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1.
Pharmacogenomics J ; 18(2): 232-237, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-28440343

RESUMO

Despite its established inter-individual variability, sildenafil has been the subject of only a few pharmacogenetic investigations, with limited data regarding the genetic modulators of its pharmacokinetics. We conducted a pharmacogenetic sub-study of patients randomized to sildenafil (n=85) in the RELAX trial, which investigated the impact of high-dose sildenafil in patients with heart failure with preserved left ventricular ejection fraction (HFpEF). In the overall population, the CYP3A4 inferred phenotype appeared associated with the dose-adjusted peak concentrations of sildenafil at week 12 and week 24 (adjusted P=0.045 for repeated measures analysis), although this P-value did not meet our corrected significance threshold of 0.0167. In the more homogeneous Caucasian subgroup, this association was significant (adjusted P=0.0165 for repeated measures). Hence, CYP3A4 inferred phenotype is associated with peak sildenafil dose-adjusted concentrations in patients with HFpEF receiving high doses of sildenafil. The clinical impact of this association requires further investigation.


Assuntos
Citocromo P-450 CYP3A/genética , Genótipo , Insuficiência Cardíaca/genética , Citrato de Sildenafila/uso terapêutico , Volume Sistólico/genética , Vasodilatadores/uso terapêutico , Idoso , Tolerância ao Exercício/efeitos dos fármacos , Tolerância ao Exercício/genética , Feminino , Insuficiência Cardíaca/sangue , Insuficiência Cardíaca/tratamento farmacológico , Humanos , Masculino , Pessoa de Meia-Idade , Citrato de Sildenafila/sangue , Citrato de Sildenafila/farmacologia , Volume Sistólico/efeitos dos fármacos , Vasodilatadores/sangue , Vasodilatadores/farmacologia
2.
Pharmacogenomics J ; 17(2): 192-200, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-26927285

RESUMO

We conducted a meta-analysis of pharmacogenomic substudies of three randomized trials conducted in patients with decompensated heart failure (HF) that were led by National Heart Lung and Blood Institute (NHLBI)-funded HF Network to test the hypothesis that candidate genes modulate net fluid loss and weight change in patients with decompensated HF treated with a furosemide-based diuretic regimen. Although none of the genetic variants previously shown to modulate the effects of loop diuretics in healthy individuals were associated with net fluid loss after 72 h of treatment, a set of rare variants in the APOL1 gene, which codes for apolipoprotein L1 (P=0.0005 in the random effects model), was associated with this end point. Moreover, a common variant in the multidrug resistance protein-4 coding gene (ABCC4, rs17268282) was associated with weight loss with furosemide use (P=0.0001). Our results suggest that both common and rare genetic variants modulate the response to a furosemide-based diuretic regimen in patients with decompensated HF.


Assuntos
Apolipoproteínas/genética , Furosemida/administração & dosagem , Insuficiência Cardíaca/tratamento farmacológico , Lipoproteínas HDL/genética , Proteínas Associadas à Resistência a Múltiplos Medicamentos/genética , Variantes Farmacogenômicos , Polimorfismo de Nucleotídeo Único , Inibidores de Simportadores de Cloreto de Sódio e Potássio/administração & dosagem , Administração Intravenosa , Idoso , Idoso de 80 Anos ou mais , Apolipoproteína L1 , Ensaios Clínicos como Assunto , Feminino , Deslocamentos de Líquidos Corporais/efeitos dos fármacos , Genótipo , Insuficiência Cardíaca/diagnóstico , Insuficiência Cardíaca/genética , Insuficiência Cardíaca/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Farmacogenética , Fenótipo , Fatores de Tempo , Resultado do Tratamento , Equilíbrio Hidroeletrolítico/efeitos dos fármacos
3.
Pharmacogenomics J ; 15(1): 13-9, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24980785

RESUMO

It is not yet known whether healthy individuals and patients with a chronic disease have similar attitudes towards pharmacogenomics. Thus we conducted a survey of 175 healthy volunteers, 175 heart failure (HF) patients and 100 heart transplant recipients to compare their opinions on this subject. Most participants (>90%) stated that they would accept pharmacogenomic testing and expressed high hopes regarding its potential applications. Overall, interest for pharmacogenomics was shared equally among the three groups. In contrast, after adjusting for age, gender, education and income, healthy individuals were more likely to voice concerns about potential employment (P=0.008 vs HF, odds ratio (OR)=2.93, confidence interval (CI)=1.33-6.47; P=0.010 vs Transplant, OR=2.46, CI=1.24-4.90) and insurance discrimination (P=0.001 vs HF, OR=5.58, CI=2.01-15.48; P<0.001 vs Transplant, OR=4.98, CI=2.03-12.21) and were possibly more worried by confidentiality issues. These findings highlight the need for strict legislation and proper educational strategies directed at the general population to facilitate the clinical implementation of pharmacogenomics.


Assuntos
Cultura , Insuficiência Cardíaca/psicologia , Transplante de Coração/psicologia , Esperança , Farmacogenética , Transplantados/psicologia , Adulto , Idoso , Estudos Transversais , Feminino , Insuficiência Cardíaca/genética , Insuficiência Cardíaca/cirurgia , Humanos , Masculino , Pessoa de Meia-Idade , Farmacogenética/tendências
4.
N Engl J Med ; 365(1): 32-43, 2011 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-21732835

