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Medical Therapy Versus Revascularization in Patients with Stable Ischemic Heart Disease and Advanced Chronic Kidney DiseasePaul, Timir K., Mamas, Mamas A., Shanmugasundaram, Madhan, Nagarajarao, Harsha S., Ojha, Chandra P., Jneid, Hani, Kumar, Gautam, White, Christopher J. 01 April 2021 (has links)
Purpose of Review: This article reviews the evidence on optimal medical therapy (OMT) versus coronary revascularization in patients with stable ischemic heart disease (SIHD) and advanced chronic kidney disease (CKD). Recent Findings: A post hoc analysis of the COURAGE trial in patients with SIHD and CKD showed no difference in freedom from angina, death, and nonfatal myocardial infarction (MI) between OMT and percutaneous intervention plus OMT compared with patients without CKD. The ISCHEMIA-CKD trial of 777 patients with advanced CKD revealed no difference in cumulative incidence of death or nonfatal MI at 3 years between OMT and revascularization but the composite of death or new dialysis was higher in the invasive arm. Additionally, there were no significant or sustained benefits in related to angina-related health status in invasive versus conservative strategy. Summary: An initial revascularization strategy does not reduce mortality or MI or relieve angina symptoms in patients with SIHD and advanced CKD.
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Percutaneous Coronary Intervention Versus Coronary Artery Bypass Graft in Left Main RevascularisationPaul, Timir Kumar 01 June 2020 (has links)
No description available.
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Wound Infection Following Coronary Artery Bypass Graft Surgery : Risk Factors and the Experiences of PatientsSwenne, Christine Leo January 2006 (has links)
<p>The primary aim was to register the incidence of surgical wound infections (SWI) in sternotomy and leg incisions and potential risk factors for SWI following coronary artery by-pass graft (CAGB) procedures. Patients’ perspectives of SWI and the subsequent treatment were also considered. </p><p>Risk factors were registered for 374 patients. Patients were contacted by telephone 30 and 60 days after surgery and interviewed according to a questionnaire about symptoms and signs of wound infections. SWI was defined according to The Centers for Disease Control. Patients with mediastinitis were also interviewed within four months about how they experienced care, how they coped and how they thought the mediastinitis would influence their future life. </p><p>SWIs were diagnosed in 30 % of the patients. Seventy-three percent of the SWIs of the leg were diagnosed within 30 days of surgery and 27% were diagnosed within 31 to 60 days. Female gender and use of a monofilament suture for skin closure were the most important risk factors for SWI of the leg. Low preoperative haemoglobin concentration was the most important risk factor for sternal SWI. Patients with mediastinitis had higher BMI and had more often received erythrocyte transfusions on postoperative day 2 or later than those without infections. Patients without a diagnosis of diabetes who had increased blood glucose concentrations during the intermediate postoperative period had an increased risk of mediastinitis. It was not possible to separate the effect of diabetes as a risk factor for SWI from that of hyperglycaemia as such. Patients’ experiences were influenced by the staffs’ medical knowledge, how care was given and how well information was provided. Perceived danger and stress influenced how they coped with the situation. The patients believed that the mediastinitis would not affect the final outcome of the CABG procedure, even though their confidence in this was influenced by uncertainties about the rehabilitation process.</p>
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Wound Infection Following Coronary Artery Bypass Graft Surgery : Risk Factors and the Experiences of PatientsSwenne, Christine Leo January 2006 (has links)
The primary aim was to register the incidence of surgical wound infections (SWI) in sternotomy and leg incisions and potential risk factors for SWI following coronary artery by-pass graft (CAGB) procedures. Patients’ perspectives of SWI and the subsequent treatment were also considered. Risk factors were registered for 374 patients. Patients were contacted by telephone 30 and 60 days after surgery and interviewed according to a questionnaire about symptoms and signs of wound infections. SWI was defined according to The Centers for Disease Control. Patients with mediastinitis were also interviewed within four months about how they experienced care, how they coped and how they thought the mediastinitis would influence their future life. SWIs were diagnosed in 30 % of the patients. Seventy-three percent of the SWIs of the leg were diagnosed within 30 days of surgery and 27% were diagnosed within 31 to 60 days. Female gender and use of a monofilament suture for skin closure were the most important risk factors for SWI of the leg. Low preoperative haemoglobin concentration was the most important risk factor for sternal SWI. Patients with mediastinitis had higher BMI and had more often received erythrocyte transfusions on postoperative day 2 or later than those without infections. Patients without a diagnosis of diabetes who had increased blood glucose concentrations during the intermediate postoperative period had an increased risk of mediastinitis. It was not possible to separate the effect of diabetes as a risk factor for SWI from that of hyperglycaemia as such. Patients’ experiences were influenced by the staffs’ medical knowledge, how care was given and how well information was provided. Perceived danger and stress influenced how they coped with the situation. The patients believed that the mediastinitis would not affect the final outcome of the CABG procedure, even though their confidence in this was influenced by uncertainties about the rehabilitation process.
