A Study to Learn About the Study Medicine (Called PF-07868489) in People With Pulmonary Arterial Hypertension Who Have Previously Participated in a Clinical Study With PF-07868489

This study is seeking participants who are: * aged 18 years or older at screening of the previous study and completed the required treatment duration with PF-07868469 and other assessments at the end of that study. * willing and able to abide with all scheduled visits, treatment plan, laboratory tests, lifestyle considerations, and other study procedures. * do not have worsening or hospitalization for worsening PAH during the qualifying study. * not on placement for a surgery to replace any tissue or part of the body (transplant), and planned surgery for PAH. * do not have an ongoing major health issue in the qualifying study, which in the opinion of the study doctor could make the participant not qualify for this study. * not suffering from or in the past have suffered from hepato-pulmonary syndrome (liver-related lung problem). * not currently prescribed or taking medicines called as GLP-1 agonist.