Browsing by Subject "Adrenergic beta-Antagonists"
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Item Open Access Anti-beta(1)-adrenergic receptor antibodies and heart failure: causation, not just correlation.(J Clin Invest, 2004-05) Freedman, Neil J; Lefkowitz, Robert JAntibodies specific for the beta(1)-adrenergic receptor are found in patients with chronic heart failure of various etiologies. From work presented in this issue of the JCI, we can now infer that these antibodies actually contribute to the pathogenesis of chronic heart failure. This commentary discusses mechanisms by which these antibodies may engender cardiomyopathy.Item Open Access Cardiac beta ARK1 inhibition prolongs survival and augments beta blocker therapy in a mouse model of severe heart failure.(Proc Natl Acad Sci U S A, 2001-05-08) Harding, VB; Jones, LR; Lefkowitz, RJ; Koch, WJ; Rockman, HAChronic human heart failure is characterized by abnormalities in beta-adrenergic receptor (betaAR) signaling, including increased levels of betaAR kinase 1 (betaARK1), which seems critical to the pathogenesis of the disease. To determine whether inhibition of betaARK1 is sufficient to rescue a model of severe heart failure, we mated transgenic mice overexpressing a peptide inhibitor of betaARK1 (betaARKct) with transgenic mice overexpressing the sarcoplasmic reticulum Ca(2+)-binding protein, calsequestrin (CSQ). CSQ mice have a severe cardiomyopathy and markedly shortened survival (9 +/- 1 weeks). In contrast, CSQ/betaARKct mice exhibited a significant increase in mean survival age (15 +/- 1 weeks; P < 0.0001) and showed less cardiac dilation, and cardiac function was significantly improved (CSQ vs. CSQ/betaARKct, left ventricular end diastolic dimension 5.60 +/- 0.17 mm vs. 4.19 +/- 0.09 mm, P < 0.005; % fractional shortening, 15 +/- 2 vs. 36 +/- 2, P < 0.005). The enhancement of the survival rate in CSQ/betaARKct mice was substantially potentiated by chronic treatment with the betaAR antagonist metoprolol (CSQ/betaARKct nontreated vs. CSQ/betaARKct metoprolol treated, 15 +/- 1 weeks vs. 25 +/- 2 weeks, P < 0.0001). Thus, overexpression of the betaARKct resulted in a marked prolongation in survival and improved cardiac function in a mouse model of severe cardiomyopathy that can be potentiated with beta-blocker therapy. These data demonstrate a significant synergy between an established heart-failure treatment and the strategy of betaARK1 inhibition.Item Open Access Coupling of beta2-adrenoceptor to Gi proteins and its physiological relevance in murine cardiac myocytes.(Circ Res, 1999-01-08) Xiao, RP; Avdonin, P; Zhou, YY; Cheng, H; Akhter, SA; Eschenhagen, T; Lefkowitz, RJ; Koch, WJ; Lakatta, EG-Transgenic mouse models have been developed to manipulate beta-adrenergic receptor (betaAR) signal transduction. Although several of these models have altered betaAR subtypes, the specific functional sequelae of betaAR stimulation in murine heart, particularly those of beta2-adrenergic receptor (beta2AR) stimulation, have not been characterized. In the present study, we investigated effects of beta2AR stimulation on contraction, [Ca2+]i transient, and L-type Ca2+ currents (ICa) in single ventricular myocytes isolated from transgenic mice overexpressing human beta2AR (TG4 mice) and wild-type (WT) littermates. Baseline contractility of TG4 heart cells was increased by 3-fold relative to WT controls as a result of the presence of spontaneous beta2AR activation. In contrast, beta2AR stimulation by zinterol or isoproterenol plus a selective beta1-adrenergic receptor (beta1AR) antagonist CGP 20712A failed to enhance the contractility in TG4 myocytes, and more surprisingly, beta2AR stimulation was also ineffective in increasing contractility in WT myocytes. Pertussis toxin (PTX) treatment fully rescued the ICa, [Ca2+]i, and contractile responses to beta2AR agonists in both WT and TG4 cells. The PTX-rescued murine cardiac beta2AR response is mediated by cAMP-dependent mechanisms, because it was totally blocked by the inhibitory cAMP analog Rp-cAMPS. These results suggest that PTX-sensitive G proteins are responsible for the unresponsiveness of mouse heart to agonist-induced beta2AR stimulation. This was further corroborated by an increased incorporation of the photoreactive GTP analog [gamma-32P]GTP azidoanilide into alpha subunits of Gi2 and Gi3 after beta2AR stimulation by zinterol or isoproterenol plus the beta1AR blocker CGP 20712A. This effect to activate Gi proteins was abolished by a selective