Qualidade de vida de pacientes em hemodiálise com doença coronariana versus sem doença coronariana / Quality of life of hemodialysis patients with coronary disease versus no coronary disease

A doença renal crônica (DRC) é um problema da saúde pública mundial e preditora para progressão da doença arterial coronariana (DAC), causando limitações e alterações na vida cotidiana dos pacientes e familiares e, consequentemente, na qualidade de vida. Nesse cenário, o Assistente Social, como integrante da equipe multiprofissional, propõe alternativas de enfrentamento às situações que comprometem o processo da saú - de-doença dos pacientes. O estudo tem como objetivos avaliar o impacto da presença da DAC na qualidade de vida dos pacientes em hemodiálise e identificar as diferenças no perfil sociodemográfico desses pacientes, conforme a presença da doença. Método: Estudo trans - versal e descritivo realizado com 51 pacientes em hemodiálise (30 com DAC e 21 sem DAC), em um hospital universitário de cardiologia de São Paulo, através de questionário de qualidade de vida para pacientes em tratamento dialítico KDQOL-SF TM 1.3, questionário socioeconômico e dados clínicos descritos em prontuário eletrônico. Resultados: No to - tal dos pacientes, houve predomínio do sexo masculino, da cor/raça autodeclarada par - da e preta, ensino fundamental incompleto e em benefício previdenciário/assistencial. Os pacientes sem DAC encontram-se aproximadamente dois anos a mais em tratamento dia - lítico. Entre as dimensões do KDQOL-SF TM 1.3, os pacientes com DAC apresentaram melhores índices de qualidade de vida. Conclusão: A qualidade de vida dos pacientes com DRC em hemodiálise que apresentam diagnóstico de DAC, apresentou-se relativamente melhor do que a dos pacientes sem DAC. Não houve diferenças sociodemográficas relevantes entre os grupo

Chronic kidney disease (CKD) is a worldwide public health problem and a predictor of the progression of coronary artery disease (CAD), causing limitations and changes in the daily lives of patients and their families and, therefore, in their quality of life. In this scenario, the Social Worker, as a member of a multiprofessional team, proposes alternatives for coping with situations that compromise patients' health-disease process. The aims of this study were to assess the impact of the presence of CAD on the quality of life of patients on hemodialysis, and to identify the differences in sociodemographic profile of these patients, according to the presence of CAD. Methods: A cross-sectional, descriptive study was conducted with 51 patients on hemodialysis treatment, (30 with CAD and 21 without CAD), at a university cardiology hospital in the city of São Paulo, using a quality of life questionnaire for patients on dialysis treatment KDQOL-SF TM 1.3, a socioeconomic questionnaire, and clinical data described in the electronic medical records. Results: Of the total patients, there was a predominance of males, with self-declared color/race Brown and Black, incomplete primary education, and receiving social security benefits. The patients without CAD had been in dialysis treatment for approximately two years more. Among the dimensions of the KDQOL-SF TM 1.3, patients with CAD had better quality of life indices. Conclusion: The quality of life of patients with CKD on hemodialysis and diagnosed with CAD was relatively better than that of patients without ut CAD. There were no relevant sociodemographic differences between the group

Goal-directed therapy for decompensated heart failure and renal dysfunction. A pilot randomized clinical trial / Terapia alvo-dirigida para insuficiência cardíaca descompensada e disfunção renal: um estudo-piloto clínico randomizado

OBJECTIVES: Acute heart failure is associated with low cardiac output syndrome and renal dysfunction. However, it is not known whether a goal-directed protocol guided by tightly controlled hemodynamic variables, including pulmonary artery catheter, will safely improve clinical renal dysfunction markers in these patients when compared to a less invasive approach. METHODS: Pilot, randomized clinical trial aimed at patients with known heart failure, low cardiac output syndrome and renal dysfunction with less than 48 hours from onset. We randomized two groups: (a) goal-directed therapy monitored with pulmonary artery catheter and (b) conventional therapy with central venous catheter. Hemodynamic parameters, venous oxygen saturation, serum lactate, fluid repositions and vasoactive drugs were compared considering renal function improvement after 72 hours as the primary study endpoint. We included 15 goal-directed therapy and 16 conventional therapy patients. The study has assessed patients on baseline looking for significant improvement at 72 hours of the following parameters in the goal-directed therapy and conventional therapy groups: urine output, serum creatinine, venous oxygen saturation and serum lactate. RESULTS: Baseline characteristics were similar in both groups. In the first 24 hours there was a lower volume of fluid reposition in the goal-directed therapy group, although 72 hours later such reposition was equivalent. The use of inotropic agents was similar between groups. There was an improvement to the renal function and the hemodynamic parameter in both study groups. CONCLUSIONS: The option for the protocol with pulmonary artery catheter setting is justified only if there is clinical evidence of serious pulmonary congestion associated to low peripheral perfusion.

