Doxorubicin-associated Cardiac Tissue Remodeling Followed by CMR of Myocardial Extracellular Volume and Myocyte Size in Breast Cancer Patients

This prospective cohort study was performed at the State University of Campinas, Brazil. The Institutional Review Board of the State University of Campinas approved the study and all participants provided informed consent. Female patients with breast cancer who received anthracycline (doxorubicin or daunorubicin or epirubicin) as part of their chemotherapy protocol were enrolled in the study.

Detailed medical history, standard anthropometric data, and measurement hemogram, troponin, CKMB, cholesterol, serum glucose, CRP and biomarkers were obtained.

As in adults, chronic anthracycline-related cardiotoxicity typically presents early, within one year after termination of chemotherapy and the peak time for the appearance of symptoms of heart failure is about three months after the last anthracycline dose, patients underwent CMR before and three times serially after DOX (two, five and twelve months).

Patients were imaged in supine position in a 3T magnet (Achieva, Philips Medical Systems, Best, The Netherlands). The CMR protocol consisted of electrocardiographically gated cine imaging with steady state free-precession to assess left ventricular (LV) function and LV mass. For imaging of late gadolinium enhancement (LGE) we used an inversion-recovery-prepared, gradient-echo sequence with segmented acquisition, which was triggered every other heartbeat. LGE images were acquired during end-expiratory breath-holding for slices matching the slice locations for cine imaging, starting within 10 min after bolus administration of a cumulative dose of 0.2 mmol/Kg of gadoterate meglumine (Dotarem, Guerbet, Aulnay-sous-Bois, France). T1 was performed with a Look-Locker sequence with a non-slice-selective adiabatic inversion pulse, followed by segmented gradient-echo acquisition for 17 times after inversion, covering approximately two cardiac cycles. The Look-Locker sequence was performed in a single short-axis slice at the level of the mid left ventricle. T1 imaging was repeated in the same LV short-axis slice, once before and five to seven times after the injection of gadolinium to cover an approximately 30-min period of slow contrast clearance.

All images were analyzed with MASS CMR software (Mass Research, Leiden University Medical Center, Leiden, the Netherlands). For LV mass and function quantification, the endocardial and epicardial borders of the LV myocardium were manually traced on short-axis cine images at end-diastole and systole. Papillary muscles were excluded from LV mass, and LV mass was indexed to body surface area.