Effects of immune checkpoint inhibitors on the pulmonary circulation in lung cancer patients.

Immune checkpoint inhibitors (ICIs) are effective anti-tumor agents, but new immune-related side effects (irAEs) are emerging. This retrospective cohort study investigated 461 lung cancer patients treated with ICIs over 2 years, analyzing changes in pulmonary artery diameter (PAD), aortic diameter (AoD), and the pulmonary artery/aortic diameter (PAD/AoD) ratio through chest computed tomography (CT) at baseline, 3 months, 6 months, 1 year, and 2 years post-treatment. The PAD increased from 25.19 to 26.33 mm (p < .001) and the PAD/AoD ratio increased from 0.70 to 0.73 (p < .001) during ICI treatment over a 2-year follow-up period, as early as within the first 3 months. High-sensitivity troponin I (hs-TnI), α-hydroxybutyrate dehydrogenase (HBDH), creatine kinase (CK), creatine kinase MB (CK-MB), and coagulation indices exhibited significant changes (p < .05), while the cardiac ultrasound result remained unchanged. In subgroup analysis, the severe group demonstrated lower overall survival (OS) (43 months vs. 56 months) (p = .008) and progression-free survival (PFS) (15 months vs. 20 months, p < .001) compared to the non-severe group. Meanwhile, the severe PAD/AoD ratio progression served as independent predictors of prognosis in lung cancer patients receiving ICI treatment, but immune-related pneumonia(CIP) did not significantly influence the PAD/AoD ratio progression (p > .999). Therefore, in lung cancer patients receiving ICIs, pulmonary vascular involvement can occur within the initial 3 months and needs to be monitored with chest CT and echocardiography.