Characterization of Cardiac Function by Echocardiographic Global Longitudinal Strain in a Cohort of Children with Neurofibromatosis Type 1 Treated with Selumetinib

Background: Plexiform neurofibromas are benign neoplasms that develop in 20-50% children with neurofibromatosis type 1 (NF1). Selumetinib was approved as treatment for symptomatic and inoperable plexiform neurofibromas. Subclinical left ventricular ejection fraction reduction is a less common effect of selumetinib. Objective: We aimed to investigate the contractile function of the heart in a cohort of children with NF1 treated with selumetinib. Methods: We designed a cross-sectional study including 17 patients with NF1 who received selumetinib. Echocardiographic parameters were compared with a cohort of 17 healthy children matched by sex and age and another group of 17 children with untreated NF1. Results: Compared with healthy controls, patients with NF1 treated with selumetinib had lower mean values of global longitudinal strain (- 22.9 ± 2% vs -25.5 ± 2%; p = 0.001), fractional shortening (36 ± 4% vs 43 ± 8%; p = 0.02) and tricuspid annular plane systolic excursion (19 ± 3 mm vs 23 ± 2 mm; p = 0.001); no difference was found in left ventricular ejection fraction (63 ± 4% vs 65 ± 3%; p = 0.2 respectively). Median treatment time with selumetinib at the time of the echocardiographic evaluation was 22 ± 16 months. Conclusions: Patients with NF1 treated with selumetinib may experience subtle changes in systolic function identified by global longitudinal strain and not revealed by left ventricular ejection fraction. Global longitudinal strain might be useful to monitor cardiac function in this cohort of patients for the duration of therapy.