RESUMO
BACKGROUND: Dilated cardiomyopathy (DCM) is a well described entity for heart failure (HF) with reduced left ventricular ejection fraction (LVEF). Recently, drugs and other substance of abuse have been recognised as potential triggers for DCM. The aim of this study was to assess the survival in patients ≤ 65 years of age with toxic cardiomyopathy (TCM). Left ventricular remodelling and the potential usefulness of left ventricular assist devices (LVADs) was also assessed. METHODS: This was a single-centre retrospective study from January 2003 to August 2019 of 553 patients ≤ 65 years old with LVEF < 40% at a tertiary-care cardiology centre. RESULTS: A total of 201 patients (36%) had a diagnosis of idiopathic DCM. Further analysis identified 38 patients (19%) for which a TCM was the most likely etiology (amphetamine [50%], cocaine [37%], anabolic steroids [8%], and energy drinks [5%]). Despite a mean LVEF of 17 ± 8% at presentation, most patients (n = 27; 71%) had event-free survival with guideline-directed medical therapy, and 61% (n = 23) recovered an LVEF ≥ 40% after a median follow-up of 21 ± 23 months. Seven patients (18%) required an LVAD and 1 patient (3%) a transplantation. All LVADs were explanted or decommissioned after partial or complete LVEF recovery after a median support time of 11 ± 4 months. CONCLUSIONS: TCM induced by substance abuse is a frequent cause of HF, accounting for almost 20% of patients ≤ 65 years of age with DCM of unknown etiology. Treatment must be tailored on an individual basis. Mechanical circulatory support demonstrated its usefulness in carefully selected patients.
Assuntos
Cardiomiopatia Dilatada/induzido quimicamente , Coração Auxiliar , Transtornos Relacionados ao Uso de Substâncias/complicações , Função Ventricular Esquerda/fisiologia , Remodelação Ventricular/efeitos dos fármacos , Cardiomiopatia Dilatada/terapia , Humanos , Estudos Retrospectivos , Função Ventricular Esquerda/efeitos dos fármacos , Adulto JovemRESUMO
This joint Canadian Heart Failure Society and the CCS Heart Failure guidelines report has been developed to provide a pan-Canadian snapshot of the current state of clinic-based ambulatory heart failure (HF) care in Canada with specific reference to elements and processes of care associated with quality and high performing health systems. It includes the viewpoints of persons with lived experience, patient care providers, and administrators. It is imperative to build on the themes identified in this survey, through engaging all health care professionals, to develop integrated and shared care models that will allow better patient outcomes. Several patient and organizational barriers to care were identified in this survey, which must inform the development of regional care models and pragmatic solutions to improve transitions for this patient population. Unfortunately, we were unsuccessful in incorporating the perspectives of primary care providers and internal medicine specialists who provide the majority of HF care in Canada, which in turn limits our ability to comment on strategies for capacity building outside the HF clinic setting. These considerations must be taken into account when interpreting our findings. Engaging all HF care providers, to build on the themes identified in this survey, will be an important next step in developing integrated and shared care models known to improve patient outcomes.
Ce rapport conjoint des lignes directrices de la Société canadienne d'insuffisance cardiaque et de la Société canadienne de cardiologie (SCC) sur l'insuffisance cardiaque a été élaboré pour fournir un aperçu pancanadien de l'état actuel des soins ambulatoires de l'insuffisance cardiaque (IC) en clinique au Canada, en se référant spécifiquement aux éléments et aux processus de soins associés à des systèmes de santé très performants et de qualité. Il comprend les points de vue de personnes ayant une expérience vécue de l'IC, de prestataires de soins aux patients et d'administrateurs. Il est impératif de s'appuyer sur les thématiques identifiées dans cette enquête, en y engageant tous les professionnels de la santé, pour développer des modèles de soins intégrés et partagés qui permettront de meilleurs pronostics pour les patients. Plusieurs obstacles relatifs aux patients et organisationnels dont il faudra se soucier ont été identifiés dans cette enquête, qui doit servir de base à l'élaboration de modèles de soins régionaux et de solutions pragmatiques pour améliorer les transitions pour cette population de patients. Malheureusement, nous n'avons pas réussi à intégrer les points de vue des prestataires de soins primaires et des spécialistes en médecine interne qui fournissent la majorité des soins en IC au Canada, ce qui limite notre capacité à commenter les stratégies de renforcement des capacités en dehors du cadre des cliniques d'IC. Ces considérations doivent être prises en compte lors de l'interprétation de nos conclusions. L'engagement de tous les prestataires de soins de santé en IC à s'appuyer sur les thématiques identifiées dans cette enquête constituera une prochaine étape importante dans le développement de modèles de soins intégrés et partagés connus pour améliorer le pronostic des patients.