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Bayesian based risk stratification of atrial fibrillation in coronary artery bypass graft patientsWiggins, Matthew Corbin 22 May 2007 (has links)
Roughly thirty percent of coronary artery bypass graft (CABG) patients develop atrial fibrillation (AF) in the five days following surgery, increasing the risk of stroke, prolonging hospital stay three to four days, and increasing the overall cost of the procedure. Current pharmacologic and nonpharmacologic means of AF prevention are suboptimal, and their side effects, expense, and inconvenience limit their widespread application. An accurate method for identifying patients at high risk for postoperative AF would allow these methods to be focused on the patients on which its utility would be highest. The main objective of this research was to develop a Bayesian network (BN) which could model/predict/assign risk of the occurrence of atrial fibrillation in CABG patients using retrospective data. A secondary objective was to develop an integrated framework for more advanced methods of feature selection and fusion for medical classification/prediction.
We determined that the naïve Bayesian network classifier used with features selected by a genetic algorithm is a better classifier to use, given our cohort. The naïve BN allows for reasonable prediction despite being presented with patients with missing data points as might occur in the hospital. This classifier achieves a sensitivity of 0.63 and a specificity of 0.73 with an AUC of 0.74. Furthermore, this system is based on probabilities that are well understood and easily incorporated into a clinical environment. These probabilities can be altered based on the cardiologists prior knowledge through Bayesian statistics, allowing for online sensitivity analysis by doctors, to perceive the best treatment options.
Contributions of this research include:
- An accurate, physician-friendly, postoperative AF risk stratification system that performs even under missing data conditions, while outperforming the state of the art system,
- A thorough analysis of previously examined and novel pre- and postoperative clinical and ECG features for postoperative AF risk stratification,
- A new methodology for genetic algorithm-built traditional Bayesian network classifiers allowing dynamic structure through novel chromosome, operator, and fitness definitions, and
- An integrated methodology for inclusion of doctor s expert knowledge into a probabilistic diagnosis support system.
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Haemostatic activation and its relationship to neuropsychological changes following cardiopulmonary bypass surgeryRaymond, Paul Douglas January 2006 (has links)
Neuropsychological impairment following cardiopulmonary bypass (CPB) remains a serious consequence of otherwise successful surgery. The incidence of neuropsychological decline is poorly understood due to varied measurement intervals, and perhaps more importantly the use of unreliable detection and classification methods. The reported incidence varies considerably, ranging anywhere from 30% to 90% of subjects. While the nature of this impairment has not been fully elucidated, recent evidence suggests that microembolism during surgery may be the principal causative agent of postoperative cerebral dysfunction. The work described in this thesis investigates one possible source of microembolism leading to postoperative decline, namely thromboembolism arising from excessive activation of the haemostatic mechanism. Crucial to the accurate detection of significant decline in individual patients, this work also focuses on the development and use of meaningful criteria to be used when describing change in neuropsychological performance measures.
The strong haemostatic activation during CPB is controlled by heparin anticoagulation. The clinical performance of the Hepcon heparin-monitoring instrument was compared to the activated clotting time (ACT), which is used in most cardiac centres. An analysis of samples from 42 elective coronary artery bypass grafting (CABG) patients shows that the ACT does not detect the significant decline in heparin concentration seen upon connection to CPB, in comparison to the Hepcon. The Hepcon appears to be in satisfactory agreement with laboratory anti-Xa analysis of heparin concentration, with the mean difference for the Hepcon at -0.46 U/ml, and the limits of agreement +/- 1.12 U/ml. Further analysis shows that that for 95% of cases, the Hepcon will give values that are between 0.53 and 1.27 times the value for anti-Xa.
