RESUMO
BACKGROUND: Myocardial infarction might result in dilated left ventricle and numerous techniques have been described to restore the original left ventricle shape and identify tools for late survival assessment. The aim of this study is to compare our experience with a modified Dor procedure using a rigid prosthesis to the septal anterior ventricular exclusion procedure (SAVE) for left ventricle restoration. The EuroScore index for prediction of late follow up survival was evaluated. METHODS: We evaluated 80 patients who underwent left ventricle restoration between 1999 to 2007 and eight patients were excluded with incomplete data. A modified Dor procedure with rigid prosthesis (MD group) was performed on 53 patients and 19 underwent the septal anterior ventricular exclusion procedure (SAVE group). The patients were classified according their left ventricle shape as type I, II or III. Kaplan-Meier and Cox proportional hazard ratio regressions analysis were performed to assess survival after both techniques and expected surgical mortality using EuroScore index ranking after 12 years of follow up. RESULTS: The operative mortality was comparable in both groups ranked by EuroScore index. The groups were comparable for all clinical data, except the MD group had more patients using intra-aortic balloon pumps before surgery, (5.7% vs. 0; P<0.01). Kaplan Meier analysis by left ventricle shape showed comparable survival for all patients, with slightly higher survival for type I. Kaplan Meier analysis of all death showed equivalent survival curves for both techniques after 12 years of follow up (71.5 ± 12.3 vs. 46.6 ± 20.5 years; P=0.08). Kaplan Meier analysis of EuroScore index for all patients showed a difference between the three ranked categories, i.e., 0 to 10%, 11 to 49% and higher than 50% expected surgical mortality after 12 years of follow up (70.9 ± 16.2 vs. 67.5 ± 12.7 vs. 53.0 ± 15.5; P=0.003). CONCLUSION: The MD procedure showed consistent ejection fraction improvements after long term follow up. Survival was comparable for all ventricular types and for the MD and SAVE procedures. The EuroScore index is a useful index for late survival assessment of ventricular restoration techniques.
Assuntos
Bioprótese , Procedimentos Cirúrgicos Cardíacos/métodos , Próteses Valvulares Cardíacas , Ventrículos do Coração/cirurgia , Remodelação Ventricular , Animais , Procedimentos Cirúrgicos Cardíacos/mortalidade , Bovinos , Métodos Epidemiológicos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , PericárdioRESUMO
BACKGROUND: Myocardial infarction might result in dilated left ventricle and numerous techniques have been described to restore the original left ventricle shape and identify tools for late survival assessment. The aim of this study is to compare our experience with a modified Dor procedure using a rigid prosthesis to the septal anterior ventricular exclusion procedure (SAVE) for left ventricle restoration. The EuroScore index for prediction of late follow up survival was evaluated. METHODS: We evaluated 80 patients who underwent left ventricle restoration between 1999 to 2007 and eight patients were excluded with incomplete data. A modified Dor procedure with rigid prosthesis (MD group) was performed on 53 patients and 19 underwent the septal anterior ventricular exclusion procedure (SAVE group). The patients were classified according their left ventricle shape as type I, II or III. Kaplan-Meier and Cox proportional hazard ratio regressions analysis were performed to assess survival after both techniques and expected surgical mortality using EuroScore index ranking after 12 years of follow up. RESULTS: The operative mortality was comparable in both groups ranked by EuroScore index. The groups were comparable for all clinical data, except the MD group had more patients using intra-aortic balloon pumps before surgery, (5.7 percent vs. 0; P<0.01). Kaplan Meier analysis by left ventricle shape showed comparable survival for all patients, with slightly higher survival for type I. Kaplan Meier analysis of all death showed equivalent survival curves for both techniques after 12 years of follow up (71.5 ± 12.3 vs. 46.6 ±20.5 years; P=0.08). Kaplan Meier analysis of EuroScore index for all patients showed a difference between the three ranked categories, i.e., 0 to 10 percent, 11 to 49 percent and higher than 50 percent expected surgical mortality after 12 years of follow up (70.9 ± 16.2 vs. 67.5 ± 12.7 vs. 53.0 ± 15.5; P=0.003). CONCLUSION: The MD procedure showed consistent ejection fraction improvements after long term follow up. Survival was comparable for all ventricular types and for the MD and SAVE procedures. The EuroScore index is a useful index for late survival assessment of ventricular restoration techniques.
