonistas Adrenérgicos beta/uso terapêutico , Citocromo P-450 CYP2D6/genética , Insuficiência Cardíaca/tratamento farmacológico , Metoprolol/farmacologia , Sístole , Antagonistas Adrenérgicos beta/administração & dosagem , Alelos , Relação Dose-Resposta a Droga , Genótipo , Humanos , EstereoisomerismoRESUMO
BACKGROUND: Natriuretic peptides have actions likely to ameliorate cardiac dysfunction. B-type natriuretic peptide (BNP) is indicated as treatment for decompensated cardiac failure. OBJECTIVE: To determine the utility of BNP in acute myocardial infarction (MI). DESIGN: Double-blind randomised placebo-controlled trial. SETTING: Tertiary hospital coronary care unit. PATIENTS: 28 patients with acute MI with delayed or failed reperfusion and moderate left ventricular dysfunction. INTERVENTIONS: Infusion of BNP or placebo for 60 hours after MI. MAIN OUTCOME MEASURES: Neurohormonal activation and renal function in response to BNP infusion, secondary end points of echocardiographic measures of left ventricular function and dimension. RESULTS: BNP infusion resulted in a significant rise in BNP (276 pg/l vs 86 pg/l, p = 0.001). NT-proBNP levels were suppressed by BNP infusion (p = 0.002). Atrial natriuretic peptide (ANP) and NT-proANP levels fell with a significant difference in the pattern between BNP infusion and placebo during the first 5 days (p<0.005). C-type natriuretic peptide (CNP) and NT-proCNP levels rose during the infusion with higher levels than placebo at all measurements during the first 3 days (p<0.01). Cyclic guanosine monophosphate (cGMP) was raised during the infusion period showing a peak of 23 pmol/l on day 2 (placebo 8.9 pmol/l, p = 0.002), with a correlation between BNP and cGMP levels (p<0.001). Glomerular filtration rate (GFR) fell with BNP infusion but was not significantly lower than with placebo (71.0 (5.6) vs 75.8 (5.4) ml/min/1.73 m2, p = 0.62). Patients receiving nesiritide exhibited favourable trends in left ventricular remodelling. CONCLUSIONS: Nesiritide, given soon after MI, induced increments in plasma cGMP and CNP and decrements in other endogenous cardiac peptides with a neutral effect on renal function and a trend towards favourable ventricular remodelling.
Assuntos
Doença da Artéria Coronariana/tratamento farmacológico , GMP Cíclico/metabolismo , Infarto do Miocárdio/tratamento farmacológico , Natriuréticos/administração & dosagem , Peptídeo Natriurético Encefálico/administração & dosagem , Receptores do Fator Natriurético Atrial/administração & dosagem , Idoso , Fator Natriurético Atrial/sangue , Doença da Artéria Coronariana/sangue , Relação Dose-Resposta a Droga , Método Duplo-Cego , Ecocardiografia Doppler de Pulso/métodos , Feminino , Seguimentos , Humanos , Rim/efeitos dos fármacos , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/sangue , Peptídeo Natriurético Encefálico/sangue , Fragmentos de Peptídeos/sangue , Receptores do Fator Natriurético Atrial/sangueRESUMO
BACKGROUND: We sought to assess the utility of serial BNP measurements in patients with severe heart failure and attempted to correlate values with invasively derived data. METHODS: In a retrospective study, we analyzed serial BNP levels in patients receiving hemodynamically guided therapy for severe heart failure and sought correlation with invasively derived data. RESULTS: Thirty-nine patients with New York Heart Association Class III-IV, with an ejection fraction of 35% or less, who had a pulmonary artery catheter inserted for hemodynamically tailored heart failure therapy, were identified and serial BNP measurements reviewed. BNP was estimated on admission, at 12 and 36 hours. Normally distributed variables are expressed as mean +/- SD and otherwise as median +/- interquartile range. Mean ejection fraction was 16% +/- 6%. Mean pulmonary artery occlusion pressures (PAOP) fell with therapy and were 25 +/- 7 mmHg, 18 +/- 7 mmHg and 19 +/- 7 mmHg at admission, 12 hours and 36 hours respectively ( P < 0.05). Median BNP levels fell from 1200 +/- 641 to 771 +/- 803 at 12 hours and to 805 +/- 771 at 36 hours (P < .001). There was no correlation between BNP and any hemodynamically derived variable. A change in BNP was not associated with a change in PAOP in any individual patient. Only 42% remained alive on medical therapy at 30 days. CONCLUSIONS: In patients with severe heart failure, BNP levels do not accurately predict serial hemodynamic changes and do not obviate the need for pulmonary artery catheterization.
