RESUMO
THE ROLE OF ALDOSTERONE: Aldosterone is the key hormone in salt-water homeostasis. In heart failure, it participates in the appearance and maintenance of signs of congestion. Predominantly synthesised in the glomerular area of the cortico-adrenal glands, extra adrenal production areas have recently been identified notably in the brain, the heart and the large artery trunks. Aldosterone is activated in the cells by the intracellular mineral corticoid receptor. IN CARDIOVASCULAR-PATHOLOGIES: In chronic heart failure, patients treated with conversion enzyme inhibitor may escape from the renin-angiotensin blockade and this may lead to increased aldosterone plasma levels. This increase can induce not only vascular lesions and myocardial fibrosis but also renal and cerebral lesions. THE EFFECTS OF SPIRONOLACTONE: In patients with NYHA stage III or IV heart failure, addition of spironolactone to the treatment with conversion enzyme inhibitor, diuretic and/or digitalis leads to a reduction in morbidity and mortality, as demonstrated in the RALES study. The mechanisms by which spironolactone has a beneficial effect remain discussed. IN CLINICAL PRACTICE: The prescription of spironolactone is limited by hormonal side effects it provokes. IN THE FUTURE: Eplerenone, a new competitive aldosterone receptor antagonist that appears to be devoid of such side effects and which, at least experimentally may well have the same beneficial effects, is presently under clinical assessment.
Assuntos
Aldosterona/fisiologia , Diuréticos/uso terapêutico , Insuficiência Cardíaca/tratamento farmacológico , Insuficiência Cardíaca/fisiopatologia , Antagonistas de Receptores de Mineralocorticoides/uso terapêutico , Espironolactona/análogos & derivados , Espironolactona/uso terapêutico , Antagonistas Adrenérgicos beta/uso terapêutico , Aldosterona/sangue , Aldosterona/metabolismo , Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Doença Crônica , Diuréticos/administração & dosagem , Eplerenona , Insuficiência Cardíaca/mortalidade , Homeostase , Humanos , Antagonistas de Receptores de Mineralocorticoides/administração & dosagem , Antagonistas de Receptores de Mineralocorticoides/efeitos adversos , Estudos Multicêntricos como Assunto , Placebos , Ensaios Clínicos Controlados Aleatórios como Assunto , Receptores de Mineralocorticoides/fisiologia , Espironolactona/administração & dosagem , Espironolactona/efeitos adversos , Fatores de TempoRESUMO
Numerous studies of anti-thrombotic medications in the treatment of acute coronary syndromes have been published in the past few years. The "technical" quality of these studies is usually good. However, the critical reader must focus on the potential use of the observed differences for his patient. In particular, the judgement criteria chosen and the comparator used as reference treatment must be examined with care. Concerning the judgement criteria, it is often combined; it must therefore be decided which is or are the components of these criteria that are favourably influenced by the treatment. Similarly the clinical relevance of the chosen criteria must be questioned. This leads to a discussion of the substitution criteria. Then the judgement criteria must reflect the risk/benefit ratio: however few studies include haemorrhagic risk in the judgement criteria. The choice of comparator reflects current practice on the one hand, and the necessity to standardise the control group treatment on the other. This can continue for several years after the publication of a study, which brings into question whether the result would be identical taking into account the evolution of current practice. Analysis of anti-thrombotic studies with reference to these two criteria allows recommendations to be made concerning the use of anti-thrombotics in acute coronary syndromes.
Assuntos
Fibrinolíticos/uso terapêutico , Infarto do Miocárdio/tratamento farmacológico , Guias de Prática Clínica como Assunto , Humanos , Infarto do Miocárdio/patologia , Seleção de Pacientes , Fatores de RiscoRESUMO
The unique findings from the HOPE (Heart Outcomes Prevention Evaluation) study strongly support extending the use of the angiotensin-converting enzyme (ACE) inhibitor ramipril as a preventive agent for patients at high risk of cardiovascular events with normal left ventricular function. In addition, ramipril provides significant benefit in diabetic patients. These findings will impact on how ramipril is used in primary care, where ACE inhibitors are currently underprescribed. Patients reflecting the inclusion criteria of the HOPE study should be considered as suitable candidates for long-term ramipril therapy as an addition to their existing drug regimen. Screening should include control of kidney function (by serum creatinine), particularly within the first two weeks of treatment, in addition to regular monitoring of serum potassium. However, the HOPE study shows that ramipril is well tolerated at high doses and over a long treatment period. The effectiveness of therapy should also be regularly reviewed and dose adjustments made where necessary. If concern remains, referral to a specialist--a cardiologist or a diabetologist--may ultimately be necessary.
