21 resultados para Failure therapeutic

em BORIS: Bern Open Repository and Information System - Berna - Suiça


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Context Long-term antiretroviral therapy (ART) use in resource-limited countries leads to increasing numbers of patients with HIV taking second-line therapy. Limited access to further therapeutic options makes essential the evaluation of second-line regimen efficacy in these settings. Objectives To investigate failure rates in patients receiving second-line therapy and factors associated with failure and death. Design, Setting, and Participants Multicohort study of 632 patients >14 years old receiving second-line therapy for more than 6 months in 27 ART programs in Africa and Asia between January 2001 and October 2008. Main Outcome Measures Clinical, immunological, virological, and immunovirological failure (first diagnosed episode of immunological or virological failure) rates, and mortality after 6 months of second-line therapy use. Sensitivity analyses were performed using alternative CD4 cell count thresholds for immunological and immunovirological definitions of failure and for cohort attrition instead of death. Results The 632 patients provided 740.7 person-years of follow-up; 119 (18.8%) met World Health Organization failure criteria after a median 11.9 months following the start of second-line therapy (interquartile range [IQR], 8.7-17.0 months), and 34 (5.4%) died after a median 15.1 months (IQR, 11.9-25.7 months). Failure rates were lower in those who changed 2 nucleoside reverse transcriptase inhibitors (NRTIs) instead of 1 (179.2 vs 251.6 per 1000 person-years; incidence rate ratio [IRR], 0.64; 95% confidence interval [CI], 0.42-0.96), and higher in those with lowest adherence index (383.5 vs 176.0 per 1000 person-years; IRR, 3.14; 95% CI, 1.67-5.90 for <80% vs ≥95% [percentage adherent, as represented by percentage of appointments attended with no delay]). Failure rates increased with lower CD4 cell counts when second-line therapy was started, from 156.3 vs 96.2 per 1000 person-years; IRR, 1.59 (95% CI, 0.78-3.25) for 100 to 199/μL to 336.8 per 1000 person-years; IRR, 3.32 (95% CI, 1.81-6.08) for less than 50/μL vs 200/μL or higher; and decreased with time using second-line therapy, from 250.0 vs 123.2 per 1000 person-years; IRR, 1.90 (95% CI, 1.19-3.02) for 6 to 11 months to 212.0 per 1000 person-years; 1.71 (95% CI, 1.01-2.88) for 12 to 17 months vs 18 or more months. Mortality for those taking second-line therapy was lower in women (32.4 vs 68.3 per 1000 person-years; hazard ratio [HR], 0.45; 95% CI, 0.23-0.91); and higher in patients with treatment failure of any type (91.9 vs 28.1 per 1000 person-years; HR, 2.83; 95% CI, 1.38-5.80). Sensitivity analyses showed similar results. Conclusions Among patients in Africa and Asia receiving second-line therapy for HIV, treatment failure was associated with low CD4 cell counts at second-line therapy start, use of suboptimal second-line regimens, and poor adherence. Mortality was associated with diagnosed treatment failure.

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Atrial fibrillation (AF) and heart failure (HF) are common and interrelated conditions, each promoting the other, and both associated with increased mortality. HF leads to structural and electrical atrial remodeling, thus creating the basis for the development and perpetuation of AF; and AF may lead to hemodynamic deterioration and the development of tachycardia-mediated cardiomyopathy. Stroke prevention by antithrombotic therapy is crucial in patients with AF and HF. Of the 2 principal therapeutic strategies to treat AF, rate control and rhythm control, neither has been shown to be superior to the other in terms of survival, despite better survival in patients with sinus rhythm compared with those in AF. Antiarrhythmic drug toxicity and poor efficacy are concerns. Catheter ablation of AF can establish sinus rhythm without the risks of antiarrhythmic drug therapy, but has important procedural risks, and data from randomized trials showing a survival benefit of this treatment strategy are still lacking. In intractable cases, ablation of the atrioventricular junction and placement of a permanent pacemaker is a treatment alternative; and biventricular pacing may prevent or reduce the negative consequences of chronic right ventricular pacing.

