Cardiovascular magnetic resonance parametric techniques to characterize myocardial effects of anthracycline therapy in adults with normal left ventricular ejection fraction: a systematic review and meta-analysis.

Background: The cardiotoxic effects of anthracyclines therapy are well recognized, both in the short and long term. Echocardiography allows monitoring of cancer patients treated with this class of drugs by serial assessment of left ventricle ejection fraction (LVEF) as a surrogate of systolic function. However, changes in myocardial function may occur late in the process when cardiac damage is already established. Novel cardiac magnetic resonance (CMR) parametric techniques, like native T1 mapping and extra-cellular volume (ECV), may detect subclinical myocardial damage in these patients, recognizing early signs of cardiotoxicity before development of overt cancer therapy-related cardiac dysfunction (CTRCD) and prompting tailored therapeutic and follow-up strategies to improve outcome.

Methods And Results: We conducted a systematic review and a meta-analysis to investigate the difference in CMR derived native T1 relaxation time and ECV values, respectively, in anthracyclines-treated cancer patients with preserved EF versus healthy controls. PubMed, Embase, Web of Science and Cochrane Central were searched for relevant studies. A total of 6 studies were retrieved from 1057 publications, of which, four studies with 547 patients were included in the systematic review on T1 mapping and five studies with 481 patients were included in the meta-analysis on ECV. Three out of the four included studies in the systematic review showed higher T1 mapping values in anthracyclines treated patients compared to healthy controls. The meta-analysis demonstrated no statistically significant difference in ECV values between the two groups in the main analysis (Hedges´s g =3.20, 95% CI -0.72-7.12, p =0.11, I =99%), while ECV was significantly higher in the anthracyclines-treated group when sensitivity analysis was performed.

Conclusions: Higher T1 mapping and ECV values in patients exposed to anthracyclines could represent early biomarkers of CTRCD, able to detect subclinical myocardial changes present before the development of overt myocardial dysfunction. Our results highlight the need for further studies to investigate the correlation between anthracyclines-based chemotherapy and changes in CMR mapping parameters that may guide future tailored follow-up strategies in this group of patients.