Assuntos
Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Doenças Cardiovasculares/prevenção & controle , Ramipril/uso terapêutico , Antagonistas Adrenérgicos beta/uso terapêutico , Algoritmos , Anticolesterolemiantes/uso terapêutico , Aspirina/uso terapêutico , Doenças Cardiovasculares/complicações , Ensaios Clínicos como Assunto , Complicações do Diabetes , Medicina de Família e Comunidade , Feminino , Humanos , Masculino , Inibidores da Agregação Plaquetária/uso terapêutico , Padrões de Prática MédicaRESUMO
BACKGROUND: Beta-blocking agents reduce the risk of hospitalization and death in patients with mild-to-moderate heart failure, but little is known about their effects in severe heart failure. METHODS: We evaluated 2289 patients who had symptoms of heart failure at rest or on minimal exertion, who were clinically euvolemic, and who had an ejection fraction of less than 25 percent. In a double-blind fashion, we randomly assigned 1133 patients to placebo and 1156 patients to treatment with carvedilol for a mean period of 10.4 months, during which standard therapy for heart failure was continued. Patients who required intensive care, had marked fluid retention, or were receiving intravenous vasodilators or positive inotropic drugs were excluded. RESULTS: There were 190 deaths in the placebo group and 130 deaths in the carvedilol group. This difference reflected a 35 percent decrease in the risk of death with carvedilol (95 percent confidence interval, 19 to 48 percent; P=0.00013, unadjusted; P=0.0014, adjusted for interim analyses). A total of 507 patients died or were hospitalized in the placebo group, as compared with 425 in the carvedilol group. This difference reflected a 24 percent decrease in the combined risk of death or hospitalization with carvedilol (95 percent confidence interval, 13 to 33 percent; P<0.001). The favorable effects on both end points were seen consistently in all the subgroups we examined, including patients with a history of recent or recurrent cardiac decompensation. Fewer patients in the carvedilol group than in the placebo group withdrew because of adverse effects or for other reasons (P=0.02). CONCLUSIONS: The previously reported benefits of carvedilol with regard to morbidity and mortality in patients with mild-to-moderate heart failure were also apparent in the patients with severe heart failure who were evaluated in this trial.
Assuntos
Antagonistas Adrenérgicos beta/uso terapêutico , Carbazóis/uso terapêutico , Insuficiência Cardíaca/tratamento farmacológico , Propanolaminas/uso terapêutico , Antagonistas Adrenérgicos beta/efeitos adversos , Idoso , Carbazóis/efeitos adversos , Carvedilol , Doença Crônica , Método Duplo-Cego , Feminino , Insuficiência Cardíaca/mortalidade , Hospitalização/estatística & dados numéricos , Humanos , Masculino , Pessoa de Meia-Idade , Propanolaminas/efeitos adversos , Modelos de Riscos Proporcionais , Estudos Prospectivos , Risco , Índice de Gravidade de Doença , Análise de SobrevidaRESUMO
BACKGROUND: We assessed the behavior of the baroreflex (BR) gain in chronic heart failure (CHF) patients using the spectral analysis method during application of a forcing stimulus, i.e. respiration. METHODS: Simultaneous RR interval and arterial pressure fluctuation recordings were obtained during two random-order periods of voluntary paced-breathing (0.15 Hz and 0.25 Hz) in seven patients with moderate CHF (NYHA class II/III; EF, 30+/-9%; peak VO(2), 18+/-5 ml kg(-1) min(-1)) and six age-matched controls. BR gain was assessed in the time (sequential method) and frequency (cross-spectral gain in the low and high frequency) domains. RESULTS: Slower breathing was associated with a BR gain decrease in CHF patients whereas a BR gain increase was evidenced in controls (BR gain: 6+/-5 ms mmHg(-1) at 0.25 Hz vs. 4+/-3 ms mmHg(-1) at 0.15 Hz, P<0.05 in CHF; BR gain: 12+/-7 ms mmHg(-1) at 0.25 Hz vs. 15+/-7 ms mmHg(-1) at 0.15 Hz, P<0.05 in controls). CONCLUSIONS: Voluntary breathing, which involves cortical centers in the brain, had major effects on cardiovascular system controller gain in CHF patients, indicating an impairment of the central neural regulation of the autonomic outflow.
Assuntos
Insuficiência Cardíaca/fisiopatologia , Pressorreceptores/fisiopatologia , Ventilação Pulmonar/fisiologia , Adulto , Sistema Nervoso Autônomo/fisiopatologia , Biorretroalimentação Psicológica/fisiologia , Pressão Sanguínea/fisiologia , Doença Crônica , Feminino , Insuficiência Cardíaca/diagnóstico , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
The aim of this study was to examine the nature of cardiovascular deaths occurring in a University Hospital. All the hospital files of 1999 of the Federation of Cardiology of Henri Mondor Hospital, Creteil, of patients who died in the department or after transfer to the intensive care unit or cardiac surgery department, were analysed. Myocardial ischaemia was the leading cause of death, occurring either in the acute phase of transmural infarction or in patients with chronic cardiac failure. Deaths occurring during acute myocardial infarction were associated with late treatment and/or non-reperfusion of the culprit artery. The delay of diagnosis seemed to be secondary to late consultation or difficulty in diagnosis. This resulted in severe left ventricular dysfunction and, in a quarter of cases, mechanical complications. They led to the early death of the patients (2.9 +/- 3.5 days after admission). Campaigns of patient information and education of doctors who see these patients would seem to be the most appropriate approach to reduce the delay before hospital admission in order to reduce mortality related to myocardial infarction. Cardiac failure is a common cause of death in cardiology departments. The deaths of patients occurred after a long follow-up and several days after hospital admission (11 +/- 10 days). Optimisation of the treatment of cardiac failure, the investigation of ischaemic heart disease, the search for new therapeutic strategies of acute cardiac failure and information of patients about their disease, seem to be the principal measures to take to improve the poor prognosis of this disease.
