Background: Pulmonary hypertension (PHT) occurs in approximately 30% of adult patients with sickle-cell disease (SCD) and is a risk factor for early death. The potential role of pulmonary artery obstruction, whether due to emboli or in situ thrombosis, in the etiology of SCD-related PHT is unknown. Methods: Consecutive SCD patients were screened for PHT (defined as a tricuspid regurgitant jet flow velocity ≥ 2.5 m/s) employing echocardiography and were evaluated for pulmonary artery obstruction with ventilation-perfusion (VQ) scintigraphy. Results: Fifty-three HbSS, 6 HbSβ0-thalassemia, 20 HbSC, and 6 HbSβ+-thalassemia patients were included. The overall prevalence of PHT was 41% in HbSS/HbSβ0-thalassemia patients and 13% in HbSC/HbSβ+-thalassemia patients. High-probability VQ defects (Prospective Investigation of Pulmonary Embolism Diagnosis criteria) were detected in two patients, one of whom had PHT. In HbSS/HbSβ0-thalassemia patients with PHT, 19 patients (86%), 2 patients (9%), and 1 patient (5%) had low-, intermediate-, or high-probability scan results as compared to 30 patients (97%), 1 patient (3%), and 0 patients (0%) in HbSS/HbSβ0-thalassemia patients without PHT (p = 0.31). In HbSC/HbSβ+-thalassemia patients with PHT, 3 patients (100%), 0 patients (0%), and 0 patients (0%) had low-, intermediate-, and a high-probability scan as compared to 19 patients (90%), 1 patient (5%), and 1 patient (5%) in HbSC/HbSβ+-thalassemia patients without PHT (p = 0.86). There were no statistical differences in irregular distribution of the radiopharmaceutical or nonspecific signs associated with PHT between patients with and without PHT. Conclusions: Although small pulmonary artery obstruction cannot be excluded, large to medium-sized pulmonary artery obstruction is an unlikely primary causative factor in SCD-related PHT.

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doi.org/10.1378/chest.07-1694, hdl.handle.net/1765/29047
Chest: the cardiopulmonary and critical care journal
Erasmus MC: University Medical Center Rotterdam

van Beers, E., van Eck-Smit, B., Mac Gillavry, M., van Tuijn, C., van Esser, J., Brandjes, D., … Schnog, J. J. B. (2008). Large and medium-sized pulmonary artery obstruction does not play a role of primary importance in the etiology of sickle-cell disease-associated pulmonary hypertension. Chest: the cardiopulmonary and critical care journal, 133(3), 646–652. doi:10.1378/chest.07-1694