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Feldman DS, Carnes CA, Abraham WT, Bristow MR. Mechanisms of disease: beta-adrenergic receptors--alterations in signal transduction and pharmacogenomics in heart failure. ACTA ACUST UNITED AC 2005; 2:475-83. [PMID: 16265588 DOI: 10.1038/ncpcardio0309] [Citation(s) in RCA: 98] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2005] [Accepted: 06/23/2005] [Indexed: 01/08/2023]
Abstract
Beta-adrenergic signaling is an important regulator of myocardial function. During the progression of heart failure (HF), a reproducible series of biochemical events occurs that affects beta-adrenergic receptor (beta-AR) signaling and cardiac function. Furthermore, there are pathophysiologic alterations in the expression and regulation of proteins that are regulated by beta-ARs during HF. Analyses of these complex signaling pathways have led to a better understanding of HF mechanisms and the use of beta-adrenergic antagonists, which have notably altered HF-related morbidity and mortality. Despite therapeutic advances that have affected beta-AR signaling, HF remains a leading cause of hospitalization and a principal cause of death in industrialized nations. In this review, we summarize current insights into beta-adrenergic signal-transduction pathways, the best-described beta-AR polymorphisms, and therapies that target the beta-AR pathway in HF.
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Bullinga JR, Alharethi R, Schram MS, Bristow MR, Gilbert EM. Changes in Heart Rate Variability Are Correlated to Hemodynamic Improvement With Chronic CARVEDILOL Therapy in Heart Failure. J Card Fail 2005; 11:693-9. [PMID: 16360965 DOI: 10.1016/j.cardfail.2005.06.435] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2004] [Revised: 06/03/2005] [Accepted: 06/17/2005] [Indexed: 12/01/2022]
Abstract
BACKGROUND Reduced heart rate variability (HRV) has been shown to predict mortality in heart failure (CHF). The relationship between improved cardiac function and improvement in HRV has not been previously studied. METHODS AND RESULTS This was substudy of a randomized, placebo-controlled, double-blinded trial of carvedilol of four months duration. Analysis of HRV was performed on 24-hour Holter monitors obtained at baseline and completion of study. All subjects had symptomatic CHF and an left ventricular ejection fraction (LVEF) <0.35. Study medication was titrated over 1 month to 50 mg/day (< or =75 kg) or 100 mg/day (<75 kg). A total of 17 subjects were randomized to carvedilol and 12 to placebo. Treatment with carvedilol was associated with significant increases in total frequency power, very low frequency power, high frequency power, SDNN, the root-mean square of difference of successive RRs, and pNN50. Change in time and frequency domain measures of HRV had a positive correlation with change in LVEF and negative correlation with change in coronary sinus norepinephrine levels. CONCLUSION Carvedilol therapy in patients with CHF significantly increased HRV. Change in HRV correlates to improved hemodynamics. This suggests that carvedilol therapy partially normalizes autonomic modulation of heart rate in patients with CHF.
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Abstract
Over the past 15-20 years the development of new heart failure pharmacologic therapy has lowered mortality by 30-40% for this serious and prevalent clinical syndrome, within clinical trials conducted in patients with a dilated cardiomyopathy phenotype. However, over the past 5 years progress in the development of additional effective drugs has slowed, in part due to the success of neurohormonal inhibitors, on which background new therapies must be developed. That there is not an absolute ceiling on the development of new heart failure therapies has been convincingly recently demonstrated in electrophysiologic device trials, conducted on the background of maximal neurohormonal inhibition. Two trials, COMPANION and CARE-HF, have demonstrated unambiguously that in advanced heart failure patients with a marker of mechanical intraventricular dyssynchrony, increased QRS duration, cardiac resynchronization therapy in the form of biventricular pacing can improve major clinical outcomes including mortality. In addition, COMPANION also demonstrated that the addition of an ICD further improved mortality reduction, by lowering the incidence of sudden death. These trials indicate that device/drug therapy is at least additive in the treatment of heart failure, and they herald a new era in the multi-modality approach to therapeutics.
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Sam F, Kerstetter DL, Pimental DR, Mulukutla S, Tabaee A, Bristow MR, Colucci WS, Sawyer DB. Increased reactive oxygen species production and functional alterations in antioxidant enzymes in human failing myocardium. J Card Fail 2005; 11:473-80. [PMID: 16105639 DOI: 10.1016/j.cardfail.2005.01.007] [Citation(s) in RCA: 155] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2004] [Revised: 01/11/2005] [Accepted: 01/25/2005] [Indexed: 12/14/2022]
Abstract
BACKGROUND The nature of oxidative stress and the activity of antioxidant enzyme systems are incompletely characterized in the failing human heart. METHODS AND RESULTS We obtained ventricular myocardium from failing, explanted human hearts in patients with nonischemic dilated cardiomyopathy at the time of heart transplant to examine whether reactive oxygen species (ROS) production and antioxidant enzyme activity or expression were altered in end-stage human heart failure. Nonfailing myocardium was obtained from organ donors who were not eligible for transplantation. Electroparamagnetic resonance (EPR) with the O(2)(-) spin trap 5-diethoxyphosphoryl-5-methyl-1-pyrroline N-oxide demonstrated that formation of superoxide anion was increased more than 2-fold in the failing (P < .001 vs. nonfailing) myocardium. Manganese superoxide dismutase (MnSOD) mRNA and catalase mRNA expression were increased by 52% (P=.05) and 116% (P < .05), respectively, in failing vs. nonfailing hearts. Copper-zinc superoxide dismutase (CuZnSOD) mRNA and glutathione peroxidase-1 (GPx-1) mRNA were unchanged. The expression of MnSOD, CuZnSOD, and catalase mRNA showed moderate correlation, suggesting coordinate regulation of gene expression. Activity was no different with regard to catalase, GPx-1, and glucose-6-phosphate dehydrogenase. MnSOD activity accounted for approximately 90% of total SOD activity, and was markedly decreased in failing hearts (by 61%, P < .05). MnSOD protein expression by western blot analysis was decreased in the failing group (P < .05 vs. nonfailing). CONCLUSION The decrease in MnSOD activity in failing myocardium, in the setting of increased mRNA expression, may reflect decreased translation or processing, or a posttranslational modification of MnSOD. The increase in MnSOD mRNA in failing hearts is consistent with the thesis that there is increased oxidative stress in failing myocardium that leads to increase transcription of antioxidant enzymes. The source of this direct measure of ROS is likely superoxide. These observations have implications for the pathophysiology and treatment of heart failure.
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Bristow MR, Adams KF, Bauman JL, Feldman AM, Giles TD, Goldstein S, Mann DL, Talbert RL. The COMET trial. ACTA ACUST UNITED AC 2005; 11:39-47. [PMID: 15722669 DOI: 10.1111/j.1527-5299.2005.04076.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Kinugawa K, Jeong MY, Bristow MR, Long CS. Thyroid hormone induces cardiac myocyte hypertrophy in a thyroid hormone receptor alpha1-specific manner that requires TAK1 and p38 mitogen-activated protein kinase. Mol Endocrinol 2005; 19:1618-28. [PMID: 15831522 PMCID: PMC1237131 DOI: 10.1210/me.2004-0503] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Alterations in TR [thyroid hormone (TH) receptor]1 isoform expression have been reported in models of both physiologic and pathologic cardiac hypertrophy as well as in patients with heart failure. In this report, we demonstrate that TH induces hypertrophy as a direct result of binding to the TRalpha1 isoform and, moreover, that overexpression of TRalpha1 alone is also associated with a hypertrophic phenotype, even in the absence of ligand. The mechanism of TH and TRalpha1-specific hypertrophy is novel for a nuclear hormone receptor and involves the transforming growth factor beta-activated kinase (TAK1) and p38. Mitigating TRalpha1 effects, both TRalpha2 and TRbeta1 attenuate TRalpha1-induced myocardial growth and gene expression by diminishing TAK1 and p38 activities, respectively. These findings refine our previous observations on TR expression in the hypertrophied and failing heart and suggest that manipulation of thyroid hormone signaling in an isoform-specific manner may be a relevant therapeutic target for altering the pathologic myocardial program.
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Movsesian MA, Bristow MR. Alterations in cAMP-mediated signaling and their role in the pathophysiology of dilated cardiomyopathy. Curr Top Dev Biol 2005; 68:25-48. [PMID: 16124995 DOI: 10.1016/s0070-2153(05)68002-7] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Dilated cardiomyopathy is a disease characterized by enlargement of the chambers of the heart and a decrease in contractility of the heart muscle. The process involves several alterations in proteins involved in cyclic adenosine monophosphate (cAMP) generation that result in a decrease in intracellular cAMP content per unit of adrenergic stimulation in cardiac myocytes. A fundamental question is whether these changes constitute a pathologic mechanism that contributes to chamber enlargement and hypocontractility or a compensatory adaptation that protects the heart from the adverse effects of increased catecholamine stimulation. Clinical studies in humans suggest that the latter effect may be more important. Studies in animal models, however, make the picture more complex: changes in cAMP-mediated signaling can have different effects depending on the specific protein whose expression or function is altered and the setting in which the alteration occurs. It may be that dilated cardiomyopathy represents a collection of different diseases in which alterations in cAMP-mediated signaling have different roles in the pathophysiology of the disease, and, furthermore, that changes in the phosphorylation of individual substrates of cAMP-dependent protein kinase may be either beneficial or harmful. Identifying differences among patients with dilated cardiomyopathy with respect to the role of altered cAMP-mediated signaling in their pathology, and identifying the "good" and "bad" substrates of cAMP-dependent protein kinase, are important areas for further research.
