B-type natriuretic peptide as a marker for cardiac dysfunction in anthracycline-treated children.
BACKGROUND
Anthracyclines (AC) are useful antineoplastic agents, whose utility is limited by progressive cardiotoxicity. Our purpose was to evaluate plasma B-type natriuretic peptide (BNP), as a screening test for detecting late cardiac dysfunction in AC-treated children and to determine the prevalence of late cardiac dysfunction at low cumulative AC doses.


MATERIALS AND METHODS
This was a prospective study in which patients who had completed AC therapy at least 1 year earlier, underwent a detailed echocardiogram and a simultaneous BNP level. Cardiac dysfunction was defined as any one of the following: shortening fraction (FS) <29%, rate corrected velocity of circumferential fiber shortening (VCFc) <0.9 c x sec(-1), end systolic wall stress (ESWS) >60 g x cm(-2), abnormal VCFc: ESWS ratio or decreased mitral inflow velocity (E/A) ratios, compared to age-specific norms.


RESULTS
The cohort (n = 63) included 37 males with a median age of 13.1 years (range, 6.5-26.5 years). Cardiac dysfunction was found in 26 (41%) patients and in 40% of patients who received cumulative doses <150 mg x m(-2). ESWS was the most common abnormality. Mean BNP levels in the subset with abnormal function were significantly higher than the normal group (23.4 +/- 25.3 vs. 14.2 +/- 8.9 pg x ml(-1), P = 0.02).


CONCLUSIONS
Plasma BNP was significantly elevated in AC-treated patients with late cardiac dysfunction, although there was considerable overlap of levels between groups with and without cardiac dysfunction. BNP may need further evaluation as a serial index of cardiac function in this population. Cardiac dysfunction was observed in a significant proportion of patients, even at low cumulative AC doses.