Recommendations for cardiomyopathy surveillance for survivors of childhood cancer: a report from the International Late Effects of Childhood Cancer Guideline Harmonization Group

Abstract

Survivors of childhood cancer treated with anthracycline chemotherapy or chest radiation are at an increased risk of developing congestive heart failure. In this population, congestive heart failure is well recognised as a progressive disorder, with a variable period of asymptomatic cardiomyopathy that precedes signs and symptoms. As a result, several clinical practice guidelines have been developed independently to help with detection and treatment of asymptomatic cardiomyopathy. These guidelines differ with regards to definitions of at-risk populations, surveillance modality and frequency, and recommendations for interventions. Differences between these guidelines could hinder the effective implementation of these recommendations. We report on the results of an international collaboration to harmonise existing cardiomyopathy surveillance recommendations using an evidence-based approach that relied on standardised definitions for outcomes of interest and transparent presentation of the quality of the evidence. The resultant recommendations were graded according to the quality of the evidence and the potential benefit gained from early detection and intervention.

Figure 1. Risk of cardiomyopathy and CHF by cumulative lifetime anthracycline (A and B) and radiotherapy dose (C)

1A: Dose-response relationship between cumulative anthracycline exposure and risk of cardiomyopathy. Patients with no exposure to anthracyclines served as the referent group. Magnitude of risk is expressed as odds ratio, which was obtained using conditional logistic regression adjusting for age at diagnosis, sex, and chest radiation. Blanco JG, Sun CL, Landier W, et al: Anthracycline-related cardiomyopathy after childhood cancer: role of polymorphisms in carbonyl reductase genes--a report from the Children's Oncology Group. J Clin Oncol 30:1415–21, 2012. 1B, C: Association between cumulative anthracycline dose and hazard ratio, and cumulative radiotherapy dose and hazard ratio (in equivalent 2-Gray [Gy] fractions) for congestive heart failure, based on the Cox model that also included sex, age at diagnosis, cisplatin, vincristine, cyclophosphamide, ifosfamide, and congenital heart disease. No cardiotoxic treatment (dose = 0) was the reference value. For cardiac events, effect of anthracycline dose is shown for zero irradiation dose and effect of irradiation dose is shown for zero dose of anthracycline. van der Pal HJ, van Dalen EC, van Delden E, et al: High risk of symptomatic cardiac events in childhood cancer survivors. J Clin Oncol 30:1429–37, 2012.