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Pittenger B, Gill EA, Holcslaw TL, Bristow MR. Relation of dose of carvedilol to reduction in QT dispersion in patients with mild to moderate heart failure secondary to ischemic or to idiopathic dilated cardiomyopathy. Am J Cardiol 2004; 94:1459-62. [PMID: 15566928 DOI: 10.1016/j.amjcard.2004.08.021] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/02/2004] [Revised: 07/30/2004] [Accepted: 07/30/2004] [Indexed: 11/27/2022]
Abstract
Carvedilol has been shown to improve survival and morbidity in patients with heart failure. It has been demonstrated that carvedilol use is associated with dose-dependent reduction in QT dispersion (QTd) independent of the cause of heart failure, suggesting that reduction in QTd may be a mechanism by which carvedilol improves outcomes in heart failure.
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Bristow MR, Krause-Steinrauf H, Nuzzo R, Liang CS, Lindenfeld J, Lowes BD, Hattler B, Abraham WT, Olson L, Krueger S, Thaneemit-Chen S, Hare JM, Loeb HS, Domanski MJ, Eichhorn EJ, Zelis R, Lavori P. Effect of baseline or changes in adrenergic activity on clinical outcomes in the beta-blocker evaluation of survival trial. Circulation 2004; 110:1437-42. [PMID: 15337700 DOI: 10.1161/01.cir.0000141297.50027.a4] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
BACKGROUND Adrenergic activation is thought to be an important determinant of outcome in subjects with chronic heart failure (CHF), but baseline or serial changes in adrenergic activity have not been previously investigated in a large patient sample treated with a powerful antiadrenergic agent. METHODS AND RESULTS Systemic venous norepinephrine was measured at baseline, 3 months, and 12 months in the beta-Blocker Evaluation of Survival Trial (BEST), which compared placebo treatment with the beta-blocker/sympatholytic agent bucindolol. Baseline norepinephrine level was associated with a progressive increase in rates of death or death plus CHF hospitalization that was independent of treatment group. On multivariate analysis, baseline norepinephrine was also a highly significant (P<0.001) independent predictor of death. In contrast, the relation of the change in norepinephrine at 3 months to subsequent clinical outcomes was complex and treatment group-dependent. In the placebo-treated group but not in the bucindolol-treated group, marked norepinephrine increase at 3 months was associated with increased subsequent risks of death or death plus CHF hospitalization. In the bucindolol-treated group but not in the placebo-treated group, the 1st quartile of marked norepinephrine reduction was associated with an increased mortality risk. A likelihood-based method indicated that 18% of the bucindolol group but only 1% of the placebo group were at an increased risk for death related to marked reduction in norepinephrine at 3 months. CONCLUSIONS In BEST, a subset of patients treated with bucindolol had an increased risk of death as the result of sympatholysis, which compromised the efficacy of this third-generation beta-blocker.
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Sucharov CC, Helmke S, Langer S, Perryman B, Bristow MR, Leinwand LA. The ku protein complex interacts with YY1, is up-regulated in human heart failure and represses alpha myosin heavy chain gene expression and promoter activity. J Card Fail 2004. [DOI: 10.1016/j.cardfail.2004.06.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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161
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Sucharov CC, Bristow MR. Phosphatase 2 A represses the human alpha myosin heavy chain promoter activity. J Card Fail 2004. [DOI: 10.1016/j.cardfail.2004.06.145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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MacGregor JF, Munger M, Stoddard G, Bristow MR, Gilbert EM. Carvedilol produces sustained benefits over 12 years of follow-up. J Card Fail 2004. [DOI: 10.1016/j.cardfail.2004.06.248] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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163
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Bristow MR, Saxon LA, Boehmer J, Krueger S, Kass DA, De Marco T, Carson P, DiCarlo L, DeMets D, White BG, DeVries DW, Feldman AM. Cardiac-resynchronization therapy with or without an implantable defibrillator in advanced chronic heart failure. N Engl J Med 2004; 350:2140-50. [PMID: 15152059 DOI: 10.1056/nejmoa032423] [Citation(s) in RCA: 4031] [Impact Index Per Article: 201.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
BACKGROUND We tested the hypothesis that prophylactic cardiac-resynchronization therapy in the form of biventricular stimulation with a pacemaker with or without a defibrillator would reduce the risk of death and hospitalization among patients with advanced chronic heart failure and intraventricular conduction delays. METHODS A total of 1520 patients who had advanced heart failure (New York Heart Association class III or IV) due to ischemic or nonischemic cardiomyopathies and a QRS interval of at least 120 msec were randomly assigned in a 1:2:2 ratio to receive optimal pharmacologic therapy (diuretics, angiotensin-converting-enzyme inhibitors, beta-blockers, and spironolactone) alone or in combination with cardiac-resynchronization therapy with either a pacemaker or a pacemaker-defibrillator. The primary composite end point was the time to death from or hospitalization for any cause. RESULTS As compared with optimal pharmacologic therapy alone, cardiac-resynchronization therapy with a pacemaker decreased the risk of the primary end point (hazard ratio, 0.81; P=0.014), as did cardiac-resynchronization therapy with a pacemaker-defibrillator (hazard ratio, 0.80; P=0.01). The risk of the combined end point of death from or hospitalization for heart failure was reduced by 34 percent in the pacemaker group (P<0.002) and by 40 percent in the pacemaker-defibrillator group (P<0.001 for the comparison with the pharmacologic-therapy group). A pacemaker reduced the risk of the secondary end point of death from any cause by 24 percent (P=0.059), and a pacemaker-defibrillator reduced the risk by 36 percent (P=0.003). CONCLUSIONS In patients with advanced heart failure and a prolonged QRS interval, cardiac-resynchronization therapy decreases the combined risk of death from any cause or first hospitalization and, when combined with an implantable defibrillator, significantly reduces mortality.
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Bristow MR, Feldman AM, Adams KF, Goldstein S. Selective versus nonselective beta-blockade for heart failure therapy: are there lessons to be learned from the COMET trial? J Card Fail 2004; 9:444-53. [PMID: 14966783 DOI: 10.1016/j.cardfail.2003.10.009] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The recently reported COMET trial found that the beta1/beta2/alpha1 receptor blocking agent carvedilol given in a relatively high beta1-receptor blocking dose regimen was superior in mortality reduction to immediate release metoprolol given in a relatively low beta1-receptor blocking dose schedule. We analyze the problems with the trial design of COMET from the standpoint of comparing 2 therapeutic agents at different positions on a common dose-response curve, and discuss the theoretical reasons why postjunctional adrenergic receptor blockade that is in addition to beta1-receptor antagonism will likely produce only minimal or no incremental benefit in chronic heart failure.
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Helmke SM, Yen CY, Cios KJ, Nunley K, Bristow MR, Duncan MW, Perryman MB. Simultaneous Quantification of Human Cardiac α- and β-Myosin Heavy Chain Proteins by MALDI-TOF Mass Spectrometry. Anal Chem 2004; 76:1683-9. [PMID: 15018568 DOI: 10.1021/ac035144l] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We have developed a novel method for quantifying protein isoforms, in both relative and absolute terms, based on MALDI-TOF mass spectrometry. The utility of the approach is demonstrated by quantifying the alpha and beta protein isoforms of myosin heavy chain (MyHC) in human atrial tissue. Alpha-MyHC (726-741) and beta-MyHC (724-739) were identified as isoform-specific tryptic peptides. A calibration curve was constructed by plotting ion current ratios against molar ratios of the two peptides prepared synthetically. MyHC was digested by trypsin and the ion current ratio determined for the two tryptic peptides. The ion current ratio was converted to the peptide ratio and hence the isoform ratio by reference to the standard curve. The accuracy of the method was confirmed by a comparison between these results and those determined by an established method of MyHC isoform ratio determination. So that the molar ratio could be converted to absolute values, a third peptide, an analogue of the two peptides being measured, was synthesized for use as an internal standard (IS). The measured ion current ratios of synthetic alpha-MyHC (726-741), beta-MyHC (724-739), and IS peptides were used to generate standard curves. A known quantity of the IS was added to the MyHC digests. The measured ion current ratios were converted to the actual quantities of the isoform-specific peptides and hence the actual quantity of each protein isoform by reference to the standard curves. This method is of general applicability, especially when isoform quantification is required.
