of a classic case include the presence of pre-capillary pulmonary hypertension
in the absence of left-sided heart disease, lung disease, or chronic thrombo embolism.
Histopathology of small pulmonary arteries reveals proliferation of medial
smooth-muscle cells and endothelial cells. In the updated classification of pulmonary
hypertension, sickle cell disease (SCD) is included as a separate entity
in the subgroup of PAH associated with identified diseases. Recent studies have
revealed that the frequency of PAH in patients with SCD is 30%.
objective of a study recently published in the New England Journal of Medicine was
to evaluate the prevalence of pulmonary hypertension (PH) in adult patients
with sickle cell disease (SCD) and confirm it with the help of right heart
catheterization. In these patients, SCD was initially suspected on the basis of
this prospective study, 398 outpatients
(average age, 34 years) were recruited from referral centers for SCD in
France. The study was also carried out in collaboration
with the National Reference Center for Pulmonary Hypertension.
All patients included in the study were homozygous
for hemoglobin S
or had Sβ0
thalassemia. Only stable outpatients
were included in the study.
Severe liver disease
Chronic restrictive lung disease.
were subjected to Doppler echocardiography, with measurement of tricuspid-valve
regurgitant jet velocity. Right heart catheterization was performed in 96
patients in whom pulmonary hypertension was suspected.
hypertension was defined as a mean pulmonary arterial pressure of a minimum of
25 mm Hg.
was carried on for three years from date of study.
Details of death, if any, were carefully documented.
In this study of adult patients with
sickle cell disease, the prevalence of a tricuspid regurgitant jet velocity, of
at least 2.5 m per second, on echocardiography was 27%. This rate of occurrence
was consistent with other studies carried out thus far.
In contrast, pulmonary hypertension
prevalence that was confirmed on right heart catheterization was only about 6%.
Approximately half of these patients,
with confirmed PH, had pre-capillary pulmonary hypertension.
Based on their samples, the study
concludes that the prevalence of pulmonary hypertension as detected on initial echocardiography
screening, and confirmed by right heart catheterization, was 6% and that echocardiography alone was not enough to
detect pulmonary hypertension.
"A Hemodynamic Study of Pulmonary Hypertension in Sickle Cell Disease"
Florence Parent, M.D., Dora Bachir, M.D.,
Jocelyn Inamo, M.D.,et al.,
N Engl J Med 2011;