Assuntos
Doenças Cardiovasculares/mortalidade , Mortalidade Hospitalar/tendências , Idoso , Idoso de 80 Anos ou mais , Doenças Cardiovasculares/terapia , Diagnóstico Diferencial , Feminino , França/epidemiologia , Insuficiência Cardíaca/mortalidade , Insuficiência Cardíaca/terapia , Humanos , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/mortalidade , Infarto do Miocárdio/terapia , Prognóstico , Listas de EsperaRESUMO
OBJECTIVE: We compared the estimated costs of coronary interventions from our hospital's cost accounting system with data from the French Diagnosis Related Group (DRG) cost database, taking the perspective of our hospital. DESIGN: Cost data on hospital resources used by patients hospitalised for acute myocardial infarction (MI), with and without complications, including deceased patients, were collected in a tertiary care university hospital located in Paris, France. The data were collected using the hospital's cost accounting system and then compared with the estimates provided by the DRG reimbursement schedule for similar conditions. MAIN OUTCOME MEASURES AND RESULTS: The estimated costs were 849 euro (EUR) for coronary angiography, EUR4762 for coronary angioplasty with stenting, and EUR4978 to 8067 for MI. The DRG reimbursement schedule provided for acute MI was EUR3920 to 5709. CONCLUSIONS: Although the current cost of treating acute MI in a teaching hospital is reasonably close to that in the current reimbursement schedule, rapid technological changes regarding both drugs and devices renders necessary a close monitoring of costs associated with the management of these acute care patients.
Assuntos
Custos de Cuidados de Saúde , Infarto do Miocárdio/economia , Angioplastia Coronária com Balão/economia , Grupos Diagnósticos Relacionados , HumanosRESUMO
BACKGROUND: The efficacy of antihypertensive drugs newer than diuretics and beta-blockers has not been established. We compared the effects of the calcium-channel blocker nifedipine once daily with the diuretic combination co-amilozide on cardiovascular mortality and morbidity in high-risk patients with hypertension. METHODS: We did a prospective, randomised, double-blind trial in Europe and Israel in 6321 patients aged 55-80 years with hypertension (blood pressure > or = 150/95 mm Hg, or > or = 160 mm Hg systolic). Patients had at least one additional cardiovascular risk factor. We randomly assigned patients nifedipine 30 mg in a long-acting gastrointestinal-transport-system (GITS) formulation (n=3157), or co-amilozide (hydrochlorothiazide 25 mg [corrected] plus amiloride 2.5 mg; n=3164). Dose titration was by dose doubling, and addition of atenolol 25-50 mg or enalapril 5-10 mg. The primary outcome was cardiovascular death, myocardial infarction, heart failure, or stroke. Analysis was done by intention to treat. FINDINGS: Primary outcomes occurred in 200 (6.3%) patients in the nifedipine group and in 182 (5.8%) in the co-amilozide group (18.2 vs 16.5 events per 1000 patient-years; relative risk 1.10 [95% CI 0.91-1.34], p=0.35). Overall mean blood pressure fell from 173/99 mm Hg (SD 14/8) to 138/82 mm Hg (12/7). There was an 8% excess of withdrawals from the nifedipine group because of peripheral oedema (725 vs 518, p<0.0001), but serious adverse events were more frequent in the co-amilozide group (880 vs 796, p=0.02). Deaths were mainly non-vascular (nifedipine 176 vs co-amilozide 172; p=0.81). 80% of the primary events occurred in patients receiving randomised treatment (157 nifedipine, 147 co-amilozide, difference 0.33% [-0.7 to 1.4]). INTERPRETATION: Nifedipine once daily and co-amilozide were equally effective in preventing overall cardiovascular or cerebrovascular complications. The choice of drug can be decided by tolerability and blood-pressure response rather than long-term safety or efficacy.
Assuntos
Amilorida/administração & dosagem , Anti-Hipertensivos/administração & dosagem , Bloqueadores dos Canais de Cálcio/administração & dosagem , Diuréticos/uso terapêutico , Hidroclorotiazida/administração & dosagem , Hipertensão/complicações , Hipertensão/tratamento farmacológico , Nifedipino/administração & dosagem , Idoso , Idoso de 80 Anos ou mais , Química Farmacêutica , Preparações de Ação Retardada , Método Duplo-Cego , Combinação de Medicamentos , Humanos , Hipertensão/mortalidade , Tábuas de Vida , Pessoa de Meia-Idade , Estudos Prospectivos , Fatores de Risco , Resultado do TratamentoRESUMO
The results of large scale clinical trials are part of the scientific data on which medical and, in particular therapeutic decisions, are base; very concordant data may even be used to define appropriate or inappropriate prescribing behaviour in the context of recommendations or references of good medical practice. Large scale clinical trials, however, have limitations inherent to their method; they give a mean result observed in an average population. The true question is to know if the therapeutic benefit proved in a therapeutic trial will be observed in a given individual in the future. If the aim of treatment is to make a symptom disappear or act on an objective intermediate criterion related to the prognosis, the benefits for the individual are easy to assess. When the aim is to prolong life or prevent a recurrence of a serious illness, the probability of avoiding a complication by treatment is only a statistic. This probability depends o: the amplitude of the therapeutic benefit observed in the trials; the resemblance of the patient to the "mean population" included in trials; the comparison of the treatment of the patient with the "mean treatment" used in the trials. An exact understanding of scientifically proven data then encounters the limits of the capacity of human memory. Probability medicine remains, however, the method which enables, for a given patient, the choice of treatment with the greatest chance of being effective, providing the elementary rules of utilisation of the information are respected.