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Shakar SF, Lowes BD, Lindenfeld J, Zolty R, Simon M, Robertson AD, Bristow MR, Wolfel EE. Peak oxygen consumption and outcome in heart failure patients chronically treated with β-blockers. J Card Fail 2004; 10:15-20. [PMID: 14966770 DOI: 10.1016/s1071-9164(03)00593-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
BACKGROUND Peak oxygen consumption (VO(2)) is an important criterion for listing patients for cardiac transplantation. Beta-blockers improve survival without affecting peak VO(2). We questioned the value of peak VO(2) in predicting outcome in patients treated with beta-blockers. METHODS AND RESULTS We reviewed the records of 127 patients who had peak VO(2) measured at baseline and were subsequently treated with beta-blockers for at least 3 months. We divided the patients into 2 groups with peak oxygen consumption >14 (VO(2) hi) and < or =14 ml.kg.min (VO(2) lo). VO(2) hi had 109 patients and VO(2) lo had 18 patients. The combined end-point of death or cardiac transplantation was compared between groups. Mean peak VO(2) and left ventricular ejection fraction were lower in VO(2) lo versus VO(2) hi: 12.4+/-1.4 ml.kg.min versus 19.1+/-3.9 ml.kg.min and 17+/-8% versus 21+/-9%, respectively. At 30 months, the percentage of patients who did not reach the combined end-point was 94% in VO(2) lo versus 79% in VO(2) hi (P=.47). In multivariate analysis, only changes in heart rate and LVEF from baseline to follow-up were predictive of survival. CONCLUSIONS Current peak VO(2) cutoff does not predict survival without transplantation of patients who tolerate chronic treatment with beta-blockers.
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Sucharov CC, Mariner PD, Bristow MR, Long CS, Leinwand LA. YY1 is increased in human heart failure and represses the activity of the human αMyHC promoter. J Card Fail 2003. [DOI: 10.1016/s1071-9164(03)00497-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Zisman LS, Meixell GE, Bristow MR, Canver CC. Angiotensin-(1-7) formation in the intact human heart: in vivo dependence on angiotensin II as substrate. Circulation 2003; 108:1679-81. [PMID: 14504185 DOI: 10.1161/01.cir.0000094733.61689.d4] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
BACKGROUND Several enzymes that hydrolyze angiotensin I (Ang I) and Ang II to Ang-(1-7) have been identified, but their relative importance in the intact human heart is not known. METHODS AND RESULTS Intracoronary (IC) 123I-Ang I was administered to 4 heart transplantation recipients. Arterial and coronary sinus (CS) samples were taken before and after coadministration of IC enalaprilat. 123I-Ang metabolites were separated by high-pressure liquid chromatography, and 123I-Ang-(1-7) and 123I-Ang II were quantified across the myocardial circulation. 123I-Ang II formation (as measured by fractional conversion) at steady state was 0.43+/-0.05 and was reduced to 0.042+/-0.02 after IC enalaprilat (P<0.01). The fractional conversion of 123I-Ang-(1-7) was 0.198+/-0.032 but was reduced to 0.06+/-0.01 during IC enalaprilat (P<0.01). Net Ang II production at steady state was 2720+/-704 pg/min. Ang-(1-7) production was 3489+/-768 pg/min. After IC enalaprilat, Ang II production fell to 436+/-66.8 pg/min (P<0.05 versus Ang II production). After suppression of Ang II production with enalaprilat, there was net uptake of Ang-(1-7): -289+/-144 pg/min (P<0.05). CONCLUSIONS Ang-(1-7) was formed in the intact human myocardial circulation and was decreased when Ang II formation was suppressed. These data indicate that the major pathway for Ang-(1-7) generation in the intact human heart was dependent on substrate availability of Ang II. Ang-(1-7)-forming enzymes that demonstrate substrate preference for Ang II are likely to play an important role in the regulation of Ang-(1-7) formation in the intact human heart.
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Zisman LS, Keller RS, Weaver B, Lin Q, Speth R, Bristow MR, Canver CC. Increased angiotensin-(1-7)-forming activity in failing human heart ventricles: evidence for upregulation of the angiotensin-converting enzyme Homologue ACE2. Circulation 2003; 108:1707-12. [PMID: 14504186 DOI: 10.1161/01.cir.0000094734.67990.99] [Citation(s) in RCA: 253] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
BACKGROUND The formation of angiotensin-(1-7) from either angiotensin (Ang) I or Ang II in failing human hearts is not well understood. METHODS AND RESULTS Angiotensinase activity in left and right ventricular membranes from 14 idiopathic dilated cardiomyopathy (IDC), 8 primary pulmonary hypertension (PPH), and 13 nonfailing human hearts was measured with either 125I-Ang I or 125I-Ang II as substrate. Ang-(1-7)-forming activity from 125I-Ang I was inhibited by thiorphan. With 125I-Ang II as substrate, Ang-(1-7) formation was inhibited by the ACE2-specific inhibitor C16. Western blotting with an anti-ACE2 antibody confirmed the presence of ACE2. Angiotensinase activity with 125I-Ang I as substrate was increased in failing IDC left ventricles (LVs) compared with nonfailing LVs (P<0.001). Ang-(1-7)-forming activity with 125I-Ang II as substrate was increased in both failing LVs and right ventricles (RVs) of IDC hearts and only in failing RVs of PPH hearts (PPH LV, 51.12+/-5.25; PPH RV, 89.97+/-11.21; IDC LV, 139.7+/-21.96; and IDC RV, 192.7+/-5.43; NF LV, 32.89+/-5.38; NF RV 40.49+/-10.66 fmol/min per milligram (P<0.05 PPH RV versus PPH LV; P<0.05 PPH RV versus NF RV; P<0.001 IDC LV versus NF LV; P<0.001 IDC RV versus NF RV). CONCLUSIONS Ang-(1-7)-forming activity from both Ang I and Ang II was increased in failing human heart ventricles but was mediated by at least two different angiotensinases. The first, which demonstrated substrate preference for Ang I, was neutral endopeptidase (NEP)-like. The second was ACE2, as demonstrated by Western blotting and inhibition of activity with C16.
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Domanski M, Krause-Steinrauf H, Deedwania P, Follmann D, Ghali JK, Gilbert E, Haffner S, Katz R, Lindenfeld J, Lowes BD, Martin W, McGrew F, Bristow MR. The effect of diabetes on outcomes of patients with advanced heart failure in the BEST trial. J Am Coll Cardiol 2003; 42:914-22. [PMID: 12957443 DOI: 10.1016/s0735-1097(03)00856-8] [Citation(s) in RCA: 171] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
OBJECTIVES This was a retrospective analysis to determine the effect of diabetes on outcome in patients with advanced heart failure (HF), and to determine the effect of beta-blockade in patients with HF with and without diabetes mellitus. BACKGROUND In chronic HF the impact on clinical outcomes and therapeutic response of the prevalent comorbid condition diabetes mellitus has not been extensively investigated. METHODS We assessed the impact of diabetes on prognosis and effectiveness of beta-blocker therapy with bucindolol in patients with HF enrolled in the Beta-Blocker Evaluation of Survival Trial (BEST). We conducted a retrospective analysis to examine the prognosis of patients with advanced HF with and without diabetes, and the effect of beta-blocker therapy on mortality and HF progression or myocardial infarction (MI). The database was the 2,708 patients with advanced HF (36% with diabetes and 64% without diabetes) who were randomized to the beta-blocker bucindolol or placebo in BEST and followed for mortality, hospitalization, and MI for an average of two years. RESULTS Patients with diabetes had more severe chronic HF and more coronary risk factors than patients without diabetes. Diabetes was independently associated with increased mortality in patients with ischemic cardiomyopathy (adjusted hazard ratio 1.33, 95% confidence interval 1.12 to 1.58, p = 0.001), but not in those with a nonischemic etiology (adjusted hazard ratio 0.98, 95% confidence interval 0.74 to 1.30, p = 0.89). Compared with patients without diabetes, in diabetic patients beta-blocker therapy was at least as effective in reducing death or HF hospitalizations, total hospitalizations, HF hospitalizations, and MI. Ventricular function and physiologic responses to beta-blockade were similar in patients with and without diabetes. CONCLUSIONS Diabetes worsens prognosis in patients with advanced HF, but this worsening appears to be limited to patients with ischemic cardiomyopathy. In advanced HF beta-blockade is effective in reducing major clinical end points in patients with and without diabetes.
