Improving the Diagnosis and Assessment of Pulmonary Hypertension by Optimising Clinical Pathways

Pulmonary hypertension (PH) is a life limiting condition, however with the development of new management strategies and treatments overall survival has improved. Nevertheless, there are still improvements to be made in the assessment of patients with PH and enhancing clinical pathways to assist with screening of patients and ongoing monitoring to allow for early detection of deterioration prompting the need for escalation of treatments.
The first part of this thesis, examines the use of natriuretic peptides in field of PH. Examining N-terminal prohormone of brain natriuretic peptide (NT-proBNP) and brain natriuretic peptide (BNP) in particular, both of which are incorporated into most risk stratification models in PH. An important limitation of these natriuretic peptides is the long laboratory processing time. Chapter 3 explores a point-of-care test (POCT) for NT-proBNP and BNP and examines its reliability. In addition, a real-world test of NT-proBNP’s potential role in remote monitoring is examined by posting blood samples to a laboratory for analysis of NT-proBNP.
The second part of this thesis, chapter 4, investigates the impact of an integrated acute pulmonary embolism (PE) pathway, in a large tertiary pulmonary vascular disease referral centre upon diagnostic rates, disease severity and outcome of patients who go on to develop chronic thromboembolic pulmonary hypertension (CTEPH) following a PE.
In conclusion, utilising POCT for both NT-proBNP and BNP produced reliable results that were quicker and easier to process than laboratory samples. Furthermore, despite a delay in processing by posting blood samples the NT-proBNP results were reliable highlighting the potential for use of this biomarker in the remote monitoring of patients with pulmonary arterial hypertension (PAH).
Since the incorporation of the integrated PE pathway, there have been increased population-based rates of both CTEPH diagnosis and pulmonary endarterectomy (PEA), identifying CTEPH patients earlier and with less severe disease. It was also demonstrated that the absence of major transient risk factors for PE and computed tomography (CT) features of PH at diagnosis predict the development of CTEPH.