Prevalence of Intracardiac Shunting in Children with Sickle Cell Disease and Stroke

Abstract

To determine the prevalence of potential intracardiac shunts, including patent foramen ovale (PFO), in children with sickle cell disease (SCD) and stroke. We performed a transthoracic echocardiogram (TTE) on 40 children with SCD (39 with hemoglobin SS and 1 with sickle-beta0 thalassemia) and earlier stroke (overt stroke in 30, silent infarction in 10). We compared 3 TTE techniques: conventional 2-dimensional imaging, color Doppler ultrasound, and intravenous agitated saline contrast injection for the detection of intracardiac shunts. We also evaluated the clinical, laboratory, and radiographic findings of the children with and without shunts. We identified PFO or other potential intracardiac shunts in 10 of 40 children with SCD and earlier stroke (25%; 95% CI, 11.6-38.4). With contrasted TTE, we failed to detect potential shunts in 2 children. In a comparison group of 60 children with stroke but without SCD, retrospective review of clinical echocardiograms identified PFO in 7 of 60 (11.7%; 95% CI, 3.6-19.8). Clinical features significantly associated with the presence of intracardiac shunts were stroke in the setting of vaso-occlusive crisis (P = .026) and headache at stroke onset (P = .014). One-quarter of children with SCD and stroke have potential intracardiac shunts. A combination of echocardiographic techniques is required for optimal shunt detection. Intracardiac shunting could be a risk factor for stroke in children with SCD because they are predisposed to thrombosis and elevations of right heart pressure, which could promote paradoxical embolization across an intracardiac shunt.