Pulmonary Haemodynamics After Mechanical Therapy With PEA and BPA Predict Survival in Patients With CTEPH - A Prospective Analysis From the National UK CURATE Registry

Chronic thromboembolic pulmonary hypertension (CTEPH) can be treated by mechanical therapy with pulmonary endarterectomy (PEA) or balloon pulmonary angioplasty (BPA). Haemodynamic treatment goal is ill-defined. We explored post-procedure mean pulmonary arterial pressure (mPAP), pulmonary vascular resistance (PVR), and its relationship with 5-Year survival and exercise capacity Using 6-min Walk Distance (6MWD). Consecutive PEA and BPA patients from the UK CURATE database, treated between 2007 and 2022 and 2015-2022, respectively, stratified by 3-month follow-up mPAP and PVR by right heart catheter (RHC), had 5-year survival and 6MWD compared, adjusted for age, sex, drug treatment, and comorbidities in the PEA cohort. Those treated by PEA achieving an mPAP ≤ 25 mmHg had significantly better survival than higher mPAP groups (all pairwise comparisons p < 0.001), with no additional survival advantage below mPAP of 25 mmHg. Those with PVR ≤ 300 dyne.s.cm-5 also had better 5-year survival (p < 0.001). Continuous PVR modelling showed a 17% decrease in 5-year survival for every 100 dyne.s.cm-5 increase in post-operative PVR (p < 0.001). And these results remained significant after proportional hazard modelling. Those treated by BPA achieving an mPAP ≤ 30 mmHg and PVR ≤ 300 had a significantly better 5-year survival with no additional survival advantage below these values. Continuous PVR modelling showed a 48% decrease in 5-year survival for every 100 dyne.s.cm-5 increase in post-operative PVR (p = 0.008). In conclusion, post-procedure haemodynamics predict 5-year survival after mechanical therapy for CTEPH. Achieving a mPAP ≤ 25 mmHg for PEA and ≤ 30 mmHg for BPA, or a PVR ≤ 300 dyne.s.cm-5 for both, conferred a better prognosis.