The loss of relationship between ACT and heparin concentration was further investigated by converting ACT values to heparin concentration. The results provide data on the degree of prolongation in ACT times brought about by factors associated with CPB. A methodology is presented by which users can adjust for the loss of relationship between ACT and heparin. This work also demonstrates that under normal usage of the ACT, the user may obtain values up to 3 times appropriate for the plasma heparin concentration.
The computer-administered neuropsychological testing tool (the MicroCog) was validated using 40 age-matched control subjects. Using a two-week interval, the summary score correlation coefficients ranged from .49 to .84, with all scores demonstrating significant practice effects. Also presented are retest normative data that may be used to determine significant change in a homogeneous sample using both reliable change and regression models of analysis. The performance of four different models of change analysis was then analysed using data from the clinical group. The regression technique of analysis was shown to be the most useful prediction model as it provides correction for both practice effects and regression toward the mean in each individual. A novel statistical rationale is presented for the choice of criteria in the identification of patients that may be defined as overall impaired when using a battery of test scores. When using one-tailed prediction models for decline, the binomial distribution of scores was shown to be a useful descriptive statistic providing an estimate of change due to chance. When applied to a suitable selection of scores that minimise shared variance, a value +/- 20% of test scores used was demonstrated to be a rational cut-off for an individual to be classified as impaired. Using this methodology, 32.7% of patients were identified as significantly deteriorated in neuropsychological test function immediately prior to discharge from hospital. Patient age was shown to be a significant predictor of neuropsychological decline following CPB. No significant relationship was identified between thrombin generation and neuropsychological change scores, however problems with patient recruitment and retention limited the statistical power of this study. An intriguing relationship with heparin concentration was noted that might warrant further investigation.
This work highlights the complex nature of post-bypass neuropsychological dysfunction and the complexities in assessing decline. The regression-based model was shown to be highly useful in the analysis of data from a suitably validated neuropsychological testing tool. The argument that no suitable criterion exists for the identification of patients as overall impaired has been challenged with the development of a rational cut-off based on the likely distribution of change scores across a series. The work presented here confirms the need for standardised testing methods based on sound statistical criteria. This work also highlights the problems associated with current methods for monitoring anticoagulation therapy during bypass surgery. Methodology is presented that allows adjustment of ACT results to account for CPB-induced prolongation of clotting times. Current techniques for heparin monitoring overestimate heparin levels on bypass by up to threefold, which may predispose to subclinical coagulation and increased delivery of protamine.
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Cognitive Deficits in Cardiac Rehabilitation: A Comparison of Post-Bypass and Post-Angioplasty PatientsBui, Matthew January 2017 (has links)
Mild cognitive deficits that negatively impact self-management education-related outcomes may be present in a proportion of cardiac rehabilitation patients and the degree of impairment may vary by the type of coronary revascularization procedure. The purpose of this study was to compare cognitive function, as measured by the Montreal Cognitive Assessment (MoCA), between coronary artery bypass graft surgery (CABG) and percutaneous coronary intervention (PCI) patients, and to determine independent variables of MoCA score. In a cross-sectional study, 78 cardiac rehabilitation patients (CABG n = 38, PCI n = 40) completed the MoCA. Demographics were collected and disease burden was calculated using the age-adjusted Charlson Comorbidity Index (ACCI). Mild cognitive deficits (MoCA ≤26) were present in 55.3% CABG and 30.0% PCI patients. An independent Student’s t test showed that MoCA scores were significantly lower among CABG patients (mean = 24.5, SD = 3.3) compared to PCI patients (M = 26.7, SD = 2.7), t (76) = 3.15, p < 0.01. Descriptive analyses of cognitive domain scores indicated that deficits in short-term memory and language were present among CABG