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Bristow MR. Microarray measurements of gene expression before and after left ventricular assist device placement. J Am Coll Cardiol 2003; 41:1107-8. [PMID: 12679208 DOI: 10.1016/s0735-1097(03)00051-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Taylor MRG, Fain PR, Sinagra G, Robinson ML, Robertson AD, Carniel E, Di Lenarda A, Bohlmeyer TJ, Ferguson DA, Brodsky GL, Boucek MM, Lascor J, Moss AC, Li WLP, Stetler GL, Muntoni F, Bristow MR, Mestroni L. Natural history of dilated cardiomyopathy due to lamin A/C gene mutations. J Am Coll Cardiol 2003; 41:771-80. [PMID: 12628721 DOI: 10.1016/s0735-1097(02)02954-6] [Citation(s) in RCA: 305] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
OBJECTIVES We examined the prevalence, genotype-phenotype correlation, and natural history of lamin A/C gene (LMNA) mutations in subjects with dilated cardiomyopathy (DCM). BACKGROUND Mutations in LMNA have been found in patients with DCM with familial conduction defects and muscular dystrophy, but the clinical spectrum, prognosis, and clinical relevance of laminopathies in DCM are unknown. BACKGROUND A cohort of 49 nuclear families, 40 with familial DCM and 9 with sporadic DCM (269 subjects, 105 affected), was screened for mutations in LMNA using denaturing high-performance liquid chromatography and sequence analysis. Bivariate analysis of clinical predictors of LMNA mutation carrier status and Kaplan-Meier survival analysis were performed. RESULTS Mutations in LMNA were detected in four families (8%), three with familial (R89L, 959delT, R377H) and one with sporadic DCM (S573L). There was significant phenotypic variability, but the presence of skeletal muscle involvement (p < 0.001), supraventricular arrhythmia (p = 0.003), conduction defects (p = 0.01), and "mildly" DCM (p = 0.006) were predictors of LMNA mutations. The LMNA mutation carriers had a significantly poorer cumulative survival compared with non-carrier DCM patients: event-free survival at the age of 45 years was 31% versus 75% in non-carriers. CONCLUSIONS Mutations in LMNA cause a severe and progressive DCM in a relevant proportion of patients. Mutation screening should be considered in patients with DCM, in particular when clinical predictors of LMNA mutation are present, regardless of family history.
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Abraham WT, Raynolds MV, Badesch DB, Wynne KM, Groves BM, Roden RL, Robertson AD, Lowes BD, Zisman LS, Voelkel NF, Bristow MR, Perryman MB. Angiotensin-converting enzyme DD genotype in patients with primary pulmonary hypertension: increased frequency and association with preserved haemodynamics. J Renin Angiotensin Aldosterone Syst 2003; 4:27-30. [PMID: 12692750 DOI: 10.3317/jraas.2003.003] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
UNLABELLED HYPOTHESIS/INTRODUCTION: A polymorphic marker within the angiotensin- converting enzyme (ACE) gene has been associated with circulating and tissue ACE activity and with a variety of forms of cardiovascular disease. Since angiotensin II (Ang II) causes pulmonary vasoconstriction and vascular and myocardial remodelling, we postulated a role for the renin-angiotensin system and the ACE DD genotype in the pathophysiology of primary pulmonary hypertension (PPH) and in the right ventricular response to pressure overload in these patients. METHODS AND RESULTS The incidence of the ACE DD genotype was evaluated in 60 patients with severe PPH compared with two normal control populations, a group of healthy population-based controls (n=158) and subjects found suitable for cardiac organ donation (n=79). Genomic DNA extracted from peripheral leukocytes was amplified using the polymerase chain reaction to detect polymorphic markers. Haemodynamics were determined by right heart catheterisation in a subset of the PPH patients. The frequency of the ACE DD genotype was 45% in the patients with PPH, compared with 24% in the organ donors, and 28% in population-based healthy controls (p=0.01 for chi-square test). Of the 32 PPH patients with baseline haemodynamics, 12 exhibited the ACE DD genotype and 20 were non-DD. While the mean pulmonary artery pressure and the duration of symptoms attributable to pulmonary hypertension was not different between the DD and non-DD groups, cardiac output was significantly lower (3.29+0.27 vs. 5.07+0.37 L/minute, p=0.002) and the mean right atrial pressure tended to be higher (8.85+1.29 vs. 4.92+1.27 mmHg, p=0.08) in the non-DD group. The reduction in cardiac output seen in the non-DD group was not due to a difference in heart rate, but to a significant reduction in stroke volume, consistent with a decreased contractile state. In addition, non-DD patients exhibited a significantly worse functional capacity (NYHA Class 3.14+0.12 vs. 2.40+0.28, p=0.02). CONCLUSIONS 1) The ACE DD genotype is significantly increased in patients with severe PPH compared with normal controls, suggesting that certain individuals may be genetically predisposed to developing pulmonary hypertension. 2) The ACE DD genotype is associated with preserved right ventricular function in PPH patients, supporting a compensatory myocardial or inotropic role for Ang II in the pressure overloaded right ventricle.
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Rathore SS, Curtis JP, Wang Y, Bristow MR, Krumholz HM. Association of serum digoxin concentration and outcomes in patients with heart failure. JAMA 2003; 289:871-8. [PMID: 12588271 DOI: 10.1001/jama.289.7.871] [Citation(s) in RCA: 487] [Impact Index Per Article: 23.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
CONTEXT The Digitalis Investigation Group (DIG) trial reported that digoxin provided no overall mortality benefit and only a modest reduction in hospitalizations among patients with heart failure and depressed left ventricular systolic function. The clinical outcomes associated with digoxin therapy at different serum concentrations in the DIG trial have not been assessed. OBJECTIVE To assess variations in serum digoxin concentration (SDC) and their association with mortality and hospitalization in patients with heart failure. DESIGN, SETTING, AND PATIENTS Post hoc analysis of the randomized, double-blinded, placebo-controlled DIG trial, conducted from August 1991 to December 1995, with the main analysis restricted to men with a left ventricular ejection fraction of 45% or less (n = 3782). Patients randomly assigned to receive digoxin were divided into 3 groups based on SDC at 1 month (0.5-0.8 ng/mL, n = 572; 0.9-1.1 ng/mL, n = 322; and > or =1.2 ng/mL, n = 277) and compared with patients randomly assigned to receive placebo (n = 2611). MAIN OUTCOME MEASURE All-cause mortality at a mean follow-up of 37 months. RESULTS Higher SDCs were associated with increased crude all-cause mortality rates (0.5-0.8 ng/mL, 29.9%; 0.9-1.1 ng/mL, 38.8%; and > or =1.2 ng/mL, 48.0%; P =.006 for trend). Patients with SDCs of 0.5 to 0.8 ng/mL had a 6.3% (95% confidence interval [CI], 2.1%-10.5%) lower mortality rate compared with patients receiving placebo. Digoxin was not associated with a reduction in mortality among patients with SDCs of 0.9 to 1.1 ng/mL (2.6% increase; 95% CI, - 3.0% to 8.3%), whereas patients with SDCs of 1.2 ng/mL and higher had an 11.8% (95% CI, 5.7%-18.0%) higher absolute mortality rate than patients receiving placebo. The association between SDC and mortality persisted after multivariable adjustment (SDC 0.5-0.8 ng/mL hazard ratio [HR] 0.80, 95% CI, 0.68-0.94; SDC 0.9-1.1 ng/mL HR 0.89, 95% CI, 0.74-1.08; SDC > or =1.2 ng/mL HR 1.16, 95% CI, 0.96-1.39; and HR of 1.00 [referent] for placebo). CONCLUSIONS Our findings demonstrate that higher SDCs were associated with increased mortality and suggest that the effectiveness of digoxin therapy in men with heart failure and a left ventricular ejection fraction of 45% or less may be optimized in the SDC range of 0.5 to 0.8 ng/mL.
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Bohlmeyer T, Ferdensi A, Bristow MR, Takahashi S, Zisman LS. Selective activation of N-acyl-D-glucosamine 2-epimerase expression in failing human heart ventricular myocytes. J Card Fail 2003; 9:59-68. [PMID: 12612874 DOI: 10.1054/jcaf.2003.6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
BACKGROUND O-linked N-acyl-glycosylation may regulate protein function by competing with phosphorylation of serine residues. Availability of substrate for this process is regulated, in part, by N-Acyl-D-glucosamine 2-epimerase (NAGE), which interconverts N-acetyl-glucosamine (GlcNAc) and N-acetylmannosamine (ManNAc). NAGE is also a putative renin-binding protein. This study tested the hypothesis that NAGE is present in the human heart and that NAGE expression is increased in the failing human heart. METHODS AND RESULTS Ribonuclease protection assays (RPAs) demonstrated increased NAGE gene expression in failing hearts from subjects with idiopathic dilated and ischemic cardiomyopathies compared with nonfailing hearts. In situ reverse transcriptase-polymerase chain reaction, using primers designed to localize NAGE mRNA, demonstrated that, in nonfailing hearts, NAGE gene expression was restricted to endothelial cells and not detectable in cardiac myocytes. However, in failing human hearts NAGE gene expression was selectively activated in cardiac myocytes, but not endothelial cells. Immunohistochemistry confirmed that the pattern of NAGE protein expression corresponded to the pattern of gene expression. CONCLUSIONS NAGE gene and protein expression were selectively activated in left ventricular myocytes from end-stage failing human hearts.
