Hemodynamic predictors of mortality in adults with sickle cell disease.
BACKGROUND
Pulmonary hypertension (PH) in adults with sickle cell disease (SCD) is associated with early mortality, but no prior studies have evaluated quantitative relationships of mortality to physiological measures of pre- and postcapillary PH.


OBJECTIVE
To identify risk factors associated with mortality and to estimate the expected survival in a cohort of patients with SCD with PH documented by right heart catheterization.


METHODS
Nine-year follow-up data (median, 4.7 yr) from the National Institutes of Health SCD PH screening study are reported. A total of 529 adults with SCD were screened by echocardiography between 2001 and 2010 with no exclusion criteria. Hemodynamic data were collected from 84 patients. PH was defined as mean pulmonary artery pressure (PAP) ≥ 25 mm Hg. Survival rates were estimated by the Kaplan-Meier method, and mortality risk factors were analyzed by the Cox proportional hazards regression.


RESULTS
Specific hemodynamic variables were independently related to mortality: mean PAP (hazard ratio [HR], 1.61; 95% confidence interval [CI], 1.05-2.45 per 10 mm Hg increase; P = 0.027), diastolic PAP (HR, 1.83; 95% CI, 1.09-3.08 per 10 mm Hg increase; P = 0.022), diastolic PAP - pulmonary capillary wedge pressure (HR, 2.19; 95% CI, 1.23-3.89 per 10 mm Hg increase; P = 0.008), transpulmonary gradient (HR, 1.78; 95% CI, 1.14-2.79 per 10 mm Hg increase; P = 0.011), and pulmonary vascular resistance (HR, 1.44; 95% CI, 1.09-1.89 per Wood unit increase; P = 0.009) as risk factors for mortality.


CONCLUSIONS
Mortality in adults with SCD and PH is proportional to the physiological severity of precapillary PH, demonstrating its prognostic and clinical relevance despite anemia-induced high cardiac output and less severely elevated pulmonary vascular resistance.
Cardiovascular and Pulmonary Branch, National Heart, Lung, and Blood Institute, Bethesda, MD, USA.
Alem
A
Mehari
Shoaib
S
Alam
Xin
X
Tian
Michael J
MJ
Cuttica
Christopher F
CF
Barnett
George
G
Miles
Dihua
D
Xu
Catherine
C
Seamon
Patricia
P
Adams-Graves
Oswaldo L
OL
Castro
Caterina P
CP
Minniti
Vandana
V
Sachdev
James G
JG
Taylor
Gregory J
GJ
Kato
Roberto F
RF
Machado
D000328:Adult; D000755:Anemia, Sickle Cell / Q000150:complications* / Q000401:mortality; D006328:Cardiac Catheterization; D002986:Clinical Trials as Topic; D015150:Echocardiography, Doppler; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006976:Hypertension, Pulmonary / Q000175:diagnosis / Q000209:etiology* / Q000401:mortality; D053208:Kaplan-Meier Estimate; D016015:Logistic Models; D008297:Male; D061213:Mortality, Premature; D016016:Proportional Hazards Models; D011669:Pulmonary Wedge Pressure / Q000502:physiology; D018570:Risk Assessment; D015996:Survival Rate