Predictive factors of in-hospital mortality and of severe perioperative complications in myocardial revascularization surgery

OBJECTIVE: To investigate preoperative predictive factors of severe perioperative intercurrent events and in-hospital mortality in coronary artery bypass graft (CABG) surgery and to develop specific models of risk prediction for these events, mainly those that can undergo changes in the preoperative period. METHODS: We prospectively studied 453 patients who had undergone CABG. Factors independently associated with the events of interest were determined with multiple logistic regression and Cox proportional hazards regression model. RESULTS: The mortality rate was 11.3% (51/453), and 21.2% of the patients had 1 or more perioperative intercurrent events. In the final model, the following variables remained associated with the risk of intercurrent events: age ³ 70 years, female sex, hospitalization via SUS (Sistema Único de Saúde - the Brazilian public health system), cardiogenic shock, ischemia, and dependence on dialysis. Using multiple logistic regression for in-hospital mortality, the following variables participated in the model of risk prediction: age ³ 70 years, female sex, hospitalization via SUS, diabetes, renal dysfunction, and cardiogenic shock. According to the Cox regression model for death within the 7 days following surgery, the following variables remained associated with mortality: age ³ 70 years, female sex, cardiogenic shock, and hospitalization via SUS. CONCLUSION: The aspects linked to the structure of the Brazilian health system, such as factors of great impact on the results obtained, indicate that the events investigated also depend on factors that do not relate to the patient's intrinsic condition.

Mildly symptomatic chronic mitral regurgitation. Analysis of left ventricular systolic function and mitral regurgitant fraction under pharmacological influence: echocardiographic study

OBJECTIVE: To study echocardiographic parameters of left ventricular systolic function and valvar regurgitation under pharmacological influence in mildly symptomatic patients with chronic mitral regurgitation (MR). METHODS: We carried out a double-blind placebo controlled study in 12 patients with MR, mean aged 12.5 years old, who were randomized in 4 phases: A) digoxin; B) enalapril; C) digoxin + enalapril; D) placebo. The medication was administered for 30 days in each phase, and the following variables were analyzed: shortening and ejection fractions, wall stress index of left ventricle, left ventricular meridional end-systolic wall stress, Doppler-derived mean rate of left ventricular pressure rise (mean dP/dt), stroke volume and MR jet area. The clinical variables analysed were heart rate and systemic arterial pressure. RESULTS: No significant variation was observed in the clinical variables analysed. The shortening and ejection fraction, the mean dP/dt and stroke volume significantly increased and the wall stress index of left ventricle, the meridional left ventricular end systolic wall stress and the mitral regurgitation jet area decreased in the phases with medication as compared with that in the placebo phase. CONCLUSION: The parameters of left ventricular systolic function improved significantly and the degree of MR decreased with the isolated administration of digoxin or enalapril in mildly symptomatic patients with chronic MR. The combination of the drugs, however, did not show better results.

New auxiliary indicators for the differential diagnosis of functional cardiorespiratory limitation in patients with chronic obstructive pulmonary disease and congestive heart failure

OBJECTIVE: To differentiate the nature of functional cardiorespiratory limitations during exercise in individuals with chronic obstructive pulmonary disease (COPD) or congestive heart failure (CHF) and to determine indicators that may help their classifications. METHODS: The study comprised 40 patients: 23 with COPD and 17 with CHF. All individuals underwent maximal cardiopulmonary exercise testing on a treadmill. RESULTS: The values of peak gas exchange ratio (R peak), peak carbon dioxide production (VCO2 peak), and peak oxygen ventilatory equivalent (V E O2 peak) were higher in the patients with CHF than in those with COPD, and, therefore, those were the variables that characterized the differences between the groups. For group classification, the differentiating functions with the R peak, VCO2 peak (L/min), and V E O2 peak variables were used as follows: group COPD: - 44.886 + 78.832 x R peak + 5.442 x VCO2 peak + 0.336 x V E O2 peak; group CHF: - 69.251 + 89.740 x R peak + 8.461 x VCO2 peak + 0.574 x V E O2 peak. The differentiating function, whose result is greater, correctly classifies the patient's group as 90%. CONCLUSION: The R peak, VCO2 peak, and V E O2 peak values may be used to identify the cause of the functional cardiorespiratory limitations in patients with COPD and CHF.

