Brazilian Journal of Cardiovascular Surgery (Mar 1995)
Evolução clínica e comportamento da função ventricular no pós-operatório tardio da cardiomioplastia Clinical and ventricular function in the late follow-up of dynamic cardiomyoplasty
Abstract
A cardiomioplastia tem sido proposta, como uma alternativa ao transplante cardíaco, no tratamento de pacientes com insuficiência miocárdica em fase avançada. O objetivo deste trabalho é estudar a evolução clínica e o comportamento da função ventricular no pós-operatório tardio desse procedimento em 34 pacientes portadores de cardiomiopatia dilatada, que foram operados no período de maio de 1988 a setembro de 1994. Vinte e sete pacientes estavam em classe funcional III e 7 pacientes em classe IV no preoperatorio, apesar do uso de terapêutica clínica otimizada. A mortalidade hospitalar foi de 2,9% e 1 paciente que evoluiu em choque cardiogênico foi submetido a transplante cardíaco 42 dias após a cardiomioplastia. O tempo de seguimento pós-operatório variou entre 2 e 73 meses, com média de 27,4 meses. Aos 6 meses de pós-operatório, 12 pacientes estavam em classe funcional 1,15 pacientes em classe 11 e 3 pacientes em classe III (p=0,001) em relação ao pré-operatório. Quatorze pacientes faleceram até 5 anos de pós-operatório e os índices de sobrevida foram 84,7% em 1 ano, 67,7% em 2 anos e 39,6% aos 5 anos de seguimento, sendo que, em 9 pacientes, os óbitos ocorreram por progressão da insuficiência cardíaca, e 5 pacientes faleceram subitamente. A análise de regressão de Gox mostrou que a mortalidade nos pacientes operados em classe funcional IV foi 5,5 vezes maior do que nos pacientes operados em classe III (p=0,006), cuja sobrevida foi de 52,7% aos 5 anos de pós-operatório. O estudo sistemático da função ventricular através da angiografia com radioisótopos, da ecocardiografia com Doppler e do cateterismo cardíaco direito documentou a melhora da fração de ejeção do ventrículo esquerdo (V E) de 19,8 ± 3 para 23,9 ± 7,2% (pDynamic cardiomyoplasty has been proposed as an alternative to heart transplantation in the treatment of severe cardiomyopathies. In this investigation, its results were investigated in 34 patients with idiopathic dilated cardiomyopathy submitted to this procedure from May 1988 to September 1994. Twenty seven patients were in New York Heart Association functional class III and 7 were in class IV before the operation, despite the use of maximal medical therapy. Hospital mortality was 2.9% and 1 patient presenting heart failure progression was submitted to urgent heart transplantation 42 days after cardiomyoplasty. The other patients were followed-up from 2 to 73 months (mean, 27.4 months). At 6 months of follow-up, 12 patients were in functional class 1,15 patients in class II and 3 patients in class III (p=0.001, in relation to preoperative data). Similar findings were observed from one to four years of follow-up. On the other hand, 14 patients died up to 5 years after the operation and the survival rates were 84.7% at 1 year, 67.7% at 2 years and 39.9% at 5 years of follow-up. The cause of death was progression of heart failure in 9 patients and 5 patients died suddenly. By stepwise Cox regression method, patients operated in functional class IV had relative risk of death 5.5 times higher than class III patients (p=0.006), whose survival rate was 52.7% at 5 years of followup. Regarding cardiomyoplasty influence on ventricular function, radioisotopic left ventricular (LV) ejection fraction improved from 19.8 + 3.1% to 23.6 + 6.2%, at 6 months of follow-up. Doppler-echocardiography documented similar changes in LV wall shortening. Also, right heart catheterization showed significant increases in mean arterial pressure, stroke index and LV stroke work index, which were associated with the decrease of mean pulmonary wedge pressure. On the other hand, it was not found any significant postoperative change in ventricular arrhythmia and atrial fibrillation incidence. At the late postoperative period, the hemodynamic improvement was maintained up to 5 years of follow-up, while LV ejection fraction and wall shortening tended to decrease after the second postoperative year returned to the preoperative levels. Finally, 3 of the 5 patients who completed 5 years of follow-up died due to heart failure progression and other died suddenly up to 73 months after the operation. Furthermore, histological examinations showed important fat tissue infiltration in the skeletal muscle flap of 9 patients submitted to necropsy studies from 20 to 73 months of follow-up. These histological changes were more severe in patients with longer follow-up. In conclusion, dynamic cardiomyoplasty improves congestive heart failure and LV function in patients with idiopathic dilated cardiomyopathy. However, long-term survival after this procedure is limited in patients operated upon in functional class IV. Furthermore, the cardiomyoplasty benefits on left ventricular function appear to be limited to a midterm period and this fact may be associated with late muscle flap degeneration.