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Bohlmeyer TJ, Helmke S, Ge S, Lynch J, Brodsky G, Sederberg JH, Robertson AD, Minobe W, Bristow MR, Perryman MB. Hypoplastic left heart syndrome myocytes are differentiated but possess a unique phenotype. Cardiovasc Pathol 2003; 12:23-31. [PMID: 12598014 DOI: 10.1016/s1054-8807(02)00127-8] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
INTRODUCTION Hypoplastic left heart syndrome (HLHS) is the term used to describe a group of congenital malformations characterized by marked underdevelopment of the left side of the heart. HLHS accounts for nearly 25% of cardiac deaths in the first year of life. Although much has been reported regarding diagnosis, gross morphology and surgical treatment, no information on gene expression in HLHS myocytes is available. METHODS We examined heart tissue from patients with HLHS using routine histology, immunohistochemistry, quantitative polymerase chain reaction (PCR), two-dimensional (2-D) gel electrophoresis and protein identification by mass spectrometry. RESULTS Histologic examination of right and left ventricles from HLHS patients revealed characteristic features of myocyte differentiation, including striations and intercalated disc formation. Immunohistochemical staining using antibody to N-cadherin demonstrated clear development of intercalated discs between myocytes. However, many of the myocytes contained scant cytoplasm and were grouped in small, disorganized bundles separated by abundant connective tissue and dilated, thin-walled vessels. Quantitative PCR analysis demonstrated that both left and right ventricular tissue from HLHS hearts expressed the fetal or "heart failure" gene expression pattern. Two-dimensional gel electrophoresis and protein identification by mass spectrometry also confirmed that myocytes from HLHS ventricles were differentiated but expressed the fetal isoform of some cardiac specific proteins. However, HLHS myocytes in all of the heart samples (n=21) were inappropriately expressing platelet-endothelial cell adhesion molecule-1 (PECAM-1, CD31), a member of the cell adhesion molecule (CAM) family that has a primary role in the regulation of tissue morphogenesis. These findings indicate that myocytes from HLHS syndrome patients, while differentiated, have a unique gene expression pattern.
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Abraham WT, Gilbert EM, Lowes BD, Minobe WA, Larrabee P, Roden RL, Dutcher D, Sederberg J, Lindenfeld JA, Wolfel EE, Shakar SF, Ferguson D, Volkman K, Linseman JV, Quaife RA, Robertson AD, Bristow MR. Coordinate Changes in Myosin Heavy Chain Isoform Gene Expression Are Selectively Associated With Alterations in Dilated Cardiomyopathy Phenotype. Mol Med 2002. [DOI: 10.1007/bf03402039] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
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Abraham WT, Gilbert EM, Lowes BD, Minobe WA, Larrabee P, Roden RL, Dutcher D, Sederberg J, Lindenfeld JA, Wolfel EE, Shakar SF, Ferguson D, Volkman K, Linseman JV, Quaife RA, Robertson AD, Bristow MR. Coordinate changes in Myosin heavy chain isoform gene expression are selectively associated with alterations in dilated cardiomyopathy phenotype. Mol Med 2002; 8:750-60. [PMID: 12520092 PMCID: PMC2039952] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/28/2023] Open
Abstract
BACKGROUND The most common cause of chronic heart failure in the US is secondary or primary dilated cardiomyopathy (DCM). The DCM phenotype exhibits changes in the expression of genes that regulate contractile function and pathologic hypertrophy. However, it is unclear if any of these alterations in gene expression are disease producing or modifying. MATERIALS AND METHODS One approach to providing evidence for cause-effect of a disease-influencing gene is to quantitatively compare changes in phenotype to changes in gene expression by employing serial measurements in a longitudinal experimental design. We investigated the quantitative relationships between changes in gene expression and phenotype n 47 patients with idiopathic DCM. In endomyocardial biopsies at baseline and 6 months later, we measured mRNA expression of genes regulating contractile function (beta-adrenergic receptors, sarcoplasmic reticulum Ca(2) + ATPase, and alpha- and beta-myosin heavy chain isoforms) or associated with pathologic hypertrophy (beta-myosin heavy chain and atrial natriuretic peptide), plus beta-adrenergic receptor protein expression. Left ventricular phenotype was assessed by radionuclide ejection fraction. RESULTS Improvement in DCM phenotype was directly related to a coordinate increase in alpha- and a decrease in beta-myosin heavy chain mRNA expression. In contrast, modification of phenotype was unrelated to changes in the expression of beta(1)- or beta(2)-adrenergic receptor mRNA or protein, or to the mRNA expression of sarcoplasmic reticulum Ca(2) + ATPase and atrial natriuretic peptide. CONCLUSION We conclude that in human DCM, phenotypic modification is selectively associated with myosin heavy chain isoform changes. These data support the hypothesis that myosin heavy chain isoform changes contribute to disease progression in human DCM.
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Metra M, Nodari S, D'Aloia A, Muneretto C, Robertson AD, Bristow MR, Dei Cas L. Beta-blocker therapy influences the hemodynamic response to inotropic agents in patients with heart failure: a randomized comparison of dobutamine and enoximone before and after chronic treatment with metoprolol or carvedilol. J Am Coll Cardiol 2002; 40:1248-58. [PMID: 12383572 DOI: 10.1016/s0735-1097(02)02134-4] [Citation(s) in RCA: 141] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
OBJECTIVE We compared the hemodynamic effects of dobutamine and enoximone administration before and after long-term beta-blocker therapy with metoprolol or carvedilol in patients with chronic heart failure (HF). BACKGROUND Patients with HF on beta-blocker therapy may need hemodynamic support with inotropic agents, and the hemodynamic response may be influenced by both the inotropic agent and the beta-blocker used. METHODS The hemodynamic effects of dobutamine (5 to 20 microg/kg/min intravenously) and enoximone (0.5 to 2 mg/kg intravenously) were assessed by pulmonary artery catheterization in 29 patients with chronic HF before and after 9 to 12 months of treatment with metoprolol or carvedilol at standard target maintenance oral doses. Hemodynamic studies were performed after >/=12 h of wash-out from all cardiovascular medications, except the beta-blockers that were administered 3 h before the second study. RESULTS Compared with before beta-blocker therapy, metoprolol treatment decreased the magnitude of mean pulmonary artery pressure (PAP) and pulmonary wedge pressure (PWP) decline during dobutamine infusion and increased the cardiac index (CI) and stroke volume index (SVI) response to enoximone administration, without any effect on other hemodynamic parameters. Carvedilol treatment abolished the increase in heart rate, SVI, and CI and caused a rise, rather than a decline, in PAP, PWP, systemic vascular resistance, and pulmonary vascular resistance during dobutamine infusion. The hemodynamic response to enoximone, however, was maintained or enhanced in the presence of carvedilol. CONCLUSIONS In contrast with its effects on enoximone, carvedilol and, to a lesser extent, metoprolol treatment may significantly inhibit the favorable hemodynamic response to dobutamine. No such beta-blocker-related attenuation of hemodynamic effects occurs with enoximone.
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Asano K, Bohlmeyer TJ, Westcott JY, Zisman L, Kinugawa K, Good M, Minobe WA, Roden R, Wolfel EE, Lindenfeld J, David Port J, Perryman MB, Clevel J, Lowes BD, Bristow MR. Altered expression of endothelin receptors in failing human left ventricles. J Mol Cell Cardiol 2002; 34:833-46. [PMID: 12099722 DOI: 10.1006/jmcc.2002.2022] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
BACKGROUND Endothelin signaling is activated in failing human hearts, and may contribute to progressive myocardial dysfunction and remodeling. However, the behavior of endothelin receptor systems (ET(A) and ET(B)) in failing human hearts is not well understood. METHODS AND RESULTS (125)[I]-endothelin-1 binding assays conducted in the presence of a non-hydrolyzable guanine nucleotide to uncouple agonist binding demonstrated that membranes prepared from nonfailing left ventricles (LVs) exhibit a mixed pattern of ET(A) ( approximately 60%) and ET(B) ( approximately 40%) receptor protein expression. Chronic LV failure from either idiopathic dilated (IDC) or ischemic (ISC) cardiomyopathy was accompanied by a significant (P<0.001) increase in ET(A) receptor density, to approximately 80% of the total population, and a significant (P<0.02) decrease in ET(B) receptor density. Ribonuclease protection assays demonstrated an increase in ET(A) mRNA abundance in IDC and ISC LVs, and a significant (P<0.04) increase in ET(B) mRNA abundance in ISC LVs. Enzyme-linked immunoabsorbent assays demonstrated a significant increase in tissue immunoreactive endothelin-1 concentration in IDC (P=0.01) and in IDC+ISC LVs (P=0.02), but receptor subtype protein or mRNA level was not significantly correlated with tissue ET-1 across all LVs. In situ reverse-transcription polymerase chain reaction in LV sections demonstrated that in both failing and nonfailing LVs the ET(A) gene is expressed in cardiac myocytes, vascular smooth muscle and endothelium; the ET(B) gene is expressed in cardiac myocytes, fibroblasts and endothelium; and the prepro-endothelin-1 gene is expressed in myocytes and interstitial cells. CONCLUSIONS In chronically failing human LVs, ET(A) receptor density is increased to become the dominant subtype while ET(B) receptor density is decreased. The ET(A), but not the ET(B) density change is accompanied by cognate regulation of mRNA abundance. Both receptor genes and prepro-endothelin-1 are expressed in cardiac myocytes. Finally, based on a lack of correlation with endothelin-1 tissue levels, it is unlikely that the failure-related changes in ET(A) and ET(B) receptor protein and mRNA expression result from homologous regulation by agonist exposure.