RESUMO
In this update, we focus on selected topics of high clinical relevance for health care providers who treat patients with heart failure (HF), on the basis of clinical trials published after 2017. Our objective was to review the evidence, and provide recommendations and practical tips regarding the management of candidates for the following HF therapies: (1) transcatheter mitral valve repair in HF with reduced ejection fraction; (2) a novel treatment for transthyretin amyloidosis or transthyretin cardiac amyloidosis; (3) angiotensin receptor-neprilysin inhibition in patients with HF and preserved ejection fraction (HFpEF); and (4) sodium glucose cotransport inhibitors for the prevention and treatment of HF in patients with and without type 2 diabetes. We emphasize the roles of optimal guideline-directed medical therapy and of multidisciplinary teams when considering transcatheter mitral valve repair, to ensure excellent evaluation and care of those patients. In the presence of suggestive clinical indices, health care providers should consider the possibility of cardiac amyloidosis and proceed with proper investigation. Tafamidis is the first agent shown in a prospective study to alter outcomes in patients with transthyretin cardiac amyloidosis. Patient subgroups with HFpEF might benefit from use of sacubitril/valsartan, however, further data are needed to clarify the effect of this therapy in patients with HFpEF. Sodium glucose cotransport inhibitors reduce the risk of incident HF, HF-related hospitalizations, and cardiovascular death in patients with type 2 diabetes and cardiovascular disease. A large clinical trial recently showed that dapagliflozin provides significant outcome benefits in well treated patients with HF with reduced ejection fraction (left ventricular ejection fraction ≤ 40%), with or without type 2 diabetes.
Assuntos
Amiloidose/complicações , Amiloidose/tratamento farmacológico , Antagonistas de Receptores de Angiotensina/uso terapêutico , Benzoxazóis/uso terapêutico , Insuficiência Cardíaca/complicações , Insuficiência Cardíaca/tratamento farmacológico , Insuficiência da Valva Mitral/complicações , Insuficiência da Valva Mitral/cirurgia , Neprilisina/antagonistas & inibidores , Inibidores do Transportador 2 de Sódio-Glicose/uso terapêutico , Cardiopatias/complicações , Cardiopatias/tratamento farmacológico , Insuficiência Cardíaca/fisiopatologia , Humanos , Insuficiência da Valva Mitral/fisiopatologia , Ensaios Clínicos Controlados Aleatórios como Assunto , Índice de Gravidade de Doença , Volume SistólicoRESUMO
The deleterious effect of energy drinks is increasingly recognized. We present a 26-year-old woman with inotrope-dependent severe dilated cardiomyopathy, potentially caused by chronic ingestion of energy drinks. The results of extensive investigation-consisting of cardiac magnetic resonance, F-18-fluorodesoxyglucose-positron emission tomography, coronary angiography, and endomyocardial biopsy-were normal. A left ventricular assist device (LVAD) was implanted as a potential bridge to recovery. After 10 months of mechanical support and pharmacological treatment, cardiac function was recovered, and the LVAD was successfully explanted. This is the first case report of energy drink abuse leading to severe heart failure requiring mechanical support for recovery.