INTRODUÇÃO: O infarto do miocárdio pode levar à dilatação do ventrículo esquerdo e numerosas técnicas têm sido descritas para remodelar o ventrículo ao seu formato original. O objetivo deste estudo foi comparar nossa experiência com a cirurgia de Dor modificada, usando prótese rígida, com a técnica de exclusão septal ventricular anterior (SAVE). Foi avaliado também o EuroScore como índice preditivo da mortalidade tardia. MÉTODOS: Avaliamos 80 pacientes que foram submetidos a remodelamento ventricular entre 1997 e 2007. Oito pacientes foram excluídos por dados incompletos. A cirurgia de Dor modificada (grupo MD) foi constituída por 53 pacientes e 19 no grupo com exclusão septal anterior (grupo SAVE). Os pacientes foram classificados de acordo com o formato do ventrículo como tipo I, II ou III. Curvas de sobrevivência de Kaplan-Meier e regressão de Cox foram utilizadas para analisar a sobrevida nas duas técnicas e a mortalidade esperada foi avaliada utilizando o EuroScore para a mortalidade operatória e após 12 anos de seguimento. RESULTADOS: A mortalidade operatória foi comparável nos dois grupos quando avaliados pelo EuroScore. Os grupos foram comparáveis quanto a dados clínicos, com exceção, que o grupo MD apresentava maior número de pacientes com balão intra-aórtico no pré-operatório (5,7 por cento vs. 0; P<0,01). A curva actuarial considerando o formato dos ventrículos foi comparável avaliando-se todos os pacientes, sendo que o formato tipo I apresentou discreta melhor sobrevida após 12 anos de seguimento. As técnicas MD e SAVE demonstraram sobrevidas semelhantes após 12 anos de seguimento (71,5 ± 12,3 vs. 46,6 ±20,5 por cento; P=0,08). Avaliando o EuroScore para todos os pacientes, observamos que nas categorias utilizadas, ou seja, 0-10 por cento; 11-49 por cento e maior que 50 por cento de mortalidade esperada, a sobrevida após 12 anos de seguimento foi diferente (70,9 ± 16,2 vs. 67,5 ± 12,7 vs. 53,0 ± 15,5; P=0,003). CONCLUSÃO: A técnica MD demonstrou melhora consistente da fração de ejeção no seguimento tardio. As duas técnicas apresentaram sobrevida comparáveis. O EuroScore pode ser um índice útil para avaliação da sobrevida tardia.
Assuntos
Animais , Bovinos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Bioprótese , Procedimentos Cirúrgicos Cardíacos/métodos , Próteses Valvulares Cardíacas , Ventrículos do Coração/cirurgia , Remodelação Ventricular , Procedimentos Cirúrgicos Cardíacos/mortalidade , Métodos Epidemiológicos , PericárdioRESUMO
BACKGROUND: Heart failure is a common and often fatal disease. Numerous animal models are used to study its aetiology, progression and treatment. This article aims to demonstrate two minimally invasive models of congestive heart failure in a rabbit model and a precise method to assess cardiac performance. METHODS: Fifty New Zealand White rabbits underwent cervicotomy incision and were then divided into three groups. Aortic regurgitation (AR group) was induced in 17 animals by catheter lesion through the right carotid artery, proximal aortic constriction (AC group) was created in 17 animals by metallic clip placement in the ascending aorta through a neck incision, while 16 animals served as controls (CO group). Eight weeks later, myocardial function and contractility indices were assessed by sonomicrometry crystals. Hearts were then collected for morphometric measurements and left ventricular tissues were subjected to immunohistochemical analysis of fibrosis, necrosis and apoptosis. Statistical analysis was by analysis of variance (ANOVA) with a Dunnett's post hoc test or by Kruskal-Wallis test with Dunn's post hoc test as appropriate, with significance at p< or =0.05. RESULTS: The model of aortic regurgitation indicated early stages of heart failure by volume overload with increased end-diastolic and end-systolic volumes, stroke volume, cardiac output and pressure-volume loop areas. The elastance was higher in the control group compared with that in the AC and AR groups (131.00+/-51.27 vs 88.77+/-40.11 vs 75.29+/-50.70; p=0.01). The preload recruitable stroke work was higher in the control group compared with that in the AC and AR groups (47.70+/-14.19 vs 33.87+/-7.46 vs 38.58+/-9.45; p=0.01). Aortic constriction produced left ventricular concentric hypertrophy. Fibrosis appeared in both heart failure models and was elevated by aortic constriction when compared with that in controls. Necrosis and apoptosis indices were very low in all the groups. Clinical signs of congestive heart failure were not present. CONCLUSIONS: The two heart failure models we describe were relatively simple to create and maintain, minimally invasive, accurate, inexpensive and, importantly, had a low mortality rate. These models rapidly induced deterioration of contractility indices and onset of fibrosis, the hallmarks of early myocardial dysfunction associated with heart failure. Sonomicrometry assessments were able to detect early contractility changes prior to clinical signs.