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Lowes BD, Gilbert EM, Abraham WT, Minobe WA, Larrabee P, Ferguson D, Wolfel EE, Lindenfeld J, Tsvetkova T, Robertson AD, Quaife RA, Bristow MR. Myocardial gene expression in dilated cardiomyopathy treated with beta-blocking agents. N Engl J Med 2002; 346:1357-65. [PMID: 11986409 DOI: 10.1056/nejmoa012630] [Citation(s) in RCA: 401] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
BACKGROUND Beta-blocker therapy may improve cardiac function in patients with idiopathic dilated cardiomyopathy. We tested the hypothesis that beta-blocker therapy produces favorable functional effects in dilated cardiomyopathy by altering the expression of myocardial genes that regulate contractility and pathologic hypertrophy. METHODS We randomly assigned 53 patients with idiopathic dilated cardiomyopathy to treatment with a beta-adrenergic-receptor blocking agent (metoprolol or carvedilol) or placebo. The amount of messenger RNA (mRNA) for contractility-regulating genes (those encoding beta1- and beta2-adrenergic receptors, calcium ATPase in the sarcoplasmic reticulum, and alpha- and beta-myosin heavy-chain isoforms) and of genes associated with pathologic hypertrophy (beta-myosin heavy chain and atrial natriuretic peptide) was measured with a quantitative reverse-transcription polymerase chain reaction in total RNA extracted from biopsy specimens of the right ventricular septal endomyocardium. Myocardial levels of beta-adrenergic receptors were also measured. Measurements were conducted at base line and after six months of treatment, and changes in gene expression were compared with changes in the left ventricular ejection fraction as measured by radionuclide ventriculography. RESULTS Twenty-six of 32 beta-blocker-treated patients (those with complete mRNA measurements) had an improvement in left ventricular ejection fraction of at least 5 ejection-fraction (EF) units (mean [+/-SE] increase, 18.8+/-1.8). As compared with the six beta-blocker-treated patients who did not have a response (mean change, a decrease of 2.5+/-1.8 EF units), those who did have a response had an increase in sarcoplasmic-reticulum calcium ATPase mRNA and alpha-myosin heavy chain mRNA and a decrease in beta-myosin heavy chain mRNA. The change in sarcoplasmic-reticulum calcium ATPase was not present in the patients in the placebo group who had a spontaneous response. There were no differences between those who had a response and those who did not in terms of the change in mRNA or protein expression of beta-adrenergic receptors. CONCLUSIONS In idiopathic dilated cardiomyopathy, functional improvement related to treatment with beta-blockers is associated with changes in myocardial gene expression.
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Swedberg K, Bristow MR, Cohn JN, Dargie H, Straub M, Wiltse C, Wright TJ. Effects of sustained-release moxonidine, an imidazoline agonist, on plasma norepinephrine in patients with chronic heart failure. Circulation 2002; 105:1797-803. [PMID: 11956122 DOI: 10.1161/01.cir.0000014212.04920.62] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND In chronic heart failure, sympathetic activation is increased. Moxonidine acts on central nervous system receptors to decrease sympathetic activation. We investigated the dose-response relationship of a new sustained-release (SR) preparation of moxonidine and the plasma concentration of norepinephrine in patients with chronic heart failure. METHODS AND RESULTS A total of 268 patients with chronic heart failure in NYHA functional class II to IV on optimal standard therapy were randomized to placebo or 1 of 5 doses of moxonidine SR: 0.3, 0.6, 0.9, 1.2, or 1.5 mg BID. After a dose-titration phase (7 weeks), patients were followed up for another 12 weeks at their maximally tolerated dose. Blood samples for plasma norepinephrine were collected at baseline and weekly during the initial 7 weeks, at week 19, and at the end of the study. At baseline and 7 and 19 weeks, sampling was also done 4 hours after the dose. After the active phases of the study, plasma norepinephrine was evaluated for an additional 3 days. A marked, statistically significant dose-related decrease in plasma norepinephrine was observed for predose levels as well as 4 hours after the dose at week 19. At the highest dose (1.5 mg BID), the trough reduction in norepinephrine was 52%. These reductions were accompanied by a modest decrease in heart rate, a modest increase in left ventricular ejection fraction, and a dose-related increase in adverse events. CONCLUSIONS Plasma norepinephrine was markedly reduced in a dose-related manner by moxonidine SR. This reduction was accompanied by evidence of reverse remodeling, but also by an increase in adverse events.
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Communal C, Colucci WS, Remondino A, Sawyer DB, Port JD, Wichman SE, Bristow MR, Singh K. Reciprocal modulation of mitogen-activated protein kinases and mitogen-activated protein kinase phosphatase 1 and 2 in failing human myocardium. J Card Fail 2002; 8:86-92. [PMID: 12016632 DOI: 10.1054/jcaf.2002.32755] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
BACKGROUND Mitogen-activated protein kinases (MAPKs), consisting of the ERK1/2, JNKs, and p38-kinase families, play a key role in the regulation of myocyte growth and apoptosis in vitro. The activity of MAPKs is regulated by dual-specificity MAPK phosphatases (MKPs). Because myocardial failure is associated with myocyte hypertrophy and apoptosis, MAPKs may play a pathophysiologic role in human myocardial failure. METHODS AND RESULTS We measured MAPKs activities and the protein levels of MAPKs and MKPs (MKP-1 and MKP-2) in the myocardium explanted at the time of transplantation from patients with end-stage failure caused by idiopathic dilated cardiomyopathy (n = 5-7). Nonfailing donor hearts (n = 5-7) were used for comparison. Although the protein levels for JNK1/2 and p38-kinase in failing hearts were not different from levels in nonfailing hearts, the activities of both were decreased (P <.05). Despite a >3-fold increase in the protein level for ERK1/2 in failing hearts, ERK1/2 activity was not increased. Expression of MKP-2 was significantly increased in failing hearts, while expression of MKP-1 was increased in 5 of 7 failing hearts as measured by Western analysis. CONCLUSIONS JNK1/2 and p38 activities are decreased in failing human myocardium. Increased expression of MKPs may therefore contribute to decreased MAPKs activity in failing human myocardium.
