Diffuse myocardial fibrosis by T1-mapping in children with subclinical anthracycline cardiotoxicity: relationship to exercise capacity,cumulative dose and remodeling |
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Authors: | Edythe B Tham Mark J Haykowsky Kelvin Chow Maria Spavor Sachie Kaneko Nee S Khoo Joseph J Pagano Andrew S Mackie Richard B Thompson |
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Affiliation: | 1.Department of Pediatrics, Stollery Children’s Hospital, University of Alberta, Edmonton, AB, Canada;2.Faculty of Rehabilitation Medicine, University of Alberta, Edmonton, AB, Canada;3.Department of Biomedical Engineering, University of Alberta, Edmonton, AB, Canada;4.Division of Cardiology, Stollery Children’s Hospital, 4C2 Walter C Mackenzie Centre, 8440-112 Street, Edmonton, AB T6G 2B7, Canada |
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Abstract: | BackgroundThe late cardiotoxic effects of anthracycline chemotherapy influence morbidity and mortality in the growing population of childhood cancer survivors. Even with lower anthracycline doses, evidence of adverse cardiac remodeling and reduced exercise capacity exist. We aim to examine the relationship between cardiac structure, function and cardiovascular magnetic resonance (CMR) tissue characteristics with chemotherapy dose and exercise capacity in childhood cancer survivors.MethodsThirty patients (15 ± 3 years), at least 2 years following anthracycline treatment, underwent CMR, echocardiography, and cardiopulmonary exercise testing (peak VO2). CMR measured ventricular function, mass, T1 and T2 values, and myocardial extracellular volume fraction, ECV, a measure of diffuse fibrosis based on changes in myocardial T1 values pre- and post-gadolinium. Cardiac function was also assessed with conventional and speckle tracking echocardiography.ResultsPatients had normal LVEF (59 ± 7%) but peak VO2 was 17% lower than age-predicted normal values and were correlated with anthracycline dose (r = −0.49). Increased ECV correlated with decreased mass/volume ratio (r = −0.64), decreased LV wall thickness/height ratio (r = −0.72), lower peak VO2(r = −0.52), and higher cumulative dose (r = 0.40). Echocardiographic measures of systolic and diastolic function were reduced compared to normal values (p < 0.01), but had no relation to ECV, peak VO2 or cumulative dose.ConclusionsMyocardial T1 and ECV were found to be early tissue markers of ventricular remodeling that may represent diffuse fibrosis in children with normal ejection fraction post anthracycline therapy, and are related to cumulative dose, exercise capacity and myocardial wall thinning. |
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Keywords: | CT CMR T1 mapping Echocardiography Contractile function Cardiovascular imaging agents/Techniques Exercise testing Cardiac function Cardiovascular magnetic resonance Myocardial fibrosis Speckle tracking echocardiography T1 mapping |
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