OBJETIVOS: A Insuficiência cardíaca aguda está associada à síndrome de baixo débito cardíaco e disfunção renal. No entanto, não se sabe se o protocolo meta-dirigido guiado por variáveis hemodinâmicas rigorosamente controladas, incluindo cateter de artéria pulmonar, irá melhorar de forma segura os marcadores de disfunção renal clínica nestes pacientes, quando comparados a uma abordagem menos invasiva. MÉTODOS: Ensaio clínico piloto randomizado incluindo pacientes com insuficiência cardíaca conhecida, síndrome de baixo débito cardíaco e disfunção renal com menos de 48 horas de evolução. Foram randomizados dois grupos: terapia alvo-dirigida monitorada com cateter de artéria pulmonar e terapia convencional com cateter venoso central. Os parâmetros hemodinâmicos, a saturação venosa, o lactato sérico, o volume de reposição de fluidos e as doses de drogas vasoativas foram comparados, considerando a melhora da função renal após 72 horas como o desfecho primário do estudo. RESULTADOS: Foram incluídos 15 pacientes no grupo de terapia alvo-dirigida e 16 pacientes em terapia convencional. As características basais foram semelhantes em ambos os grupos. O estudo avaliou os seguintes parâmetros dos pacientes na linha de base e após 72 horas para os dois grupos: excreção urinária, creatinina sérica, saturação venosa de oxigênio e lactato. Nas primeiras 24 horas houve menor reposição de fluido no grupo de terapia dirigida mas, ao fim de 72 horas, a reposição tornou-se equivalente. O uso de agentes inotrópicos foi semelhante entre os grupos. CONCLUSÕES: Houve uma melhora da função renal e dos parâmetros hemodinâmicos em ambos os grupos de estudo. A opção para o protocolo com cateter de artéria pulmonar só se justifica se houver evidência clínica de congestão pulmonar grave associada à baixa perfusão periférica.

Predictors of Arrhythmic Events Detected by Implantable Loop Recorders in Renal Transplant Candidates / Preditores de Eventos Arrítmicos Detectados por Loop Recorders Implantáveis em Candidatos a Transplante Renal

AbstractBackground:The recording of arrhythmic events (AE) in renal transplant candidates (RTCs) undergoing dialysis is limited by conventional electrocardiography. However, continuous cardiac rhythm monitoring seems to be more appropriate due to automatic detection of arrhythmia, but this method has not been used.Objective:We aimed to investigate the incidence and predictors of AE in RTCs using an implantable loop recorder (ILR).Methods:A prospective observational study conducted from June 2009 to January 2011 included 100 consecutive ambulatory RTCs who underwent ILR and were followed-up for at least 1 year. Multivariate logistic regression was applied to define predictors of AE.Results:During a mean follow-up of 424 ± 127 days, AE could be detected in 98% of patients, and 92% had more than one type of arrhythmia, with most considered potentially not serious. Sustained atrial tachycardia and atrial fibrillation occurred in 7% and 13% of patients, respectively, and bradyarrhythmia and non-sustained or sustained ventricular tachycardia (VT) occurred in 25% and 57%, respectively. There were 18 deaths, of which 7 were sudden cardiac events: 3 bradyarrhythmias, 1 ventricular fibrillation, 1 myocardial infarction, and 2 undetermined. The presence of a long QTc (odds ratio [OR] = 7.28; 95% confidence interval [CI], 2.01–26.35; p = 0.002), and the duration of the PR interval (OR = 1.05; 95% CI, 1.02–1.08; p < 0.001) were independently associated with bradyarrhythmias. Left ventricular dilatation (LVD) was independently associated with non-sustained VT (OR = 2.83; 95% CI, 1.01–7.96; p = 0.041).Conclusions:In medium-term follow-up of RTCs, ILR helped detect a high incidence of AE, most of which did not have clinical relevance. The PR interval and presence of long QTc were predictive of bradyarrhythmias, whereas LVD was predictive of non-sustained VT.

