Prevalence and predictors of anthracycline cardiotoxicity in children treated for acute myeloid leukaemia: Retrospective cohort study in a single centre in the United Kingdom

BACKGROUND: Anthracycline cardiomyopathy is of concern in children treated for acute myeloid leukaemia (AML), but there are few data on the incidence and natural history of cardiotoxicity after AML treatment in the United Kingdom, where regimens have included high anthracycline exposure. PROCEDURE: Prevalence and predictors of cardiotoxicity were retrospectively reviewed in 124 children treated on the MRC AML 10 and AML 12 trials in a single, large centre from November 1987 to September 2004. Subclinical cardiotoxicity was defined as a shortening fraction of less than 28% and clinical cardiomyopathy as evidence of heart failure, and both were classified as late cardiotoxicity 1 year after completing first line therapy. RESULTS: Cumulative survival was 61% at 10 years. The prevalence of early and late cardiotoxicity was 13.7% (95%-CI: 8.2-22.0%) and 17.4% (95%-CI: 10.9-26.8%), respectively. Early cardiotoxicity was a strong predictor (OR = 9.18; 95%-CI: 2.10-40.11; P < 0.005) and children who received salvage therapy following relapse showed a trend towards increased late cardiotoxicity (OR = 3.53; 95%-CI: 0.86-14.48; P < 0.08). Subclinical cardiotoxicity resolved spontaneously in all but one case, but clinical cardiomyopathy always required continuing therapy. Two children died of cardiomyopathy and six remained on medical therapy. CONCLUSIONS: Anthracycline cardiotoxicity remains a major concern for survivors of childhood AML and correlates with early cardiotoxicity and treatment intensity. Long-term follow-up is required to fully determine the outcome for children with subclinical cardiotoxicity.