RESUMO

BACKGROUND: Nesiritide is approved in the United States for early relief of dyspnea in patients with acute heart failure. Previous meta-analyses have raised questions regarding renal toxicity and the mortality associated with this agent. METHODS: We randomly assigned 7141 patients who were hospitalized with acute heart failure to receive either nesiritide or placebo for 24 to 168 hours in addition to standard care. Coprimary end points were the change in dyspnea at 6 and 24 hours, as measured on a 7-point Likert scale, and the composite end point of rehospitalization for heart failure or death within 30 days. RESULTS: Patients randomly assigned to nesiritide, as compared with those assigned to placebo, more frequently reported markedly or moderately improved dyspnea at 6 hours (44.5% vs. 42.1%, P=0.03) and 24 hours (68.2% vs. 66.1%, P=0.007), but the prespecified level for significance (P≤0.005 for both assessments or P≤0.0025 for either) was not met. The rate of rehospitalization for heart failure or death from any cause within 30 days was 9.4% in the nesiritide group versus 10.1% in the placebo group (absolute difference, -0.7 percentage points; 95% confidence interval [CI], -2.1 to 0.7; P=0.31). There were no significant differences in rates of death from any cause at 30 days (3.6% with nesiritide vs. 4.0% with placebo; absolute difference, -0.4 percentage points; 95% CI, -1.3 to 0.5) or rates of worsening renal function, defined by more than a 25% decrease in the estimated glomerular filtration rate (31.4% vs. 29.5%; odds ratio, 1.09; 95% CI, 0.98 to 1.21; P=0.11). CONCLUSIONS: Nesiritide was not associated with an increase or a decrease in the rate of death and rehospitalization and had a small, nonsignificant effect on dyspnea when used in combination with other therapies. It was not associated with a worsening of renal function, but it was associated with an increase in rates of hypotension. On the basis of these results, nesiritide cannot be recommended for routine use in the broad population of patients with acute heart failure. (Funded by Scios; ClinicalTrials.gov number, NCT00475852.).


Assuntos
Dispneia/tratamento farmacológico , Insuficiência Cardíaca/tratamento farmacológico , Natriuréticos/uso terapêutico , Peptídeo Natriurético Encefálico/uso terapêutico , Readmissão do Paciente/estatística & dados numéricos , Doença Aguda , Idoso , Método Duplo-Cego , Dispneia/etiologia , Feminino , Insuficiência Cardíaca/complicações , Insuficiência Cardíaca/mortalidade , Humanos , Hipotensão/induzido quimicamente , Análise de Intenção de Tratamento , Nefropatias/etiologia , Masculino , Pessoa de Meia-Idade , Natriuréticos/efeitos adversos , Peptídeo Natriurético Encefálico/efeitos adversos , Recidiva
5.
Circulation ; 104(15): 1856-62, 2001 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-11591626

RESUMO

The cardiovascular system is regulated by hemodynamic and neurohumoral mechanisms. These regulatory systems play a key role in modulating cardiac function, vascular tone, and structure. Although neurohumoral systems are essential in vascular homeostasis, they become maladaptive in disease states such as hypertension, coronary disease, and heart failure. The clinical success of ACE inhibitors has led to efforts to block other humoral systems. Neutral endopeptidase (NEP) is an endothelial cell surface zinc metallopeptidase with similar structure and catalytic site. NEP is the major enzymatic pathway for degradation of natriuretic peptides, a secondary enzymatic pathway for degradation of kinins, and adrenomedullin. The natriuretic peptides can be viewed as endogenous inhibitors of the renin angiotensin system. Inhibition of NEP increases levels of atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP) of myocardial cell origin, and C-type natriuretic peptide (CNP) of endothelial cell origin as well as bradykinin and adrenomedullin. By simultaneously inhibiting the renin-angiotensin-aldosterone system and potentiating the natriuretic peptide and kinin systems, vasopeptidase inhibitors reduce vasoconstriction, enhance vasodilation, improve sodium/water balance, and, in turn, decrease peripheral vascular resistance and blood pressure and improve local blood flow. Within the blood vessel wall, this leads to a reduction of vasoconstrictor and proliferative mediators such as angiotensin II and increased local levels of bradykinin (and, in turn, nitric oxide) and natriuretic peptides. Preliminary clinical experiences with vasopeptidase inhibitors are encouraging. Thus, the combined inhibition of ACE and neutral endopeptidase is a new and promising approach to treat patients with hypertension, atherosclerosis, or heart failure.


Assuntos
Doenças Cardiovasculares/tratamento farmacológico , Sistema Cardiovascular/enzimologia , Inibidores Enzimáticos/uso terapêutico , Peptídeo Hidrolases/efeitos dos fármacos , Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Animais , Sistema Cardiovascular/efeitos dos fármacos , Endotélio Vascular/metabolismo , Humanos , Cininas/metabolismo , Natriuréticos/metabolismo , Neprilisina/antagonistas & inibidores , Sistema Renina-Angiotensina/efeitos dos fármacos , Sistema Renina-Angiotensina/fisiologia , Sistema Vasomotor/efeitos dos fármacos , Sistema Vasomotor/fisiologia
6.
Circulation ; 104(8): 939-44, 2001 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-11514383

RESUMO

BACKGROUND: The role of kinins in the cardioprotective effects of ACE inhibitors remains controversial. METHODS AND RESULTS: Right ventricular pressure overload in rabbits was produced by pulmonary artery banding for 21 days. Rabbits were untreated, or they received the ACE inhibitor ramipril with or without bradykinin B(1) and B(2) receptor blockers or the angiotensin (Ang) II type I (AT(1)) receptor blocker losartan. Pulmonary artery banding caused right ventricular hypertrophy, depressed papillary muscle contractility, and loss of Ang II contractile effects because of a signaling defect downstream of AT(1) receptors. Paradoxically, AT(1) receptor density and G protein alpha subunits alphaq and alphai1/2 increased. Inotropic responsiveness to the alpha-receptor agonist phenylephrine was normal. Ramipril preserved cardiac contractility, but this effect was attenuated by simultaneous use of kinin receptor blockers. Ramipril also maintained responsiveness to Ang II and prevented AT(1) receptor and G protein upregulation. The simultaneous use of a kinin receptor blocker attenuated but did not prevent upregulation in the AT(1) receptor and G protein. Losartan had no effect on baseline contractility, but it maintained cardiac inotropic responsiveness to Ang II, prevented upregulation of AT(1) receptors, but did not modify G protein upregulation. CONCLUSIONS: Pressure overload of the right ventricle decreases contractility, uncouples AT(1) receptors to downstream signaling pathways, and changes the expression of components of the AT(1) receptor signaling pathway. Ramipril attenuates these effects via kinins. Interventions that prevent local increases in Ang II or block AT(1) receptors also prevent decreased responsiveness of the AT(1) receptor in this model.