ResumoFundamento:A documentação de eventos arrítmicos (EA) em candidatos a transplante renal (CTR) submetidos à diálise é limitada pelo registro de eletrocardiograma convencional. Um monitoramento contínuo do ritmo cardíaco parece ser o procedimento mais adequado para a detecção automática de arritmia, contudo esse método não foi explorado anteriormente.Objetivo:O objetivo deste estudo foi investigar a incidência e os preditores de EA em CTR usando um gravador de eventos implantável, do inglês, “loop recorder implantável” (ILR).Métodos:Um estudo prospectivo observacional foi conduzido entre Junho/2009 a Janeiro/2011. Cem CTR ambulatoriais consecutivos foram submetidos ao ILR e acompanhados pelo menos por um ano. Uma regressão logística multivariada foi aplicada para definir os preditores de EA.Resultados:Durante o tempo médio de acompanhamento de 424 ± 127 dias, EA foram detectados em 98% dos pacientes, sendo que 92% deles tinham mais de um tipo de arritmia, a maioria não considerada potencialmente séria. Taquicardia atrial sustentada e fibrilação atrial ocorreram respectivamente em 7% e 13% dos pacientes; bradiarritmia em 25% e taquicardia ventricular (TV) não-sustentada ou sustentada em 57%. Ocorreram 18 óbitos, 7 por morte cardíaca súbita, 3 por bradiarritmias, 1 por fibrilação ventricular, 1 por infarto do miocárdio e 2 óbitos devido à causas desconhecidas. A presença de QTc longo (Razão de Probabilidade [RP] = 7,28; intervalo de confiança de 95% [IC] 2,01-26,35; p = 0,002) e duração do intervalo PR (RP = 1,05; IC 95%: 1,02-1,08; p < 0,001) foram associados independentemente a bradiarritmias. A dilatação ventricular esquerda (DVE) foi independentemente associada à TV não-sustentada (RP = 2,83; IC 95%: 1,01-7,96; p = 0,041).Conclusões:Em acompanhamento de médio prazo de CTR, o ILR detectou uma alta incidência de EA, a maioria sem relevância clínica. O intervalo PR e a presença de QTc longo foram preditivos de bradiarritmias e DVE de TV não‑sustentada.

Predictors of Arrhythmic Events Detected by Implantable Loop Recorders in Renal Transplant Candidates.

BACKGROUND: The recording of arrhythmic events (AE) in renal transplant candidates (RTCs) undergoing dialysis is limited by conventional electrocardiography. However, continuous cardiac rhythm monitoring seems to be more appropriate due to automatic detection of arrhythmia, but this method has not been used. OBJECTIVE: We aimed to investigate the incidence and predictors of AE in RTCs using an implantable loop recorder (ILR). METHODS: A prospective observational study conducted from June 2009 to January 2011 included 100 consecutive ambulatory RTCs who underwent ILR and were followed-up for at least 1 year. Multivariate logistic regression was applied to define predictors of AE. RESULTS: During a mean follow-up of 424 ± 127 days, AE could be detected in 98% of patients, and 92% had more than one type of arrhythmia, with most considered potentially not serious. Sustained atrial tachycardia and atrial fibrillation occurred in 7% and 13% of patients, respectively, and bradyarrhythmia and non-sustained or sustained ventricular tachycardia (VT) occurred in 25% and 57%, respectively. There were 18 deaths, of which 7 were sudden cardiac events: 3 bradyarrhythmias, 1 ventricular fibrillation, 1 myocardial infarction, and 2 undetermined. The presence of a long QTc (odds ratio [OR] = 7.28; 95% confidence interval [CI], 2.01-26.35; p = 0.002), and the duration of the PR interval (OR = 1.05; 95% CI, 1.02-1.08; p < 0.001) were independently associated with bradyarrhythmias. Left ventricular dilatation (LVD) was independently associated with non-sustained VT (OR = 2.83; 95% CI, 1.01-7.96; p = 0.041). CONCLUSIONS: In medium-term follow-up of RTCs, ILR helped detect a high incidence of AE, most of which did not have clinical relevance. The PR interval and presence of long QTc were predictive of bradyarrhythmias, whereas LVD was predictive of non-sustained VT.

Prognostic Value of Serum Uric Acid in Patients on the Waiting List before and after Renal Transplantation.

