Pulmonary hypertension, diagnosed by Doppler echocardiography, is common in adults with sickle cell disease. It appears to be a complication of chronic hemolysis, is resistant to hydroxyurea therapy, and confers a high risk of death. Therapeutic trials targeting this population of patients are indicated.

Diastolic dysfunction and pulmonary hypertension each contribute independently to prospective mortality in patients with SCD. Patients with both risk factors have an extremely poor prognosis. These data support the implementation of echocardiographic screening of adult patients with SCD to identify high-risk individuals for further evaluation.

Background. Pulmonary hypertension, defined by an elevated pulmonary artery systolic pressure measured by Doppler-echocardiogram, has been identified as the major predictor of death in the adult sickle cell disease population. While diastolic dysfunction is also observed in this population, the prevalence in unselected patients, the association with high pulmonary artery systolic pressure, and the attributable mortality remain unknown. Methods. Diastolic function parameters, pulmonary artery systolic pressures and right and left ventricular size and function were measured prospectively in 215 subjects with sickle cell disease. Associations between these parameters, lab and echocardiographic variables and prospective mortality were determined. Results. Diastolic dysfunction, measured by conventional and tissue-Doppler echocardiography, was present in 19% of patients with sickle cell disease. Diastolic dysfunction and pulmonary hypertension were both present in approximately 11% of patients and diastolic dysfunction accounted for approximately 10–20% of the variability in tricuspid regurgitant jet velocity. Importantly, Cox Proportional Hazards analysis revealed that diastolic dysfunction, as reflected by low E/A ratio, was associated with prospective mortality with a risk ratio of 1.9 (95%CI 1.0 to 3.7; p=0.028), even after adjustment for tricuspid regurgitant jet velocity. While pulmonary hypertension remained the dominant determinant of mortality risk, even after adjustment for measures of diastolic function (adjusted rate ratio of 5.3; 95% CI= 1.9 to15.0; p<0.001), the risk was additive such that patients with both risk factors had an odds ratio for death of 10.1 (95% CI= 3.2 to 31.9; p<0.001). Conclusions. Diastolic dysfunction and pulmonary hypertension due to other causes each contribute independently to prospective mortality in patients with sickle cell disease. Patients with both risk factors have an extremely poor prognosis. These data support the implementation of Doppler-echocardiographic screening of adult patients with sickle cell disease to identify individuals at high risk of death for intensified therapy. Figure Figure

Summary Pulmonary hypertension is associated with sudden death and is a risk factor for mortality in adult patients with sickle cell disease. The high mortality despite only mild‐to‐moderate increases in pulmonary vascular resistance remains an unresolved paradox. Accordingly, little is known about the cardiovascular effects of stressors, such as vaso‐occlusive pain crisis (VOC) and exercise, which may acutely increase pulmonary pressures and impair right heart function. We therefore evaluated pulmonary artery pressures by echocardiogram in 25 patients with sickle cell disease in steady‐state and during VOC, and by right heart catheterisation with exercise in a second cohort of 21 patients to determine whether pulmonary hypertension worsens during acute cardiopulmonary stress. TRV increased during VOC (P < 0·001), and the increased pulmonary pressures during VOC were associated with decreases in haemoglobin levels (P < 0·001), and increases in lactate dehydrogenase (P < 0·001) and plasma haemoglobin levels (P = 0·03). During exercise stress performed during cardiac catheterisation, mean pulmonary artery pressures (P < 0·001) and pulmonary vascular resistance increased (P < 0·001) in all subjects. These data suggest that acute elevations in pulmonary pressures during VOC or exercise may contribute to morbidity and mortality in patients with sickle cell disease.