Predictive factors of complications after coronary stent implantation

OBJECTIVE: To analyze the predictive factors of complications after implantation of coronary stents in a consecutive cohort study. METHODS: Clinical and angiographic characteristics related to the procedure were analyzed, and the incidence of major cardiovascular complications (myocardial infarction, urgent surgery, new angioplasty, death) in the in-hospital phase were recorded. Data were stored in an Access database and analyzed by using the SPSS 6.0 statistical program and a stepwise backwards multiple logistic regression model. RESULTS: One thousand eighteen (mean age of 61±11 years, 29% females) patients underwent 1,070 stent implantations. The rate of angiographic success was 96.8%, the rate of clinical success was 91%, and the incidence of major cardiovascular complications was 7.9%. The variables independently associated with major cardiovascular complications, with their respective odds ratio (OR) were: rescue stent, OR = 5.1 (2.7-9.6); filamentary stent, OR = 4.5 (2.2-9.1); first-generation tubular stent, OR = 2.4 (1.2-4.6); multiple stents, OR = 3 (1.6-5.6); complexity of the lesion, OR = 2.4 (1.1-5.1); thrombus, OR = 2 (1.1-3.5). CONCLUSION: The results stress the importance of angiographic variables and techniques in the risk of complications and draw attention to the influence of the stent's design on the result of the procedure.

Frequency of hypertension in chronic Chagas' disease: retrospective clinical study

OBJECTIVE: To assess the frequency of hypertension in chagasic patients, as well as its clinical behavior and cardiologic findings. METHODS: We carried out a retrospective study with 225 patients with chronic Chagas' disease and hypertension (104 males), mean age of 55.1 ± 11.8. These patients were being followed up in the outpatient care clinics from 1984 to 2000. The study assessed the clinical, electrocardiographic, and radiological viewpoints. RESULTS: Of the 225 hypertensive patients (prevalence = 33.3%), 78 (34.7%) had mild hypertension, 108 (48%) had moderate hypertension, and 39 (17.3%) had severe hypertension. The association of left anterosuperior divisional block and right bundle-branch block occurred in 39 cases (17.3%), and enlargement of the cardiac area on radiological examination occurred in 93 (44.9%) of the 207 cases studied. The undetermined form of Chagas' disease was the most prevalent, 30.2% of the cases, followed by the form associated with conduction disorders in 27.1%, and the isolated form of conduction disorders in 21.3%. CONCLUSION: Chagasic patients had a frequency of hypertension similar to that of the general population, and the clinical profile of the hypertensive chagasic patients seemed not to differ a lot from that of the chagasic patients.

Influence of skeletal muscle mass on ventilatory and hemodynamic variables during exercise in patients with chronic heart failure

OBJECTIVE: To assess the influence of skeletal muscle mass on ventilatory and hemodynamic variables during exercise in patients with chronic heart failure (CHF). METHODS: Twenty-five male patients underwent maximum cardiopulmonary exercise testing on a treadmill with a ramp protocol and measurement of the skeletal muscle mass of their thighs by using magnetic resonance imaging. The clinically stable, noncachectic patients were assessed and compared with 14 healthy individuals (S) paired by age and body mass index, who underwent the same examinations. RESULTS: Similar values of skeletal muscle mass were found in both groups (CHF group: 3863 ± 874 g; S group: 3743 ± 540 g; p = 0.32). Significant correlations of oxygen consumption in the anaerobic threshold (CHF: r = 0.39; P= 0.02 and S: r = 0.14; P = 0.31) and of oxygen pulse also in the anaerobic threshold (CHF: r = 0.49; P = 0.01 and S: r =0.12; P = 0.36) were found only in the group of patients with chronic heart failure. CONCLUSION: The results obtained indicate that skeletal muscle mass may influence the capacity of patients with CHF to withstand submaximal effort, due to limitations in their physical condition, even maintaining a value similar to that of healthy individuals. This suggests qualitative changes in the musculature.

Estudio de los mecanismos inmunosupresores involucrados en la cronicidad de la infección intramamaria por staphylococcus aureus en bovinos. Immunosuppressive mechanisms involved in intrammary chronic infection by staphylococcus aureus in bovine.