Background. High serum uric acid (UA) is associated with increased cardiovascular (CV) risk in the general population. The impact of UA on CV events and mortality in CKD is unclear. Objective. To assess the relationship between UA and prognosis in hemodialysis (HD) patients before and after renal transplantation (TX). Methods. 1020 HD patients assessed for CV risk and followed from the time of inception until CV event, death, or TX (HD) or date of TX, CV event, death, or return to dialysis (TX). Results. 821 patients remained on HD while 199 underwent TX. High UA (≥428 mmol/L) was not associated with either composite CV events or mortality in HD patients. In TX patients high UA predicted an increased risk of events (P = 0.03, HR 1.6, and 95% CI 1.03-2.54) but not with death. In the Cox proportional model UA was no longer significantly associated with CV events. Instead, a reduced GFR (<50 mL/min) emerged as the independent risk factor for events (P = 0.02, HR 1.79, and % CI 1.07-3.21). Conclusion. In recipients of TX an increased posttransplant UA is related to higher probability of major CV events but this association probably caused concurrent reduction in GFR.

A new risk score model to predict the presence of significant coronary artery disease in renal transplant candidates.

BACKGROUND: Renal transplant candidates are at high risk of coronary artery disease (CAD). We sought to develop a new risk score model to determine the pre-test probability of the occurrence of significant CAD in renal transplant candidates. METHODS: A total of 1,060 renal transplant candidates underwent a comprehensive cardiovascular risk evaluation. Patients considered at high risk of CAD (age ≥50 years, with either diabetes mellitus (DM) or cardiovascular disease (CVD)), or having noninvasive testing suggestive of CAD were referred for coronary angiography (n = 524). Significant CAD was defined by the presence of luminal stenosis ≥70%. A binary logistic regression model was built, and the resulting logistic regression coefficient B for each variable was multiplied by 10 and rounded to the next whole number. For each patient, a corresponding risk score was calculated and the receiver operating characteristic (ROC) curve was constructed. RESULTS: The final equation for the model was risk score = (age × 0.4) + (DM × 9) + (CVD × 14) and for the probability of CAD (%) = (risk score × 2) - 23. The corresponding ROC for the accuracy of the diagnosis of CAD was 0.75 (P <0.0001) in the developmental model. CONCLUSIONS: We developed a simple clinical risk score to determine the pre-test probability of significant CAD in renal transplant candidates. This model may help those directly involved in the care of patients with end-stage renal disease being considered for transplantation in an attempt to reduce the rate of cardiovascular events that presently hampers the long-term prognosis of such patients.

Which patients are more likely to benefit from renal transplantation?

BACKGROUND: We evaluated whether the advantages conferred by renal transplantation encompass all individuals or whether they favor more specific groups of patients. METHODS: One thousand and fifty-eight patients on the transplant waiting list and 270 receiving renal transplant were studied. End points were the composite incidence of CV events and death. Patients were followed up from date of placement on the list until transplantation, CV event, or death (dialysis patients), or from the date of transplantation, CV event, return to dialysis, or death (transplant patients). RESULTS: Younger patients with no comorbidities had a lower incidence of CV events and death independently of the treatment modality (log-rank=0.0001). Renal transplantation was associated with better prognosis only in high-risk patients (p=0.003). CONCLUSIONS: Age and comorbidities influenced the prevalence of CV complications and death independently of the treatment modality. A positive effect of renal transplantation was documented only in high-risk patients. These findings suggest that age and comorbidities should be considered indication for early transplantation even considering that, as a group, such patients have a shorter survival compared with low-risk individuals.

Unexplained sudden death in patients on the waiting list for renal transplantation.

BACKGROUND: The incidence of unexplained sudden death (SD) and the factors involved in its occurrence in patients with chronic kidney disease are not well known. METHODS: We investigated the incidence and the role of co-morbidities in unexplained SD in 1139 haemodialysis patients on the renal transplant waiting list. RESULTS: Forty-four patients died from SD of undetermined causes (20% of all deaths; 3.9 deaths/1000 patients per year), while 178 died from other causes and 917 survived. SD patients were older and likely to have diabetes, hypertension, past/present cardiovascular disease, higher left ventricular mass index, and lower ejection fraction. Multivariate analysis showed that cardiovascular disease of any type was the only independent predictor of SD (P = 0.0001, HR = 2.13, 95% CI 1.46-3.22). Alterations closely associated with ischaemic heart disease like angina, previous myocardial infarction and altered myocardial scan were not independent predictors of SD. The incidence of unexplained SD in these haemodialysis patients is high and probably a consequence of pre-existing cardiovascular disease. CONCLUSIONS: Factors influencing SD in dialysis patients are not substantially different from factors in the general population. The role played by ischaemic heart disease in this context needs further evaluation.