Assuntos
Cardiomiopatia Dilatada/etiologia , Cardiomiopatia Dilatada/terapia , Bebidas Energéticas/efeitos adversos , Insuficiência Cardíaca/etiologia , Insuficiência Cardíaca/terapia , Coração Auxiliar , Adulto , Feminino , HumanosRESUMO
AIM: To evaluate the impact of AGTR1 A1166C (rs5186) on the response to candesartan in patients with heart failure. MATERIALS & METHODS: Prospective, multicentre, open-label study. We studied 299 symptomatic patients with heart failure presenting a left ventricular ejection fraction ≤40%. RESULTS: Reductions in the primary end points of natriuretic peptides were not significantly associated with AGTR1 A1166C. Nevertheless, carrying the 1166C allele was associated with a greater compensatory increase in renin activity (p = 0.037) after 16 weeks of treatment with candesartan and a more modest effect on aldosterone concentrations (p = 0.022). CONCLUSION: AGTR1 1166C carriers may experience a greater long-term compensatory renin-angiotensin-aldosterone system activation following treatment with candesartan. Whether these associations ultimately influence clinical outcomes requires investigation. Clinicaltrials.gov : NCT00400582.
Assuntos
Bloqueadores do Receptor Tipo 1 de Angiotensina II/uso terapêutico , Benzimidazóis/uso terapêutico , Insuficiência Cardíaca/tratamento farmacológico , Polimorfismo de Nucleotídeo Único , Receptor Tipo 1 de Angiotensina/genética , Sistema Renina-Angiotensina/efeitos dos fármacos , Tetrazóis/uso terapêutico , Idoso , Bloqueadores do Receptor Tipo 1 de Angiotensina II/farmacocinética , Benzimidazóis/farmacocinética , Biomarcadores/sangue , Compostos de Bifenilo , Pressão Sanguínea/efeitos dos fármacos , Feminino , Insuficiência Cardíaca/sangue , Insuficiência Cardíaca/genética , Humanos , Testes de Função Renal , Masculino , Peptídeo Natriurético Encefálico/sangue , Fragmentos de Peptídeos/sangue , Farmacogenética , Estudos Prospectivos , Sistema Renina-Angiotensina/genética , Tetrazóis/farmacocinética , Resultado do TratamentoRESUMO
Since the inception of the Canadian Cardiovascular Society heart failure (HF) guidelines in 2006, much has changed in the care for patients with HF. Over the past decade, the HF Guidelines Committee has published regular updates. However, because of the major changes that have occurred, the Guidelines Committee believes that a comprehensive reassessment of the HF management recommendations is presently needed, with a view to producing a full and complete set of updated guidelines. The primary and secondary Canadian Cardiovascular Society HF panel members as well as external experts have reviewed clinically relevant literature to provide guidance for the practicing clinician. The 2017 HF guidelines provide updated guidance on the diagnosis and management (self-care, pharmacologic, nonpharmacologic, device, and referral) that should aid in day-to-day decisions for caring for patients with HF. Among specific issues covered are risk scores, the differences in management for HF with preserved vs reduced ejection fraction, exercise and rehabilitation, implantable devices, revascularization, right ventricular dysfunction, anemia, and iron deficiency, cardiorenal syndrome, sleep apnea, cardiomyopathies, HF in pregnancy, cardio-oncology, and myocarditis. We devoted attention to strategies and treatments to prevent HF, to the organization of HF care, comorbidity management, as well as practical issues around the timing of referral and follow-up care. Recognition and treatment of advanced HF is another important aspect of this update, including how to select advanced therapies as well as end of life considerations. Finally, we acknowledge the remaining gaps in evidence that need to be filled by future research.
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Cardiologia , Gerenciamento Clínico , Insuficiência Cardíaca/terapia , Sociedades Médicas , Canadá , HumanosRESUMO
Hypereosinophilic syndromes (HESs) are a group of disorders characterized by end-organ damage caused by eosinophilic infiltration. We present a patient with idiopathic HES with severe tricuspid and mitral regurgitation secondary to Loeffler's endocarditis. In addition to prednisone, imatinib therapy initially helped control the eosinophil count. However, successful long-term remission was achieved with hydroxyurea therapy.
