Surgical support to the failing heart has been investigated in the treatment of severe myocardial failure. Dynamic cardiomyoplasty was indicated in 32 patients with dilated or chagasic cardiomyopathy who were in New York Heart Association (NYHA) class III or IV despite maximum medical therapy. Fifteen patients were operated on, and 17 refused the surgical treatment and were maintained by clinical means. With an average follow-up period of 12.3 months, actuarial survival rates for cardiomyoplasty patients were 86.6% at 6 months, 78.7% at 1 year, and 65.6% at 2 years of follow-up, whereas patients under medical therapy presented survival rates of 58.8%, 41.1%, and 27.4% at the same periods, respectively (p = 0.03). Furthermore, five of the 11 surviving patients of the cardiomyoplasty group are in NYHA class I, five in class II, and one in class III. At 6 months of cardiomyoplasty follow-up, rest radioisotopic left ventricular ejection fraction increased from 20.1 +/- 3.9% to 26.8 +/- 7.5% (p less than 0.01). Cardiopulmonary exercise testing showed that maximum oxygen consumption during treadmill testing improved from 14.7 +/- 3.9 to 18.3 +/- 3.9 ml/kg/min (p = 0.01). At 1 year of follow-up, these data remained essentially unchanged. In conclusion, dynamic cardiomyoplasty reverses congestive heart failure and improves the long-term survival of patients with severe cardiomyopathies.