Assuntos
Cateterismo de Swan-Ganz , Insuficiência Cardíaca/diagnóstico , Peptídeo Natriurético Encefálico/sangue , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores/sangue , Feminino , Insuficiência Cardíaca/sangue , Insuficiência Cardíaca/tratamento farmacológico , Insuficiência Cardíaca/fisiopatologia , Hemodinâmica , Humanos , Masculino , Pessoa de Meia-Idade , Curva ROC , Sensibilidade e EspecificidadeRESUMO
The drug treatment of heart failure, once simple, has become complex. Apart from a loop diuretic and digoxin, most patients should now be receiving an angiotensin-converting enzyme inhibitor (or angiotensin II receptor blocker), a beta-blocker and spironolactone. Newer drugs, such as endothelin-receptor antagonists and combined blockers of converting-enzyme and neutral endopeptidase, might soon become available. When to introduce these drugs and what dose is optimal for any individual, are questions that currently vex clinicians. We proposed that plasma levels of the cardiac hormone brain natriuretic peptide (BNP, or better, its 1-76 amino-acid N-terminal fragment, N-BNP), would provide an objective index for guiding drug treatment in patients with established, stable cardiac failure. In a pilot study, 69 patients were randomized to drug treatment based on clinical criteria, or based on plasma levels of N-BNP. After a median follow-up of 9.6 months, those in the N-BNP group had fewer clinical end-points than those in the group managed by clinical criteria alone (19 vs 54; P= 0.02). These preliminary data encourage the concept that the increasingly complex pharmacotherapy for heart failure, both chronic (as in this trial) and acute, might best be guided by an objective measure such as plasma levels of BNP or N-BNP.
Assuntos
Insuficiência Cardíaca/sangue , Insuficiência Cardíaca/tratamento farmacológico , Peptídeo Natriurético Encefálico/sangue , Insuficiência Cardíaca/mortalidade , Humanos , Projetos Piloto , Sistemas Automatizados de Assistência Junto ao Leito , Resultado do TratamentoRESUMO
Experimental data indicate that adrenomedullin (AM) interacts at various levels with the renin-angiotensin-aldosterone system and the hypothalamic-pituitary-adrenal axis, but data from humans are scant. We examined the effects of intermediate-dose, short-term AM infusion on angiotensin II- and adrenocorticotrophic hormone (ACTH)-mediated hormone and haemodynamic responses in healthy subjects. Seven normal volunteers (age 18-25 years) completed a placebo-controlled crossover study. Each subject was studied on day 4 of two periods of a low-salt diet (40 mmol of sodium and 80 mmol of potassium daily), receiving incremental infusions of angiotensin II in the morning and ACTH in the afternoon of each study day, on a background infusion of AM (4 pmol.min(-1).kg(-1)) or vehicle (hemaccel). Achieved plasma AM levels (23+/-6 pmol/l) and peak angiotensin II levels (160 pmol/l) were similar on the two experimental days. While the pressor action of angiotensin II was attenuated by AM (P<0.01) and noradrenaline levels rose (P<0.05), the aldosterone response was unaltered. During ACTH infusion, AM increased heart rate (P<0.01), plasma adrenaline (P<0.01) and plasma noradrenaline (P<0.05), and augmented the cortisol response (P<0.01), but was without effect on aldosterone levels and blood pressure. We conclude that the threshold for the effects of AM on aldosterone secretion in humans is set higher than for other biological responses to this hormone, namely blood pressure, heart rate, sympathetic activity and cortisol secretion, under these experimental conditions.
Assuntos
Hormônio Adrenocorticotrópico/fisiologia , Angiotensina II/fisiologia , Hemodinâmica/efeitos dos fármacos , Peptídeos/farmacologia , Vasodilatadores/farmacologia , Adolescente , Adrenomedulina , Adulto , Aldosterona/sangue , Análise de Variância , Angiotensina II/sangue , Estudos Cross-Over , Dieta Hipossódica , Epinefrina/sangue , Hemodinâmica/fisiologia , Humanos , Infusões Intravenosas , Masculino , Norepinefrina/sangue , Peptídeos/sangue , Método Simples-Cego , Vasodilatadores/sangueRESUMO
Plasma levels of adrenomedullin are increased in chronic renal failure. The significance of this finding is uncertain, because the biological effects of adrenomedullin in renal impairment are unknown. Therefore, we studied the effects of adrenomedullin infusion in subjects with chronic renal impairment. Eight males with IgA nephropathy and plasma creatinine of 0.19+/-0.03 mmol/L (mean+/-SEM) were studied in a vehicle-controlled crossover design. Each subject was studied twice; subjects were administered either adrenomedullin at a low dose and then a high dose (2.9 and 5.8 pmol/kg per minute, respectively, for 2 hours each) or a 4-hour vehicle control (Hemaccel), in random order, on day 4 of controlled metabolic diets. Adrenomedullin infusion achieved plasma adrenomedullin concentrations in the pathophysiological range after the low (31.2+/-5.1 pmol/L) and high (47.4+/-4.3 pmol/L) dose, and plasma cAMP was increased. Compared with vehicle control, high-dose adrenomedullin increased peak heart rate (+21.7+/-3.3 bpm, P<0.01) and cardiac output (+2.9+/-0.2 L/min, P<0.01) and lowered both systolic and diastolic blood pressures by >10 mm Hg (P<0.05). Plasma renin activity, angiotensin II, and norepinephrine increased by up to 50% above baseline levels (P<0.05 for all), whereas aldosterone and epinephrine were unchanged. Urinary volume and sodium excretion increased significantly (P<0.05) with low-dose adrenomedullin, whereas creatinine clearance was stable, and proteinuria tended to decrease. In subjects with chronic renal impairment due to IgA nephropathy, adrenomedullin infusion lowered blood pressure, stimulated sympathetic activity and renin release, and caused diuresis and natriuresis. Adrenomedullin may have a role in modulating blood pressure and kidney function in renal disease.