Assuntos
Ensaios Clínicos como Assunto , Medicina Baseada em Evidências , Insuficiência Cardíaca/terapia , Humanos , Guias de Prática Clínica como AssuntoRESUMO
The Study on COgnition and Prognosis in the Elderly (SCOPE) is a multi-centre, prospective, randomized, double-blind, parallel-group study. The primary objective of SCOPE is to assess the effect of the angiotensin II type 1 (AT1) receptor blocker, candesartan cilexetil 8-16 mg once daily, on major cardiovascular events in elderly patients (70-89 years of age) with mild hypertension (DBP 90-99 and/or SBP 160-179 mmHg). The secondary objectives of the study are to test the hypothesis that antihypertensive therapy can prevent cognitive decline (as measured by the Mini Mental State Examination, MMSE) and dementia, and to assess the effect of therapy on total mortality, myocardial infarction (MI), stroke, renal function, and hospitalization. A total of 4964 patients from 15 participating countries were recruited during the randomization phase of SCOPE, exceeding the target population of 4000. The mean age of the patients at enrolment was 76 years, the ratio of male to female patients was approximately 1:2, and 52% of patients were already being treated with an antihypertensive agent at enrolment. The majority of patients (88%) were educated to at least primary school level. At randomization, mean sitting blood pressure values were SBP 166 mmHg and DBP 90 mmHg, and the mean MMSE score was 28. Previous cardiovascular disease in the study population included myocardial infarction (4%), stroke (4%) and atrial fibrillation (4%). Men, more often than women, had a history of previous MI, stroke and atrial fibrillation. A greater percentage of men were smokers (13% vs 6% in women) and had attended university (11% vs 3% of women). Of the randomized patients, 21% were 80 years of age. In this age group smoking was less common (4% vs 10% for 70-79-year-olds) and fewer had attended university (4% vs 7% for 70-79-year-olds). The incidence of MI was similar in both age groups. However, stroke and atrial fibrillation had occurred approximately twice as frequently in the older patients. The patients' mean age at baseline was similar in the participating countries, and most countries showed the approximate 1:2 ratio for male to female patients. There was also little inter-country variation in terms of mean SBP, DBP or MMSE score. However, there was considerable regional variation in the percentage of patients on therapy prior to enrolment.
Assuntos
Envelhecimento/psicologia , Antagonistas de Receptores de Angiotensina , Anti-Hipertensivos/uso terapêutico , Benzimidazóis/uso terapêutico , Compostos de Bifenilo/uso terapêutico , Doenças Cardiovasculares/prevenção & controle , Cognição/fisiologia , Tetrazóis , Idoso , Idoso de 80 Anos ou mais , Doenças Cardiovasculares/epidemiologia , Doenças Cardiovasculares/etiologia , Transtornos Cognitivos/prevenção & controle , Demência/prevenção & controle , Método Duplo-Cego , Feminino , Humanos , Incidência , Masculino , Prognóstico , Receptor Tipo 1 de Angiotensina , Receptor Tipo 2 de Angiotensina , Fatores de Risco , Caracteres SexuaisRESUMO
The aim of our investigation was to determine whether the presence of additional risk factors or type of hypertension (diastolic or isolated systolic) influences blood pressure (BP) response to treatment. The International Nifedipine GITS Study: Intervention as a Goal in Hypertension Treatment (INSIGHT) study is a double-blinded outcome comparison of calcium channel blockade with diuretics in high-risk patients aged 55 to 80 years. Dynamic randomization between nifedipine once daily and hydrochlorothiazide/amiloride was performed to ensure that approximately equal numbers of patients in the 2 groups had each of the major cardiovascular risk factors. Patients with isolated systolic hypertension were also separately randomized. Atenolol or enalapril was the mandatory second-line drug. In 5669 patients who completed the 18-week titration, BP fell from 172+/-15/99+/-9 mm Hg (mean+/-SD) while receiving placebo to 139+/-12/82+/-7 mm Hg. Twenty-six percent of patients required 2 drugs, and 4% required 3 drugs. Patients with diabetes were the most resistant to treatment, requiring second and third drugs 40% and 100% more frequently than patients without diabetes and achieving marginally the highest final BP, for any risk group, of 141+/-13/82+/-8 mm Hg. Age, smoking, gender, hypercholesterolemia, left ventricular hypertrophy, and existing atherosclerosis had little (<1 mm Hg) or no influence on BP at the end of titration, but all except smoking slightly reduced the initial response of either systolic or diastolic BP. Patients with isolated systolic hypertension were slightly more responsive than average to treatment. Our findings suggest that in patients at high absolute risk of cardiovascular complications from hypertension, the risk factors themselves do not prevent the recommended BP targets from being achieved.