patients. Using a backward regression, coronary revascularization procedure (CABG vs. PCI) (p = 0.006) and disease burden (ACCI) (p = 0.015) remained significant, while heart failure diagnosis became non-significant and was removed from the model (F (2, 75) = 8.382, p < 0.001). The final model explained 16.1% of the total variance in MoCA score (adjusted R2 = 0.161). Results indicate that cognitive deficits were present in cardiac rehabilitation participants and associated with the type of coronary revascularization procedure, suggesting the need for formal cognitive screening and adaptation of education interventions in cardiac rehabilitation. A future prospective cohort study is required to establish temporality, and to measure education-related outcomes, such as health-related quality of life (HRQOL) and self-management. / Thesis / Master of Science (MSc) / Cardiac rehabilitation (CR) is a multifaceted program consisting of exercise and education that is essential to the care of post-coronary revascularization patients. While exercise has shown to improve health outcomes, education has demonstrated inconsistent effects. Since education has imposed cognitive demands, this discrepancy in outcomes may, in part, be due to cognitive deficits present in a proportion of program attendees: the degree of impairment may vary by type of coronary revascularization procedure prior to CR. This study compared cognitive function between two groups of coronary revascularization patients, post-coronary bypass surgery and post-coronary angioplasty, and determined independent variables for cognitive function. Results showed that coronary bypass surgery patients had significantly lower cognitive function than coronary angioplasty patients at program intake. Coronary bypass surgery and accumulated disease burden were weakly associated with decreased cognitive function. Cognitive screening and adapted education for patients with cognitive deficits should be considered to improve CR outcomes.
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Nurses' monitoring of central venous and pulmonary artery catheters after coronary artery bypass graft operationEllis, Margaret 28 February 2002 (has links)
A quantitative research design for a descriptive and contextual study to determine
the critical care nurses knowledge and data preferences regarding the central
venous and pulmonary artery catheters management and decision making after
coronary arte.y bypass graft operations and the utmzation period of the pulmonary
artery catheter after coronary artery bypass graft operations. The data was
collected through a questionnaire completed by critical care nurses and
retrospective analysis of patient records through a structured checklist. Data
analysis indicated the following: critical care nurses have a knowledge deficit in the
management of the central venous and pulmonary artery catheters and felt more
competent and confident in the central venous measurements. The utilization
period of the pulmonary artery catheter was 48% compared to the 100% of the
central venous catheter. / Advanced Nursing Science / M.A. (Advanced Nursing Science)
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Mechanism and Prediction of Post-Operative Atrial Fibrillation Based on Atrial ElectrogramsXiong, Feng 03 1900 (has links)
La fibrillation auriculaire (FA) est une arythmie touchant les oreillettes. En FA, la contraction auriculaire est rapide et irrégulière. Le remplissage des ventricules devient incomplet, ce qui réduit le débit cardiaque. La FA peut entraîner des palpitations, des évanouissements, des douleurs thoraciques ou l’insuffisance cardiaque. Elle augmente aussi le risque d'accident vasculaire. Le pontage coronarien est une intervention chirurgicale réalisée pour restaurer le flux sanguin dans les cas de maladie coronarienne sévère. 10% à 65% des patients qui n'ont jamais subi de FA, en sont victime le plus souvent lors du deuxième ou troisième jour postopératoire. La FA est particulièrement fréquente après une chirurgie de la valve mitrale, survenant alors dans environ 64% des patients. L'apparition de la FA postopératoire est associée à une augmentation de la morbidité, de la durée et des coûts d'hospitalisation. Les mécanismes responsables de la FA postopératoire ne sont pas bien compris. L'identification des patients à haut risque de FA après un pontage coronarien serait utile pour sa prévention. Le présent projet est basé sur l'analyse d’électrogrammes cardiaques enregistrées chez les patients après pontage un aorte-coronaire. Le premier objectif de la recherche est d'étudier si les enregistrements affichent des changements typiques avant l'apparition de la FA. Le deuxième objectif est d'identifier des facteurs prédictifs permettant d’identifier les patients qui vont développer une FA.
