Elevated tricuspid regurgitation velocity and decline in exercise capacity over 22 months of follow up in children and adolescents with sickle cell anemia.
BACKGROUND
While in adults with sickle cell disease an elevation of tricuspid regurgitation velocity is associated with increased mortality, the importance of this finding in children has not been established. The role of intravascular hemolysis in the development of this complication is controversial.


METHODS
We conducted a prospective, longitudinal, multi-center study of 160 individuals aged 3-20 years with hemoglobin SS, performing baseline and follow-up determinations of clinical markers, six-minute walk distance less than tricuspid regurgitation velocity and E/Etdi ratio by echocardiography.


RESULTS
At baseline, 14.1% had tricuspid regurgitation velocity of 2.60 m/sec or over, which suggests elevated systolic pulmonary artery pressure, and 7.7% had increased E/Etdi, which suggests elevated left ventricular filling pressure. Over a median of 22 months, baseline elevation in tricuspid regurgitation velocity was associated with an estimated 4.4-fold increase in the odds of a 10% or more decline in age-standardized six-minute-walk distance (P = 0.015). During this interval, baseline values above the median for a hemolytic component derived from four markers of hemolysis were associated with a 9.0-fold increase in the odds of the new onset of elevated tricuspid regurgitation velocity (P = 0.008) and baseline E/Etdi elevation was associated with an estimated 6.1-fold increase in the odds (P = 0.039). In pathway analysis, higher baseline hemolytic component and E/Etdi predicted elevated tricuspid regurgitation velocity at both baseline and follow up, and these elevations in turn predicted decline in six-minute-walk distance.


CONCLUSIONS
Further studies should define the long-term risks of elevated tricuspid regurgitation velocity in childhood and identify potential interventions to prevent increased pulmonary artery pressure and preserve function.
Gordeuk
Victor R
VR
Center for Sickle Cell Disease, Howard University, Washington, DC 20060, USA. vgordeuk@howard.edu
Minniti
Caterina P
CP
Nouraie
Mehdi
M
Campbell
Andrew D
AD
Rana
Sohail R
SR
Luchtman-Jones
Lori
L
Sable
Craig
C
Dham
Niti
N
Ensing
Gregory
G
Prchal
Josef T
JT
Kato
Gregory J
GJ
Gladwin
Mark T
MT
Castro
Oswaldo L
OL
D000293:Adolescent; D000328:Adult; D000755:Anemia, Sickle Cell / Q000150:complications* / Q000503:physiopathology; D002648:Child; D002675:Child, Preschool; D004452:Echocardiography; D015444:Exercise; D005260:Female; D005500:Follow-Up Studies; D006461:Hemolysis; D006801:Humans; D008297:Male; D008944:Mitral Valve Insufficiency; D011446:Prospective Studies; D014262:Tricuspid Valve Insufficiency / Q000209:etiology* / Q000503:physiopathology; D055815:Young Adult