Assuntos
Anti-Hipertensivos/farmacologia , Falência Renal Crônica/fisiopatologia , Natriurese/efeitos dos fármacos , Peptídeos/farmacologia , Adrenomedulina , Adulto , Anti-Hipertensivos/efeitos adversos , Pressão Sanguínea/efeitos dos fármacos , Estudos Cross-Over , Frequência Cardíaca/efeitos dos fármacos , Hormônios/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Peptídeos/efeitos adversosRESUMO
Although the biological effects of adrenomedullin (AM) and PAMP have been reported extensively in animal studies and from in-vitro experiments, relatively little information is available on responses to the hormone administered to man. This review summarizes data from the few studies carried out in man. In healthy volunteers, i.v. infusion of AM reduces arterial pressure, probably at a lower rate of administration than is required to elicit other responses. AM stimulates heart rate, cardiac output, plasma levels of cAMP, prolactin, norepinephrine and renin whilst inhibiting any concomitant response in plasma aldosterone. Little or no increase in urine volume or sodium excretion has been observed. Patients with essential hypertension differ only in showing a greater fall in arterial pressure and in the development of facial flushing and headache. In patients with heart failure or chronic renal failure, i.v. AM has similar effects to those seen in normal subjects but also induces a diuresis and natriuresis, depending on the dose administered. Infusion of AM into the brachial artery results in a dose-related increase in forearm and skin blood flow, more prominent and more dependent on endogenous nitric oxide in healthy volunteers than in patients with cardiac failure. When infused into a dorsal hand vein, AM partially reversed the venoconstrictor action of norepinephrine. Although much more information is required to clarify the role of AM under physiological and pathophysiological circumstances, it is clear that it has prominent hemodynamic and neurohormonal effects, though generally lesser urinary effects when administered short-term in doses sufficient to raise its levels in plasma to those seen in a number of clinical disorders. The only study of PAMP in man showed that its skeletal muscle vasodilator potency, when infused into the brachial artery of healthy volunteers, was less than one hundredth that of AM, and it was without effect on skin blood flow.
Assuntos
Doenças Cardiovasculares/prevenção & controle , Fragmentos de Peptídeos/uso terapêutico , Peptídeos/uso terapêutico , Proteínas/uso terapêutico , Adrenomedulina , Ensaios Clínicos como Assunto , Insuficiência Cardíaca/prevenção & controle , Humanos , Hipertensão/prevenção & controle , Hipertensão Pulmonar/prevenção & controle , Falência Renal Crônica/prevenção & controle , Fragmentos de Peptídeos/farmacologia , Peptídeos/farmacologia , Proteínas/farmacologia , Veias/efeitos dos fármacosRESUMO
Omapatrilat is a member of the new drug class of vasopeptidase inhibitors that may offer benefit in the treatment of heart failure (HF) through simultaneous inhibition of angiotensin-converting enzyme and neutral endopeptidase. We examined the effects of omapatrilat in a placebo-controlled crossover study using a pacing model of HF. Seven sheep were paced sequentially at 180 bpm (mild HF) and then 225 bpm (severe HF) for 7 days each. Omapatrilat (0.005 mg/kg) or vehicle was administered by intravenous bolus on days 4 to 7 of each paced period. Omapatrilat lowered mean arterial and left atrial pressure and increased cardiac output acutely and chronically in both mild and severe HF (P<0.01 for all). Plasma atrial and brain natriuretic peptide and cGMP levels were stable acutely (P=NS), while brain natriuretic peptide increased after repeated dosing in severe HF (P<0.05). Plasma renin activity rose, whereas angiotensin II and aldosterone levels fell after acute and repeated dosing in both states (P<0.01 for all). Omapatrilat increased urinary sodium excretion by day 7 in both mild and severe HF (P<0.05). Effective renal plasma flow and glomerular filtration rate increased or were stable after omapatrilat in mild and severe HF after both acute and repeated dosing. Omapatrilat exhibited pronounced acute and sustained beneficial hemodynamic and renal effects in both mild and severe heart failure.