Cardiovascular data are unavailable for children with Hb SC and they have not been distinguished from Hb SS patients. Effective preventive strategies are dependent on understanding the long term effects of this disease. 72 adults with Hb SC and 225 with Hb SS, age 35-55 years were compared. A history, physical, Hb, ECG, nuclear scan, echocardiogram (Echo) and treadmill exercise (Ex) were performed. SC patients were less disabled. Smoking histories were similar. SC patients were more likely to be on blood pressure(BP) medications (14 vs 5%) and less likely to be on cardiac drugs (4 vs 16%). Renal failure was not reported in SC patients and heart failure was rare (1% vs 6%, NS). No significant differences were found for age (SC 42.4 ± 6.0, SS 41.2 ± 5.4), gender (SC 36% male, SS 38% male) and height (cm)(SC 166 ± 12, SS 167 ± 10). SC patients were heavier (kg) (SC 77.6 ± 18, SS 62.6 ± 11) and had higher systolic (SC 120± 18, SS 116 ± 15) and diastolic (SC 81 ± 12, SS 71± 9) BP. Hb was significantly higher in SC patients (11.7 ± 1.3 vs 8.0 ± 1.6). ECG's in SC were significantly different from SS in rhythm (0 vs 7% abnormal) and chamber enlargement (12 vs 27%). No significant differences were found for heart rate(HR) (SC 72 ± 14, SS 73 ± 9), ejection fraction (left ventricle - SC 0.60 ±0.09, SS 0.59± 0.09; right ventricle - SC 0.48 ± 0.11, SS 0.47 ± 0.12) or wall motion abnormalities (SC 21%, SS 20%). Echo dimensions (cm) were normal in SC; significant dilatation was noted in SS: right ventricle (SC 1.98 ± 0.61, SS 2.16 ± 0.53), left ventricle (diastole - SC 4.72 ± 0.45, SS 5.53 ± 0.62; systole - SC 2.96 ± 0.46, SS 3.5 ± 0.56) and left atrium (SC 3.54 ± 0.46, SS 4.03 ± 0.61). No difference in wall thicknesses were noted. Doppler volocities were normal in SC but increased in SS subjects. Ex duration (min) (SC 13.4 ± 5.1, SS 11.0 ± 4.9) and peak workload (METS) (SC 6.6 ± 1.7, SS 5.7± 1.7) were decreased, but significantly less in SC. SC patients had less J point depression on Ex ECG (12 vs 28%) and higher peak diastolic BP (82± 14 vs 74 ± 12). No differences were noted in peak HR, systolic BP, Ex arrhythmia or other symptoms.

Adult SC patients are spared the cardiac effects of sickle cell disease yet they are heavier, have higher BP and are more often on BP medications than SS patients. SC children are on a different path and should be treated accordingly.