LATE CARDIOTOXICITY AFTER TREATMENT FOR A MALIGNANT BONE-TUMOR

Cardiac function was assessed in longterm survivors of malignant bone tumors who were treated according to Rosen's T-5 or T-10 protocol, bot h including doxorubicin. Thirty-one patients, ages 10-45 years (median age 17.8 years) were evaluated 2.3-14.1 years (median 8.9 years) foll owing completion of treatment. Cumulative doses of doxorubicin were 22 5-550 mg/m(2) (median dose 360). The evaluation consisted of a history , physical examination, electrocardiogram (EGG), signal averaged EGG, 24-hour ambulatory ECC, echocardiography and radionuclide angiography. Eighteen of 31 (58%) patients showed cardiac toxicity, defined as hav ing one or more of the following abnormalities: late potentials, compl ex ventricular arrhythmias, left ventricular dilatation, decreased sho rtening fraction, or decreased ejection fraction. The incidence of car diac abnormalities increased with length of follow-up (P less than or equal to .05). No correlation could be demonstrated between cumulative dose of doxorubicin and cardiac status, except for heart rate variabi lity. When adjusted to body surface area, the left ventricular posteri or wall thickness (LVPW index) was decreased in all patients. The inci dence of doxorubicin-induced cardiotoxicity is high and increases with follow-up, irrespective of cumulative dose. Life-long cardiac follow- up in these patients is warranted. The results of our study suggest th at heart rate variability and LVPW index could be sensitive indicators for cardiotoxicity. (C) 1996 Wiley-Liss, Inc.