Assuntos
Anti-Hipertensivos/administração & dosagem , Pressão Sanguínea/efeitos dos fármacos , Diabetes Mellitus/fisiopatologia , Hipertensão/tratamento farmacológico , Hipertensão/fisiopatologia , Idoso , Idoso de 80 Anos ou mais , Atenolol/administração & dosagem , Bloqueadores dos Canais de Cálcio/administração & dosagem , Complicações do Diabetes , Diástole , Diuréticos/administração & dosagem , Método Duplo-Cego , Enalapril/administração & dosagem , Feminino , Humanos , Hipertensão/complicações , Masculino , Pessoa de Meia-Idade , Fatores de Risco , SístoleRESUMO
OBJECTIVES: To evaluate the effects of exogenous bradykinin on coronary epicardial and microcirculatory tone in transplant patients (HTXs), and to compare them with the effects of acetylcholine. BACKGROUND: Coronary endothelial dysfunction has been reported to occur early after heart transplantation, most notably when acetylcholine was the endothelium-function marker used. The effects of bradykinin on coronary vasomotion are unknown in HTXs. METHODS: Sixteen HTXs were compared 3.6 +/- 1.7 months after transplantation to seven control subjects. Coronary flow velocity was measured using guide-wire Doppler. Diameters (D) of three segments of the left coronary artery and coronary blood flow (CBF) were assessed at baseline, after 3-min infusions of increasing bradykinin doses (50, 150 and 250 ng/min) then of increasing acetylcholine doses (estimated blood concentrations of 10(-8), 10(-7) and 10(-6) M). RESULTS: Bradykinin induced similar dose-dependent increases in D and CBF in both groups: D was 11 +/- 12%, 19 +/- 14% and 22 +/- 16% (all p < 0.0001), and CBF was 50 +/- 40%, 130 +/- 68% and 186 +/- 77% (all p < 0.0001). Acetylcholine induced significant epicardial vasodilation in control subjects and vasoconstriction in HTX, as well as a marked increase in CBF in both groups. Acute allograft rejection, present in 8 of the 16 HTXs, did not modify responses to bradykinin, but was associated with a smaller CBF increase in response to acetylcholine (p < 0.05). CONCLUSIONS: The coronary vasodilating effects of bradykinin are preserved early after heart transplantation, even in the presence of acute allograft rejection. Although there is an abnormal vasoconstricting response to acetylcholine reflecting endothelium dysfunction, the endothelium remains a functionally active organ in heart transplant recipients.
Assuntos
Bradicinina , Circulação Coronária/efeitos dos fármacos , Rejeição de Enxerto/diagnóstico , Transplante de Coração/fisiologia , Resistência Vascular/efeitos dos fármacos , Acetilcolina , Adulto , Velocidade do Fluxo Sanguíneo/efeitos dos fármacos , Velocidade do Fluxo Sanguíneo/fisiologia , Cineangiografia , Circulação Coronária/fisiologia , Endotélio Vascular/efeitos dos fármacos , Endotélio Vascular/fisiopatologia , Feminino , Rejeição de Enxerto/fisiopatologia , Humanos , Fluxometria por Laser-Doppler , Masculino , Pessoa de Meia-Idade , Valores de Referência , Resistência Vascular/fisiologiaRESUMO
BACKGROUND: Constitutive bradykinin B(1) receptors have been identified in dogs; however, their physiological implications involving the coronary circulation remain to be determined. This study examined, in conscious dogs, the coronary response to des-Arg(9)-bradykinin (a B(1) receptor agonist) and the mechanisms involved. METHODS AND RESULTS: Eleven dogs were instrumented with a left ventricular micromanometer, a circumflex coronary catheter, a cuff occluder, a Doppler flow probe, and ultrasonic crystals to measure coronary blood flow velocity (CBFv) and coronary diameter (CD). Intracoronary des-Arg(9)-bradykinin (3 to 100 ng/kg) and bradykinin (0.1 to 10 ng/kg) did not modify systemic hemodynamics but dose-dependently increased CBFv and CD. Des-Arg(9)-bradykinin was less potent than bradykinin. Hoe 140 (a B(2) antagonist, 10 microg/kg) abolished the effects of bradykinin but did not influence the effects of des-Arg(9)-bradykinin. When CBFv increase was prevented by the cuff occluder, CD responses to bradykinin and des-Arg(9)-bradykinin were maintained. Intracoronary lisinopril (0. 75 mg) increased the CD response to bradykinin, with only minimal effect on CBFv, and extended the duration of the effect. Lisinopril did not alter des-Arg(9)-bradykinin responses. Intracoronary N(omega)-nitro-L-arginine (2 mg/kg) decreased the CD effect of bradykinin and prevented the CBFv and CD effects of des-Arg(9)-bradykinin. The relaxing effect of des-Arg(9)-bradykinin on isolated coronary rings was prevented by des-Arg(9), [Leu(8)]-bradykinin. CONCLUSIONS: In the conscious dog, B(1) receptors are present in coronary vessels, and their stimulation produces vasodilation in conductance and resistance vessels, which is mediated essentially by NO but not modulated by angiotensin-converting enzyme. However, the coronary vasodilation induced by B(1) receptor stimulation is not as great as that produced by B(2) receptor stimulation.
