Pulmonary hypertension following lung transplant: a systematic review

Post-lung-transplant development of pulmonary hypertension (PH) is an increasingly recognized disease process with limited data regarding its etiologies and clinical course. We performed a systematic review to evaluate reported causes and patterns of PH following lung transplantation.

This systematic review was registered with PROSPERO (CRD42025649383) and conducted according to PRISMA guidelines. A comprehensive search strategy was developed with a medical librarian and applied to MEDLINE (Ovid), Embase (Ovid), and the Cochrane Library. Studies were screened and managed using Covidence. Two reviewers independently screened titles, abstracts, and full texts, with disagreements resolved by consensus or a third reviewer. Eligible studies included case reports, retrospective or cohort studies, randomized controlled trials, and conference abstracts reporting post-lung-transplant PH with defined diagnostic criteria and plausible etiology. Studies without full text or sufficient data, non-original analyses, animal models, or non-English articles were excluded. Data were extracted using standardized forms, and risk of bias was assessed using the Newcastle-Ottawa Scale.

Fifteen studies met the inclusion criteria, including 12 case reports and 3 retrospective cohort studies, encompassing 223 patients. The most common etiology was chronic lung allograft dysfunction (CLAD), particularly bronchiolitis obliterans syndrome (BOS), accounting for 63% of cases. Other etiologies included vascular or anastomotic complications, recurrence of idiopathic pulmonary arterial hypertension, and recurrent thromboembolic disease.

Post-lung-transplant PH most frequently occurs in association with CLAD/BOS. Prospective longitudinal studies are needed to better define the temporal relationship between CLAD/BOS and PH and to inform surveillance and management strategies.