Assuntos
Inibidores da Enzima Conversora de Angiotensina/farmacologia , Cininas/metabolismo , Receptores de Angiotensina/metabolismo , Transdução de Sinais/efeitos dos fármacos , Disfunção Ventricular Direita/tratamento farmacológico , Angiotensina II/metabolismo , Angiotensina II/farmacologia , Antagonistas de Receptores de Angiotensina , Animais , Antagonistas dos Receptores da Bradicinina , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Estimulação Elétrica , Proteínas de Ligação ao GTP/metabolismo , Hemodinâmica/efeitos dos fármacos , Técnicas In Vitro , Losartan/farmacologia , Masculino , Contração Miocárdica/efeitos dos fármacos , Miocárdio/metabolismo , Miocárdio/patologia , Tamanho do Órgão/efeitos dos fármacos , Músculos Papilares/efeitos dos fármacos , Músculos Papilares/metabolismo , Subunidades Proteicas , Artéria Pulmonar/fisiopatologia , Coelhos , Ramipril/farmacologia , Receptor Tipo 1 de Angiotensina , Receptor Tipo 2 de Angiotensina , Disfunção Ventricular Direita/fisiopatologia
7.
Circulation ; 100(12): 1338-45, 1999 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-10491380

RESUMO

Background-Endocardial (EE) and myocardial capillary vascular endothelial (myocap VE) cells have been shown to modulate the contractile characteristics of myocardium in a calcium-dependent manner. We evaluated the endothelial-myocardial interaction in the rat postinfarction myocardial infarction (MI) model and the effects of captopril. Methods and Results-Wistar rats were divided into 4 groups treated for 4 weeks: (1) control; (2) infarcted controls (left anterior coronary artery ligation); (3) infarcted+captopril 2 g/L in drinking water; and (4) infarct+captopril+triton intracoronary injection. Coronary VE function was evaluated by infusion of serotonin in Langendorff preparations (n=31), and the myocardial contractile characteristics were investigated by use of isolated papillary muscles (n=44). Cardiac mRNA for endothelial constitutive nitric oxide synthase (ecNOS) was measured, and its cellular location was evaluated by immunohistochemistry. Serotonin-induced increase in coronary flow was decreased in infarct controls compared with controls (4.6% versus 53.4%, P<0.01) but not in the 2 infarct+captopril groups. Intracoronary triton injection decreased serotonin-induced coronary flow in the infarct+captopril+triton group. All MI groups had decreased total tension in isolated papillary muscles. EE removal by triton immersion decreased total tension in all groups except for infarct controls (3.3 versus 3.2 g/mm(2)). Cardiac ecNOS mRNA decreased in the control infarct group but remained normal in the infarct+captopril group. Conclusions-Chronic postinfarction endothelium-induced coronary vasodilatation is impaired, and both EE and myocap VE dysfunction contribute to myocardial depression. Captopril use prevents these abnormalities and the reduction of cardiac ecNOS mRNA.


Assuntos
Inibidores da Enzima Conversora de Angiotensina/farmacologia , Captopril/farmacologia , Vasos Coronários/fisiopatologia , Endocárdio/fisiopatologia , Endotélio Vascular/fisiopatologia , Coração/efeitos dos fármacos , Contração Miocárdica/efeitos dos fármacos , Infarto do Miocárdio/fisiopatologia , Animais , Capilares/fisiologia , Imuno-Histoquímica , Miocárdio/enzimologia , Óxido Nítrico Sintase/análise , Óxido Nítrico Sintase Tipo III , RNA Mensageiro/análise , Ratos , Ratos Wistar , Serotonina/farmacologia
8.
Circulation ; 104(17): 2075-81, 2001 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-11673349

RESUMO

BACKGROUND: Some controversy exists as to the effects of endothelin (ET) receptor antagonism on long-term post-myocardial infarction (MI) evolution, particularly as it relates to the timing of the intervention after MI (<24 hours versus 10 days). METHODS AND RESULTS: Sham rats and rats surviving an acute MI for >20 hours (n=301) were assigned to treatment with saline or the nonselective ET(A) and ET(B) receptor antagonist LU 420627 (LU) started <24 hours (early) or 10 days (late) after MI and continued for 100 days. Long-term LU treatment led to increased mortality of rats with large MI, regardless of the timing of initiation of therapy. Early initiation of LU reduced survival from 61% to 16% (P<0.001 versus untreated), and later initiation reduced survival to 36% (P=0.012 versus untreated and P<0.001 versus early initiation). Early initiation of LU led to scar thinning, further left ventricular (LV) dilatation, LV dysfunction, and an excessive rise in right ventricular systolic pressure. Later initiation of LU did not modify scar formation but resulted in LV dilatation and dysfunction compared with the untreated group. Cardiac fibrosis tended to increase in the LU-treated MI groups. LU in the sham group reduced cardiac endothelial constitutive nitric oxide synthase but did not modify the changes that occurred with a large MI. CONCLUSIONS: The use of the nonselective ET(A) and ET(B) receptor antagonist LU results in reduced survival, ventricular dilatation, and dysfunction whether started early or late after MI. Early initiation of LU resulted in scar expansion and a particularly unfavorable outcome.