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Leier CV, Silver MA, Rich MW, Eichhorn EJ, Fowler MB, Giles TD, Johnstone DE, Le Jemtel TH, Lachmann JS, Levine TB, Armstrong PW, Dec WG, Jessup M, Howlett J, Hershberger RE, Cohn JN, Adams KF, Colucci WS, Warner-Stevenson L, Hosenpud JD, Bristow MR, Pina I, Baughman KL, Binkley PF, Ventura HO, Francis GS, White M, Miller LW, Berry B, Missov E. Nuggets, pearls, and vignettes of master heart failure clinicians. Part 4--treatment. CONGESTIVE HEART FAILURE (GREENWICH, CONN.) 2002; 8:98-124. [PMID: 11927786 DOI: 10.1111/j.1527-5299.2002.01169.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Tsvetkova TO, Lowes BD, Robertson AD, Shakar SF, Lindenfeld J, Bristow MR, Wolfel EE. Ventilatory response to exercise in heart failure patients treated with beta-blockers is a better predictor of survival than peak oxygen consumption. J Am Coll Cardiol 2002. [DOI: 10.1016/s0735-1097(02)80650-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Wolfel EE, Tsvetkova TO, Lowes BD, Lindenfeld J, Shakar SF, Abraham WT, Robertson AD, Gilbert EM, Bristow MR. Improved ventilatory response at peak exercise despite no change in peak oxygen consumption with chronic beta-blockade in heart failure patients. J Am Coll Cardiol 2002. [DOI: 10.1016/s0735-1097(02)80810-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Lindenfeld J, Robertson AD, Lowes BD, Bristow MR. Aspirin impairs reverse myocardial remodeling in patients with heart failure treated with beta-blockers. J Am Coll Cardiol 2001; 38:1950-6. [PMID: 11738299 DOI: 10.1016/s0735-1097(01)01641-2] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
OBJECTIVES We hypothesized that aspirin (ASA) might alter the beneficial effect of beta-blockers on left ventricular ejection fraction (LVEF) in patients with chronic heart failure. BACKGROUND Aspirin blunts the vasodilation caused by both angiotensin-converting enzyme (ACE) inhibitors and beta-blockers in hypertensive patients and in patients with heart failure. Several studies suggest that ASA also blunts some of beneficial effects of ACE inhibitors on mortality in patients with heart failure. To our knowledge, there have been no data evaluating the possible interaction of ASA and beta-blockers on left ventricular remodeling in patients with heart failure. METHODS We retrospectively evaluated patients entered into the Multicenter Oral Carvedilol Heart failure Assessment (MOCHA) trial, a 6-month, double-blind, randomized, placebo-controlled, multicenter, dose-response evaluation of carvedilol in patients with chronic stable symptomatic heart failure. Multivariate analysis was performed to determine if aspirin independently influenced the improvement in LVEF. RESULTS Over all randomized patients (n = 293), LVEF improved 8.2 +/- 0.8 ejection fraction (EF) units in ASA nonusers and 4.5 +/- 0.7 EF units in ASA users (p = 0.005). In subjects randomized to treatment with carvedilol (n = 231), LVEF improved 9.5 +/- 0.9 EF units in ASA nonusers and 5.8 +/- 0.8 EF units in ASA users (p = 0.02). In subjects randomized to treatment with placebo (n = 62), LVEF improved 2.8 +/- 1.2 EF units in ASA nonusers and 0.5 +/- 1.4 EF units in ASA users (p = 0.20). Aspirin did not significantly affect the heart rate or systolic blood pressure response in either the placebo or carvedilol groups. The effect of ASA became more significant on multivariate analysis. The change in LVEF was also influenced by carvedilol dose, etiology of heart failure, baseline heart rate, EF and coumadin use. The detrimental effect of ASA on the improvement in LVEF was dose-related and was present in both placebo and carvedilol groups, although the effect was statistically significant only in the much larger carvedilol group. CONCLUSIONS Aspirin significantly affects the changes in LVEF over time in patients with heart failure and systolic dysfunction treated with carvedilol. The specific mechanism(s) underlying this interaction are unknown and further studies are needed to provide additional understanding of the molecular basis of factors influencing reverse remodeling in patients with heart failure.
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Lowes BD, Tsvetkova T, Eichhorn EJ, Gilbert EM, Bristow MR. Milrinone versus dobutamine in heart failure subjects treated chronically with carvedilol. Int J Cardiol 2001; 81:141-9. [PMID: 11744130 DOI: 10.1016/s0167-5273(01)00520-4] [Citation(s) in RCA: 99] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
OBJECTIVE To compare the efficacy of milrinone and dobutamine in patients chronically treated with carvedilol. BACKGROUND Milrinone and dobutamine are used to manage decompensated heart failure, but their efficacy in patients on beta-blocker therapy was unknown. METHODS Twenty patients with decompensated heart failure were prospectively enrolled. Inotropic responses to milrinone (12.5, 25 or 50 microg/kg bolus infusions) or dobutamine (5, 10, 15 or 20 microg/kg/min infusions) were evaluated by right-heart catheterization. RESULTS Milrinone increased cardiac index (2.0-2.6 l/min/m2, P=0.0001) without significantly altering heart rate (70-75 bpm, P=0.19). Milrinone decreased mean pulmonary artery pressure (36-29 mm Hg, P=0.0001), pulmonary capillary wedge pressure (24-18 mm Hg, P=0.0001) and mean arterial blood pressure (78-75 mm Hg, P=0.0002). Left ventricular stroke volume index increased in the milrinone group (31-35 ml/beat/m2, P=0.0001). Dobutamine produced an increase in cardiac index (2.4-3.3 l/min/m2, P=0.0001) only at doses that are not typically used to treat heart failure (15-20 microg/kg/min). At these doses, dobutamine increased heart rate (68-82 bpm, P=0.008), mean systemic pressure (90-117 mm Hg, P=0.0001) and mean pulmonary artery pressure (21-30 mm Hg, P=0.001). Dobutamine did not alter left ventricular stroke volume index or pulmonary capillary wedge pressure. CONCLUSIONS Dobutamine and milrinone have different hemodynamic effects in patients treated chronically with carvedilol. These differences should be considered when selecting inotropic therapy for decompensated heart failure.
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Leier CV, Young JB, Levine TB, Pina I, Armstrong PW, Fowler MB, Warner-Stevenson L, Cohn JN, O'Connell JB, Bristow MR, Nicklas JM, Johnstone DE, Howlett J, Ventura HO, Giles TD, Greenberg BH, Chatterjee K, Bourge RC, Yancy CW, Gottleib SS. Nuggets, pearls, and vignettes of master heart failure clinicians. Part 2-the physical examination. CONGESTIVE HEART FAILURE (GREENWICH, CONN.) 2001; 7:297-308. [PMID: 11828174 DOI: 10.1111/j.1527-5299.2001.01167.x] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Port JD, Bristow MR. beta-Adrenergic receptors, transgenic mice, and pharmacological model systems. Mol Pharmacol 2001; 60:629-31. [PMID: 11562422] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/21/2023] Open
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Kinugawa K, Yonekura K, Ribeiro RC, Eto Y, Aoyagi T, Baxter JD, Camacho SA, Bristow MR, Long CS, Simpson PC. Regulation of thyroid hormone receptor isoforms in physiological and pathological cardiac hypertrophy. Circ Res 2001; 89:591-8. [PMID: 11577024 DOI: 10.1161/hh1901.096706] [Citation(s) in RCA: 126] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Physiological and pathological cardiac hypertrophy have directionally opposite changes in transcription of thyroid hormone (TH)-responsive genes, including alpha- and beta-myosin heavy chain (MyHC) and sarcoplasmic reticulum Ca(2+)-ATPase (SERCA), and TH treatment can reverse molecular and functional abnormalities in pathological hypertrophy, such as pressure overload. These findings suggest relative hypothyroidism in pathological hypertrophy, but serum levels of TH are usually normal. We studied the regulation of TH receptors (TRs) beta1, alpha1, and alpha2 in pathological and physiological rat cardiac hypertrophy models with hypothyroid- and hyperthyroid-like changes in the TH target genes, alpha- and beta-MyHC and SERCA. All 3 TR subtypes in myocytes were downregulated in 2 hypertrophy models with a hypothyroid-like mRNA phenotype, phenylephrine in culture and pressure overload in vivo. Myocyte TRbeta1 was upregulated in models with a hyperthyroid-like phenotype, TH (triiodothyronine, T3), in culture and exercise in vivo. In myocyte culture, TR overexpression, or excess T3, reversed the effects of phenylephrine on TH-responsive mRNAs and promoters. In addition, TR cotransfection and treatment with the TRbeta1-selective agonist GC-1 suggested different functional coupling of the TR isoforms, TRbeta1 to transcription of beta-MyHC, SERCA, and TRbeta1, and TRalpha1 to alpha-MyHC transcription and increased myocyte size. We conclude that TR isoforms have distinct regulation and function in rat cardiac myocytes. Changes in myocyte TR levels can explain in part the characteristic molecular phenotypes in physiological and pathological cardiac hypertrophy.
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Asano K, Zisman LS, Yoshikawa T, Headley V, Bristow MR, Port JD. Bucindolol, a nonselective beta 1- and beta 2-adrenergic receptor antagonist, decreases beta-adrenergic receptor density in cultured embryonic chick cardiac myocyte membranes. J Cardiovasc Pharmacol 2001; 37:678-91. [PMID: 11392464 DOI: 10.1097/00005344-200106000-00005] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Bucindolol and carvedilol, nonselective beta1- and beta2-adrenergic receptor antagonists, have been widely used in clinical therapeutic trials of congestive heart failure. The aim of the current study was to investigate long-term effects of bucindolol or carvedilol on beta-adrenergic receptor protein and gene expression in cardiac myocytes. Embryonic chick cardiac myocytes were cultured and incubated with bucindolol (1 microM), carvedilol (1 microM), or norepinephrine (1 microM) for 24 h. 125I-iodocyanopindolol binding assays demonstrated that incubation with norepinephrine or bucindolol, but not carvedilol, significantly decreased beta-adrenergic receptor density in crude membranes prepared from the myocytes. Neither bucindolol nor carvedilol significantly stimulated adenylyl cyclase activity in membranes from drug-untreated cells. Unlike by norepinephrine, the receptor density reduction by bucindolol incubation was not accompanied by a change in beta1-adrenergic receptor messenger RNA abundance. A decrease in membrane beta-adrenergic receptor density without a change in cognate messenger RNA abundance was also observed in hamster DDT1 MF2 cell line incubated with bucindolol (1 microM, 24 h). We conclude that incubation with bucindolol, but not carvedilol, results in true reduction of beta-adrenergic receptor density in chick cardiac myocyte membranes by mechanisms that are distinct from those responsible for receptor density reduction by the agonist norepinephrine.