Validation of a strategy to diagnose coronary artery disease and predict cardiac events in high-risk renal transplant candidates.

BACKGROUND: We validated a strategy for diagnosis of coronary artery disease (CAD) and prediction of cardiac events in high-risk renal transplant candidates (at least one of the following: age > or =50 years, diabetes, cardiovascular disease). METHODS: A diagnosis and risk assessment strategy was used in 228 renal transplant candidates to validate an algorithm. Patients underwent dipyridamole myocardial stress testing and coronary angiography and were followed up until death, renal transplantation, or cardiac events. RESULTS: The prevalence of CAD was 47%. Stress testing did not detect significant CAD in 1/3 of patients. The sensitivity, specificity, and positive and negative predictive values of the stress test for detecting CAD were 70, 74, 69, and 71%, respectively. CAD, defined by angiography, was associated with increased probability of cardiac events [log-rank: 0.001; hazard ratio: 1.90, 95% confidence interval (CI): 1.29-2.92]. Diabetes (P=0.03; hazard ratio: 1.58, 95% CI: 1.06-2.45) and angiographically defined CAD (P=0.03; hazard ratio: 1.69, 95% CI: 1.08-2.78) were the independent predictors of events. CONCLUSION: The results validate our observations in a smaller number of high-risk transplant candidates and indicate that stress testing is not appropriate for the diagnosis of CAD or prediction of cardiac events in this group of patients. Coronary angiography was correlated with events but, because less than 50% of patients had significant disease, it seems premature to recommend the test to all high-risk renal transplant candidates. The results suggest that angiography is necessary in many high-risk renal transplant candidates and that better noninvasive methods are still lacking to identify with precision patients who will benefit from invasive procedures.

Oxidative stress and endothelial dysfunction in chronic kidney disease.

BACKGROUND: Chronic kidney disease (CKD) is characterized by the high prevalence of atherosclerosis. Considering that endothelial dysfunction and oxidative stress are promoters of atherosclerosis, it is of interest to verify whether the two conditions are associated in CKD patients still free of clinical cardiovascular disease (CVD). OBJECTIVE: To evaluate the association between oxidative stress and endothelial function in end-stage CKD patients without clinically evident CVD. METHODS: We studied 22 nondiabetic, nonsmoker CKD patients without clinical CVD treated by maintenance hemodialysis and 22 healthy controls. Endothelium- dependent and independent vascular reactivity and oxidative stress, as determined by the plasma levels of thiobarbituric acid-reactive substances--TBARS, were evaluated in all subjects. RESULTS: Endothelium-dependent (6.0 +/- 4.25 vs. 11.3 +/- 4.46%, p<0.001) and endothelium-independent (11.9 +/- 7.68 vs. 19.1% +/- 6.43%, p<0.001) vascular reactivity were reduced, while TBARS (2.63 +/- 0.51 vs. 1.49 +/- 0.42 nmols/mL) was increased in CKD patients when compared to controls. TBARS levels were significantly related to endothelium-dependent vascular reactivity (r=-0.56, p<0.001) and to systolic blood pressure (r=-0.48, p=0.002). CONCLUSION: Oxidative stress is increased in CKD patients free of CVD and is associated with endothelial dysfunction in patients and controls. The results suggest that oxidative stress and endothelial dysfunction may be involved in the increased susceptibility of CKD patients to CVD and cardiovascular complications.

Estresse oxidativo e disfunção endotelial na doença renal crônica / Oxidative stress and endothelial dysfunction in chronic kidney disease / Estrés oxidativo y disfunción endotelial en la enfermedad renal crónica