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After the publication of DIG trial, the therapeutic target of serum digoxin concentration (SDC) for the treatment of heart failure (HF) has been lowered (0.40-1.00 ng/ml). However, the majority of equations to calculate digoxin dosages were developed for higher SDCs. Recently, a new equation was validated in Asian population for low SDCs by Konishi et al., but results in Caucasians are unknown.

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In the human body, over 1000 different G protein-coupled receptors (GPCRs) mediate a broad spectrum of extracellular signals at the plasma membrane, transmitting vital physiological features such as pain, sight, smell, inflammation, heart rate and contractility of muscle cells. Signaling through these receptors is primarily controlled and regulated by a group of kinases, the GPCR kinases (GRKs), of which only seven are known and thus, interference with these common downstream GPCR regulators suggests a powerful therapeutic strategy. Molecular modulation of the kinases that are ubiquitously expressed in the heart has proven GRK2, and also GRK5, to be promising targets for prevention and reversal of one of the most severe pathologies in man, chronic heart failure (HF). In this article we will focus on the structural aspects of these GRKs important for their physiological and pathological regulation as well as well known and novel therapeutic approaches that target these GRKs in order to overcome the development of cardiac injury and progression of HF.

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Representing the common endpoint of various cardiovascular disorders, heart failure (HF) shows a dramatically growing prevalence. As currently available therapeutic strategies are not capable of terminating the progress of the disease, HF is still associated with a poor clinical prognosis. Among the underlying molecular mechanisms, the loss of cardiomyocyte Ca(2+) cycling integrity plays a key role in the pathophysiological development and progression of the disease. The cardiomyocyte EF-hand Ca(2+) sensor protein S100A1 emerged as a regulator both of sarcoplasmic reticulum (SR), sarcomere and mitochondrial function implicating a significant role in cardiac physiology and dysfunction. In this review, we aim to recapitulate the translation of S100A1-based investigation from first clinical observations over basic research experiments back to a near-clinical setting on the verge of clinical trials today. We also address needs for further developments towards "second-generation" gene therapy and discuss the therapeutic potential of S100A1 gene therapy for HF as a promising novel strategy for future cardiologists. This article is part of a Special Section entitled "Special Section: Cardiovascular Gene Therapy".

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One of the most powerful regulators of cardiovascular function is catecholamine-stimulated adrenergic receptor (AR) signaling. The failing heart is characterized by desensitization and impaired beta-AR responsiveness as a result of upregulated G protein-coupled receptor kinase-2 (GRK2) present in injured myocardium. Deterioration of cardiac function is progressively enhanced by chronic adrenergic over-stimulation due to increased levels of circulating catecholamines. Increased GRK2 activity contributes to this pathological cycle of over-stimulation but lowered responsiveness. Over the past two decades the GRK2 inhibitory peptide betaARKct has been identified as a potential therapy that is able to break this vicious cycle of self-perpetuating deregulation of the beta-AR system and subsequent myocardial malfunction, thus halting development of cardiac failure. The betaARKct has been shown to interfere with GRK2 binding to the betagamma subunits of the heterotrimeric G protein, therefore inhibiting its recruitment to the plasma membrane that normally leads to phosphorylation and internalization of the receptor. In this article we summarize the current data on the therapeutic effects of betaARKct in cardiovascular disease and report on recent and ongoing studies that may pave the way for this peptide towards therapeutic application in heart failure and other states of cardiovascular disease.

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Despite significant improvements in pharmacological therapy heart failure is still one of the leading causes for death in the Western World. The gold standard treatment of end-stage heart failure remains cardiac transplantation, but there is a great excess of eligible candidates compared with the low number of suitable donor organs. The variety of surgical organ preserving treatment strategies has significantly increased during the last 20 years, intenting either to delay or even to prevent the need for cardiac transplantation. An individually tailored surgical concept should be considered as an alternative in any heart failure patient who has reached the limits of pharmacologic therapy. This article gives an overview about current and potential future therapeutic options in end-stage heart failure.