Assuntos
Antagonistas dos Receptores de Endotelina , Infarto do Miocárdio/fisiopatologia , Animais , Dilatação Patológica/induzido quimicamente , Dilatação Patológica/fisiopatologia , Modelos Animais de Doenças , Esquema de Medicação , Endotelinas/farmacologia , Ligantes , Masculino , Infarto do Miocárdio/tratamento farmacológico , Fragmentos de Peptídeos/farmacologia , Ratos , Ratos Wistar , Receptor de Endotelina A , Receptor de Endotelina B , Receptores de Endotelina/agonistas , Taxa de Sobrevida , Tempo , Disfunção Ventricular/induzido quimicamente , Disfunção Ventricular/fisiopatologia
9.
Circulation ; 99(2): 216-23, 1999 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-9892586

RESUMO

BACKGROUND: The role of lipid modification in stroke prevention is controversial, although increasing evidence suggests that HMG-CoA reductase inhibition may reduce cerebrovascular events in patients with prevalent coronary artery disease. METHODS AND RESULTS: To test the hypothesis that cholesterol reduction with pravastatin may reduce stroke incidence after myocardial infarction, we followed 4159 subjects with average total and LDL serum cholesterol levels (mean, 209 and 139 mg/dL, respectively) who had sustained an infarction an average of 10 months before study entry and who were randomized to pravastatin 40 mg/d or placebo in the Cholesterol and Recurrent Events (CARE) trial. Using prospectively defined criteria, we assessed the incidence of stroke, a prespecified secondary end point, and transient ischemic attack (TIA) over a median 5-year follow-up period. Patients were well matched for stroke risk factors and the use of antiplatelet agents (85% of subjects in each group). Compared with placebo, pravastatin lowered total serum cholesterol by 20%, LDL cholesterol by 32%, and triglycerides by 14% and raised HDL cholesterol by 5% over the course of the trial. A total of 128 strokes (52 on pravastatin, 76 on placebo) and 216 strokes or TIAs (92 on pravastatin, 124 on placebo) were observed, representing a 32% reduction (95% CI, 4% to 52%, P=0.03) in all-cause stroke and 27% reduction in stroke or TIA (95% CI, 4% to 44%, P=0.02). All categories of strokes were reduced, and treatment effect was similar when adjusted for age, sex, history of hypertension, cigarette smoking, diabetes, left ventricular ejection fraction, and baseline total, HDL, and LDL cholesterol and triglyceride levels. There was no increase in hemorrhagic stroke in patients on pravastatin compared with placebo (2 versus 6, respectively). CONCLUSIONS: Pravastatin significantly reduced stroke and stroke or TIA incidence after myocardial infarction in patients with average serum cholesterol levels despite the high concurrent use of antiplatelet therapy.


Assuntos
Anticolesterolemiantes/uso terapêutico , Transtornos Cerebrovasculares/prevenção & controle , Infarto do Miocárdio/complicações , Pravastatina/uso terapêutico , Idoso , Animais , Gatos , Colesterol/sangue , HDL-Colesterol/sangue , LDL-Colesterol/sangue , Feminino , Seguimentos , Humanos , Ataque Isquêmico Transitório/prevenção & controle , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Resultado do Tratamento , Triglicerídeos/sangue
10.
J Am Coll Cardiol ; 16(4): 923-31, 1990 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-1976661

RESUMO

To better understand the mechanism of nitrate tolerance in patients with congestive heart failure, 13 patients received a 24 h infusion of nitroglycerin (1.5 micrograms/kg body weight per min) with or without N-acetylcysteine (225 mg/kg per 24 h). The infusions were separated by a 24 h nitrate-free interval. By the end of the nitroglycerin infusion, mean arterial pressure had returned to baseline values and there was a significant increase in ventricular filling pressures and systemic vascular resistance compared with values after 1 h of treatment. The simultaneous infusion of N-acetylcysteine had no effect on these changes. Although a strict fluid restriction of 1.5 liters/day was maintained for 1 week before and throughout the study, after 24 h of nitroglycerin infusion there was a significant and similar degree of hemodilution whether nitroglycerin was infused alone (9.1 +/- 4.3%) or with N-acetylcysteine (8.7 +/- 4.1%). This hemodilution corresponded to an increase in intravascular volume of 745 +/- 382 ml, most of which occurred during the 1st h. Plasma renin activity increased and plasma atrial natriuretic peptide decreased during the infusion. The results of this study suggest that nitrate tolerance is multifactorial. In addition to the previously described pharmacologic tolerance to the effect of nitroglycerin on vascular smooth muscle, a capillary fluid shift from the extravascular to intravascular space appears to be involved, especially during the 1st h of the infusion. A third mechanism, reflex neurohumoral activation, also seems to contribute to the genesis of nitroglycerin tolerance.


Assuntos
Acetilcisteína/uso terapêutico , Volume Sanguíneo/efeitos dos fármacos , Insuficiência Cardíaca/tratamento farmacológico , Neurotransmissores/metabolismo , Nitroglicerina/uso terapêutico , Pressão Sanguínea/efeitos dos fármacos , Tolerância a Medicamentos , Humanos , Infusões Intravenosas , Masculino , Pessoa de Meia-Idade , Nitroglicerina/administração & dosagem , Resistência Vascular/efeitos dos fármacos
11.
J Am Coll Cardiol ; 23(2): 505-13, 1994 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-8294707