beta2AR blocker ICI 118,551 or by PTX treatment. Thus, we conclude that (1) beta2ARs in murine cardiac myocytes couple to concurrent Gs and Gi signaling, resulting in null inotropic response, unless the Gi signaling is inhibited; (2) as a special case, the lack of cardiac contractile response to beta2AR agonists in TG4 mice is not due to a saturation of cell contractility or of the cAMP signaling cascade but rather to an activation of beta2AR-coupled Gi proteins; and (3) spontaneous beta2AR activation may differ from agonist-stimulated beta2AR signaling.Item Open Access Early propranolol treatment induces lung heme-oxygenase-1, attenuates metabolic dysfunction, and improves survival following experimental sepsis.(Crit Care, 2013-09-10) Wilson, Joel; Higgins, David; Hutting, Haley; Serkova, Natalie; Baird, Christine; Khailova, Ludmila; Queensland, Kelly; Vu Tran, Zung; Weitzel, Lindsay; Wischmeyer, Paul EINTRODUCTION: Pharmacological agents that block beta-adrenergic receptors have been associated with improved outcome in burn injury. It has been hypothesized that injuries leading to a hypermetabolic state, such as septic shock, may also benefit from beta-blockade; however, outcome data in experimental models have been contradictory. Thus, we investigated the effect of beta-blockade with propranolol on survival, hemodynamics, lung heat shock protein (HSP) expression, metabolism and inflammatory markers in a rat cecal ligation and puncture (CLP) model of sepsis. METHODS: Sprague-Dawley rats receiving either repeated doses (30 minutes pre-CLP and every 8 hours for 24 hours postoperatively) of propranolol or control (normal saline), underwent CLP and were monitored for survival. Additionally, lung and blood samples were collected at 6 and 24 hours for analysis. Animals also underwent monitoring to evaluate global hemodynamics. RESULTS: Seven days following CLP, propranolol improved survival versus control (P < 0.01). Heart rates in the propranolol-treated rats were approximately 23% lower than control rats (P < 0.05) over the first 24 hours, but the mean arterial blood pressure was not different between groups. Metabolic analysis of lung tissue demonstrated an increase in lung ATP/ADP ratio and NAD+ content and a decreased ratio of polyunsaturated fatty acids to monounsaturated fatty acids (PUFA/MUFA). Cytokine analysis of the inflammatory cytokine tumor necrosis factor alpha (TNF-alpha) demonstrated decreased expression of TNF-alpha in both lung and plasma at 24 hours post CLP induced sepsis. Finally, propranolol led to a significant increase in lung hemeoxygenase-1 expression, a key cellular protective heat shock protein (HSP) in the lung. Other lung HSP expression was unchanged. CONCLUSIONS: These results suggest that propranolol treatment may decrease mortality during sepsis potentially via a combination of improving metabolism, suppressing aspects of the inflammatory response and enhancing tissue protection.Item Open Access Impact of beta-blockade premedication on image quality of ECG-gated thoracic aorta CT angiography.(Acta radiologica (Stockholm, Sweden : 1987), 2014-12) Entezari, Pegah; Collins, Jeremy; Chalian, Hamid; Tore, Huseyin Gurkan; Carr, James; Yaghmai, VahidBACKGROUND: Thoracic aortic aneurysm is one of the most common aorta pathologies worldwide, which is commonly evaluated by computed tomography angiography (CTA). One of the routine methods to improve the image quality of CTA is heart rate reduction prior to study by beta-blockade administration. PURPOSE: To assess the effect of beta-blockade on image quality of the ascending aorta in electrocardiography (ECG)-gated dual-source CTA (DSCTA) images. MATERIAL AND METHODS: In this retrospective study, ECG-gated thoracic aorta CTA images of 40 patients without beta-blocker administration were compared with ECG-gated images of 40 patients with beta-blockade. Images of the aorta were analyzed objectively and subjectively at three levels: sinus of Valsalva (sinus), sinotubular junction (STJ), and mid ascending aorta (MAA). Quantitative sharpness index (SI) and signal-to-noise ratio (SNR) were calculated and two radiologists evaluated the image quality using a 3-point scale. RESULTS: Mean heart rate in beta-blocker and non-beta-blocker groups was 61.7 beats per minute (bpm) (range, 58.1-63.9 bpm) and 72.9 bpm (range, 69.3-84.1 bpm), respectively (P < 0.05). Aorta wall SI, SNR, and subjective grading were comparable between the two groups at all three levels (P > 0.05). CONCLUSION: Beta-blocker premedication may not be necessary for imaging of ascending aorta with ECG-gated DSCTA.Item Open Access International variation in characteristics and clinical outcomes of patients with type 2 diabetes and heart failure: Insights from TECOS.