OBJECTIVES: To evaluate the effects of sympathectomy on the myocardium in an experimental model. METHODS: The study evaluated three groups of male Wistar rats: control (CT; n=15), left unilateral sympathectomy (UNI; n=15), and bilateral sympathectomy (BIL; n=31). Sympathectomy was performed by injection of absolute alcohol into the space of the spinous process of the C7 vertebra. After 6 weeks, we assessed the chronotropic properties at rest and stress, cardiovascular autonomic modulation, myocardial and peripheral catecholamines, and beta-adrenergic receptors in the myocardium. The treadmill test consisted of an escalated protocol with a velocity increment until the maximal velocity tolerated by the animal was reached. RESULTS: The bilateral group had higher levels of peripheral catecholamines, and consequently, a higher heart rate (HR) and blood pressure levels. This suggests that the activation of a compensatory pathway in this group may have deleterious effects. The BIL group had basal tachycardia immediately before the exercise test and increased tachycardia at peak exercise (p<0.01); the blood pressure had the same pattern (p=0.0365). The variables related to autonomic modulation were not significantly different between groups, with the exception of the high frequency (HF) variable, which showed significant differences in CT vs UNI. There was no significant difference in beta receptor expression between groups. There was a higher concentration of peripheral norepinephrine in the BIL group (p=0.0001), and no significant difference in myocardial norepinephrine (p=0.09). CONCLUSION: These findings suggest that an extra cardiac compensatory pathway increases the sympathetic tonus and maintains a higher HR and higher levels of peripheral catecholamines in the procedure groups. The increase in HF activity can be interpreted as an attempt to increase the parasympathetic tonus to balance the greater sympathetic activity.

Fundamento: O enxerto de artéria radial (AR) foi o segundo enxerto arterial a ser introduzido na prática clínica para revascularização miocárdica. A técnica de esqueletização da artéria torácica interna esquerda (ATIE) pode, de fato, alterar a capacidade de fluxo do enxerto com potenciais vantagens, o que leva à suposição de que o comportamento da AR, como enxerto coronariano, seja semelhante ao da ATIE esqueletizada. Objetivo: Este estudo avaliou enxertos aortocoronários "livres" de AR, quer esqueletizados, quer com tecidos adjacentes. Métodos: Foi realizado um estudo prospectivo randomizado comparando 40 pacientes distribuídos em dois grupos. No grupo I, foram utilizadas artérias radiais esqueletizadas (20 pacientes), e no grupo II, artérias radiais com tecidos adjacentes (20 pacientes). Após o procedimento cirúrgico, os pacientes foram submetidos a medidas da velocidade de fluxo. Resultados: As principais variáveis cirúrgicas foram: diâmetro interno, comprimento e fluxo sanguíneo livre da AR. Os diâmetros médios dos enxertos de AR calculados através de angiografia quantitativa no pós-operatório imediato foram semelhantes, assim como as variáveis de medidas de velocidade de fluxo. Por outro lado, a cinecoronariografia mostrou a presença de oclusão em um enxerto de AR e estenose em cinco enxertos de AR no GII, enquanto que apenas um caso de estenose em um enxerto de AR no GI (p = 0,045). Conclusão: Os resultados mostram que tanto as características morfológicas e anatomopatológicas quanto o desempenho hemodinâmico dos enxertos livres de artéria radial, quer preparados de forma esqueletizada ou com tecidos adjacentes, são semelhantes. Entretanto, pode-se observar um maior número de lesões não obstrutivas quando a AR é preparada com tecidos adjacentes.

