Health care utilisation in patients with mild pulmonary hypertension - EVIDENCE-PAH UK study
Authors: Karia N , Dhunnookchand R , Howard L , Kiely D , Lordan J , Mccabe C , Pepke-Zaba J , Knight D , Muthurangu V , Coghlan J G 
Published: October 2024

Abstract

Background
ESC/ERS 2022 guidelines1, redefined precapillary pulmonary hypertension (PH) as patients with a mPAP&gt;20mmHg,PVR&gt;2WU and PAWP&lt;15mmHg1.We and others identified patients with mildly elevated pulmonary artery(PA) pressures demonstrates a higher mortality2-4. It is important to understand healthcare resource utilisation(HRCU) in this newly defined group who now meet the thresholds for diagnosis, however, treatment options are limited.

Purpose
The EVIDENCE-PAH aims to describe mortality and hospitalisation outcomes, baseline demographics in mild elevations in PA pressure in a national cohort. We report preliminary analysis of HRCU from data obtained from NHS Hospital Episode Statistics(HES); inpatient admissions, outpatient(OP) and emergency attendances(AE).

Method
Retrospective analysis of all patients with a mPAP&lt;25mmHg and a sample of patients with a mPAP≥25mmHg at index-right heart catheterisation(RHC), across all UK PH tertiary centres between 2009-2017 with hospitalisation data captured 24-months pre and post index-RHC. For analysis patients were categorised into 3 groups; normal haemodynamics(mPAP&lt;21mmHg & PVR≤2WU), mild elevation in haemodynamics(mPAP&lt;21mmHg & PVR&gt;2WU, mPAP21-24mmHg with all PVR groups, mPAP&gt;25mmHg & PVR≤3WU) and abnormal haemodynamics(mPAP&gt;25mmHg & PVR&gt;3WU).

Results
A total of 2413(82.3%) patients had complete records 24-months pre and post index-RHC; 561(23.2%), 1228(50.9%) and 624(25.9%) in the normal haemodynamic, mildly elevated haemodynamic and abnormal haemodynamic groups respectively. Figure 1, demonstrates HRCU; Unscheduled admissions are significantly higher in the abnormal haemodynamic group 24-months pre index-RHC compared to the normal/mild elevations in haemodynamic groups (p-value&lt;0.05). There was reduction in unscheduled encounters 24-months post index-RHC in the normal/abnormal haemodynamic group. No significant difference identified in AE attendance and OP 24-months post across all haemodynamic groups. Total HRCU demonstrates a lower attendance 24-months post RHC in normal versus abnormal haemodynamic group (p-value&lt;0.05). Multivariate analysis demonstrates unscheduled admissions 24-months pre/post index RHC, as an independent predictor of survival, adjusted for age, sex and haemodynamics (Figure 2;p-value&lt;0.05).

Conclusion
Unscheduled admissions may act as a discriminator identifying advanced PH (abnormal haemodynamics), but not normal versus mild elevations in haemodynamics. Meanwhile AE and OP attendances fails to discriminate between normal and mild elevation in haemodynamics. Unscheduled admissions 24-months pre/post index RHC is an independent predictor of survival which may lend as a useful surrogate marker for mortality in the PH population as a whole. Although total HRCU appears high across haemodynamics groups referred to PH centre, in the 24-months post RHC HRCU increases in the mild/abnormal haemodynamic groups, this may represent ongoing unmet need in this group.