(American heart journal, 2019-12) Bhatt, Ankeet S; Luo, Nancy; Solomon, Nicole; Pagidipati, Neha J; Ambrosio, Giuseppe; Green, Jennifer B; McGuire, Darren K; Standl, Eberhard; Cornel, Jan H; Halvorsen, Sigrun; Lopes, Renato D; White, Harvey D; Holman, Rury R; Peterson, Eric D; Mentz, Robert J; TECOS Study GroupInternational differences in management/outcomes among patients with type 2 diabetes and heart failure (HF) are not well characterized. We sought to evaluate geographic variation in treatment and outcomes among these patients. METHODS AND RESULTS: Among 14,671 participants in the Trial Evaluating Cardiovascular Outcomes with Sitagliptin (TECOS), those with HF at baseline and a documented ejection fraction (EF) (N = 1591; 10.8%) were categorized by enrollment region (North America, Latin America, Western Europe, Eastern Europe, and Asia Pacific). Cox models were used to examine the association between geographic region and the primary outcome of all-cause mortality (ACM) or hospitalization for HF (hHF) in addition to ACM alone. Analyses were stratified by those with EF <40% or EF ≥40%. The majority of participants with HF were enrolled in Eastern Europe (53%). Overall, 1,267 (79.6%) had EF ≥40%. β-Blocker (83%) and angiotensin-converting enzyme inhibitor/angiotensin receptor blocker (86%) use was high across all regions in patients with EF <40%. During a median follow-up of 2.9 years, Eastern European participants had lower rates of ACM/hHF compared with North Americans (adjusted hazard ratio: 0.45; 95% CI: 0.32-0.64). These differences were seen only in the EF ≥40% subgroup and not the EF <40% subgroup. ACM was similar among Eastern European and North American participants (adjusted hazard ratio: 0.79; 95% CI: 0.44-1.45). CONCLUSIONS: Significant variation exists in the clinical features and outcomes of HF patients across regions in TECOS. Patients from Eastern Europe had lower risk-adjusted ACM/hHF than those in North America, driven by those with EF ≥40%. These data may inform the design of future international trials.Item Open Access Ligand-induced overexpression of a constitutively active beta2-adrenergic receptor: pharmacological creation of a phenotype in transgenic mice.(Proc Natl Acad Sci U S A, 1997-01-07) Samama, P; Bond, RA; Rockman, HA; Milano, CA; Lefkowitz, RJTransgenic overexpression (40- to 100-fold) of the wild-type human beta2-adrenergic receptor in the hearts of mice leads to a marked increase in cardiac contractility, which is apparently due to the low level of spontaneous (i.e., agonist-independent) activity inherent in the receptor. Here we report that transgenic mice expressing a mutated constitutively active form of the receptor (CAM) show no such phenotype, owing to its modest expression (3-fold above endogenous cardiac beta-adrenergic receptor levels). Surprisingly, treatment of the animals with a variety of beta-adrenergic receptor ligands leads to a 50-fold increase in CAM beta2-adrenergic receptor expression, by stabilizing the CAM beta2-adrenergic receptor protein. Receptor up-regulation leads in turn to marked increases in adenylate cyclase activity, atrial tension determined in vitro, and indices of cardiac contractility determined in vivo. These results illustrate a novel mechanism for regulating physiological responses, i.e., ligand-induced stabilization of a constitutively active but inherently unstable protein.Item Open Access Preoperative CYP2D6 metabolism-dependent β-blocker use and mortality after coronary artery bypass grafting surgery.(J Thorac Cardiovasc Surg, 2014-04) Kertai, Miklos D; Esper, Stephen A; Akushevich, Igor; Voora, Deepak; Ginsburg, Geoffrey S; Stafford-Smith, Mark; Grichnik, Katherine; Newman, Mark F; Fontes, Manuel L; Smith, Peter; Podgoreanu, Mihai V; Mathew, Joseph P; Cardiothoracic Anesthesia Research Endeavors (CARE) GroupOBJECTIVE: Recently, the role of β-blockers (BBs) in reducing perioperative mortality has been challenged. The conflicting results might have resulted from the extent of BB metabolism by the cytochrome P-450 (CYP2D6) isoenzyme. The purpose of the present study was to assess the association between the preoperative use of BBs dependent on metabolism of the CYP2D6 isoenzyme with operative mortality after coronary artery bypass