RESUMO

OBJECTIVES: The purpose of this study was to determine whether the type and extent of ventricular remodeling after infarction influence inducibility of ventricular arrhythmias after infarction. BACKGROUND: Although serious ventricular arrhythmias after infarction are related to ventricular dysfunction, the relation between inducibility of ventricular arrhythmias and ventricular remodeling remains incompletely understood. METHODS: Rats that survived ligation of the left anterior descending coronary artery (n = 218) were randomized to receive placebo (saline solution) or captopril or propranolol therapy and were followed up for 5 weeks. Hemodynamic and neurohumoral blood measurements were obtained, and therapy was stopped. Two days later, susceptibility to ventricular arrhythmias was assessed by programmed electrical stimulation, and hearts were prepared for pathologic studies. RESULTS: Placebo-treated rats with a large myocardial infarction had ventricular dysfunction, marked neurohumoral activation, ventricular enlargement (endocardial circumference 16 +/- 3 [mean +/- SD] to 20 +/- 4 mm, p < 0.05) and increased cardiac fibrosis (volume density of collagen 2.3 +/- 0.8% to 5.6 +/- 2.4%, p < 0.05). In many rats this resulted in easily inducible ventricular arrhythmias (inducibility quotient 4.9 +/- 2.2). Captopril attenuated the development of ventricular dysfunction, neurohumoral activation, ventricular hypertrophy and dilation (endocardial circumference 18 +/- 3 mm) and cardiac fibrosis (3.1 +/- 0.8%, p < 0.05). These modifications were accompanied by decreased inducibility of ventricular arrhythmias (inducibility quotient 1.1 +/- 2.0, p < 0.05). Propranolol did not prevent ventricular dysfunction, had variable effects on neurohumoral activation and led to increased ventricular dilation (endocardial circumference 25 +/- 4 mm, p < 0.05) and cardiac fibrosis (7.7 +/- 1.2%, p < 0.05). Nevertheless, these morphologic changes led to decreased inducibility of ventricular arrhythmias (inducibility quotient 2.2 +/- 2.5%, p < 0.05). CONCLUSIONS: This study indicates that the inducibility of ventricular arrhythmias can be reduced as a result of markedly different effects on ventricular remodeling, indicating that the relation between ventricular remodeling, arrhythmias and survival is more complex than previously thought.


Assuntos
Captopril/uso terapêutico , Hipertrofia Ventricular Esquerda/prevenção & controle , Infarto do Miocárdio/complicações , Propranolol/uso terapêutico , Taquicardia Ventricular/etiologia , Fibrilação Ventricular/etiologia , Animais , Estimulação Cardíaca Artificial , Hipertrofia Ventricular Esquerda/etiologia , Hipertrofia Ventricular Esquerda/fisiopatologia , Masculino , Infarto do Miocárdio/tratamento farmacológico , Ratos , Ratos Wistar , Taquicardia Ventricular/fisiopatologia , Fibrilação Ventricular/fisiopatologia , Função Ventricular Esquerda/fisiologia
12.
J Am Coll Cardiol ; 9(3): 622-30, 1987 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-2880884

RESUMO

Nisoldipine, a calcium entry blocker, was given to 10 patients with congestive heart failure. During a 2 month follow-up period, 7 of the 10 patients were readmitted with pulmonary edema; daily furosemide doses were increased (128 +/- 87 to 192 +/- 135 mg/day, p less than 0.01), and plasma creatinine increased (1.5 +/- 0.5 to 1.8 +/- 0.6 mg/dl, p less than 0.05) (all values mean +/- SD). Despite this unfavorable clinical course, nisoldipine caused some beneficial chronic (1 month) hemodynamic effects. It decreased systemic vascular resistance (from 1,781 +/- 229 to 1,306 +/- 345 dynes X s X cm-5, p less than 0.01), decreased mean arterial pressure (from 88 +/- 0 to 74 +/- 4 mm Hg, p less than 0.001) and increased stroke volume index (from 27 +/- 6 to 33 +/- 9 ml/min per m2, p less than 0.02). Heart rate, pulmonary capillary wedge pressure and stroke work index did not change. However, nisoldipine's chronic renal and neurohumoral effects were not as favorable. These were assessed during a 5 hour water load (15 ml/kg body weight of 5% dextrose in water) and compared with the effects of a water load before therapy. Nisoldipine did not change creatinine clearance or sodium excretion, but decreased water excretion (from 58 +/- 35 to 46 +/- 40% of water load in 5 hours). Over this 5 hour study, mean plasma vasopressin was also higher with nisoldipine (1.9 +/- 2.3 versus 2.7 +/- 3.2 pg/ml, p less than 0.05), but mean plasma aldosterone was lower (67 +/- 31 to 47 +/- 27 mg/dl, p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Bloqueadores dos Canais de Cálcio/uso terapêutico , Insuficiência Cardíaca/tratamento farmacológico , Rim/efeitos dos fármacos , Neurotransmissores/metabolismo , Nifedipino/análogos & derivados , Água Corporal/metabolismo , Hemodinâmica/efeitos dos fármacos , Humanos , Masculino , Pessoa de Meia-Idade , Nifedipino/efeitos adversos , Nifedipino/uso terapêutico , Nisoldipino , Fatores de Tempo
13.
J Am Coll Cardiol ; 18(7): 1631-7, 1991 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-1960307

RESUMO

Patients with congestive heart failure have abnormal coronary hemodynamics, characterized by decreased coronary sinus oxygen content, increased coronary sinus blood flow and increased myocardial oxygen consumption. To evaluate their prognostic importance, the clinical characteristics and systemic and coronary hemodynamics were related to survival in 91 patients with severe congestive heart failure and decreased ejection fraction (25.5 +/- 10% [mean +/- SD]). In 69 patients congestive heart failure was due to or secondary to coronary artery disease (group 1) and in 22 it was due to idiopathic dilated cardiomyopathy (group 2). Five patients were in functional class II, 48 in class III and 38 in class IV. The median survival time was 20.7 months. As assessed with the Cox proportional hazards model, coronary sinus oxygen content was most strongly associated with a poor prognosis. On the basis of a comparison between the lowest (coronary sinus oxygen content less than or equal to 4.44 vol%) and highest quintile (coronary sinus oxygen content greater than 4.44 vol%), a low coronary sinus oxygen content was associated with a 2.34-fold increased risk of dying (95% confidence interval, 1.31 to 4.08). A low systolic blood pressure and a high diastolic pulmonary artery pressure were also significantly associated with increased mortality. Patients in the subgroup with a low coronary sinus oxygen content had values for functional class, ejection fraction and systemic hemodynamics similar to those of patients in the subgroup with high coronary sinus oxygen content. It is concluded that a low coronary sinus oxygen content indicative of noncompensated metabolic demand suggests a poor prognosis in patients with severe congestive heart failure.