Assuntos
Bioprótese , Implante de Prótese de Valva Cardíaca , Síndrome Hipereosinofílica , Mesilato de Imatinib/administração & dosagem , Insuficiência da Valva Mitral , Valva Mitral , Músculos Papilares/patologia , Valva Tricúspide , Adulto , Ecocardiografia/métodos , Fibrose , Testes Genéticos/métodos , Implante de Prótese de Valva Cardíaca/instrumentação , Implante de Prótese de Valva Cardíaca/métodos , Ventrículos do Coração/diagnóstico por imagem , Ventrículos do Coração/patologia , Humanos , Síndrome Hipereosinofílica/diagnóstico , Síndrome Hipereosinofílica/patologia , Síndrome Hipereosinofílica/fisiopatologia , Síndrome Hipereosinofílica/terapia , Imagem Cinética por Ressonância Magnética/métodos , Masculino , Valva Mitral/diagnóstico por imagem , Valva Mitral/cirurgia , Insuficiência da Valva Mitral/diagnóstico , Insuficiência da Valva Mitral/etiologia , Insuficiência da Valva Mitral/fisiopatologia , Insuficiência da Valva Mitral/terapia , Inibidores de Proteínas Quinases/administração & dosagem , Trombose/diagnóstico , Trombose/etiologia , Trombose/terapia , Resultado do Tratamento , Valva Tricúspide/diagnóstico por imagem , Valva Tricúspide/cirurgiaRESUMO
The Canadian Cardiovascular Society Heart Failure (HF) Guidelines Program has generated annual HF updates, including formal recommendations and supporting Practical Tips since 2006. Many clinicians indicate they routinely use the Canadian Cardiovascular Society HF Guidelines in their daily practice. However, many questions surrounding the actual implementation of the Guidelines into their daily practice remain. A consensus-based approach was used, including feedback from the Primary and Secondary HF Panels. This companion is intended to answer several key questions brought forth by HF practitioners such as appropriate timelines for initial assessments and subsequent reassessments of patients, the order in which medications should be added, how newer medications should be included in treatment algorithms, and when left ventricular function should be reassessed. A new treatment algorithm for HF with reduced ejection fraction is included. Several other practical issues are addressed such as an approach to management of hyperkalemia/hypokalemia, treatment of gout, when medications can be stopped, and whether a target blood pressure or heart rate is suggested. Finally, elements and teaching of self-care are described. This tool will hopefully function to allow better integration of the HF Guidelines into clinical practice.
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Cardiologia , Gerenciamento Clínico , Insuficiência Cardíaca/terapia , Guias de Prática Clínica como Assunto , Sociedades Médicas , Canadá , HumanosRESUMO
The 2014 Canadian Cardiovascular Society Heart Failure Management Guidelines Update provides discussion on the management recommendations on 3 focused areas: (1) anemia; (2) biomarkers, especially natriuretic peptides; and (3) clinical trials that might change practice in the management of patients with heart failure. First, all patients with heart failure and anemia should be investigated for reversible causes of anemia. Second, patients with chronic stable heart failure should undergo natriuretic peptide testing. Third, considerations should be given to treat selected patients with heart failure and preserved systolic function with a mineralocorticoid receptor antagonist and to treat patients with heart failure and reduced ejection fraction with an angiotensin receptor/neprilysin inhibitor, when the drug is approved. As with updates in previous years, the topics were chosen in response to stakeholder feedback. The 2014 Update includes recommendations, values and preferences, and practical tips to assist the clinicians and health care workers to best manage patients with heart failure.
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Anemia/prevenção & controle , Biomarcadores/sangue , Cardiologia/organização & administração , Insuficiência Cardíaca/diagnóstico , Sociedades Médicas/organização & administração , Anemia/sangue , Antagonistas de Receptores de Angiotensina/uso terapêutico , Pressão Sanguínea , Canadá , Ensaios Clínicos como Assunto , Insuficiência Cardíaca/sangue , Insuficiência Cardíaca/tratamento farmacológico , Humanos , Antagonistas de Receptores de Mineralocorticoides/uso terapêutico , Neprilisina/antagonistas & inibidoresRESUMO
The 2013 Canadian Cardiovascular Society Heart Failure Management Guidelines Update provides focused discussions on the management recommendations on 2 topics: (1) exercise and rehabilitation; and (2) surgical coronary revascularization in patients with heart failure. First, all patients with stable New York Heart Association class I-III symptoms should be considered for enrollment in a tailored exercise training program, to improve exercise tolerance and quality of life. Second, selected patients with suitable coronary anatomy should be considered for bypass graft surgery. As in previous updates, the topics were chosen in response to stakeholder feedback. The 2013 Update also includes recommendations, values and preferences, and practical tips to assist the clinicians and health care workers manage their patients with heart failure.
