Early doxorubicin cardiotoxicity in Malawian children admitted to Queen Elizabeth Central Hospital, Malawi.

Background: Doxorubicin is known to cause chemotherapy-induced cardiotoxicity. In resource-poor settings, monitoring for cardiotoxicity is not routinely done, and its incidence is unknown. The aim of this study was to determine the proportion of children who developed doxorubicin-induced cardiotoxicity within 1 year of having received treatment at paediatric oncology ward.

Methods: Children aged 3 months to 18 years with cancer were prospectively enrolled and followed up between January 2016 to June 2019. Transthoracic echocardiogram was done at baseline, 1 month, 6 months and a year after completion of therapy. Cardiotoxicity was defined as a decline in left ventricular ejection fraction (LVEF) of ≥10% to a final value of <50%. An overall incidence risk of developing cardiotoxicity was estimated. A one-way analysis of variance (ANOVA) was conducted to compare baseline LVEF with follow-up measurements.

Findings: Ninety-one children were enrolled, 74% (68/91) were male, and 67% (62/91) were aged 5 months to 14 years. Most patients received a doxorubicin cumulative dose between 100 and 200 mg/m and no cardiotoxicity was observed during the study period. However, of 77 children with at least one follow up, five children 6.54% (95% CI: 2.1-14.5) experienced LVEF reduction of >10%, though not to a final value of <50%. No deterioration of systolic function was found among 20 children who completed follow-up (F = 2.43, p-value = .07).

Interpretation: In this cohort of patients, most received a low cumulative doxorubicin dose and only 22% were available for evaluation at study end; no cardiotoxic events associated with doxorubicin administration were observed after 12 months.