RESULTS: Twelve patients were included. 70% of subjects were female. The mean age was 35.4. The mean estimated systolic pulmonary artery pressure (eSPAP) measured was 42.7 mmHg (SD=17.2) and 71.7 mmHg (SD = 28), in TTE's performed as outpatient while not in an acute sickle cell crisis and inpatient during an acute sickle cell crisis, respectively (p<0.001). The eSPAP mean difference between measurement while in and not in crisis was 29 mmHg (SD = 20.8). A Pearson Correlation Coefficient for outpatient versus inpatient eSPAP revealed a moderate positive correlation (R=0.67; p < 0.05). The prevalence of pulmonary hypertension, as defined by eSPAP >40 mmHg, was 100% while in crisis compared to 50% while not in crisis (p=0.005).