Les enregistrements ont été réalisés par l'équipe du Dr Pierre Pagé sur 137 patients traités par pontage coronarien. Trois électrodes unipolaires ont été suturées sur l'épicarde des oreillettes pour enregistrer en continu pendant les 4 premiers jours postopératoires. La première tâche était de développer un algorithme pour détecter et distinguer les activations auriculaires et ventriculaires sur chaque canal, et pour combiner les activations des trois canaux appartenant à un même événement cardiaque. L'algorithme a été développé et optimisé sur un premier ensemble de marqueurs, et sa performance évaluée sur un second ensemble. Un logiciel de validation a été développé pour préparer ces deux ensembles et pour corriger les détections sur tous les enregistrements qui ont été utilisés plus tard dans les analyses. Il a été complété par des outils pour former, étiqueter et valider les battements sinusaux normaux, les activations auriculaires et ventriculaires prématurées (PAA, PVA), ainsi que les épisodes d'arythmie.
Les données cliniques préopératoires ont ensuite été analysées pour établir le risque préopératoire de FA. L’âge, le niveau de créatinine sérique et un diagnostic d'infarctus du myocarde se sont révélés être les plus importants facteurs de prédiction. Bien que le niveau du risque préopératoire puisse dans une certaine mesure prédire qui développera la FA, il n'était pas corrélé avec le temps de l'apparition de la FA postopératoire.
Pour l'ensemble des patients ayant eu au moins un épisode de FA d’une durée de 10 minutes ou plus, les deux heures précédant la première FA prolongée ont été analysées. Cette première FA prolongée était toujours déclenchée par un PAA dont l’origine était le plus souvent sur l'oreillette gauche. Cependant, au cours des deux heures pré-FA, la distribution des PAA et de la fraction de ceux-ci provenant de l'oreillette gauche était large et inhomogène parmi les patients. Le nombre de PAA, la durée des arythmies transitoires, le rythme cardiaque sinusal, la portion basse fréquence de la variabilité du rythme cardiaque (LF portion) montraient des changements significatifs dans la dernière heure avant le début de la FA.
La dernière étape consistait à comparer les patients avec et sans FA prolongée pour trouver des facteurs permettant de discriminer les deux groupes. Cinq types de modèles de régression logistique ont été comparés. Ils avaient une sensibilité, une spécificité et une courbe opérateur-receveur similaires, et tous avaient un niveau de prédiction des patients sans FA très faible. Une méthode de moyenne glissante a été proposée pour améliorer la discrimination, surtout pour les patients sans FA. Deux modèles ont été retenus, sélectionnés sur les critères de robustesse, de précision, et d’applicabilité. Autour 70% patients sans FA et 75% de patients avec FA ont été correctement identifiés dans la dernière heure avant la FA. Le taux de PAA, la fraction des PAA initiés dans l'oreillette gauche, le pNN50, le temps de conduction auriculo-ventriculaire, et la corrélation entre ce dernier et le rythme cardiaque étaient les variables de prédiction communes à ces deux modèles. / Atrial fibrillation (AF) is an abnormal heart rhythm (cardiac arrhythmia). In AF, the atrial contraction is rapid and irregular, and the filling of the ventricles becomes incomplete, leading to reduce cardiac output. Atrial fibrillation may result in symptoms of palpitations, fainting, chest pain, or even heart failure. AF is an also an important risk factor for stroke. Coronary artery bypass graft surgery (CABG) is a surgical procedure to restore the perfusion of the cardiac tissue in case of severe coronary heart disease. 10% to 65% of patients who never had a history of AF develop AF on the second or third post CABG surgery day. The occurrence of postoperative AF is associated with worse morbidity and longer and more expensive intensive-care hospitalization. The fundamental mechanism responsible of AF, especially for post-surgery patients, is not well understood. Identification of patients at high risk of AF after CABG would be helpful in prevention of postoperative AF. The present project is based on the analysis of cardiac electrograms recorded in patients after CABG surgery. The first aim of the research is to investigate whether the recordings display typical changes prior to the onset of AF. A second aim is to identify predictors that can discriminate the patients that will develop AF.