La producción de productos lácteos conforma un complejo productivo de larga trayectoria en Argentina, con grandes transformaciones en el sector lechero en los últimos años. La provincia de Córdoba es una de las principales áreas de producción lechera, participando del 34.5 por ciento de la producción nacional. Esta provincia cuenta con un alto número de industrias, principalmente localizadas en la cuenca de Villa María, y concentra el 35 por ciento de los establecimientos lecheros del país. La Mastitis bovina (MB) es la principal causa de pérdidas económicas para el productor y la industria láctea a nivel mundial y regional, por lo cual se plantea la necesidad de mejorar la calidad higiénica y sanitaria de la leche a través de un mayor control de la mastitis. La MB es una inflamación de la glándula mamaria (GM) asociada a una infección bacteriana. Es la enfermedad más común y de mayor incidencia en el ganado lechero, siendo la principal causa de pérdidas económicas para la industria láctea a nivel mundial. Las medidas actuales de control de MB están basadas en prácticas de higiene apropiadas, reducción de la exposición ambiental al patógeno y terapia antibiótica del ganado, las cuales no son totalmente efectivas en el control de la infección. La defensa de la GM contra los patógenos causantes de MB depende de factores anatómicos, celulares y solubles, siendo la eficiencia de esos mecanismos la que determina la resistencia a nuevas infecciones. Los mediadores inmunes innatos y adquiridos de los tejidos y secreciones de la GM actúan en forma coordinada en la protección de la glándula contra enfermedades contagiosas. Staphylococcus aureus es el agente etiológico más importante en la mastitis. Esta bacteria evade la respuesta inmune inflamatoria mediante la inducción de mecanismos inmunosupresores, llevando a la patología a un curso crónico. S. aureus además puede colonizar el tejido epitelial y formar películas bacterianas conocidas como biofilms. Así, S. aureus adquiere más resistencia a la terapia antibiótica y a la acción del sistema inmunológico determinando la persistencia de la enfermedad. Nuestra hipótesis es que una respuesta inmune desarrollada en un microambiente particular de citoquinas, quimioquinas y células, podría contribuir a la evasión del patógeno y al desarrollo de una infección crónica. El polisacárido Quitosano (Q) presenta un efecto antibacteriano e inmunoestimulante en cultivos de células inmunes de ganado bovino, un efecto protectivo en modelos murinos de mastitis y actividad anti-biofilms de distintas cepas bacterianas. Por sus propiedades intrínsecas, este polisacárido es un candidato ideal en la regulación de las respuestas inmunológicas. El objetivo de este proyecto es caracterizar el microambiente local y sistémico, las señales inducidas por el microorganismo que promueven una falla inmunológica y caracterizar el efecto de Q sobre las respuestas generadas en la GM, mediante la realización de numerosos estudios in vivo e in vitro. Las estrategias para controlar la MB por S. aureus y disminuir el impacto de esta patología en la industria láctea, podrían orientarse a la manipulación del sistema inmunológico de la GM bovina a fin de incrementar los mecanismos de defensa naturales del huésped. Los resultados que se desprendan del proyecto permitirán adquirir conocimiento para el desarrollo de nuevas estrategias de inmunointervención a fin de controlar la MB por S. aureus y disminuir el impacto de esta patología en la industria láctea. Siendo la MB una patología relevante no solo en lo que hace a status sanitario animal, línea prioritaria definida en el Plan Estratégico Nacional de Ciencia, Tecnología e Innovación "Bicentenario 2006-2010", sino también a las implicancias económicas de esta problemática, y dado el desarrollo de la actividad lechera en la región y en el país, los resultados obtenidos podrían tener un importante impacto socioeconómico.

Procesos de plasticidad sináptica en gyrus dentado hipocampal durante la administración crónica y el síndrome de abstinencia a cocaína. Synaptic plasticity in hippocampal dentate gyrus during chronic administration and withdrawal from cocaine.

