BackgroundChemotherapy with anthracyclines and trastuzumab can cause cardiotoxicity.
Alteration of cardiac adrenergic function assessed by
metaiodobenzylguanidine labeled with iodine-123 (123I-mIBG) seems
to precede the drop in left ventricular ejection fraction.ObjectiveTo evaluate and to compare the presence of cardiovascular abnormalities among
patients with breast cancer undergoing chemotherapy with anthracyclines and
trastuzumab, and only with anthracycline.MethodsPatients with breast cancer were analyzed clinical, laboratory,
electrocardiographic and echocardiographic and cardiac sympathetic activity.
In scintigraphic images, the ratio of 123I-mIBG uptake between
the heart and mediastinum, and the washout rate were calculated. The
variables were compared between patients who received anthracyclines and
trastuzumab (Group 1) and only anthracyclines (Group 2).ResultsTwenty patients, with mean age 57 ± 14 years, were studied. The mean left
ventricular ejection fraction by echocardiography was 67.8 ± 4.0%. Mean
washout rate was 28.39 ± 9.23% and the ratio of 123I-mIBG uptake
between the heart and mediastinum was 2.07 ± 0.28. Of the patients, 82%
showed an increased in washout rate, and the ratio of 123I-mIBG
uptake between the heart and mediastinum decreased in 25%. Concerning the
groups, the mean washout rate of Group 1 was 32.68 ± 9.30% and of Group 2
was 24.56 ± 7.72% (p = 0,06). The ratio of 123I-mIBG uptake
between the heart and mediastinum was normal in all patients in Group 2,
however, the Group 1, showed 50% the ratio of 123I-mIBG uptake
between the heart and mediastinum ≤ 1.8 (p = 0.02).ConclusionIn women with breast cancer undergoing chemotherapy, assessment of cardiac
sympathetic activity with 123I-mIBG appears to be an early marker
of cardiotoxicity. The combination of chemotherapy showed higher risk of
cardiac adrenergic hyperactivity.