Assuntos
Vasos Coronários/fisiologia , Receptores da Bradicinina/fisiologia , Vasodilatação/fisiologia , Inibidores da Enzima Conversora de Angiotensina/farmacologia , Anilidas/farmacologia , Animais , Arginina/análogos & derivados , Arginina/farmacologia , Bradicinina/análogos & derivados , Bradicinina/farmacologia , Antagonistas dos Receptores da Bradicinina , Vasos Coronários/efeitos dos fármacos , Cães , Hemodinâmica/efeitos dos fármacos , Técnicas In Vitro , Lisinopril/farmacologia , Óxido Nítrico/fisiologia , Óxido Nítrico Sintase/antagonistas & inibidores , Receptor B1 da Bradicinina , Receptor B2 da BradicininaRESUMO
OBJECTIVE: To determine the long-term efficacy and safety of a fixed, very-low-dose tablet combining one-half the standard dose of perindopril with one-quarter the standard dose of indapamide as first-line treatment in elderly patients. DESIGN: Double-blind, randomized, placebo-controlled study in an outpatient setting. PATIENTS AND INTERVENTIONS: Following a single-blind, placebo run-in period of 4 weeks, patients [65-85 years, with mild-to-moderate essential hypertension or isolated systolic hypertension (ISH)] were randomized to receive one tablet of perindopril 2 mg/indapamide 0.625 mg (Per/ Ind) (n=193) or placebo (n=190), daily for 12 weeks. After this first 12-week period, all patients on Per/Ind (n=138) and patients responding to placebo (n=61) were maintained on their previous regimen for a further 48 weeks. Patients in the placebo group whose blood pressure was not normalized, were switched to Per/Ind (n=60). MAIN OUTCOME MEASURE: The primary endpoint was the proportion of patients with blood pressure that normalized between weeks 0 and 60. RESULTS: After 1 year of treatment (intention-to-treat) supine systolic and diastolic blood pressure decreased by 23.0 +/- 15.3 mmHg and 13.3 +/- 94 mmHg with Per/Ind (n=253: 193 from randomized Per/Ind group and 60 from the placebo group switched at week 12). The mean decreases in systolic blood pressure were similar in essential hypertension and ISH (systolic blood pressure 23.2 versus 22.7 mmHg, respectively). Per/Ind treatment (n=253) achieved an initial normalization of blood pressure in 96.2% [95% confidence interval (CI) 93.6-98.9%; Kaplan-Meier estimate] of Per/Ind-treated patients; 79.8% (95% CI 74.1-85.5%) of these maintained a normalized blood pressure throughout the 1 -year follow-up. The incidence of adverse events was similarly low in the placebo and active therapy groups. Efficacy and safety results for the over 75 years subgroup were similar to those for the younger elderly subjects CONCLUSIONS: The fixed, very low-dose combination of perindopril 2 mg/indapamide 0.625 mg results in sustained blood pressure control when used as first line treatment of elderly hypertensive patients over 1-year, and is well-tolerated.
Assuntos
Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Anti-Hipertensivos/uso terapêutico , Diuréticos/uso terapêutico , Hipertensão/tratamento farmacológico , Indapamida/uso terapêutico , Perindopril/uso terapêutico , Idoso , Idoso de 80 Anos ou mais , Inibidores da Enzima Conversora de Angiotensina/efeitos adversos , Anti-Hipertensivos/efeitos adversos , Pressão Sanguínea/efeitos dos fármacos , Diuréticos/efeitos adversos , Relação Dose-Resposta a Droga , Método Duplo-Cego , Feminino , Humanos , Hipertensão/fisiopatologia , Indapamida/efeitos adversos , Estudos Longitudinais , Masculino , Perindopril/efeitos adversos , Resultado do TratamentoRESUMO
The Study on COgnition and Prognosis in the Elderly (SCOPE) is a multicentre, prospective, randomized, double-blind, parallel-group study designed to compare the effects of candesartan cilexetil and placebo in elderly patients with mild hypertension. The primary objective of the study is to assess the effect of candesartan cilexetil on major cardiovascular events. The secondary objectives of the study are to assess the effect of candesartan cilexetil on cognitive function and on total mortality, cardiovascular mortality, myocardial infarction, stroke, renal function, hospitalization, quality of life and health economics. Male and female patients aged between 70 and 89 years, with a sitting systolic blood pressure (SBP) of 160-179 mmHg and/or diastolic blood pressure (DBP) of 90-99 mmHg, and a Mini-Mental State Examination (MMSE) score of 24 or above, are eligible for the study. The overall target study population is 4000 patients, at least 1000 of whom are also to be assessed for quality of life and health economics data. After an open run-in period lasting 1-3 months, during which patients are assessed for eligibility and those who are already on antihypertensive therapy at enrolment are switched to hydrochlorothiazide 12.5 mg o.d., patients are randomized to receive either candesartan cilexetil 8 mg once daily (o.d.) or matching placebo o.d. At subsequent study visits, if SBP remains >160 mmHg, or has decreased by <10 mmHg since the randomization visit, or DBP is >85 mmHg, study treatment is doubled to candesartan cilexetil 16 mg o.d. or two placebo tablets o.d. Recruitment was completed in January 1999. At that time 4964 patients had been randomized. All randomized patients will be followed for an additional 2 years. If the event rate is lower than anticipated, the follow-up will be prolonged.