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Bristow MR, Shakar SF, Linseman JV, Lowes BD. Inotropes and beta-blockers: is there a need for new guidelines? J Card Fail 2001; 7:8-12. [PMID: 11605160 DOI: 10.1054/jcaf.2001.26655] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Beta-adrenergic blocking agents are standard treatment for patients with mild-to-moderate heart failure. When patients receiving beta-blockers decompensate they often need treatment with a positive inotropic agent. The beta-agonist dobutamine may not produce much increase in cardiac output during full-dose beta-blocker treatment and may increase systemic vascular resistance via alpha-adrenergic stimulation. In contrast, phosphodiesterase inhibitors (PDEIs) such as milrinone or enoximone retain full hemodynamic effects during complete beta-blockade because the site of action of PDEIs is beyond the beta-adrenergic receptor and because beta-blockade reverses some of the desensitization phenomena that account for the attenuation of PDEI response in heart failure related to upregulation in G(alphai). Inotrope-requiring subjects with decompensated heart failure who are undergoing long-term therapy with beta-blocking agents should be treated with a type III-specific PDEI, not a beta-agonist such as dobutamine.
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Eichhorn EJ, Domanski MJ, Krause-Steinrauf H, Bristow MR, Lavori PW. A trial of the beta-blocker bucindolol in patients with advanced chronic heart failure. N Engl J Med 2001; 344:1659-67. [PMID: 11386264 DOI: 10.1056/nejm200105313442202] [Citation(s) in RCA: 833] [Impact Index Per Article: 36.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
BACKGROUND Although beta-adrenergic-receptor antagonists reduce morbidity and mortality in patients with mild-to-moderate chronic heart failure, their effect on survival in patients with more advanced heart failure is unknown. METHODS A total of 2708 patients with heart failure designated as New York Heart Association (NYHA) functional class III (in 92 percent of the patients) or IV (in 8 percent) and a left ventricular ejection fraction of 35 percent or lower were randomly assigned to double-blind treatment with either bucindolol (1354 patients) or placebo (1354 patients) and followed for the primary end point of death from any cause. RESULTS The data and safety monitoring board recommended stopping the trial after the seventh interim analysis. At that time, there was no significant difference in mortality between the two groups (unadjusted P=0.16). The results presented here are based on complete follow-up at the time of study termination (average, 2.0 years). There were a total of 449 deaths in the placebo group (33 percent) and 411 deaths in the bucindolol group (30 percent; adjusted P=0.13). The risk of the secondary end point of death from cardiovascular causes was lower in the bucindolol group (hazard ratio, 0.86; 95 percent confidence interval, 0.74 to 0.99), as was the risk of heart transplantation or death (hazard ratio, 0.87; 95 percent confidence interval, 0.77 to 0.99). CONCLUSIONS In a demographically diverse group of patients with NYHA class III and IV heart failure, bucindolol resulted in no significant overall survival benefit.
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Yancy CW, Fowler MB, Colucci WS, Gilbert EM, Bristow MR, Cohn JN, Lukas MA, Young ST, Packer M. Race and the response to adrenergic blockade with carvedilol in patients with chronic heart failure. N Engl J Med 2001; 344:1358-65. [PMID: 11333992 DOI: 10.1056/nejm200105033441803] [Citation(s) in RCA: 229] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
BACKGROUND The benefits of angiotensin-converting-enzyme inhibitors and beta-blockers may be smaller in black patients than in patients of other races, but it is unknown whether race influences the response to carvedilol in patients with chronic heart failure. METHODS In the U.S. Carvedilol Heart Failure Trials Program, 217 black and 877 nonblack patients (in New York Heart Association class II, III, or IV and with a left ventricular ejection fraction of no more than 0.35) were randomly assigned to receive placebo or carvedilol (at doses of 6.25 to 50 mg twice daily) for up to 15 months. The effects of carvedilol on ejection fraction, clinical status, and major clinical events were retrospectively compared between black and nonblack patients. RESULTS As compared with placebo, carvedilol lowered the risk of death from any cause or hospitalization for any reason by 48 percent in black patients and by 30 percent in nonblack patients. Carvedilol reduced the risk of worsening heart failure (heart failure leading to death, hospitalization, or a sustained increase in medication) by 54 percent in black patients and by 51 percent in nonblack patients. The ratios of the relative risks associated with carvedilol for these two outcome variables in black as compared with nonblack patients were 0.74 (95 percent confidence interval, 0.42 to 1.34) and 0.94 (95 percent confidence interval, 0.43 to 2.05), respectively. Carvedilol also improved functional class, ejection fraction, and the patients' and physicians' global assessments in both the black patients and the nonblack patients. For all these measures of outcome and clinical status, carvedilol was superior to placebo within each racial cohort (P<0.05 in all analyses), and there was no significant interaction between race and treatment (P> 0.05 in all analyses). CONCLUSIONS The benefit of carvedilol was apparent and of similar magnitude in both black and nonblack patients with heart failure.
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Fowler MB, Vera-Llonch M, Oster G, Bristow MR, Cohn JN, Colucci WS, Gilbert EM, Lukas MA, Lacey MJ, Richner R, Young ST, Packer M. Influence of carvedilol on hospitalizations in heart failure: incidence, resource utilization and costs. U.S. Carvedilol Heart Failure Study Group. J Am Coll Cardiol 2001; 37:1692-9. [PMID: 11345386 DOI: 10.1016/s0735-1097(01)01190-1] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
BACKGROUND Carvedilol reduces disease progression in heart failure, but to our knowledge, its effects on hospitalizations and costs have not been evaluated. OBJECTIVES We examined the effects on hospitalization frequency and costs in the U.S. Carvedilol Heart Failure Trials Program. This program consisted of four concurrent, multicenter, double-blind, placebo-controlled studies involving 1,094 patients with New York Heart Association class II to IV heart failure, which treated patients with placebo or carvedilol for up to 15 months (median, 6.5 months). METHODS Detailed resource utilization data were collected for all hospitalizations occurring between randomization and the end of follow-up. In-patient care costs were estimated based on observed levels of resource use. RESULTS Compared with placebo, carvedilol reduced the risk of hospitalization for any reason by 29% (p = 0.009), cardiovascular hospitalizations by 28% (p = 0.034) and heart failure hospitalizations by 38% (p = 0.041). Carvedilol also decreased the mean number of hospitalizations per patient (for cardiovascular reasons 30% [p = 0.02], for heart failure 53% [p = 0.03]). Among hospitalized patients, carvedilol reduced severity of illness during hospital admission, as reflected by shorter length of stay and less frequent use of intensive care. For heart failure hospital admissions, carvedilol decreased mean length of stay by 37% (p = 0.03) and mean number of intensive care unit/coronary care unit days by 83% (p = 0.001), with similar effects on cardiovascular admissions. As a result, estimated inpatient care costs with carvedilol were 57% lower for cardiovascular admissions (p = 0.016) and 81% lower for heart failure admissions (p = 0.022). CONCLUSIONS Carvedilol added to angiotensin-converting enzyme inhibition reduces hospitalization risk as well as severity of illness and resource utilization during admission in patients with chronic heart failure.
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Port JD, Bristow MR. Altered beta-adrenergic receptor gene regulation and signaling in chronic heart failure. J Mol Cell Cardiol 2001; 33:887-905. [PMID: 11343413 DOI: 10.1006/jmcc.2001.1358] [Citation(s) in RCA: 189] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
J. D. Port and M. R. Bristow. Altered Beta-adrenergic Receptor Gene Regulation and Signaling in Chronic Heart Failure. Journal of Molecular and Cellular Cardiology (2001) 33, 887-905. Beta adrenergic receptors (beta -ARs) are critical regulators of cardiac function in both normal and pathophysiological states. Under normal conditions, beta -ARs and their signaling pathways modulate both the rate and force of myocardial contraction and relaxation, allowing individuals to respond appropriately to physiological stress or exercise. However, in chronic heart failure, sustained activation of the beta -AR signaling pathways can have overtly negative biological consequences. This notion is reinforced by the positive outcomes of a number of clinical trials demonstrating the usefulness of beta-blocker therapy in chronic congestive heart failure. During the last few years, significant progress has been made in understanding the molecular biological basis of beta -AR function, both at the biochemical and genetic levels. In this review, the biological basis of adrenergic signaling and how this changes in heart failure is discussed. Aspects of adrenergic receptor pharmacology relevant to heart failure are reviewed, including the recently emerging differences described for beta(1)- v beta(2)-AR signaling pathways. Highlighting these differences is recent evidence that over-stimulation of the beta(1)-AR pathway in cardiac myocytes appears to be pro-apoptotic, whereas stimulation of the beta(2)-AR pathway may be anti-apoptotic. Overview of beta -AR gene regulation, transgenic models of beta -AR overexpression, and beta -AR polymorphisms as they relate to heart failure progression are also discussed.
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