Evaluation of biomarkers for cardiotoxicity of anthracyclin-based chemotherapy.

Introduction: The clinical assessment of the myocardial damage caused by anthracyclin (ANT)-therapy is difficult. Therefore a study was performed to evaluate non-invasive markers of anthracyclin-induced cardiac effects, with emphasis on course-to-course variation.
Methods: Eligible for study participation were patients, without known cardiologic abnormalities who did not use cardiotoxic medication (except for ANT-therapy), who had previously completed at least three cycles of anthracyclin-containing chemotherapy (n = 14) and patients who were ANT-naïve and who were scheduled to receive doxorubicin-containing chemotherapy (n = 12). Seven patients in this last group also completed at least three cycles and were available for follow-up assessments; thus a total population of 21 patients (12F/9M) completed at least three courses ANT-chemotherapy. In these patients blood samples and ECG-recordings were taken within 6 months after completion of ANT-therapy. In 12 patients (10F/2M) assessments were also done before, immediately afterwards and at 24 h after each course of ANT.
Results and Conclusions: In the patients who completed chemotherapy, NT-proBNP was 277% (n = 21; 95% CI: 86-661%, P < 0.001) higher compared to healthy volunteers. During the first course NT-proBNP rose 269% (n = 12; 167-409%, P < 0.0001) at 24 h post-administration. The linear corrected QT (QTcL) directly after the first administration of ANT increased by 9.56 ms (n = 12; 3.85-15.27, P < 0.001) and this prolongation was still present at 24 h, 11.48 ms (n = 12; 5.61-17.34, P < 0.0001). Both NT-proBNP and QTcL returned to baseline before the start of the next course and a similar pattern was observed during each course. NT-proBNP and QTcL may be useful markers for course-to-course evaluation of anthracyclin-induced cardiotoxicity.