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Exertional oscillatory ventilation (EOV) is an ominous prognostic sign in chronic heart failure (CHF), but little is known about the success of specific therapeutic interventions. Our aim was to study the impact of an exercise training on exercise capacity and cardiopulmonary adaptation in stable CHF patients with left ventricular systolic dysfunction and EOV. 96 stable CHF patients with EOV were included in a retrospective analysis (52 training versus 44 controls). EOV was defined as follows: 1) three or more oscillatory fluctuations in minute ventilation (V'(E)) during exercise; 2) regular oscillations; and 3) minimal average ventilation amplitude ≥5 L. EOV disappeared in 37 (71.2%) out of 52 patients after training, but only in one (2.3%) out of 44 without training (p<0.001). The decrease of EOV amplitude correlated with changes in end-tidal carbon dioxide tension (r= -0.60, p<0.001) at the respiratory compensation point and V'(E)/carbon dioxide production (V'(CO(2))) slope (r=0.50, p<0.001). Training significantly improved resting values of respiratory frequency (f(R)), V'(E), tidal volume (V(T)) and V'(E)/V'(CO(2)) ratio. During exercise, V'(E) and V(T) reached significantly higher values at the peak, while f(R) and V'(E)/V'(CO(2)) ratio were significantly lower at submaximal exercise. No change was noted in the control group. Exercise training leads to a significant decrease of EOV and improves ventilatory efficiency in patients with stable CHF.

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Although experimental prevention studies have suggested therapeutic potential of endothelin (ET) antagonists for the treatment of heart failure, the results of clinical trials using ET antagonists on top of standard heart failure medications have been largely disappointing. This experimental study investigated the effects of chronic ET(A) receptor blockade in long-term survivors of myocardial infarction who had developed stable chronic heart failure in the absence of other treatments. Systolic blood pressure, heart rate, organ weights of the right atrium and ventricle, and the lungs were determined, and tissue ET-1 peptide levels were measured in cardiac tissue, lung, and aorta. The results show that chronic blockade of ET(A) receptors stabilizes systolic blood pressure and reverses the heart failure-induced weight increases of right heart chambers and lung. The changes observed occurred independently of tissue ET-1 concentrations and heart rate, suggesting mechanisms independent of local cardiac or pulmonary ET-1 synthesis, which are yet to be identified.

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Therapy has improved the survival of heart failure (HF) patients. However, many patients progress to advanced chronic HF (ACHF). We propose a practical clinical definition and describe the characteristics of this condition. Patients that are generally recognised as ACHF often exhibit the following characteristics: 1) severe symptoms (NYHA class III to IV); 2) episodes with clinical signs of fluid retention and/or peripheral hypoperfusion; 3) objective evidence of severe cardiac dysfunction, shown by at least one of the following: left ventricular ejection fraction<30%, pseudonormal or restrictive mitral inflow pattern at Doppler-echocardiography; high left and/or right ventricular filling pressures; elevated B-type natriuretic peptides; 4) severe impairment of functional capacity demonstrated by either inability to exercise, a 6-minute walk test distance<300 m or a peak oxygen uptake<12-14 ml/kg/min; 5) history of >1 HF hospitalisation in the past 6 months; 6) presence of all the previous features despite optimal therapy. This definition identifies a group of patients with compromised quality of life, poor prognosis, and a high risk of clinical events. These patients deserve effective therapeutic options and should be potential targets for future clinical research initiatives.

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With water immersion, gravity is partly eliminated, and the water exerts a pressure on the body surface. Consequently there is a blood volume shift from the periphery to the central circulation, resulting in marked volume loading of the thorax and heart. This paper presents a selection of published literature on water immersion, balneotherapy, aqua exercises, and swimming, in patients with left ventricular dysfunction (LVD) and/or stable chronic heart failure (CHF). Based on exploratory studies, central hemodynamic and neurohumoral responses of aquatic therapies will be illustrated. Major findings are: 1. In LVD and CHF, a positive effect of therapeutic warm-water tub bathing has been observed, which is assumed to be from afterload reduction due to peripheral vasodilatation caused by the warm water. 2. In coronary patients with LVD, at low-level water cycling the heart is working more efficiently than at lowlevel cycling outside of water. 3. In patients with previous extensive myocardial infarction, upright immersion to the neck resulted in temporary pathological increases in mean pulmonary artery pressure (mPAP) and mean pulmonary capillary pressures (mPCP). 4. Additionally, during slow swimming (20-25m/min) the mPAP and/or PCP were higher than during supine cycling outside water at a 100W load. 5. In CHF patients, neck- deep immersion resulted in a decrease or no change in stroke volume. 6. Although patients are hemodynamically compromised, they usually maintain a feeling of well-being during aquatic therapy. Based on these findings, clinical indications for aquatic therapies are proposed and ideas are presented to provoke further research.