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Cardiologia , Terapia por Exercício/estatística & dados numéricos , Insuficiência Cardíaca/terapia , Revascularização Miocárdica/normas , Guias de Prática Clínica como Assunto , Sociedades Médicas , Canadá , Gerenciamento Clínico , HumanosRESUMO
The 2012 Canadian Cardiovascular Society Heart Failure (HF) Guidelines Update provides management recommendations for acute and chronic HF. In 2006, the Canadian Cardiovascular Society HF Guidelines committee first published an overview of HF management. Since then, significant additions to and changes in many of these recommendations have become apparent. With this in mind and in response to stakeholder feedback, the Guidelines Committee in 2012 has updated the overview of both acute and chronic heart failure diagnosis and management. The 2012 Update also includes recommendations, values and preferences, and practical tips to assist the medical practitioner manage their patients with HF.
Assuntos
Gerenciamento Clínico , Insuficiência Cardíaca/terapia , Guias de Prática Clínica como Assunto/normas , Sociedades Médicas , Canadá , HumanosRESUMO
BACKGROUND: Elevated pulmonary vascular resistance (PVR) in heart transplant (HT) candidates is associated with poor survival after HT. This study assessed the effect of peri-operative sildenafil administration on pulmonary hemodynamics and clinical outcomes in patients with advanced heart failure who were considered high-risk for HT because of elevated PVR and transpulmonary gradient (TPG). METHODS: The study included 119 consecutive patients who underwent HT between 2004 and 2011. Fifteen patients (Group A) had severe pulmonary hypertension (PH), defined as mean pulmonary pressure (MPAP)>25 mm Hg and PVR>2.5 Wood units (WU), and/or TPG>12 mm Hg after vasodilator test or the continuous administration of inotropics drugs, and 104 patients (Group B) were without severe PH. Group A received sildenafil therapy. Pulmonary hemodynamics were evaluated before HT with and without sildenafil therapy. Right catheterization was performed early after HT with sildenafil therapy and late after HT without sildenafil. Survival after HT was compared between the groups. RESULTS: The sildenafil dosage was 109±42 mg/day during 163±116 days before HT. After sildenafil therapy MPAP, PVR, and TPG decreased from 43.9±12.5 to 33.4±5.8 mm Hg, 5.0±1.1 to 3.0±1.6 WU, and 17.3±3.2 to 10.2±4.1 mm Hg, respectively (p<.01). All patients underwent successful HT. Sildenafil dosage was 140±70 mg/day for 43±45 days after HT. There were no differences in PVR and TPG with sildenafil therapy early after HT and without sildenafil 6 months after HT. Survival after HT was similar between the groups. CONCLUSION: Sildenafil therapy before and after HT in patients with severe PH is associated with improved pulmonary hemodynamics and successful HT, without an increase in post-HT mortality.
Assuntos
Transplante de Coração , Hemodinâmica/efeitos dos fármacos , Pulmão/irrigação sanguínea , Piperazinas/farmacologia , Sulfonas/farmacologia , Vasodilatadores/farmacologia , Feminino , Insuficiência Cardíaca/cirurgia , Humanos , Hipertensão Pulmonar/tratamento farmacológico , Pulmão/efeitos dos fármacos , Masculino , Pessoa de Meia-Idade , Período Perioperatório , Piperazinas/uso terapêutico , Purinas/farmacologia , Purinas/uso terapêutico , Citrato de Sildenafila , Sulfonas/uso terapêutico , Resultado do Tratamento , Resistência Vascular/efeitos dos fármacos , Vasodilatadores/uso terapêuticoRESUMO
Posttransplant lymphoproliferative disorders remain an uncommon complication of heart transplant with a high mortality rate reported after conventional therapies. Four patients with posttransplant lymphoproliferative disorders, of whom 3 were CD20 positive, received intravenous dosages of rituximab, 375 mg/m(2), weekly, for 6 ± 2 weeks. The overall response rate was 75% with 3 complete responses (CD20 positive) and 1 case of progressive disease (CD20 negative). Rituximab should be considered as a first-line therapy for patients with CD20 positive posttransplant lymphoproliferative disorders.
