Background: Palliative procedures have been proposed for treatment of dilated cardiomyopathies. This study analyzes long-term outcomes of 43 patients who underwent dynamic cardiomyoplasty.
Methods: Patients were in New York Heart Association class III (n = 35) or IV (n = 8) before the procedure. Hospital mortality was 2.2%, and patients were followed for 44 +/- 33 months. Thirty-nine patients completed the skeletal muscle adaptation period, and the muscle flaps were stimulated to contract in concert with every cardiac beat (n = 27) or with every other beat (n = 12).
Results: One-year event-free survival was 81.3% +/- 5.9%; 2-year, 65.1% +/- 7.2%; 5-year, 34.7% +/- 7.2%; and 9-year, 10.8% +/- 5.3%. Causes of late deaths were equally divided between progressive heart failure and arrhythmia-related events. Multivariable Cox proportional hazard regression identified that functional class IV, high pulmonary vascular resistance, and muscle flap stimulation synchronized to every cardiac beat were independent predictors of poor event-free survival. The same factors were associated with the occurrence of progressive heart failure, but none was a predictor of arrhythmia-related deaths. Five-year survival of patients maintained with the muscle flap stimulated at every other cardiac beat was 58.3% +/- 14.2%. Skeletal muscle stimulation protocols also influenced the long-term behavior of left ventricular ejection fraction.
Conclusions: Long-term results of dynamic cardiomyoplasty are limited by the patient's preoperative condition and by a high incidence of sudden cardiac death. These results may be improved using modified skeletal muscle stimulation protocols and cardioverter-defibrillator implantation, while maintaining dynamic cardiomyoplasty as an option for selected patients.