grafting surgery. METHODS: We performed a retrospective study of 5248 patients who had undergone coronary bypass grafting surgery from January 1, 2001 to November 30, 2009 at Duke University Medical Center. The cohorts were defined by the preoperative use of BBs and BB type (non-CYP2D6_BBs, CYP2D6_BBs, or no BBs). Operative mortality was analyzed using inverse probability-weighted estimators with propensity score adjustment. RESULTS: Of the 5248 patients, 14% received non-CYP2D6_BBs, 43%, CYP2D6_BBs, and 43%, no BBs. The incidence of operative mortality was 0.8%, 2.1%, and 3.7% in the non-CYP2D6_BB, CYP2D6_BB, and no BB groups, respectively. Multivariable inverse probability-weighted-adjusted analyses showed that non-CYP2D6_BBs were associated with a lower incidence of operative mortality (odds ratio, 0.33; 95% confidence interval, 0.13-0.83; P = .02) compared with no BB use and a trend toward lower operative mortality (odds ratio, 0.44; 95% confidence interval, 0.16-1.07; P = .06) compared with CYP2D6_BBs. No significant decrease occurred in the risk of operative mortality between the CYP2D6_BB and no BB groups (odds ratio, 0.85; 95% confidence interval, 0.54-1.34; P = .48). CONCLUSIONS: Among these patients, preoperative non-CYP2D6_BB use, but not CYP2D6_BB use, was associated with a decreased risk of operative mortality.Item Open Access Projected Clinical Benefits of Implementation of SGLT-2 Inhibitors Among Medicare Beneficiaries Hospitalized for Heart Failure.(Journal of cardiac failure, 2022-04) Vaduganathan, Muthiah; Greene, Stephen J; Zhang, Shuaiqi; Solomon, Nicole; Chiswell, Karen; Devore, Adam D; Butler, Javed; Heidenreich, Paul A; Huang, Joanna C; Kittleson, Michelle M; Joynt Maddox, Karen E; Mcdermott, James J; Owens, Anjali Tiku; Peterson, Pamela N; Solomon, Scott D; Vardeny, Orly; Yancy, Clyde W; Fonarow, Gregg CBackground
The sodium-glucose cotransporter-2 (SGLT-2) inhibitors form the latest pillar in the management of heart failure with reduced ejection fraction (HFrEF) and appear to be effective across a range of patient profiles. There is increasing interest in initiating SGLT-2 inhibitors during hospitalization, yet little is known about the putative benefits of this implementation strategy.Methods
We evaluated Medicare beneficiaries with HFrEF (≤ 40%) hospitalized at 228 sites in the Get With The Guidelines-Heart Failure (GWTG-HF) registry in 2016 who had linked claims data for ≥ 1 year postdischarge. We identified those eligible for dapagliflozin under the latest U.S. Food and Drug Administration label (excluding estimated glomerular filtration rates < 25 mL/min per 1.73 m2, dialysis and type 1 diabetes). We evaluated 1-year outcomes overall and among key subgroups (age ≥ 75 years, gender, race, hospital region, kidney function, diabetes status, triple therapy). We then projected the potential benefits of implementation of dapagliflozin based on the risk reductions observed in the Dapagliflozin and Prevention of Adverse Outcomes in Heart Failure (DAPA-HF) trial.Results
Among 7523 patients hospitalized for HFrEF, 6576 (87%) would be candidates for dapagliflozin (mean age 79 ± 8 years, 39% women, 11% Black). Among eligible candidates, discharge use of β-blockers, ACEi/ARB, MRA, ARNI, and triple therapy (ACEi/ARB/ARNI+β-blocker+MRA) was recorded in 88%, 64%, 29%, 3%, and 20%, respectively. Among treatment-eligible patients, the 1-year incidence (95% CI) of mortality was 37% (36-38%) and of HF readmission was 33% (32-34%), and each exceeded 25% across all key subgroups. Among 1333 beneficiaries eligible for dapagliflozin who were already on triple therapy, the 1-year incidence of mortality was 26% (24%-29%) and the 1-year readmission due to HF was 30% (27%-32%). Applying the relative risk reductions observed in DAPA-HF, absolute risk reductions with complete implementation of dapagliflozin among treatment-eligible Medicare beneficiaries are projected to be 5% (1%-9%) for mortality and 9% (5%-12%) for HF readmission by 1 year. The projected number of Medicare beneficiaries who would need to be treated for 1 year to prevent 1 death is 19 (11-114), and 12 (8-21) would need to be treated to prevent 1 readmission due to HF.Conclusions