Recordings were made by the team of Dr. Pierre Pagé on 137 patients treated with CABG surgery. Three unipolar electrodes were sutured on the epicardium of the atria to record continuously during the first 4 post-surgery days. As a first stage of the research, an automatic and unsupervised algorithm was developed to detect and distinguish atrial and ventricular activations on each channel, and join together the activation of the different channels belonging to the same cardiac event. The algorithm was developed and optimized on a training set, and its performance assessed on a test set. Validation software was developed to prepare these two sets and to correct the detections over all recordings that were later used in the analyses. It was complemented with tools to detect, label and validate normal sinus beats, atrial and ventricular premature activations (PAA, PVC) as well as episodes of arrhythmia.
Pre-CABG clinical data were then analyzed to establish the preoperative risk of AF. Age, serum creatinine and prior myocardial infarct were found to be the most important predictors. While the preoperative risk score could to a certain extent predict who will develop AF, it was not correlated with the post-operative time of AF onset.
Then the set of AF patients was analyzed, considering the last two hours before the onset of the first AF lasting for more than 10 minutes. This prolonged AF was found to be usually triggered by a premature atrial PAA most often originating from the left atrium. However, along the two pre-AF hours, the distribution of PAA and of the fraction of these coming from the left atrium was wide and inhomogeneous among the patients. PAA rate, duration of transient atrial arrhythmia, sinus heart rate, and low frequency portion of heart rate variability (LF portion) showed significant changes in last hour before the onset of AF. Comparing all other PAA, the triggering PAA were characterized by their prematurity, the small value of the maximum derivative of the electrogram nearest to the site of origin, as well as the presence of transient arrhythmia and increase LF portion of the sinus heart rate variation prior to the onset of the arrhythmia.
The final step was to compare AF and Non-AF patients to find predictors to discriminate the two groups. Five types of logistic regression models were compared, achieving similar sensitivity, specificity, and ROC curve area, but very low prediction accuracy for Non-AF patients. A weighted moving average method was proposed to design to improve the accuracy for Non-AF patient. Two models were favoured, selected on the criteria of robustness, accuracy, and practicability. Around 70% Non-AF patients were correctly classified, and around 75% of AF patients in the last hour before AF. The PAA rate, the fraction of PAA initiated in the left atrium, pNN50, the atrio-ventricular conduction time, and the correlation between the latter and the heart rhythm were common predictors of these two models.
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Avaliação da disposição cinética do atenolol em pacientes coronarianos submetidos à revascularização do miocárdio. Influência da circulação extracorpórea sobre as concentrações plasmáticas do atenolol no intra-operatório de cirurgia cardíaca / Evaluation of kinetic disposition of atenolol in coronary patients submitted to the CABG surgery. Influence of cardiopulmonary bypass on the plasma concentration of atenolol during the intra-operative period.Leite, Fátima da Silva 04 September 2006 (has links)
Pacientes submetidos à revascularização do miocárdio (RM), frequentemente utilizam beta-bloqueadores no pré-operatório para o controle da angina pectoris, e continuam o tratamento após a cirurgia, para a redução de mortalidade e complicações cardiovasculares perioperatórias. Entretanto, a circulação extracorpórea (CEC), empregada na maioria das cirurgias cardíacas, pode alterar as concentrações plasmáticas e a disposição cinética de muitos fármacos, e consequentemente seus efeitos terapêuticos. O atenolol é um beta-bloqueador altamente hidrossolúvel, de absorção incompleta e eliminação renal-dependente. O objetivo deste estudo foi o de investigar a influência da CEC sobre as concentrações plasmáticas do atenolol no intra-operatório de cirurgia cardíaca, além de comparar a sua farmacocinética no pré e pós-operatório de RM com CEC, em pacientes com insuficiência coronariana. Investigou-se ainda, a variabilidade das concentrações plasmáticas do atenolol no período que antecede a cirurgia cardíaca. Na primeira etapa, avaliaram-se 19 pacientes coronarianos, em terapia crônica com atenolol PO, submetidos à cirurgia cardíaca com ou sem CEC. Na segunda parte, investigaram-se os períodos pré e pós-cirúrgico de 7 pacientes submetidos à RM com CEC e tratados com atenolol PO em regime de doses múltiplas. Todos os pacientes investigados apresentavam função renal dentro da normalidade ou leve disfunção renal, decorrente da idade e da insuficiência coronariana. O