Fundamento: A doença renal crônica (DRC) caracteriza-se pela alta prevalência de aterosclerose. Uma vez que o estresse oxidativo e a disfunção endotelial são promotores da aterosclerose, é interessante verificar se as duas condições estão associadas em pacientes com DRC, ainda sem doença cardiovascular (DCV) clínica.Objetivo: Avaliar as relações entre o estresse oxidativo e a função endotelial em pacientes com DRC estágio 5, sem DCV. Métodos: Foram estudados 22 pacientes com DRC, não-diabéticos, não-fumantes, sem DCV e tratados por hemodiálise; além de 22 indivíduos normais. Em todos os indivíduos foram avaliados a reatividade vascular, dependente e independente de endotélio (ultra-som de alta resolução da artéria braquial), e o estresse oxidativo (níveis plasmáticos de substâncias reativas ao ácido tiobarbitúrico - TBARS). Resultados: A reatividade vascular dependente de endotélio (6,0 ± 4,25% vs. 11,3 ± 4,46%, p <0,001) e a reatividade independente de endotélio (11,9 ± 7,68% vs. 19,1 ± 6,43%, p <0,001) foram reduzidas na DRC, enquanto o estresse oxidativo (2,63 ± 0,51 vs. 1,49 ± 0,43, p <0,001) foi aumentado. Os níveis de TBARS, quando utilizado na totalidade de indivíduos do estudo (pacientes e controles), correlacionaram-se com a reatividade vascular dependente de endotélio (r = -0,56, p<0,001) e com a pressão arterial sistólica (r = 0,48, p = 0,002). Conclusão: O estresse oxidativo é associado à disfunção endotelial. Pacientes com DRC apresentam aumento do estresse oxidativo e comprometimento da reatividade vascular. Os resultados sugerem ainda que o estresse oxidativo e a disfunção endotelial podem estar envolvidos na susceptibilidade exagerada da DRC às complicações cardiovasculares.

Background: Chronic kidney disease (CKD) is characterized by the high prevalence of atherosclerosis. Considering that endothelial dysfunction and oxidative stress are promoters of atherosclerosis, it is of interest to verify whether the two conditions are associated in CKD patients still free of clinical cardiovascular disease (CVD).Objective: To evaluate the association between oxidative stress and endothelial function in end-stage CKD patients without clinically evident CVD.Methods: We studied 22 nondiabetic, nonsmoker CKD patients without clinical CVD treated by maintenance hemodialysis and 22 healthy controls. Endothelium- dependent and independent vascular reactivity and oxidative stress, as determined by the plasma levels of thiobarbituric acid-reactive substances – TBARS, were evaluated in all subjects. Results: Endothelium-dependent (6.0 ± 4.25 vs. 11.3 ± 4.46 %, p< 0.001) and endothelium-independent (11.9 ± 7.68 vs. 19.1 % ± 6.43 %, p< 0.001) vascular reactivity were reduced, while TBARS (2.63 ± 0.51 vs. 1.49 ± 0.42 nmols/mL) was increased in CKD patients when compared to controls. TBARS levels were significantly related to endothelium-dependent vascular reactivity (r= - 0.56, p< 0.001) and to systolic blood pressure (r= - 0.48, p= 0.002). Conclusion: Oxidative stress is increased in CKD patients free of CVD and is associated with endothelial dysfunction in patients and controls. The results suggest that oxidative stress and endothelial dysfunction may be involved in the increased susceptibility of CKD patients to CVD and cardiovascular complications.

Fundamento: La enfermedad renal crónica (ERC) se caracteriza por la alta prevalencia de aterosclerosis Siendo el estrés oxidativo y la disfunción endotelial promotores de la aterosclerosis, es interesante verificar si las dos condiciones están asociadas en pacientes con ERC, aun sin enfermedad cardiovascular (ECV) clínica. Objetivo: Evaluar las relaciones entre el estrés oxidativo y la función endotelial en pacientes con ERC estado 5, sin ECV. Métodos: Se estudiaron 22 pacientes con ERC, no diabéticos, no fumadores, sin ECV y tratados por hemodiálisis; además de 22 individuos normales. En todos los individuos se evaluaron la reactividad vascular, dependiente e independiente de endotelio (ecografía de alta resolución de la arteria braquial), y el estrés oxidativo (niveles plasmáticos de sustancias reactivas al ácido tiobarbitúrico – TBARS). Resultados: La reactividad vascular dependiente de endotelio (6,0 ± 4,25% vs. 11,3 ± 4,46%, p <0,001) y la reactividad independiente de endotelio (11,9 ± 7,68% vs. 19,1 ± 6,43%, p <0,001) se redujeron en la ERC, mientras el estrés oxidativo (2,63 ± 0,51 vs. 1,49 ± 0,43, p <0,001) se vio aumentado. Los niveles de TBARS, cuando se utiliza en la totalidad de individuos del estudio (pacientes y controles), se correlacionaron con la reactividad vascular dependiente de endotelio (r = -0,56, p<0,001) y con la presión arterial sistólica (r = 0,48, p = 0,002). Conclusión: El estrés oxidativo está asociado a la disfunción endotelial. Pacientes con ERC presentan aumento del estrés oxidativo y compromiso de la reactividad vascular. Los resultados sugieren además que el estrés oxidativo y la disfunción endotelial pueden estar involucrados en la susceptibilidad exagerada de la ERC a las complicaciones cardiovasculares.

