ProANP and NT-proBNP levels to prospectively assess cardiac function in breast cancer patients treated with cardiotoxic chemotherapy

BackgroundCardiac function impairment is a known side effect of epirubicin-based chemotherapy. Activation of natriuretic peptides is demonstrated in patients with heart failure.AimsTo identify prospectively the cardiotoxic profile of epirubicin-based chemotherapy in breast cancer patients and to evaluate the sensitivity of proANP and NT-proBNP as early biochemical markers of cardiac dysfunction.MethodsForty cancer patients divided in two nonrandomized groups received either epirubicin and paclitaxel (Group A, n = 26) or mitoxantrone and docetaxel (Group B, n = 14). Control groups, Group C (n = 13) and Group D (n = 20), consisted of female patients with heart failure and healthy women respectively. Natriuretic peptides and LVEF were determined in all patients.ResultsA statistically significant difference was recorded regarding LVEF before and after treatment in Group A patients (p = 0.0001). Three patients had a significant LVEF decline between 10% and 18% from baseline values, while three reached an LVEF value below 50%. All of them presented an increase in proANP and NT-proBNP values (mean increase 270.31 ± 124 fmol/ml and 303.57 ± 108 fmol/ml, respectively). A significant correlation between the increase in plasma proANP (r = 0.8, p < 0.0001), as well as NT-proBNP (r = 0.7, p < 0.0001) and the decrease in LVEF was observed. Regarding Group A, levels of proANP increased from 192.25 fmol/ml before treatment to 287.84 fmol/ml after treatment (p = 0.0001), whereas NT-proBNP increased from 152.50 to 242 fmol/ml (p < 0.0001) respectively. During follow up, two Group A patients developed congestive heart failure twelve and fourteen months after the completion of chemotherapy respectively. A significant LVEF decline was recorded in both patients during the episode. Regarding Group B, no statistically significant differences were demonstrated.ConclusionProANP and NT-proBNP levels might be used as reliable and sensitive markers in the detection of early cardiac impairment caused by epirubicin-based chemotherapy.