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Anticorpos Monoclonais Murinos/uso terapêutico , Transplante de Coração/efeitos adversos , Fatores Imunológicos/uso terapêutico , Transtornos Linfoproliferativos/tratamento farmacológico , Complicações Pós-Operatórias/tratamento farmacológico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Indução de Remissão , Rituximab , Resultado do Tratamento , Adulto JovemRESUMO
OBJECTIVES: Single nucleotide polymorphisms (SNPs) in the transforming growth factor-ß1 gene (TGFB1) have been inconsistently associated with calcineurin inhibitor (CNI)-induced renal dysfunction following cardiac transplantation. The impact of genetic variants related to the renin-angiotensin-aldosterone system (RAAS) and natriuretic peptides, which are implicated in CNI nephrotoxicity, is unknown. The primary objective of this study was to validate the association between two common variants in TGFB1 (rs1800470, rs1800471) and postcardiac transplant renal function. The secondary objective was to investigate the effect of candidate genes related to the RAAS, natriuretic peptides, and other elements involved in the intracellular signaling of these pathways. METHODS: We conducted a retrospective cohort study of 158 heart transplant recipients treated with CNIs, and evaluated the association between select SNPs and the estimated glomerular filtration rate as calculated by the Modification of Diet in Renal Disease simplified formula. A total of 273 SNPs distributed in 44 genes were tested. RESULTS: No association was observed between TGFB1 variants and renal function. One polymorphism in the protein kinase C-ß gene (PRKCB; rs11074606), which is implicated in the RAAS intracellular signaling, was significantly associated with post-transplant estimated glomerular filtration rate after adjusting for possible confounders (P=0.00049). This marker is in linkage disequilibrium with two variants located in putative regulatory regions of the gene (rs2283541, rs1013316). CONCLUSION: Our results suggest that PRKCB may be a potential predictor of CNI-induced nephrotoxicity in heart transplant recipients, and could therefore be a promising candidate to identify patients who are most susceptible to this adverse drug reaction.
Assuntos
Calcineurina/administração & dosagem , Calcineurina/efeitos adversos , Transplante de Coração/efeitos adversos , Proteína Quinase C/genética , Insuficiência Renal/etiologia , Adulto , Inibidores de Calcineurina , Feminino , Estudos de Associação Genética , Taxa de Filtração Glomerular/genética , Humanos , Desequilíbrio de Ligação , Masculino , Pessoa de Meia-Idade , Peptídeos Natriuréticos/genética , Polimorfismo de Nucleotídeo Único , Proteína Quinase C beta , Insuficiência Renal/genética , Sistema Renina-Angiotensina/genética , Transdução de Sinais , Fator de Crescimento Transformador beta1/genéticaRESUMO
The 2011 Canadian Cardiovascular Society Heart Failure (HF) Guidelines Focused Update reviews the recently published clinical trials that will potentially impact on management. Also reviewed is the less studied but clinically important area of sleep apnea. Finally, patients with advanced HF represent a group of patients who pose major difficulties to clinicians. Advanced HF therefore is examined from the perspectives of HF complicated by renal failure, the role of palliative care, and the role of mechanical circulatory support (MCS). All of these topics are reviewed from a perspective of practical applications. Important new studies have demonstrated in less symptomatic HF patients that cardiac resynchronization therapy will be of benefit. As well, aldosterone receptor antagonists can be used with benefit in less symptomatic HF patients. The important role of palliative care and the need to address end-of-life issues in advanced HF are emphasized. Physicians need to be aware of the possibility of sleep apnea complicating the course of HF and the role of a sleep study for the proper assessment and management of the conditon. Patients with either acute severe or chronic advanced HF with otherwise good life expectancy should be referred to a cardiac centre capable of providing MCS. Furthermore, patients awaiting heart transplantation who deteriorate or are otherwise not likely to survive until a donor organ is found should be referred for MCS.