Avaliação da doença arterial coronária no nefropata / Evaluation of coronary artery disease in patients with chronic kidney disease

A doença arterial coronária (DAC) ocorre em 40% a 50% dos pacientes com doença renal crônica avançada (estágio V) e apresenta taxa de mortalidade anual de 9%. Transplante renal se acompanha de redução da mortalidade cardiovascular ecoronária, mas a incidência dessas complicações é ainda muito elevada em comparação com a da população geral. Por esses motivos, a investigação de DAC é uma etapa prioritária da avaliação de candidatos a transplante renal. Essa investigação é complicada pela baixa especificidade dos testes não-invasivos em renais crônicos e pela exclusão desses pacientes da maioria dos trabalhos sobre DAC. Atualmente, existem dois algoritmos para a avaliação de DAC em nefropatas: a proposta pela American Society of Transplantation (AST) e pela European Renal Association (ERA). No presente trabalho, discutimos as vantagens e limitações desses algoritmos e propomos um novo algoritmo com base em nossa experiência com uma coorte de mais de 1.000 pacientes candidatos a transplante renal avaliados em nosso serviço.

Coronary artery disease (CAD) is observed in 40% to 50% of patients with chronic kidney disease stage V with an annual mortality of 9%. Although renal transplantation is associated with a reduction of cardiovascular and coronary mortality, the incidence of these complications remains elevated compared to general population. As a consequence, evaluation of CAD is a fundamental step in the evaluation of patients candidates to renal transplantation. However, this task is complicated by the relatively low negative predictive value of non invasive testing and by the exclusion of renal patients in the majority of the trials on CAD. The America Society of Transplantation (AST) and The European Renal Association (ERA) proposed algorithms for the detectionof CAD in renal patients. In the present work, we discussed the main advantage and drawback of both algorithms and also forward a new algorithm based on our extensive experience with a cohort of more 1.000 renal transplant candidates evaluated in our Service.

Underuse of American College of Cardiology/American Heart Association Guidelines in hemodialysis patients.

Patients with end-stage renal disease (ESRD) are at high risk for cardiovascular disease (CVD) and therefore should be treated according to ACC/AHA Guidelines. Scant data are available concerning the actual use of cardioprotective drugs in this population. The use of angiotensin-converting enzyme inhibitors (ACE-I), beta-blockers, aspirin, and statins was assessed in 271 (72% males, 66% Caucasians) high-risk ESRD patients on hemodialysis. The study population comprised 27% smokers, 95% with hypertension, 38% with diabetes, and 44% with dyslipidemia; 44% of patients had overt CVD at baseline, including 9% with heart failure, 9% with prior myocardial infarction, and 3% with previous myocardial revascularization. One-third of all patients were not receiving any cardioprotective drugs; among those patients who were, 42% were on one drug, 21% were on two, 3.7% were on three, and 1.5% were on four. The most prescribed agent was ACE-I (35.8%), followed by aspirin (30.6%), and beta-blockers (28.0%). The use of statins was remarkably and significantly low (4.1%) (p < 0.001), even in the higher risk subgroups (patients with diabetes or macrovascular disease). ACE-I plus aspirin was the most prescribed combination (8.5%). Cardioprotective agents recommended for risk-factor modification by the ACC/AHA Guidelines for their well-established efficacy in the general population were underutilized in this cohort of high-risk hypertensive hemodialysis patients, despite an elevated prevalence of clinically evident CVD. Speculatively, this fact may be relevant to better understand the known increased cardiovascular morbidity-mortality associated with chronic renal disease.

