Exercise assessment of cardiac function in children and young adults before and after bone marrow transplantation

Cardiac toxicity is a potential complication of bone marrow transplantation because recipients frequently receive cardiotoxic chemotherapy and/or irradiation before transplantation. Most studies indicate that transient cardiac toxicity occurs within weeks of transplantation, but few studies have evaluated either cardiac status before or late after transplantation. Cardiac performance was assessed via cycle ergometry in 20 children and young adults before transplantation and 31 other children and young adults after transplantation. Mean survival time in the group post-transplantation was 3.9 years with a range of 11 months to 12.1 years. Left ventricular size and shortening fraction at rest were assessed via echocardiography. Data were compared to those of 70 healthy subjects from our laboratory. Patients before and after transplantation had normal oxygen consumptions and cardiac indices at rest. During exercise, however, patients treated for cancer both before and after bone marrow transplantation had reduced exercise times, reduced maximal oxygen consumptions, and reduced ventilatory anaerobic thresholds. Cardiac reserve, as judged by the response of the cardiac output during exercise, was reduced severely. There were no significant differences between the groups tested before and after transplantation. Patients who had been treated for aplastic anemia, who had received less intensive therapy before transplantation, performed significantly better than did patients treated for cancer. Despite these findings, only four patients had abnormalities by echocardiography. In conclusion, before transplantation patients with oncologic diagnoses had serious limitations in exercise performance, most likely as a result of the effects of the cardiotoxic therapy given as part of their conventional cancer therapy. Long-term survivors of bone marrow transplantation also had similar abnormalities.(ABSTRACT TRUNCATED AT 250 WORDS)