Clinical Research Office. A partnership between Sheffield Teaching Hospitals NHS Foundation Trust and the University of Sheffield

PHoenix Study

Plain language summary:

A study using monitors placed into your lungs and over your heart to help choose the best medications for pulmonary arterial hypertension (PAH)

Scientific title: A multicentre randomised cross-over trial of disease specific therapy in patients with Pulmonary Arterial Hypertension (PAH) implanted with pulmonary artery pressure and cardiac rhythm monitoring devices (CardioMEMS/Confirm Rx)

Short Title: Pulmonary Hypertension: intensification and personalisation of combination Rx (PHoenix)

Chief Investigator: Dr Alex Rothman, Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield and Honorary Consultant Cardiologist, Sheffield Teaching Hospitals NHS Foundation Trust
Email: / Tel: 0114 215 9521

STH project reference number: STH21653



PHoenix is a study is for patients with a diagnosis of pulmonary arterial hypertension (PAH). This is a condition that results in high blood pressure in the blood vessels called pulmonary arteries (PA) supplying the lungs. High pressure in the PA can cause strain on the heart and progress to heart failure. There are now multiple, clinically approved medication combinations for PAH that aim to reduce the pressure in the heart and PA, but we don’t yet know how best to match these therapies to achieve the best treatment for you.

In this study, we will implant 2 small monitors, one in the PA (CardioMEMS) and a second under the skin near the heart (Confirm RX cardiac monitor). Patients will be able to record readings from any location (including while on holiday) which can be remotely accessed by clinical teams. The CardioMEMS is a wireless pressure sensor that can be used to provide daily measurements of pulmonary and flow in the PA and the Confirm Rx records abnormal heart rhythms. The medications we are comparing are riociguat and selexipag and patients will be tried on both of these medications (albeit in different orders and at different doses) to see how they respond. Along with patient reported quality of life (QoL) and activity assessments, these small monitors are highly sensitive in detecting early treatment effects for different medication combinations and will help us to determine the best treatments for individual patients with PAH and hopefully lead to fewer hospital visits.

Figure 1 gives a simple overview of the study:

Figure 1. Study overview



This study is sponsored by Sheffield Teaching Hospitals and recruitment will be run through The UK National Pulmonary Hypertension Clinical Studies Network (UNIPHY), a collaboration of each of the UK centres commissioned for the treatment of PAH, thereby providing access to all UK patients. Currently there are >6000 patients on targeted therapy all of whom are managed by a centre participating in this study. Patients will be screened by local teams from existing patient lists and approached through clinical and research teams. Patients cannot self-refer for recruitment into the study.

PHoenix opened to recruitment in June 2023 and aims to recruit 40 patients by January 2026.



Participants will be enrolled in the study for 27 weeks and are expected to come into clinic for 4 visits, along with tele-visits on non-clinic weeks.

Figure 2 gives a summary of the study including the visit procedures:

Figure 2. Summary of PHoenix trial assessments



  • MRC Experimental Medicine Award MR/W026279/1
  • Abbott Laboratories (Medical Devices Heart Failure Division)



If you are a health-care professional wishing to find out more about this study, please see our study entry on (NCT05825417). You may also contact the Clinical Trial Manager for more information at


Page updated July 2023