Assuntos
Gasometria , Vasos Coronários , Insuficiência Cardíaca/mortalidade , Oxigênio/sangue , Idoso , Seguimentos , Insuficiência Cardíaca/sangue , Insuficiência Cardíaca/fisiopatologia , Hemodinâmica , Humanos , Pessoa de Meia-Idade , Consumo de Oxigênio , Valor Preditivo dos Testes , Prognóstico , Modelos de Riscos Proporcionais , Fatores de Risco , Índice de Gravidade de Doença , Taxa de Sobrevida
14.
J Am Coll Cardiol ; 22(2): 390-8, 1993 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-8101532

RESUMO

OBJECTIVES: This study was conducted to evaluate the degree of neurohumoral activation around the time of hospital discharge after myocardial infarction. BACKGROUND: Because pharmacologic interventions that block the effects of neurohumoral activation improve the prognosis after infarction, we hypothesized that widespread neurohumoral activation persists in some patients until at least the time of hospital discharge and that the determinants of activation vary from one system to another. METHODS: Five hundred nineteen patients in the Survival and Ventricular Enlargement Study (SAVE) had plasma neurohormones measured before randomization at a mean of 12 days after infarction. All patients had left ventricular dysfunction (left ventricular ejection fraction < or = 40%) but no overt heart failure. RESULTS: Although all neurohormones except epinephrine were increased compared with values in age-matched control subjects, plasma norepinephrine (301 +/- 193 vs. 222 +/- 87 pg/ml, p < 0.001), renin activity (3.0 +/- 3.7 vs. 1.2 +/- 1.2 ng/ml per h, p < 0.001), arginine vasopressin (1.9 +/- 6.9 vs. 0.7 +/- 0.3 pg/ml, p < 0.001) and atrial natriuretic peptide (75 +/- 75 vs. 21 +/- 9 pg/ml, p < 0.001) values ranged from normal to very high, indicating a wide spectrum of neurohumoral activation. Activation of one system did not correlate with activation of another. The clinical and laboratory variables most closely associated with neurohumoral activation were Killip class, left ventricular ejection fraction, age and use of diuretic drugs. The association between neurohumoral activation and clinical and laboratory variables varied from one neurohormone to another. CONCLUSIONS: Neurohumoral activation occurs in a significant proportion of patients at the time of hospital discharge after infarction. Which neurohormone is activated and which clinical and laboratory variables determine this activation vary from one neurohormone to another.


Assuntos
Baixo Débito Cardíaco/fisiopatologia , Infarto do Miocárdio/sangue , Neurotransmissores/sangue , Função Ventricular Esquerda , Idoso , Aldosterona/sangue , Fator Natriurético Atrial/sangue , Baixo Débito Cardíaco/sangue , Dopamina/sangue , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/fisiopatologia , Neurotransmissores/metabolismo , Norepinefrina/sangue , Renina/sangue , Volume Sistólico , Vasopressinas/sangue
15.
J Am Coll Cardiol ; 24(3): 583-91, 1994 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-7915733

RESUMO

OBJECTIVES: This study attempted to evaluate whether neurohumoral activation at the time of hospital discharge in postinfarction patients helps to predict long-term prognosis and whether long-term therapy with the angiotensin-converting enzyme inhibitor captopril modifies this relation. BACKGROUND: Neurohumoral activation persists at the time of hospital discharge in a large number of postinfarction patients. The Survival and Ventricular Enlargement (SAVE) study demonstrated that the angiotensin-converting enzyme inhibitor captopril improves survival and decreases the development of severe heart failure in patients with left ventricular dysfunction (left ventricular ejection fraction < or = 40%) but no overt postinfarction heart failure. METHODS: In 534 patients in the SAVE study, plasma neurohormone levels were measured a mean of 12 days after infarction. Patients were then randomized to receive captopril or placebo and were followed up for a mean (+/- SD) of 38 +/- 6 months (range 24 to 55). The association between activation of plasma neurohormones at baseline and subsequent cardiovascular mortality or the development of heart failure was assessed with and without adjustment for other important prognostic factors. RESULTS: By univariate analysis, activation of plasma renin activity and aldosterone, norepinephrine, atrial natriuretic peptide and arginine vasopressin levels were related to subsequent cardiovascular events, whereas epinephrine and dopamine levels were not. By multivariate analysis, only plasma renin activity (relative risk 1.6, 95% confidence interval [CI] 1.0 to 2.5) and atrial natriuretic peptide (relative risk 2.2, 95% CI 1.3 to 3.8) were independently predictive of cardiovascular mortality, whereas the other neurohormones were not. Only plasma renin activity and aldosterone, atrial natriuretic peptide and arginine vasopressin were independent predictors of the combined end points of cardiovascular mortality, development of severe heart failure or recurrent myocardial infarction. Except for 1-year cardiovascular mortality, the use of captopril did not significantly modify these relations. CONCLUSIONS: Neurohumoral activation at the time of hospital discharge in postinfarction patients is an independent sign of poor prognosis. This is particularly true for plasma renin activity and atrial natriuretic peptide. Except for 1-year cardiovascular mortality, captopril does not significantly modify these relations.


