Circulating acetylcholine serves as a potential biomarker role in pulmonary hypertension.

"Declarations Ethics approval and consent to participateThe clinical research was carried out according to The Code of Ethics of the World Medical Association (Declaration of Helsinki), written informed consent was obtained, and the ethics committees of Fuwai Hospital approved the study. Consent for publicationNot applicable. Competing interestsThe authors declare no competing interests. Competing interests The authors declare no competing interests."

"Funding This work was supported by CAMS Innovation Fund for Medical Sciences (CIFMS, 2021-I2M-C&T-A-009), Capital Medical Development Research Fund (2020-2-4035), High-level hospital clinical research fees of Fuwai Hospital, CAMS (2022-GSP-TS-6), and Special Discipline Development Project of Fuwai Hospital, CAMS (2022-FWTS04)."