Abstract
9536 Background: To evaluate whether clinical signs or symptoms of congestive heart failure, serial assessment of systolic and diastolic cardiac function by low dose dobutamine stress echo (LDSE) and serum cardiac troponin T (cTnT) can predict doxorubicin (DOXO) cardiotoxicity. Methods: Twenty five patients with osteosarcoma enrolled in the Brazilian osteosarcoma treatment group study 2000, from january 2000 to may 2004, were studied with LDSE (>5μg/kg/min) before chemotherapy, 160 mg/m2 DOXO and after 160 mg/m2 DOXO. cTnT were measured before and during DOXO infusion. Cardiotoxicity was defined as shortening fraction (SF) less than 30% assessed by rest echo 1 to 6 months off chemotherapy. Group A comprised those without cardiotoxicity (16 patients, 10 male, 14.3 ± 4.7 years) whereas group B included those with a SF < 30% (9 patients, 6 male, 15.4 ± 3 years). Elevated serum cTnT was defined as seric levels above 0.01ng/ml. Results: Patients were submitted to a mean 3.4 LDSE and a mean of 32.5 serum cTnT. One patient (group B) presented clinical manifestation of cardiotoxicity. There was no statistical difference of elevated serum cTnT between the group B and group A (87.5% vs 46.2%; p=0,06). Left ventricular dimensions by M- MODE and transmitral Doppler inflow diastolic parameters were not significantly different between the two groups. Resting SF showed comparable values in both groups until cumulative doses of DOXO reached 160mg/m2, then the resting SF in group B was significant lower than group A (27% ± 2 and 34.1% ± 2, p<0.01). During dobutamine infusion, SF and ΔSF (dobutamine-rest) were significantly lower in group B as compared to group A at a DOXO dose 160mg/m2 (SF 36.1%±3,4 and ΔSF 2.1±2.3 vs. SF 45.2%±4.9 and ΔSF 9.4±3; p< 0.01 and p < 0.01) as well as at a DOXO dose > 160mg/m2 (30.3%±3 and 3.1±1.9 vs. 40.8%±5.9 and 7.2±4.2;p<0.01 and p<0.01). Conclusions: This study suggests that LDSE is more reliable than cTnT and clinical evaluation for predicting future subclinical cardiotoxicity,even at lower doxorubicin dose. No significant financial relationships to disclose.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have