Assuntos
Antagonistas de Receptores de Angiotensina , Anti-Hipertensivos/uso terapêutico , Benzimidazóis/uso terapêutico , Compostos de Bifenilo/uso terapêutico , Doenças Cardiovasculares/prevenção & controle , Cognição/efeitos dos fármacos , Hipertensão/tratamento farmacológico , Hipertensão/psicologia , Tetrazóis , Idoso , Idoso de 80 Anos ou mais , Doenças Cardiovasculares/etiologia , Doenças Cardiovasculares/mortalidade , Método Duplo-Cego , Feminino , Serviços de Saúde/economia , Serviços de Saúde/estatística & dados numéricos , Humanos , Hipertensão/complicações , Masculino , Prognóstico , Estudos Prospectivos , Qualidade de Vida , Fatores de RiscoRESUMO
Platelet active drugs are part of the antithrombotics. Their biological effect is not assessed in current practice. Their clinical efficacy has been firmly established in randomised controlled trials. Aspirin has been the most widely tested drug and is effective in various forms of coronary artery disease and in the secondary prevention after a first ischaemic stroke; in these settings, aspirin reduces the incidence of myocardial infarction, stroke and cardiac death; aspirin has been tested in various daily doses from 30 to 1300 mg: best evidence has been gathered for dosages between 75 and 300 mg; good clinical practice is to use the lowest effective dose. Ticlopidine and clopidogrel have been shown to be superior to aspirin in 2 trials where the incidence of myocardial infarction has been lowered by the new drugs; nevertheless the superiority is apparent only in patients with lower limb atherosclerosis and after stroke. The combination of dipyridamole and aspirin has been proven to be superior to aspirin in the secondary prevention of stroke in one trial contrasting with the other trials performed with other combinations of those two drugs. Glycoprotein GP IIb/IIIa antagonists have been tested in coronary angioplasty and in acute coronary syndromes and only in short intravenous administration; these drugs reduce the incidence of myocardial infarction without any effect on 6-month mortality.
Assuntos
Infarto do Miocárdio/prevenção & controle , Inibidores da Agregação Plaquetária/uso terapêutico , Acidente Vascular Cerebral/prevenção & controle , Relação Dose-Resposta a Droga , Humanos , Inibidores da Agregação Plaquetária/administração & dosagem , Inibidores da Agregação Plaquetária/farmacologiaRESUMO
The alphaIIbbeta3 platelet receptor antagonist abciximab (c7E3Fab, ReoPro(R)) has proved to be effective in preventing arterial thrombosis. However, its binding capacity to the platelet precursors, megakaryocytes (MKs), which also express alphaIIbbeta3, is not known. The purpose of this study was to establish whether abciximab is able to react with alphaIIbbeta3 located on human MKs, and to follow its subsequent intracellular trafficking. MKs were grown from CD34+ progenitors from normal subjects and from a patient with type I Glanzmann's thrombasthenia, and abciximab was added at day 10 of culture (4 microgram/ml). Cells were fixed at day 12, cryosectioned, and immunolabelled for abciximab. Labelling was prominent on the MK plasma membrane; it also lined the demarcation membration system. Interestingly, alpha-granule membranes were labelled showing that the antibody was internalized and further stored into MK secretory granules. Abciximab was also strongly detected on and in newly-formed platelets. Glanzmann's disease MKs (which completely lacked alphaIIbbeta3) were consistently negative, confirming that the antibody fragment was specifically interacting with alphaIIbbeta3. In conclusion, this study demonstrated that abciximab: (i) binds MK plasma membrane and demarcation membranes, (ii) trafficks into alpha-granules, and (iii) is expressed on and in nascent platelets. These findings could be taken in account when monitoring anti-alphaIIbbeta3 receptor therapy.
Assuntos
Anticorpos Monoclonais/metabolismo , Fragmentos Fab das Imunoglobulinas/metabolismo , Megacariócitos/metabolismo , Inibidores da Agregação Plaquetária/metabolismo , Trombastenia/metabolismo , Abciximab , Transporte Biológico , Células Cultivadas , Humanos , Immunoblotting , Megacariócitos/ultraestrutura , Microscopia EletrônicaRESUMO
The efficacy and safety of 12 weeks treatment with an oral fixed low-dose perindopril 2 mg + indapamide 0.625 mg (Per/Ind) combination in elderly and very elderly patients (65-85 years) with mild to moderate systolic and diastolic hypertension (SDH) or isolated systolic hypertension (ISH) were investigated vs placebo. This trial was a multinational randomized double-blind study with doubling of active drug dosage in nonresponders. Intention to treat analysis was performed in 383 patients (age 72.4 years; ISH 32%). 58.5% remained on their initial dosage. Per/Ind decreased supine diastolic and systolic blood pressure (sDBP/sSBP) by 13.2+/-8.0 mm Hg and 22.5+/-13.9 mm Hg (P <.0001) versus placebo -7.3+/-9.0 mm Hg and -12.3+/-15.2 mm Hg, respectively. In ISH (n = 123), Per/Ind decreased sSBP by 23.0+/-11.8 mm Hg (P <.0001). Overall response and normotension rates was 81.3% with Per/Ind (P <.0001). Adverse event rates (including hypokalemia) were similarly low in both groups. Analysis in the over-75 year subgroup showed similar safety and efficacy results. Fixed low-dose Per/Ind is a safe and effective treatment of hypertension including isolated systolic hypertension in the elderly.