Assuntos
Captopril/uso terapêutico , Infarto do Miocárdio/sangue , Neurotransmissores/sangue , Idoso , Aldosterona/sangue , Análise de Variância , Arginina Vasopressina/sangue , Fator Natriurético Atrial/sangue , Canadá , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Infarto do Miocárdio/tratamento farmacológico , Infarto do Miocárdio/mortalidade , Norepinefrina/sangue , Prognóstico , Modelos de Riscos Proporcionais , Renina/sangue
16.
J Am Coll Cardiol ; 29(2): 229-36, 1997 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-9014971

RESUMO

OBJECTIVES: This study assessed whether treatment with a beta-adrenergic blocking agent in addition to the use of the angiotensin-converting enzyme (ACE) inhibitor captopril decreases cardiovascular mortality and morbidity in patients with asymptomatic left ventricular dysfunction after myocardial infarction (MI) and whether the presence of neurohumoral activation at the time of hospital discharge predicts the effects of beta-blocker treatment in these patients. BACKGROUND: Both beta-blockers and ACE inhibitors have been shown to have beneficial effects in patients with left ventricular dysfunction but no overt heart failure after MI. These patients often have persistent neurohumoral activation at the time of hospital discharge, and one would expect that patients with activation of the sympathetic nervous system derive the most benefit from treatment with beta-blockers. However, beta-blockers are underutilized in this high risk group of patients, and it is unknown whether their beneficial effects are additive to those of ACE inhibitors. METHODS: We performed a retrospective analysis of data from the Survival and Ventricular Enlargement (SAVE) study and its neurohumoral substudy. The relations between beta-blocker use at the time of randomization and neurohumoral activation and the subsequent development of cardiovascular events were analyzed by use of Cox proportional hazards models controlling for covariates. RESULTS: After adjustment for baseline imbalances, beta-blocker use was associated with a significant reduction in risk of cardiovascular death (30%, 95% confidence interval [CI] 12% to 44%) and development of heart failure (21%, 95% CI 3% to 36%), but the reduction in recurrent MI (11%, 95% CI 13% to 31%) was not significant. These reductions were independent of the use of captopril. Beta-blockers were not found to have a greater effect in patients with neurohumoral activation at the time of hospital discharge. CONCLUSIONS: The beneficial effects of beta-blocker use at the time of hospital discharge in patients with asymptomatic left ventricular dysfunction after MI appear to be additive to those of captopril and other interventions known to improve prognosis. Neurohumoral activation at the time of hospital discharge fails to identify those patients who will derive the greatest benefit from treatment with beta-blockers.


Assuntos
Antagonistas Adrenérgicos beta/uso terapêutico , Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Captopril/uso terapêutico , Infarto do Miocárdio/tratamento farmacológico , Disfunção Ventricular Esquerda/tratamento farmacológico , Idoso , Ensaios Clínicos como Assunto , Quimioterapia Combinada , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/complicações , Infarto do Miocárdio/mortalidade , Infarto do Miocárdio/fisiopatologia , Neurotransmissores/sangue , Prognóstico , Modelos de Riscos Proporcionais , Estudos Retrospectivos , Taxa de Sobrevida , Disfunção Ventricular Esquerda/sangue , Disfunção Ventricular Esquerda/etiologia , Disfunção Ventricular Esquerda/mortalidade
17.
J Am Coll Cardiol ; 34(1): 106-12, 1999 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10399998

RESUMO

OBJECTIVES: This analysis was carried out to determine if revascularized patients derive benefit from the 3-hydroxy-3 methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor pravastatin. BACKGROUND: The HMG-CoA reductase inhibitors result in substantial reductions in serum cholesterol and stabilization of atherosclerotic plaques in patients with coronary artery disease. METHODS: Pravastatin was found to reduce clinical cardiovascular events in the Cholesterol and Recurrent Events (CARE) trial consisting of 4,159 patients with a documented myocardial infarction and an average cholesterol level (mean 209 mg/dl and all <240 mg/dl). A total of 2,245 patients underwent coronary revascularization before randomization including 1,154 patients with percutaneous transluminal coronary angioplasty (PTCA) alone, 876 patients with coronary artery bypass graft (CABG) alone, and 215 patients with both procedures. Clinical events in revascularized patients were compared between patients on placebo and on pravastatin. RESULTS: In the 2,245 patients who had undergone revascularization, the primary endpoint of coronary heart disease death or nonfatal myocardial infarction (MI) was reduced by 4.1% with pravastatin (relative risk [RR] reduction 36%, 95% confidence interval [CI] 17 to 51, p = 0.001). Fatal or nonfatal MI was reduced by 3.3% (RR reduction 39%, 95% CI 16 to 55, p = 0.002), postrandomization repeat revascularization was reduced by 2.6% (RR reduction 18%, 95% CI 1 to 33, p = 0.068) and stroke was reduced by 1.5% (RR reduction 39%, 95% CI 3 to 62, p = 0.037) with pravastatin. Pravastatin was beneficial in both the 1,154 PTCA patients and in the 1,091 CABG patients who had undergone revascularization before randomization. CONCLUSIONS: Pravastatin reduced clinical events in revascularized postinfarction patients with average cholesterol levels. This therapy was well tolerated and its use should be considered in most patients following coronary revascularization.


Assuntos
Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Infarto do Miocárdio/prevenção & controle , Pravastatina/uso terapêutico , Angioplastia Coronária com Balão , Ponte de Artéria Coronária , Progressão da Doença , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Multicêntricos como Assunto , Infarto do Miocárdio/sangue , Infarto do Miocárdio/mortalidade , Infarto do Miocárdio/terapia , Prevenção Secundária , Análise de Sobrevida , Resultado do Tratamento
18.
J Am Coll Cardiol ; 1(6): 1453-60, 1983 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-6304174

RESUMO

The effect of verapamil, a drug that reduces the concentration of intracellular calcium, on atherogenesis was evaluated in rabbits fed a cholesterol-rich diet for 10 weeks. Ten rabbits received oral verapamil, 8 mg/kg daily; eight received the same oral dose and 0.5 mg/kg daily subcutaneously; nine received oral lanthanum, 35 mg/kg daily, and nine were controls. Over the 10 week period, all groups had average serum cholesterol levels greater than 1,500 mg/dl (normal = 90 +/- 63 mg/dl). At the end of the experiment, the aortas were removed, opened and stained for lipid with Sudan IV. The extent of atherosclerosis was determined by planimetry. The group receiving oral and parenteral verapamil had significantly less atherosclerosis (25 +/- 26% of total intimal area; mean +/- standard deviation), as compared with the controls (73 +/- 24%). Reduction of atherosclerosis with oral verapamil (51 +/- 22%) and lanthanum (59 +/- 31) was not statistically significant. Indexes of contractility in isolated right ventricular papillary muscles (developed tension at maximal length [Lmax] and maximal velocity of shortening [Vmax]) were reduced in the group treated with oral and parenteral verapamil, but not in the others. It is concluded that verapamil suppresses the development of atherosclerosis in rabbits fed a cholesterol-rich diet.