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Very recently, the concept of artificial intracorporeal oxygenation of blood for patients suffering from respiratory failure has been introduced into clinical practice through development of a totally implantable intravascular oxygenator (IVOX). We report on the use of such a device in a patient who developed severe respiratory insufficiency secondary to prolonged hypovolaemic shock and pneumonia following successful repair of a ruptured abdominal aortic aneurysm in September, 1990. Postoperatively, severe hypoxaemia occurred (AaDO2 548-602 torr) despite extensive mechanical ventilatory support. There was no obvious chance to overcome this situation by conventional therapeutic measures and the decision was made to institute IVOX therapy. Hypoxaemia was resolved immediately and both FiO2 and tidal volume could be reduced within hours. The patient's respiratory condition continued to improve over the next days leading to termination of IVOX therapy after 71 hours. However, the necessity of long-term ventilatory support secondary to recurrent pneumonia and sepsis, multiple abdominal reoperations for ischemic colitis and retroperitoneal abscess prolonged his recovery. He was discharged from the hospital after four months and is alive and well now 14 months after his operation. He is the first long-term survivor after IVOX therapy in Europe. IVOX may be successfully used in selected patients while the indications and it's potential role in the therapy of severe respiratory failure still need to be defined.

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The current therapeutic strategy in breast cancer is to identify a target, such as estrogen receptor (ER) status, for tailoring treatments. We investigated the patterns of recurrence with respect to ER status for patients treated in two randomized trials with 25 years' median follow-up. In the ER-negative subpopulations most breast cancer events occurred within the first 5-7 years after randomization, while in the ER-positive subpopulations breast cancer events were spread through 10 years. In the ER-positive subpopulation, 1 year endocrine treatment alone significantly prolonged disease-free survival (DFS) with no additional benefit observed by adding 1 year of chemotherapy. In the small ER-negative subpopulation chemo-endocrine therapy had a significantly better DFS than endocrine alone or no treatment. Despite small numbers of patients, "old-fashioned" treatments, and competing causes of treatment failure, the value of ER status as a target for response to adjuvant treatment is evident through prolonged follow-up.

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Introduction Reconstitution of peripheral blood (PB) B cells after therapeutic depletion with the chimeric anti-CD20 antibody rituximab (RTX) mimics lymphatic ontogeny. In this situation, the repletion kinetics and migratory properties of distinct developmental B-cell stages and their correlation to disease activity might facilitate our understanding of innate and adaptive B-cell functions in rheumatoid arthritis (RA). Methods Thirty-five 'RTX-naïve' RA patients with active arthritis were treated after failure of tumour necrosis factor blockade in an open-label study with two infusions of 1,000 mg RTX. Prednisone dose was tapered according to clinical improvement from a median of 10 mg at baseline to 5 mg at 9 and 12 months. Conventional disease-modifying antirheumatic drugs were kept stable. Subsets of CD19+ B cells were assessed by flow cytometry according to their IgD and CD27 surface expression. Their absolute number and relative frequency in PB were followed every 3 months and were determined in parallel in synovial tissue (n = 3) or synovial fluid (n = 3) in the case of florid arthritis. Results Six of 35 patients fulfilled the European League Against Rheumatism criteria for moderate clinical response, and 19 others for good clinical response. All PB B-cell fractions decreased significantly in number (P < 0.001) after the first infusion. Disease activity developed independently of the total B-cell number. B-cell repopulation was dominated in quantity by CD27-IgD+ 'naïve' B cells. The low number of CD27+IgD- class-switched memory B cells (MemB) in the blood, together with sustained reduction of rheumatoid factor serum concentrations, correlated with good clinical response. Class-switched MemB were found accumulated in flaring joints. Conclusions The present data support the hypothesis that control of adaptive immune processes involving germinal centre-derived, antigen, and T-cell-dependently matured B cells is essential for successful RTX treatment.