Late cardiotoxicity after bolus versus infusion anthracycline therapy for childhood cancers

OBJECTIVE: To compare the long-term myocardial function of patients who had been treated with infusion anthracycline therapy (administered continuously over >24 hr, IG) versus bolus therapy (administered over <30 min, BG). METHODS: We selected 25 patients (BG) and 19 patients (IG) who had three or more years of disease free survival. We evaluated the echocardiograms for left ventricular shortening fraction (SF) obtained at baseline, within one year after the end of therapy (early follow-up), and on long-term follow-up. RESULTS: The mean anthracycline dose in the BG was 385 mg/m(2) and in the IG was 345 mg/m(2) (P = 0.07). During therapy, one patient in BG and none in IG developed diminished SF. During early follow-up, five of the 22 patients in BG and one of the 17 patients in IG developed diminished SF (P = 0.2). Of these five patients with diminished SF, three patients in BG and none in IG continued to have abnormally low SF long-term. At mean of 7 years, five of the 25 patients in BG and two of the 19 in IG had diminished SF on (P = 0.7). Late left ventricular dilatation was seen in 8% in BG and 5% in IG (P = 1.0). CONCLUSIONS: At mean of 7 years after end of therapy, diminished cardiac function was seen in 20% of the patient who had received bolus anthracycline compared to 11% of patients who had received it via infusion. This difference did not prove to be statistically significant.