Los procesos neuronales adaptativos que se observan como consecuencia de la administración crónica de drogas de abuso, son similares a los procesos plásticos que subyacen al aprendizaje y la memoria. Por otra parte, el hipocampo forma parte del circuito neuronal responsable de los cambios conductuales observados como consecuencia de la administración crónica de diferentes drogas de abuso. De acuerdo con esto, resultados previos de nuestro laboratorio demostraron que la plasticidad sináptica en el hipocampo y las claves contextuales relacionadas con la administración de la droga, son relevantes para el incremento de la plasticidad hipocampal por la administración crónica de diazepam. Específicamente en el gyrus dentado hipocampal se han descripto fenómenos plásticos relacionados con la exposición crónica a psicofármacos, tales como facilitación en la transmisión sináptica, disminución de la proliferación celular y el aumento del factor de transcripción ?Fos B. Debido a la correlación existente entre los mecanismos de plasticidad neuronal, los aprendizaje asociativos y formación de memorias y aquellos responsables de la adicción, el objetivo general de este trabajo es caracterizar los cambios inducidos por la exposición repetida de cocaína y durante el periodo de abstinencia, en la excitabilidad neuronal de las células del gyrus dentado hipocampal, los canales iónicos afectados y los posibles mecanismos bioquímicos involucrados en dichos cambios, que podrían explicar las alteraciones conductuales observadas después de dicho tratamiento. Con este propósito, se estudiará: 1) la plasticidad sináptica (potenciación a largo plazo, LTP y depotenciación a largo plazo, LTD) en el gyrus dentado, mediante registros electrofisiológios multiunitarios; 2)la excitabilidad de las células granulares del gyrus dentado y la actividad de los canales iónicos, utilizando la técnica de patch clamp; 3) las alteraciones en la neurotransmisión glutamatergica, midiendo los niveles del neurotransmisor in vivo, utilizando la técnica de microdiálisis; el tráfico de receptores glutamatérgicos, utilizando la técnica de western-blott, 4) la participación del óxido nítrico en los cambios adaptativos observados como consecuencia de la sensibilización a cocaína. Además, mediante la utilización de técnicas comportamentales (avoidance inhibitorio), se estudiarán las posibles alteraciones de conductas que se sabe dependen de la integridad funcional del hipocampo.En relación a los resultados del presente proyecto se espera obtener un incremento en la plasticidad sináptica, en la excitabilidad neuronal de las células granulares del gyrus dentado de la formación hipocámpica, en la liberación extracelular de glutamato in vivo, como así también en el tráfico de receptores glutamatérgicos. Además se espera obtener un aumento de las vías de señalización activadas por la acción de glutamato, como la de óxido nítrico/GMPc, como consecuencia de la administración crónica de cocaína. Con este aumento global de la plasticidad sináptica hipocampal, las conductas dependientes de esta estructura debieran estar facilitadas, demostrando así una participación activa del hipocampo en los procesos de sensibilización y posiblemente en la adicción a psicoestimulantes. La caracterización del impacto del desarrollo de sensibilización a cocaína en la excitabilidad neuronal en el hipocampo, sobre los sistemas de neurotransmisión y las vías de señalización involucradas contribuirían a dilucidar los mecanismos que contribuyen al desarrollo de sensibilización a cocaína, los cuales podrían representar potenciales blancos terapéuticos para el tratamiento de la adicción, considerando principalmente aspectos específicos de la actividad eléctrica neuronal y la plasticidad sináptica asociada con las diferentes fases del ciclo de la adicción.

Functional Vascular Study in Hypertensive Subjects with Type 2 Diabetes Using Losartan or Amlodipine

Background: Antihypertensive drugs are used to control blood pressure (BP) and reduce macro- and microvascular complications in hypertensive patients with diabetes. Objectives: The present study aimed to compare the functional vascular changes in hypertensive patients with type 2 diabetes mellitus after 6 weeks of treatment with amlodipine or losartan. Methods: Patients with a previous diagnosis of hypertension and type 2 diabetes mellitus were randomly divided into 2 groups and evaluated after 6 weeks of treatment with amlodipine (5 mg/day) or losartan (100 mg/day). Patient evaluation included BP measurement, ambulatory BP monitoring, and assessment of vascular parameters using applanation tonometry, pulse wave velocity (PWV), and flow-mediated dilation (FMD) of the brachial artery. Results: A total of 42 patients were evaluated (21 in each group), with a predominance of women (71%) in both groups. The mean age of the patients in both groups was similar (amlodipine group: 54.9 ± 4.5 years; losartan group: 54.0 ± 6.9 years), with no significant difference in the mean BP [amlodipine group: 145 ± 14 mmHg (systolic) and 84 ± 8 mmHg (diastolic); losartan group: 153 ± 19 mmHg (systolic) and 90 ± 9 mmHg (diastolic)]. The augmentation index (30% ± 9% and 36% ± 8%, p = 0.025) and augmentation pressure (16 ± 6 mmHg and 20 ± 8 mmHg, p = 0.045) were lower in the amlodipine group when compared with the losartan group. PWV and FMD were similar in both groups. Conclusions: Hypertensive patients with type 2 diabetes mellitus treated with amlodipine exhibited an improved pattern of pulse wave reflection in comparison with those treated with losartan. However, the use of losartan may be associated with independent vascular reactivity to the pressor effect.

