Long-term clinical outcomes after pulmonary artery denervation (PADN) in patients with Group 1 pulmonary arterial hypertension (PAH) have not been reported.We aimed to investigate the effect of PADN on 1-year outcomes in patients with PAH.In the multicentre PADN-CFDA trial, 128 patients with Group 1 PAH were randomly assigned to PADN plus a phosphodiesterase-5 inhibitor (PDE-5i) versus a sham PADN procedure plus a PDE-5i. The principal endpoint of interest for the present study was clinical worsening at 1 year after randomisation, the composite of worsening of PAH (increase in WHO functional class, need for additional PAH treatments or PAH-related hospitalisation), atrial septostomy, listing for lung transplantation, or all-cause death.One-year clinical follow-up was available in all patients. At 1 year, clinical worsening had occurred in 3 (4.8%) patients in the PADN plus PDE-5i group and in 15 patients (23.1%) in the sham plus PDE-5i group (adjusted hazard ratio: 0.17; 95% confidence interval [CI]: 0.05-0.60; p=0.006), driven by significantly increased rates of PAH-related hospitalisations, worsening functional class and the requirement for additional PAH treatments in the sham group. Results were consistent in high-risk, intermediate-risk and low-risk patients (pinteraction=0.186). Patients treated with PADN plus PDE-5i had an improvement in the between-group change in the six-minute walking distance (6MWD) from baseline to 1 year of 81.2 m (95% CI: 50.3-112.2; p<0.001) compared with PDE-5i treatment alone.In this multicentre sham-controlled randomised trial, PADN treatment for Group 1 PAH significantly reduced clinical worsening and improved the 6MWD during 1-year follow-up in patients treated with a PDE-5i.