Natriuretic peptides as markers of cardiotoxicity during doxorubicin treatment for non‐Hodgkin's lymphoma

Thirty adult patients with non-Hodgkin's lymphoma who were planned to receive up to 8-10 cycles of CHOP (cyclophosphamide, doxorubicin, vincristine and prednisolone) to a cumulative doxorubicin dose of 400-500 mg/m2 were studied to evaluate the value of serial plasma atrial natriuretic peptide (ANP), N-terminal pro-ANP (NT-proANP) and brain natriuretic peptide (BNP) measurements in the early detection of doxorubicin-induced left ventricular dysfunction. Plasma levels of natriuretic peptides were measured before every treatment course and 4 wk after the last one. Cardiac function was monitored with serial radionuclide ventriculography. Twenty-eight patients were evaluable for cardiotoxicity. Clinical heart failure developed in 2 patients (7%). Left ventricular ejection fraction (LVEF) decreased from 58.0+/-1.3% to 49.6+/-1.7% (p <0.001). Plasma levels of ANP increased from 16.4+/-1.3 pmol/l to 22.7+/-2.4 pmol/l (p= 0.002), NT-proANP from 288+/-22 to 380+/-42 pmol/l (p = 0.019) and BNP from 3.3+/-0.4 to 8.5+/-2.0 pmol/l (p = 0.020). There was a significant correlation between the increase in plasma ANP and the decrease in LVEF (r = -0.447, p = 0.029), and a trend towards significance between the increase in NT-proANP and the decrease in LVEF (r=-0.390, p=0.059). The decrease in LVEF started very early and could already be seen after the cumulative doxorubicin dose of 200 mg/m2, whereas the increase in plasma natriuretic peptides was not evident until the cumulative doxorubicin dose of 400 mg/m2. Our results show that neuroendocrine activation - increased concentrations of plasma natriuretic peptides - occurs when left ventricular function has reduced substantially and its compensatory capacity has been exceeded resulting in atrial and ventricular overload. Thus, serial natriuretic peptide measurements cannot be used in predicting the impairment of left ventricular function. On the other hand, our study suggests that natriuretic peptides are useful in the detection of subclinical left ventricular dysfunction in patients receiving doxorubicin therapy.