monitoramento do atenolol plasmático no intra-operatório de RM e o estudo farmacocinético realizado antes e após a revascularização, exigiram coletas de amostras sangüíneas seriadas. A quantificação do atenolol em plasma foi realizada através da cromatografia líquida de alta eficiência com detector de fluorescência e consistiu num procedimento analítico rápido, simples e de baixo custo. Apenas 200 L de plasma foram utilizados em cada análise cromatográfica. O estudo de validação demonstrou que o método desenvolvido apresenta alta linearidade, sensibilidade e seletividade adequadas, alta recuperação, boa precisão e exatidão, além de estabilidade e robustez. Conclui-se que a circulação extracorpórea altera as concentrações do atenolol no intra-operatório de RM, visto que o decaimento das concentrações plasmáticas mostrou-se mais pronunciado na ausência da CEC. Entretanto, apesar das maiores concentrações obtidas ao final da cirurgia com CEC, o atenolol mostra-se seguro, em virtude do baixo acúmulo do fármaco administrado em regime de doses múltiplas. Além disso, a disposição cinética do atenolol permaneceu inalterada, quando os períodos pré e pós-operatórios foram comparados; entretanto, registrou-se uma tendência à normalização do volume de distribuição e da depuração plasmática do atenolol após a revascularização. Adicionalmente, a ausência de correlação entre meia-vida biológica e volume aparente de distribuição sugere que, tanto no pré quanto no pós-operatório, as concentrações do atenolol dependem apenas da sua depuração plasmática. Finalmente, verificou-se que o atenolol apresenta baixa variabilidade inter-pacientes nos regimes posológicos empregados no tratamento da insuficiência coronariana. / Patients submitted to coronary artery bypass grafting (CABG) surgery frequently are using beta-blockers agents for the control of angina pectoris, and continue the treatment after the surgery to reduce the mortality and cardiovascular events. However, the technique of cardiopulmonary bypass (CPB), used in most cardiac surgeries with cardioplegia, causes important changes in the plasma concentrations and pharmacokinetics of many drugs and may also alter their therapeutic effects. Atenolol is a hydrophilic beta-blocker characterized by incomplete absorption, a relatively small volume of distribution and a renal function-dependent elimination. The objective of this study was to investigate the effects of CPB on the plasma concentrations of atenolol during the intra-operative period of cardiac surgery, as well as, to compare the pharmacokinetics of atenolol in the pre and post-operative periods of revascularization with CPB, in patients with coronary insufficiency. In addition, it was investigated the variability of plasma atenolol concentrations before the cardiac surgery. In the first part of the study, it was investigated 19 coronary patients, under chronic therapy with atenolol and submitted to cardiac surgery performed with and without CPB. At the second part, it was evaluated the pre and post-operative periods from 7 patients submitted to the CABG surgery with CPB, who were chronically treated with atenolol in a multiple regimen. All enrolled patients presented normal or slightly reduced renal function as a result of age and underlying disease. A serial blood samples collection was required for monitoring of plasma atenolol concentrations at the intra-operative period and also for pharmacokinetic study at the pre and post-CABG. The quantification of plasma atenolol was performed using high-performance liquid chromatography with fluorescence detection and consisted of a relatively rapid, simple and low-cost analytical procedure. Only 200 µL of plasma was used for each chromatographic analysis. Validation of this analytical method showed high linearity, adequate sensitivity and selectivity, high recovery, good accuracy and precision, in addition to stability and a guarantee of robustness. It was concluded that the CPB changes plasma atenolol concentrations in the intra-operative period, since a marked decrease in plasma atenolol concentrations was observed in patients undergoing cardiac surgery without CPB. Thus, despite the lower decline in plasma levels observed in patients submitted to CPB, atenolol can be used safely, due to the low accumulation of the drug administrated at multiple dose regimens. In addition, pharmacokinetics of atenolol remained unaltered when pre and post-operative periods were compared; although it was observed a tendency of normalization of volume of distribution and plasma clearance of atenolol after the revascularization. Moreover, the lack of correlation between biological half-life and apparent volume of distribution suggests that, in both periods, plasma atenolol concentration only depends on its plasma clearance. Finally, it was verified a small inter-patient variability of atenolol in the dose regimens used for the control of coronary insufficiency.
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