Assuntos
Arteriosclerose/prevenção & controle , Colesterol na Dieta/administração & dosagem , Verapamil/uso terapêutico , Adenosina Trifosfatases/metabolismo , Administração Oral , Animais , Aorta/patologia , Dieta Aterogênica , Canais Iônicos/efeitos dos fármacos , Lantânio/uso terapêutico , Contração Miocárdica , Miosinas/metabolismo , Nifedipino/uso terapêutico , Músculos Papilares/fisiopatologia , Coelhos , Verapamil/administração & dosagem
19.
J Am Coll Cardiol ; 33(1): 125-30, 1999 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9935018

RESUMO

OBJECTIVES: We sought to assess the influence of baseline lipid levels on coronary event rates and the effectiveness of pravastatin therapy in the Cholesterol And Recurrent Events (CARE) study. BACKGROUND: The CARE study cohort provided a relatively unique opportunity to examine the relation between lipid levels and clinical events in a post-myocardial infarction (MI) population with relatively low cholesterol and low density lipoprotein (LDL) cholesterol values. METHODS: There were 4,159 patients with a previous infarct and a total cholesterol level <240 mg/dl, LDL cholesterol level 115 to 174 mg/dl and triglyceride level <350 mg/dl randomly allocated to placebo (n=2,078) or pravastatin 40 mg/day (n=2,081). Time to either coronary death or nonfatal MI (primary end point) or to the secondary end point, which included undergoing a coronary revascularization procedure, was determined as a function of baseline lipids (total, LDL, high density lipoprotein [HDL] cholesterol and triglyceride levels). RESULTS: Quartile analysis indicated important effects for LDL cholesterol, in which a higher LDL was associated with greater cardiac event rates (in the placebo group, every 25-mg/dl increment in LDL was associated with a 28% increased risk [5% to 56%, p=0.015]) in the primary event. The differential event rates with respect to baseline LDL cholesterol for placebo and pravastatin groups reduced the difference in clinical outcomes at lower LDL cholesterol levels. In both the placebo and pravastatin groups, an inverse relation between baseline HDL cholesterol and cardiac events was observed (10 mg/dl lower baseline HDL cholesterol level was associated with a 10% [0% to 19%, p=0.046] increase in coronary death or nonfatal MI). CONCLUSIONS: Within the LDL cholesterol levels in CARE (115 to 174 mg/dl), baseline values influenced both the risk of events in the placebo group as well as the clinical effectiveness of pravastatin therapy.


Assuntos
Anticolesterolemiantes/uso terapêutico , Hipercolesterolemia/tratamento farmacológico , Lipídeos/sangue , Infarto do Miocárdio/tratamento farmacológico , Pravastatina/uso terapêutico , Adulto , Idoso , Anticolesterolemiantes/efeitos adversos , Colesterol/sangue , LDL-Colesterol/sangue , Estudos de Coortes , Feminino , Humanos , Hipercolesterolemia/sangue , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/sangue , Pravastatina/efeitos adversos , Recidiva , Taxa de Sobrevida , Resultado do Tratamento , Triglicerídeos/sangue
20.
J Am Coll Cardiol ; 32(1): 140-6, 1998 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-9669262

RESUMO

OBJECTIVES: We sought to determine the effect of pravastatin on recurrent cardiovascular events in women with average cholesterol levels after myocardial infarction (MI). BACKGROUND: Little information is available on the effectiveness of lipid lowering in secondary prevention of coronary heart disease (CHD) in women; in particular, those with CHD and average cholesterol levels. METHODS: In the Cholesterol and Recurrent Events (CARE) trial, 576 postmenopausal women, between 3 and 20 months after MI, with a total cholesterol level <240 mg/dl and a low density lipoprotein cholesterol level 115 to 174 mg/dl, were randomized to receive pravastatin 40 mg/day or matching placebo for a median follow-up period of 5 years. The main outcome measures were combined coronary events (coronary death, nonfatal MI, percutaneous transluminal coronary angioplasty [PTCA] or coronary artery bypass graft surgery [CABG]), the primary trial end point (coronary death or nonfatal MI) and stroke. RESULTS: Women treated with pravastatin had a risk reduction of 43% for the primary end point (p = 0.035), 46% for combined coronary events (p = 0.001), 48% for PTCA (p = 0.025), 40% for CABG (p = 0.14) and 56% for stroke (p = 0.07). The 3,583 men in the CARE trial also showed a reduction in risk, but the magnitude tended to be less. Pravastatin improved plasma lipids similarly in men and women. There were no differences in risk of coronary events in the placebo group between men and women. Minor differences between men and women were present in baseline characteristics and treatment for MI, in general, conferring a higher risk status and a lower incidence of CABG in the women. CONCLUSIONS: Pravastatin led to significant early reduction of a wide range of cardiovascular events in post-MI women with average cholesterol levels.


Assuntos
Anticolesterolemiantes/uso terapêutico , Colesterol/sangue , Infarto do Miocárdio/tratamento farmacológico , Pravastatina/uso terapêutico , Adulto , Angioplastia Coronária com Balão , Anticolesterolemiantes/efeitos adversos , LDL-Colesterol/sangue , Ponte de Artéria Coronária , Método Duplo-Cego , Feminino , Seguimentos , Humanos , Lipídeos/sangue , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/sangue , Infarto do Miocárdio/mortalidade , Pós-Menopausa , Pravastatina/efeitos adversos , Recidiva , Taxa de Sobrevida
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