Cardiovascular effects of hypertransfusion therapy in children with sickle cell anemia

Summary

Thirteen children, age 1.9 to 14.8 years with documented sickle cell disease, underwent echocardiographic assessment of cardiac status while on and off periodic hypertransfusion therapy (HTX). Two to three units of washed packed red blood cells were transfused every 2–4 weeks in children with splenic sequestration crises, cerebrovascular accidents (CVA), aseptic necrosis of the femoral head, and miscellaneous complications of sickle cell disease to maintain hemoglobin (Hgb) concentrations of ≧10g/dl and % sickle hemoglobin (S Hgb) of ≦20%. This therapy administered over an average duration of 24 months resulted in normalization of left heart chamber enlargement and statistically significant decrease in heart rate, left ventricular mass, and cardiac output. Echocardiographically derived left ventricular function parameters remained normal on and off transfusion therapy. Changes in left ventricular diastolic dimension and cardiac output correlated with changes in % S Hgb (r=0.59,p<0.001; andr =0.54,p<0.001, respectively), and with changes in Hgb concentration (r=−0.78,r=−0.76,p<0.001). Expression of left heart abnormalities as a single composite function (Ydv), using multivariate regression analysis, allowed a comparison of cardiac status of 99 normal black controls, nontransfused sickle cell anemia (SCA) patients, and 13 study patients on and off HTX, and permitted serial assessment of cardiac status on and off treatment over 5 years in a single patient. Normalization of left heart abnormalities in children with sickle cell disease receiving HTX provides further evidence that the major cardiac changes are due to the hypervolemia that results from chronic anemia, and that these changes are reversible with correction of the anemia. Although the specific effect of iron-overload from chronic transfusion therapy was not assessed, we did not find evidence for myocardial dysfunction in children with SCA on or off HTX.