Long-Term Hydroxyurea May Improve Cardiac Abnormalities in Young Patients With Sickle Cell Disease

Long-term hydroxyurea therapy in children with sickle cell disease (SCD) may reverse cardiac remodeling, according to new research findings. Lead study author Arushi Dhar, MD, of Northwell Health in New Hyde Park, New York, said that these findings emphasize “the need for close cardiac monitoring of children with sickle cell anemia, including asymptomatic patients.” The findings from the study were published in Blood Advances.

Hydroxyurea is a U.S. Food and Drug Administration–approved disease-modifying treatment for SCD that has been employed for disease management for the past few decades. “We hope to highlight the importance of timely initiation of treatment with hydroxyurea per the 2014 National Heart, Lung, and Blood Institute guidelines,” said Dr. Dhar, “which dictate that hydroxyurea should be offered to all children with sickle cell anemia starting at 9 months of age, regardless of disease severity.”

Despite the utility of hydroxyurea, there is currently a lack of robust long-term assessments of echocardiographic abnormalities in hydroxyurea-treated pediatric patients and young adults with SCD.

To close this research gap, Dr. Dhar and colleagues retrospectively evaluated the prevalence of echocardiographic abnormalities among 100 children and young adults with SCD who underwent routine cardiac screening at a single children’s medical center between 2010 and 2017. Of this cohort, 60 patients had received hydroxyurea.

In the overall population, the mean age was 12±4.9 years but ranged from 3 to 22 years. Approximately 58% of the cohort was male. At baseline, half of all patients had dilated left ventricle (LV), defined as an LV end-diastolic (LVEDd) and/or LV end-diastolic volume (LVEDv) z-score of 2 or higher.

No difference was observed between patients who received or did not receive hydroxyurea in regard to LV size, LV mass, and tricuspid valve regurgitation velocity.

The researchers performed 169 serial echocardiograms in the 60 patients treated with hydroxyurea. The mean duration of treatment at the last recorded visit was 630±285 days. To determine whether the duration of hydroxyurea affected outcomes, Dr. Dhar and colleagues analyzed echocardiogram findings from the 25 patients (41.7%) who were treated with hydroxyurea for less than one year and the 35 patients (58.3%) who were treated for at least one year. Those who received hydroxyurea for less than one year had a significantly higher prevalence of LV dilation compared with patients who had received treatment for one year or more (mean LVEDd z-score = 2.24±1.3 vs. 1.57±1.1, respectively, p=0.04; mean LVEDv z-score = 2.62±1.5 vs. 1.72±1.2, p=0.02; see TABLE).

Overall, treatment with hydroxyurea was associated with significant improvements in LV dilation and hypertrophy. The researchers also found that there was a negative correlation between duration of treatment with hydroxyurea and LV volume and mass.

While the study was limited by its “inability to discern if poor patient medication adherence contributed to the lack of significant difference found in change in certain echocardiographic parameters among patients taking hydroxyurea,” the researchers concluded that the study indicates that the use of disease-modifying therapies such as hydroxyurea “may limit the progression of, and potentially improve, cardiac abnormalities over time.”

The study was a single-center retrospective study, further limiting the findings. “It would be good to see a prospective multicenter study that follows these patients for a longer period of time, and even into adulthood, when cardiac complications become even more common,” commented Dr. Dhar.

Study authors report no relevant conflicts of interest.

Reference

Dhar A, Leung TM, Appiah-Kubi A, et al. Longitudinal analysis of cardiac abnormalities in pediatric patients with sickle cell anemia and effect of hydroxyurea therapy [published online ahead of print, 2021 Sep 16]. Blood Adv. doi: 10.1182/bloodadvances.2021005076.