Dislipidemia na doença renal crônica / Dyslipidemia in chronic kidney disease

As alterações do metabolismo dos lípides são parte integrante da síndrome urêmica e ocorrem em cerca de 70% dos pacientes com doença renal crônica. O perfil lipídico típico da doença renal crônica difere daquele observado na população geral e caracteriza-se por níveis normais de colesterol total e de colesterol de lipoproteína de baixa densidade (LDLcolesterol), redução do colesterol de lipoproteína de alta densidade (HDL-colesterol) e aumento das partículas ricas em triglicerídeos, como lipoproteína de muito alta densidade (VLDL) e lipoproteína de densidade intermediária (IDL). Esse perfil lipídico apresenta comprovado potencial aterogênico e é provável que desempenhe papel importante na alta prevalência de doença cardiovascular associada à uremia. O mecanismo da dislipidemia da doença renal crônica não é bem conhecido, mas acredita-se que resistência à insulina, aumento do estresse oxidativo e alterações na estrutura e na função das apolipoproteínas sejam os fatores mais importantes. Apesar do grande número de trabalhos sobre o assunto, ainda não existem provas definitivas de que a dislipidemia aumente o risco cardiovascular em renais crônicos e de que o tratamento com estatinas reduza significativamente esse risco. Mesmo com essa ressalva, as diretivas internacionais e nacionais recomendam o uso de estatinas na doença renal crônica, seguindo as mesmas regras observadas para pacientes com doença cardiovascular. Espera-se que estudos, já em curso, especificamente concebidos para avaliar o papel das estatinas na prevenção de eventos cardiovasculares na doença renal crônica possam em breve contribuir para o melhor planejamento terapêutico da doença renal.

Lipid alterations are an integral part of the uremic syndrome, occurring in roughly 70% of patients with chronic kidney disease. Typical lipid profile associated with chronic kidney disease differs substantially from that observed in the general population and is characterized by normal total- and low density lipoprotein cholesterol (LDL-cholesterol), reduced high density lipoprotein cholesterol (HDL-cholesterol) and increased levels of triglyceride-rich particles, like very low density lipoprotein (VLDL) and intermediate density lipoprotein (IDL). This lipid profile exhibits substantial atherogenic potential and probably plays a significant role in the increased prevalence of cardiovascular disease associated with chronic uremia. The mechanism of the lipid abnormalities observed in chronic kidney disease is not well known but insulin resistance, increased oxidative stress and alterations in the structure and function of apolipoproteins are believed to be involved. In spite of the great number of investigations on the subject, there is still no conclusive proof that dyslipidemia increases the cardiovascular risk of chronic kidney disease patients and that this risk is significantly reduced by statins. However, despite these considerations, national and international guidelines recommend prescription of statins to chronic kidney disease patients following the same rules observed for individuals of the general population with established cardiovascular disease. It is expected that a number of trials, already in course, specifically designed to verify the preventive role of statins on cardiovascular events in chronic kidney disease, would clarify this important subject in near future.

Diabetes and coronary artery disease impose similar cardiovascular morbidity and mortality on renal transplant candidates.

BACKGROUND: In renal transplant candidates (RTC), diabetes and coronary artery disease (CAD) are commonly observed. However, whether diabetes imparts a cardiovascular risk equivalent to that of CAD and whether CAD adds to the cardiovascular risk associated with diabetes is unknown. METHODS: To assess the interplay between diabetes and CAD as a determinant of major adverse cardiovascular events (MACE), 288 high-risk RTC (56.4+/-8.1 years old, 72% males) underwent a comprehensive cardiovascular evaluation including coronary angiography. Patients were divided into four groups based on the diagnoses of diabetes and CAD (>70% narrowing), and followed up for 1-60 months (median, 17). The primary endpoint was the composite incidence of fatal/non-fatal MACE. RESULTS: During follow-up, 80 MACE occurred. Patients with diabetes (P=0.03) or CAD (P<0.0001) had a worse long-term prognosis. However, only in patients without diabetes was CAD associated with an increased incidence of MACE (10.6% vs 45.9%, P<0.0001). In patients with diabetes, the endpoints were not different between those with and without CAD. No difference occurred in the long-term prognosis of patients with diabetes (with or without CAD) and patients without diabetes with CAD. CONCLUSIONS: We concluded that in high-risk RTC, diabetes confers a cardiovascular risk comparable to that of CAD in patients without diabetes, independent of coronary obstruction. In patients with diabetes, concomitant CAD does not add to the already very high cardiovascular risk of this population.

Practical ways to deal with the high burden of cardiovascular disease in hemodialysis patients.

Cardiovascular disease is the main cause of death among hemodialysis patients. Although uremia by itself may be considered to be a cardiovascular risk factor, a significant proportion of dialysis patients die because of cardiovascular disease not directly attributable to uremia. Indeed, many of the cardiovascular diseases and cardiovascular risk factors in these patients are common to those occurring in the general population and are amenable to intervention. Lack of proper medical care during the early stages of renal insufficiency and present-day dialysis routines, by failing to correct hypertension, hypervolemia and left ventricular hypertrophy in many patients, may also add to the cardiovascular burden. The author suggests that, in addition to early treatment and referral to a specialist, chronic renal failure patients should undergo intensive cardiovascular screening and treatment, and correction of cardiovascular risk factors based on guidelines established for the general population.