Assuntos
Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Diuréticos/uso terapêutico , Hipertensão/tratamento farmacológico , Indapamida/uso terapêutico , Perindopril/uso terapêutico , Administração Oral , Idoso , Idoso de 80 Anos ou mais , Inibidores da Enzima Conversora de Angiotensina/administração & dosagem , Pressão Sanguínea/efeitos dos fármacos , Diuréticos/administração & dosagem , Método Duplo-Cego , Quimioterapia Combinada , Feminino , Humanos , Hipertensão/sangue , Hipertensão/fisiopatologia , Indapamida/administração & dosagem , Masculino , Pessoa de Meia-Idade , Perindopril/administração & dosagem , Potássio/sangue , Segurança , Resultado do TratamentoRESUMO
OBJECTIVES: We sought to evaluate dobutamine stress echocardiography (DSE) for predicting recovery of viable myocardium after revascularization with cineangiography as a gold standard for left ventricular (LV) function. We studied the influence of late vessel reocclusion on regional LV function. BACKGROUND: Dobutamine stress echocardiography is a well established evaluation method for myocardial viability assessment. In previous studies the reference method for assessing LV recovery was echocardiography, long-term vessel patency has not been systematically addressed. METHODS: Sixty-eight patients with a first acute myocardial infarction (AMI) and residual stenosis of the infarct related artery (IRA) underwent DSE (mean +/- standard deviation) 21 +/- 12 days after AMI to evaluate myocardial viability. Revascularization of the IRA was performed in 54 patients by angioplasty (n = 43) or bypass grafting (n = 11). Coronary angiography and LV cineangiography were repeated at four months to assess LV function and IRA patency. RESULTS: Sensitivity and specificity of DSE for predicting myocardial recovery after revascularization were 83% and 82%. In the case of late IRA patency, specificity increased to 95%, whereas sensitivity remained unchanged. In the 16 patients with myocardial viability and late IRA patency, echocardiographic wall motion score index decreased after revascularization from 1.83 +/- 0.15 to 1.36 +/- 0.17 (p = 0.0001), and left ventricular ejection fraction (LVEF) increased from 0.52 +/- 0.06 to 0.57 +/- 0.06 (p = 0.0004), whereas in five patients, reocclusion of the IRA prevented improvement of segmental or global LV function despite initially viable myocardium. CONCLUSIONS: Dobutamine stress echocardiography is reliable to predict recovery of viable myocardium after revascularization in postinfarction patients. Late reocclusion of the IRA may prevent LV recovery and influence the accuracy of DSE.
Assuntos
Angioplastia Coronária com Balão , Ponte de Artéria Coronária , Contração Miocárdica/fisiologia , Infarto do Miocárdio/terapia , Função Ventricular Esquerda/fisiologia , Adulto , Idoso , Cardiotônicos , Cineangiografia , Angiografia Coronária , Dobutamina , Ecocardiografia , Teste de Esforço , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/diagnóstico , Infarto do Miocárdio/fisiopatologia , Variações Dependentes do Observador , Sensibilidade e Especificidade , Sobrevivência de Tecidos/fisiologiaRESUMO
BACKGROUND AND METHODS: Aldosterone is important in the pathophysiology of heart failure. In a doubleblind study, we enrolled 1663 patients who had severe heart failure and a left ventricular ejection fraction of no more than 35 percent and who were being treated with an angiotensin-converting-enzyme inhibitor, a loop diuretic, and in most cases digoxin. A total of 822 patients were randomly assigned to receive 25 mg of spironolactone daily, and 841 to receive placebo. The primary end point was death from all causes. RESULTS: The trial was discontinued early, after a mean follow-up period of 24 months, because an interim analysis determined that spironolactone was efficacious. There were 386 deaths in the placebo group (46 percent) and 284 in the spironolactone group (35 percent; relative risk of death, 0.70; 95 percent confidence interval, 0.60 to 0.82; P<0.001). This 30 percent reduction in the risk of death among patients in the spironolactone group was attributed to a lower risk of both death from progressive heart failure and sudden death from cardiac causes. The frequency of hospitalization for worsening heart failure was 35 percent lower in the spironolactone group than in the placebo group (relative risk of hospitalization, 0.65; 95 percent confidence interval, 0.54 to 0.77; P<0.001). In addition, patients who received spironolactone had a significant improvement in the symptoms of heart failure, as assessed on the basis of the New York Heart Association functional class (P<0.001). Gynecomastia or breast pain was reported in 10 percent of men who were treated with spironolactone, as compared with 1 percent of men in the placebo group (P<0.001). The incidence of serious hyperkalemia was minimal in both groups of patients. CONCLUSIONS: Blockade of aldosterone receptors by spironolactone, in addition to standard therapy, substantially reduces the risk of both morbidity and death among patients with severe heart failure.