Medicare beneficiaries with HFrEF who are eligible for dapagliflozin after hospitalization due to HF, including those well-treated with other disease-modifying therapies, face high risks of mortality and HF readmission by 1 year. If the benefits of reductions in death and hospitalizations due to HF observed in clinical trials can be fully realized, the absolute benefits of implementation of SGLT-2 inhibitors among treatment-eligible candidates are anticipated to be substantial in this high-risk postdischarge setting.Item Open Access The Association Between Beta-blocker and Renin-Angiotensin System Inhibitor Use After Heart Failure With Reduced Ejection Fraction Hospitalization and Outcomes in Older Patients.(Journal of cardiac failure, 2023-04) Gilstrap, Lauren; Solomon, Nicole; Chiswell, Karen; James O'Malley, A; Skinner, Jonathan S; Fonarow, Gregg C; Bhatt, Deepak L; Yancy, Clyde W; Devore, Adam DIntroduction
Beta-blockers (BB) and renin-angiotensin system inhibitors (RASi) are foundational for the treatment of heart failure with reduced ejection fraction (HFrEF). However, given the increased risk of side effects in older patients, uncertainty remains as to whether, on net, older patients benefit as much as the younger patients studied in trials.Methods and results
Using the Get With The Guidelines-Heart Failure registry linked with Medicare data, overlap propensity weighted Cox proportional hazard models were used to examine the association between BB and RASi use at hospital discharge and 30-day and 1-year outcomes among patients with HFrEF. Among the 48,711 patients (aged ≥65 years) hospitalized with HFrEF, there were significant associations between BB and/or RASi use at discharge and lower rates of 30-day and 1-year mortality, including those over age 85 (30-day hazard ratio 0.56, 95% confidence interval 0.45-0.70; 1-year hazard ratio 0.69, 95% confidence interval 0.61-0.78). In addition, the magnitude of benefit associated with BB and/or RASi use after discharge did not decrease with advancing age. Even among the oldest patients, those over age 85, with hypotension, renal insufficiency or frailty, BB and/or RASi use at discharge was still associated with lower 1-year mortality or readmission.Conclusions
Among older patients hospitalized with HFrEF, BB and/or RASi use at discharge is associated with lower rates of 30-day and 1-year mortality across all age groups and the magnitude of this benefit does not seem to decrease with advancing age. These data suggest that, absent a clinical contraindication, BB and RASi should be considered in all patients hospitalized with HFrEF before or at hospital discharge, regardless of age.Item Open Access The β-arrestin-biased β-adrenergic receptor blocker carvedilol enhances skeletal muscle contractility.(Proceedings of the National Academy of Sciences of the United States of America, 2020-06) Kim, Jihee; Grotegut, Chad A; Wisler, James W; Mao, Lan; Rosenberg, Paul B; Rockman, Howard A; Lefkowitz, Robert JA decrease in skeletal muscle strength and functional exercise capacity due to aging, frailty, and muscle wasting poses major unmet clinical needs. These conditions are associated with numerous adverse clinical outcomes including falls, fractures, and increased hospitalization. Clenbuterol, a β2-adrenergic receptor (β2AR) agonist enhances skeletal muscle strength and hypertrophy; however, its clinical utility is limited by side effects such as cardiac arrhythmias mediated by G protein signaling. We recently reported that clenbuterol-induced increases in contractility and skeletal muscle hypertrophy were lost in β-arrestin 1 knockout mice, implying that arrestins, multifunctional adapter and signaling proteins, play a vital role in mediating the skeletal muscle effects of β2AR agonists. Carvedilol, classically defined as a βAR antagonist, is widely used for the treatment of chronic systolic heart failure and hypertension, and has been demonstrated to function as a β-arrestin-biased ligand for the β2AR, stimulating β-arrestin-dependent but not G protein-dependent signaling. In this study, we investigated whether treatment with carvedilol could enhance skeletal muscle strength via β-arrestin-dependent pathways. In a murine model, we demonstrate chronic treatment with carvedilol, but not other β-blockers, indeed enhances contractile force in skeletal muscle and this is mediated by β-arrestin 1. Interestingly, carvedilol enhanced skeletal muscle contractility despite a lack of effect on skeletal muscle hypertrophy. Our findings suggest a potential unique clinical role of carvedilol to stimulate skeletal muscle contractility while avoiding the adverse effects with βAR agonists. This distinctive signaling profile could present an innovative approach to treating sarcopenia, frailty, and secondary muscle wasting.