Dynamic 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.
Cardiomyoplasty; Heart failure; Heart failure; Cardiomyopathies