Hemodynamic and functional assessment of patients with sickle cell disease and pulmonary hypertension.
BACKGROUND
Although pulmonary hypertension (PH) is a common complication of sickle cell disease (SCD) associated with high mortality, there exist few data characterizing hemodynamics and cardiopulmonary function in this population.


OBJECTIVE
To characterize hemodynamics and cardiopulmonary function in patients with SCD with and without PH.


METHODS
Patients with SCD with PH (n = 26) were compared with control subjects with SCD but without PH (n = 17), matched for age, hemoglobin levels, and fetal hemoglobin levels.


RESULTS
Upon catheterization, 54% of the patients with PH had pulmonary arterial hypertension, and 46% had pulmonary venous hypertension. When compared with control subjects, patients with PH exhibited lower six-minute-walk distance (435 +/- 31 vs. 320 +/- 20 m, p = 0.002) and oxygen consumption (50 +/- 3% vs. 41 +/- 2% of predicted, p = 0.02), and also had mild restrictive lung disease and more perfusion abnormalities on radionuclide lung scans. The six-minute-walk distance in this population inversely correlated with tricuspid regurgitant jet velocity (r = -0.55, p < 0.001), and mean pulmonary artery pressure (r = -0.57, p < 0.001), and directly correlated with maximal oxygen consumption (r = 0.49, p = 0.004), even after adjustment for hemoglobin, supporting an independent contribution of increasing pulmonary artery pressures to loss of exercise capacity.


CONCLUSIONS
Patients with SCD-associated PH have both pulmonary arterial and venous PH associated with severe limitations in exercise capacity, likely compounded by interstitial lung fibrosis and severe anemia. These data support the use of the six-minute-walk distance as an index of PH and cardiopulmonary function in patients with SCD.
Anthi
Anastasia
A
Vascular Medicine Branch, Clinical Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 2089, USA.
Machado
Roberto F
RF
Jison
Maria L
ML
Taveira-Dasilva
Angelo M
AM
Rubin
Lewis J
LJ
Hunter
Lori
L
Hunter
Christian J
CJ
Coles
Wynona
W
Nichols
James
J
Avila
Nilo A
NA
Sachdev
Vandana
V
Chen
Clara C
CC
Gladwin
Mark T
MT
D000328:Adult; D000755:Anemia, Sickle Cell / Q000150:complications / Q000503:physiopathology*; D006328:Cardiac Catheterization; D002302:Cardiac Output; D005080:Exercise Test; D017079:Exercise Tolerance; D005260:Female; D005355:Fibrosis; D006801:Humans; D006976:Hypertension, Pulmonary / Q000000981:diagnostic imaging / Q000209:etiology / Q000503:physiopathology*; D008168:Lung / Q000000981:diagnostic imaging / Q000473:pathology; D008297:Male; D008875:Middle Aged; D010101:Oxygen Consumption; D012129:Respiratory Function Tests; D014057:Tomography, X-Ray Computed; D014692:Ventilation-Perfusion Ratio