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Insuficiência Cardíaca/epidemiologia , Insuficiência Cardíaca/terapia , Falência Renal Crônica/epidemiologia , Cuidados Paliativos/normas , Guias de Prática Clínica como Assunto , Síndromes da Apneia do Sono/epidemiologia , Canadá , Terapia Combinada , Comorbidade , Feminino , Insuficiência Cardíaca/diagnóstico , Coração Auxiliar , Humanos , Falência Renal Crônica/diagnóstico , Falência Renal Crônica/terapia , Testes de Função Renal , Masculino , Prognóstico , Medição de Risco , Síndromes da Apneia do Sono/diagnóstico , Síndromes da Apneia do Sono/terapia , Sociedades Médicas , Análise de Sobrevida , Resultado do TratamentoRESUMO
BACKGROUND: The renal expression of the cytochrome P450 3A5 (CYP3A5) isoenzyme and of the adenosine triphosphate (ATP)-binding cassette (ABC) efflux transporter P-glycoprotein is inversely associated with calcineurin-induced nephrotoxicity. The aim of this study was to evaluate the association between polymorphisms of the genes encoding these proteins and the long-term renal function of heart transplant recipients treated with calcineurin inhibitors. METHODS: We performed a retrospective cohort study of 160 heart transplant recipients from two institutions who were discharged alive after transplant and who received a calcineurin inhibitor during follow-up. The aim of this study was to evaluate the impact of common variants of the genes encoding this isoenzyme (CYP3A5*1 and *3) and the transporter (ABCB1 G2677T/A and C3435T) on the renal function of these patients after heart transplantation. The primary end-point of the study was changes in the estimated glomerular filtration rate (eGFR) at hospital discharge; at 3, 6, 12, 18 and 24 months after heart transplant; and then every year for up to 9 years. RESULTS: After adjusting for independent predictors of eGFR during follow-up, CYP3A5 was significantly associated with eGFR after transplantation (p = 0.0002), with carriers of the CYP3A5*1 allele exhibiting a higher eGFR. None of the ABCB1 variants or haplotypes were associated with eGFR after transplantation. CONCLUSION: The CYP3A5*1 genetic polymorphism is a promising marker to identify heart transplant recipients least likely to develop renal dysfunction during long-term treatment with a calcineurin inhibitor.
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Membro 1 da Subfamília B de Cassetes de Ligação de ATP/genética , Inibidores de Calcineurina , Citocromo P-450 CYP3A/genética , Taxa de Filtração Glomerular , Transplante de Coração , Imunossupressores/uso terapêutico , Subfamília B de Transportador de Cassetes de Ligação de ATP , Adulto , Feminino , Seguimentos , Marcadores Genéticos , Genótipo , Humanos , Rim/metabolismo , Masculino , Pessoa de Meia-Idade , Polimorfismo Genético , Estudos Retrospectivos , Resultado do TratamentoRESUMO
A simple, specific, sensitive, inexpensive and rapid HPLC method for enantioselective quantification of carvedilol in human plasma was developed in this study. S(-)- and R(+)-carvedilol and R(+)-propranolol as the internal standard were extracted from human plasma by liquid-liquid extraction using methyl tert-butyl ether. Enantioseparation was performed on a reverse-phase C18 Phenomenex Luna 5micron 150mmx2mm column after chiral derivatization with 2,3,4,6-tetra-O-acetyl-beta-d-glucopyranosyl isothiocyanate. The mobile phase was a mixture of water and acetonitrile. The peaks were detected using a fluorescence detector, where the excitation and emission wavelengths were set at 242 and 344nm, respectively. The limits of quantification for the S(-)- and R(+)-carvedilol enantiomers were both 0.5ng/ml. Combined intra- and inter-day variations for both enantiomers were less than 8.3%. The combined accuracy for both enantiomers ranged from 91.7 to 104.7%. This method was used to assay the carvedilol enantiomers in human plasma samples obtained from heavily medicated heart failure patients within the framework of a clinical trial.