Effects of Yoga in Patients with Chronic Heart Failure: A Meta-Analysis

The use of yoga as an effective cardiac rehabilitation in patients with chronic heart failure (CHF) remains controversial. We performed a meta-analysis to examine the effects of yoga on exercise capacity and health-related quality of life (HRQOL) in patients with CHF. Methods: We searched MEDLINE, Cochrane Central Register of Controlled Trials, Excerpta Medica database, LILACS, Physiotherapy Evidence Database, The Scientific Electronic Library Online, and Cumulative Index to Nursing and Allied Health (from the earliest date available to December 2013) for randomized controlled trials (RCTs) examining the effects of yoga versus exercise and/or of yoga versus control on exercise capacity (peakVO2) and quality-of-life (HRQOL) in CHF. Two reviewers selected studies independently. Weighted mean differences (WMDs) and 95% confidence intervals (CIs) were calculated, and heterogeneity was assessed using the I2 test. Two studies met the selection criteria (total: 30 yoga and 29 control patients). The results suggested that yoga compared with control had a positive impact on peak VO2 and HRQOL. Peak VO2, WMD (3.87 95% CI: 1.95 to 5.80), and global HRQOL standardized mean differences (-12.46 95% CI: -22.49 to -2.43) improved in the yoga group compared to the control group. Yoga enhances peak VO2 and HRQOL in patients with CHF and could be considered for inclusion in cardiac rehabilitation programs. Larger RCTs are required to further investigate the effects of yoga in patients with CHF.

Chronic Stress Improves NO- and Ca2+ Flux-Dependent Vascular Function: A Pharmacological Study

Background: Stress is associated with cardiovascular diseases. Objective: This study aimed at assessing whether chronic stress induces vascular alterations, and whether these modulations are nitric oxide (NO) and Ca2+ dependent. Methods: Wistar rats, 30 days of age, were separated into 2 groups: control (C) and Stress (St). Chronic stress consisted of immobilization for 1 hour/day, 5 days/week, 15 weeks. Systolic blood pressure was assessed. Vascular studies on aortic rings were performed. Concentration-effect curves were built for noradrenaline, in the presence of L-NAME or prazosin, acetylcholine, sodium nitroprusside and KCl. In addition, Ca2+ flux was also evaluated. Results: Chronic stress induced hypertension, decreased the vascular response to KCl and to noradrenaline, and increased the vascular response to acetylcholine. L-NAME blunted the difference observed in noradrenaline curves. Furthermore, contractile response to Ca2+ was decreased in the aorta of stressed rats. Conclusion: Our data suggest that the vascular response to chronic stress is an adaptation to its deleterious effects, such as hypertension. In addition, this adaptation is NO- and Ca2+-dependent. These data help to clarify the contribution of stress to cardiovascular abnormalities. However, further studies are necessary to better elucidate the mechanisms involved in the cardiovascular dysfunction associated with stressors. (Arq Bras Cardiol. 2014; [online].ahead print, PP.0-0)

Progression of Blood Pressure and Cardiovascular Outcomes in Hypertensive Patients in a Reference Center

Background: Hypertension is a public health problem, considering its high prevalence, low control rate and cardiovascular complications. Objective: Evaluate the control of blood pressure (BP) and cardiovascular outcomes in patients enrolled at the Reference Center for Hypertension and Diabetes, located in a medium-sized city in the Midwest Region of Brazil. Methods: Population-based study comparing patients enrolled in the service at the time of their admission and after an average follow-up of five years. Participants were aged ≥18 years and were regularly monitored at the Center up to 6 months before data collection. We assessed demographic variables, BP, body mass index, risk factors, and cardiovascular outcomes. Results: We studied 1,298 individuals, predominantly women (60.9%), and with mean age of 56.7±13.1 years. Over time, there was a significant increase in physical inactivity, alcohol consumption, diabetes, dyslipidemia, and excessive weight. As for cardiovascular outcomes, we observed an increase in stroke and myocardial revascularization, and a lower frequency of chronic renal failure. During follow-up, there was significant improvement in the rate of BP control (from 29.6% to 39.6%; p = 0.001) and 72 deaths, 91.7% of which were due to cardiovascular diseases. Conclusion: Despite considerable improvements in the rate of BP control during follow-up, risk factors worsened and cardiovascular outcomes increased.