P41 CT lung parenchymal appearances in chronic thromboembolic pulmonary hypertension (CTEPH). (11th November 2022)

• Record Type: Journal Article
• Authors: Abdulaal, L; Dwivedi, K; Sharkey, MJ; Alabed, S; Mamalakis, M; Alkhanfar, D; Condliffe, R; Kiely, DG; Swift, AJ
• Is Part Of: Thorax. Volume 77(2022)Supplement 1
• Page Start: A103
• Page End: A104
• Publication Date: 2022-11-11
• Subjects: Chest -- Diseases -- Periodicals; Thorax; Chest -- Diseases; Periodicals; Periodicals; 617.54
• DOI: 10.1136/thorax-2022-BTSabstracts.177
• Languages: English
• ISSNs: 0040-6376

Abstract

Abstract : Background: CT pulmonary angiography (CTPA) is recommended in suspected chronic thromboembolic pulmonary hypertension (CTEPH) and supports therapeutic planning. Mosaic perfusion and lung scarring are common features in CTEPH, but their clinical relevance is less understood. CTEPH is a challenging diagnosis and a commonly overlooked condition that's tough to spot and frequently misinterpreted. Aim: To evaluate the association of mosaic perfusion and lung scarring with prognostic indicators in CTEPH before pulmonary endarterectomy (PEA). Methods: 290 patients with CTEPH who underwent CTPA were identified. PEA-specific CTEPH treatment was administered to 50 (17.2%) of the patients, other patients 240 may go on to have PEA, just at the time of the scan most had not had surgery. Radiological assessment of mosaic perfusion (nil/minor/mild/moderate-severe), lung scarring (nil/minor/mild/moderate-severe) and emboli (proximal/segmental/distal) were scored blinded to clinical parameters. Right heart catheterisation data, pulmonary vascular resistance (PVR) and mixed venous oxygen saturation (SvO2) (n=118) were collected alongside CT cardiac measurements and the transfer factor for carbon monoxide (TLCO)(n=112). The correlation was assessed using Spearman's correlation coefficient. Group comparison was made on dichotomised mosaicism/scarring data (nil/minor vs mild/moderate-severe) using an independent t-test. Results: The mean pre-PEA PVR was (571.22 ± 409.88 dyne.s.cm -5 ). In pre-PEA patients, a significant correlation was found between both mosaicism and scarring, with PVR and SVO2 (all p≤0.01), whereas no correlation was identified with clot location (p=0.93, 0.10). RV: LV ratio correlated with scarring and mosaicism (p≤0.02, p≤0.01). Patients with greater mosaicism had higher PVR and lower SvO2 (all p<0.05) (mean difference 371.5 dyns, 95% confidence interval [CI] 175.6 to 942.3), (-10.9%, CI -18.4 to -3.4), respectively. Patients with greater than minor scarring had lower SvO2 (p≤0.01) (-10.6%, CI -17.9 to -3.3) and lower TLCO (p≤0.04) (-1.78 mmol/min/kPa, CI -3.70 to -0.02). Conclusion: CT lung features in CTEPH relate to prognostic indicators and are important to assess disease severity before and after PEA treatment. Please refer to page A213 for declarations of interest related to this abstract.