Assuntos
Carbazóis/sangue , Carbazóis/química , Insuficiência Cardíaca/sangue , Insuficiência Cardíaca/tratamento farmacológico , Propanolaminas/sangue , Propanolaminas/química , Carbazóis/administração & dosagem , Carvedilol , Cromatografia Líquida de Alta Pressão/métodos , Humanos , Propanolaminas/administração & dosagem , EstereoisomerismoRESUMO
BACKGROUND: UGT1A4 is primarily expressed in the liver and exhibits catalytic activities for various drugs. Amongst the few UGT1A4 polymorphisms evaluated, studies support the alteration of UGT1A4-mediated glucuronidation by a few variations including the Pro²4Thr and Leu48Val variants (referred to as UGT1A4*2 and *3). METHODS: We therefore investigated genetic mechanisms that might contribute to interindividual variation in UGT1A4 expression and activity. The UGT1A4 gene was sequenced from -4963 bp relative to the ATG to 2000 bp after the first exon in 184 unrelated Caucasians and African-Americans. RESULTS: We identified a large number of genetic variations, including 13 intronic, 39 promoter, as well as 14 exonic polymorphisms, with 10 that lead to amino-acid changes. Of the nucleotide variations found in the -5 kb promoter region, five are located in the proximal region (first 500 bp), and positioned in putative HNF-1 and OCT-1 binding sites. Four of these variants, placed at -163, -219, -419 and -463, are in complete linkage disequilibrium with the Leu48Val coding region variant and with several variants in the upstream region of the promoter. Transient transfections of reference and variant promoter constructs (from position -500 to +1) in different cell lines with or without co-expression of HNF-1 and/or OCT-1 showed limited effect of these variations. CONCLUSION: Additional functional studies on promoter variants are still required to predict their potential influence on UGT1A4 expression in vivo. Besides, several coding variants significantly modified the enzyme kinetics for tamoxifen and Z-4-hydroxytamoxifen (Val48, Asp5°, Gln56, Phe¹76, Asn²5°, Leu²76) and are expected to have a potential in vivo effect.
Assuntos
Glucuronosiltransferase/genética , Glucuronosiltransferase/metabolismo , Preparações Farmacêuticas/metabolismo , Polimorfismo Genético , Negro ou Afro-Americano/genética , Humanos , Cinética , Farmacogenética , Regiões Promotoras Genéticas , Análise de Sequência de DNA , População Branca/genéticaRESUMO
INTRODUCTION: Patients with systolic heart failure often have concomitant left ventricular (LV) diastolic dysfunction. Although in animal models diastolic dysfunction is associated with worsening exercise capacity and prognosis, information regarding these relationships in patients with established systolic heart failure (HF) is sparse. METHODS: HF-ACTION was a large, multicenter National Institutes of Health-funded trial of exercise training in systolic HF (LV ejection fraction [LVEF] < or = 35%) and included detailed Doppler-echocardiographic (echo) and cardiopulmonary exercise testing at baseline. We tested the hypothesis that echo measures of LV diastolic function predict key cardiopulmonary exercise outcomes, including aerobic exercise capacity (peak exercise oxygen consumption, VO(2)), distance in the 6-minute walk test (6MWD), and ventilatory efficiency (VE/VCO(2) slope) in patients with systolic HF. RESULTS: Overall, 2,331 patients (28% women, median age 59 years, median LVEF 25%) were enrolled. There were significant bivariate correlations between echo diastolic function variables and peak VO(2) (inverse) and VE/VCO(2) slope (direct) that were strongest for ratio of early diastolic peak transmitral (MV) to myocardial tissue velocity (E/E'), peak MV early-to-late diastolic velocity ratio (E/A), and left atrial dimension (range of absolute r = 0.16-0.28). Both MV E/A and E/E' were more strongly related to all 3 exercise variables than was LVEF. The relationships of E/A and E/E' with 6MWD were weaker than with peak VO(2) or VE/VCO(2) slope. A multivariable model with peak VO(2) as the dependent variable, which included MV E/A and 9 demographic predictors including age, sex, race, body mass index, and New York Heart Association class, explained 40% of the variation in peak VO(2), with MV E/A explaining 6% of the variation. Including LVEF in the model explained less than an additional 1% of the variance in peak VO(2). In a multivariable model for VE/VCO(2) slope, MV E/A was the strongest independent echo predictor, explaining 10% of the variance. The relationship of LV diastolic function variables with 6MWD was weaker than with peak VO(2) or VE/VCO(2) slope. CONCLUSION: In patients with systolic HF, LV early diastolic function is a modest independent predictor of aerobic exercise capacity and appears to be a better predictor than LVEF.