Trends in HU utilization and cerebrovascular outcomes before and after publication of the 2014 National Heart, Lung, and Blood Institute sickle cell disease guidelines

The 2014 National Heart, Lung, and Blood Institute (NHLBI) guidelines recommend offering hydroxyurea to all patients with sickle cell disease SS/Sβ0 (SCD) aged ≥ 9 months. The relationship between early hydroxyurea initiation and the development of cerebrovascular disease (CVD) is unclear. This retrospective study describes trends in HU prescriptions and CVD outcomes in patients with SCD SS/Sβ⁰ followed at a single center before and after guideline publication. CVD was defined as the first of abnormal transcranial Doppler ultrasound, silent cerebral infarct, steno-occlusive vasculopathy, or arterial ischemic stroke. Among 530 patients with SCD, hydroxyurea prescriptions rose post-guideline, with lower age at initiation. CVD was lower post-guideline (2.2/100py) versus pre-guideline (4.4/100py). However, MRI screening also decreased post-guideline, leading to lower CVD detection. Results suggest decreased CVD, including silent cerebral infarcts, in the era of early hydroxyurea use; further analyses addressing age at hydroxyurea initiation and relevant confounders are needed to confirm whether earlier hydroxyurea initiation improves protection against CVD.