CT Features of Sickle Cell Disease-Associated Pulmonary Hypertension

Background/Objectives: Sickle cell disease (SCD) frequently leads to pulmonary hypertension (PH), affecting 6-11% of patients and increasing mortality. Computed tomography (CT) can assess pulmonary vascular changes, but its role in SCD-associated PH remains unclear. This retrospective study aims to evaluate CT findings in adults with SCD-associated PH and their association with disease severity as assessed by Transthoracic Echocardiography (TTE) and right heart catheterization (RHC). Methods: We conducted a retrospective cohort study at a tertiary center in Riyadh, reviewing CT scans from 2015 to 2024. Adults with confirmed SCD were included if PH was suggested by echocardiography or confirmed by RHC. CT findings, including pulmonary artery diameter and parenchymal abnormalities, were analyzed alongside demographic and clinical data using Fisher's exact tests with FDR correction for multiple comparisons. Results: Eighteen adults were included (mean age 35.9 ± 10.8 years; 50% male). Of the 18 patients, five (27.8%) had RHC-confirmed PH, whereas the remaining 13 (72.2%) were included based on TTE findings suggestive of PH without RHC confirmation. Echocardiographic probability data were available for 17 patients, among whom intermediate probability was the most frequent category (11/17, 64.7%). CT demonstrated PH signs in 55.6% of patients. Mean pulmonary artery diameter was 2.90 ± 0.60 cm, greatest in patients assessed by both TTE and RHC (3.61 ± 0.58 cm). The most frequent CT findings were cardiomegaly (44.4%) and pleural effusion (38.9%). Using Fisher's exact test, no individual CT feature was significantly associated with PH severity after correction for multiple comparisons; the presence of any CT sign of PH showed a nominal association with severity (exact p = 0.042) that was no longer significant after correction for multiple comparisons (q = 0.33). CT classified more patients as mild or moderate, but fewer as severe than TTE; neither septal flattening nor RV hypertrophy was significantly associated with severe PH on exact testing (p = 0.10 and p = 0.20, respectively, on CT-based assessment), and these associations should be considered exploratory given the small sample size. Conclusions: CT identifies vascular, cardiac, and parenchymal abnormalities, but does not replace TTE and RHC in evaluating SCD-associated PH.