Background: Radial artery (RA) was the second arterial graft introduced in clinical practice for myocardial revascularization. The skeletonization technique of the left internal thoracic artery (LITA) may actually change the graft's flow capacity with potential advantages. This leads to the assumption that the behavior of the RA, as a coronary graft, is similar to that of the LITA, when skeletonized. Objective: This study evaluated 'free' aortic-coronary radial artery (RA) grafts, whether skeletonized or with adjacent tissues. Methods: A prospective randomized study comparing 40 patients distributed into two groups was conducted. In group I, we used skeletonized radial arteries (20 patients), and in group II, we used radial arteries with adjacent tissues (20 patients). After the surgical procedure, patients underwent flow velocity measurements. Results: The main surgical variables were: RA internal diameter, RA length, and free blood flow in the radial artery. The mean RA graft diameters as calculated using quantitative angiography in the immediate postoperative period were similar, as well as the flow velocity measurement variables. On the other hand, coronary cineangiography showed the presence of occlusion in one RA graft and stenosis in five RA grafts in GII, while GI presented stenosis in only one RA graft (p = 0.045). Conclusion: These results show that the morphological and pathological features, as well as the hemodynamic performance of the free radial artery grafts, whether prepared in a skeletonized manner or with adjacent tissues, are similar. However, a larger number of non-obstructive lesions may be observed when RA is prepared with adjacent tissues.

FUNDAMENTO: Escores de risco apresentam dificuldades para obter o mesmo desempenho em diferentes populações. OBJETIVO: Criar um modelo simples e acurado para avaliação do risco nos pacientes operados de doença coronariana e/ou valvar no Instituto do Coração da Universidade de São Paulo (InCor-HCFMUSP). MÉTODOS: Entre 2007 e 2009, 3.000 pacientes foram operados consecutivamente de doença coronariana e/ou valvar no InCor-HCFMUSP. Desse registro, dados de 2/3 dos pacientes foram utilizados para desenvolvimento do modelo (técnica de bootstrap) e de 1/3 para validação interna do modelo. O desempenho do modelo (InsCor) foi comparado aos complexos 2000 Bernstein-Parsonnet (2000BP) e EuroSCORE (ES). RESULTADOS: Apenas 10 variáveis foram selecionadas: Idade > 70 anos; sexo feminino; cirurgia de revascularização coronariana + valva; infarto de miocárdio < 90 dias; reoperação; tratamento cirúrgico da valva aórtica; tratamento cirúrgico da valva tricúspide; creatinina < 2mg/dL; fração de ejeção < 30%; e eventos. O teste de Hosmer Lemeshow para o InsCor foi de 0,184, indicando uma excelente calibração. A área abaixo da curva ROC foi de 0,79 para o InsCor, 0,81 para o ES e 0,82 para o 2000BP, confirmando que os modelos são bons e similares na discriminação. CONCLUSÕES: O InsCor e o ES tiveram melhor desempenho que o 2000BP em todas as fases da validação; pórem o novo modelo, além de se identificar com os fatores de risco locais, é mais simples e objetivo para a predição de mortalidade nos pacientes operados de doença coronariana e/ou valvar no InCor-HCFMUSP.

BACKGROUND: Risk scores show difficulties to attain the same performance in different populations. OBJECTIVE: To create a simple and accurate risk assessment model for patients submitted to surgery due to coronary and/or valvular disease at Instituto do Coração da Universidade de São Paulo (InCor-HCFMUSP). METHODS: Between 2007 and 2009, 3,000 patients were submitted to surgical procedure due to coronary artery and/or valvular disease at InCor-HCFMUSP. From this record, data of 2/3 of the patients were used for model development (bootstrap technique), and 1/3 for internal validation of the model. The performance of the model (InsCor) was compared to the 2000 Bernstein-Parsonnet (2000BP) and EuroSCORE (ES) complexes. RESULTS: Only 10 variables were selected: age > 70 years, female sex; coronary revascularization + valve, myocardial infarction < 90 days; reoperation; surgical treatment of aortic valve; surgical treatment of tricuspid valve; creatinine < 2mg/dL; ejection fraction < 30%, and events. The Hosmer Lemeshow test for the InsCor was 0.184, indicating excellent calibration. The area under the ROC curve was 0.79 for the InsCor, 0.81 for the ES and 0.82 for 2000BP, confirming that the models are good and have similar discrimination. CONCLUSIONS: The InsCor and ES performed better than 2000BP at all stages of validation, but the new model, in addition to showing identification with the local risk factors, is simpler and more objective for mortality prediction in patients undergoing surgery due to coronary and/or valvular disease at InCor-HCFMUSP.