Open Access Highly Accessed Research

Early detection of doxorubicin myocardial injury by ultrasonic tissue characterization in an experimental animal model

Minna Moreira Dias Romano1, Antônio Pazin-Filho2, João Lucas O’Connel1, Marcus Vinícius Simões1, André Schmidt1, Érica C Campos3, Marcos Rossi3 and Benedito Carlos Maciel14*

Author Affiliations

1 Divisions of Cardiology, Medical School of Ribeirão Preto, University of São Paulo, São Paulo, Brazil

2 Divisions of Cardiology and Clinical Emergencies, Medical School of Ribeirão Preto, University of São Paulo, São Paulo, Brazil

3 Department of Internal Medicine, Departament of Pathology, Medical School of Ribeirão Preto, University of São Paulo, São Paulo, Brazil

4 Division of Cardiology, Department of Internal Medicine, Medical School of Ribeirão Preto, 14048-900, Ribeirão Preto, SP, Brazil

For all author emails, please log on.

Cardiovascular Ultrasound 2012, 10:40  doi:10.1186/1476-7120-10-40

Published: 10 October 2012

Abstract

In the clinical setting, the early detection of myocardial injury induced by doxorubicin (DXR) is still considered a challenge. To assess whether ultrasonic tissue characterization (UTC) can identify early DXR-related myocardial lesions and their correlation with collagen myocardial percentages, we studied 60 rats at basal status and prospectively after 2mg/Kg/week DXR endovenous infusion. Echocardiographic examinations were conducted at baseline and at 8,10,12,14 and 16 mg/Kg DXR cumulative dose. The left ventricle ejection fraction (LVEF), shortening fraction (SF), and the UTC indices: corrected coefficient of integrated backscatter (IBS) (tissue IBS intensity/ phantom IBS intensity) (CC-IBS) and the cyclic variation magnitude of this intensity curve (MCV) were measured. The variation of each parameter of study through DXR dose was expressed by the average and standard error at specific DXR dosages and those at baseline. The collagen percent (%) was calculated in six control group animals and 24 DXR group animals. CC-IBS increased (1.29±0.27 x 1.1±0.26-basal; p=0.005) and MCV decreased (9.1± 2.8 x 11.02±2.6-basal; p=0.006) from 8 mg/Kg to 16mg/Kg DXR. LVEF presented only a slight but significant decrease (80.4±6.9% x 85.3±6.9%-basal, p=0.005) from 8 mg/Kg to 16 mg/Kg DXR. CC-IBS was 72.2% sensitive and 83.3% specific to detect collagen deposition of 4.24%(AUC=0.76). LVEF was not accurate to detect initial collagen deposition (AUC=0.54). In conclusion: UTC was able to early identify the DXR myocardial lesion when compared to LVEF, showing good accuracy to detect the initial collagen deposition in this experimental animal model.

Keywords:
Doxorubicin; Ultra-sonic tissue characterization; Echocardiography; Rats