Long-term prospective follow-up study of cardiac function after cardiotoxic therapy for malignancy in children.

Abstract

To evaluate cardiac function by means of conventional and three-dimensional echocardiography (3DE) and measurement of natriuretic peptides in children and adolescents previously treated for childhood malignancy using individual follow-up data and matched control children as reference criteria. Thirty-nine survivors of childhood malignancy were examined in 1994 and 1998. The mean time from the diagnosis was 8.6 (3.9 to 16.8) years and between cardiac evaluations was 4.1 (3.3 to 5.1) years. Patients were divided into two groups according to therapies given (group I (n = 30): no cardiac irradiation, median cumulative anthracycline dose 210 mg/m2; group II (n = 9): irradiation in the cardiac region, median cumulative anthracycline dose 180 mg/m2). Fractional shortening (FS) in 1994 was higher than in 1998 (32.5 +/- 4.3 vs. 30.3% +/- 3.3%, P =.009). 33% of patients in group I and 56% in group II in 1994 and 30% of patients in group I and 67% in group II in 1998 had N-terminal of the propeptide-atrial natriuretic peptide (NT-proANP) levels exceeding the 90th percentile of controls. In 1998, both groups (I and II) had lower ejection fraction (EF) measured by 3DE than their matched controls (52.9 +/- 5.2 vs. 58.8% +/- 3.1%, P <.001 and 50.0 +/- 6.6 vs. 60.8% +/- 3.2%, P =.024, respectively). Left atrial maximum volumes/body surface area were smaller in the patients than in controls. B-Type natriuretic peptide values did not differ significantly in either group. Left ventricular contractility decreases slowly even years after cardiotoxic cancer therapy in children. 3DE and NT-proANP measurements are effective methods to evaluate the cardiac function in these patients.