Elevated pulmonary vascular resistance is associated with increased lung transplant waitlist mortality among patients with chronic obstructive pulmonary disease and pulmonary hypertension: a retrospective cohort analysis

Abstract

BackgroundThe latest European Society of Cardiology and European Respiratory Society guidelines have changed the definition of both pre-capillary pulmonary hypertension (PH) and severe PH in chronic lung disease. The clinical significance of these new criteria are unclear among patients with chronic obstructive pulmonary disease (COPD)-PH. We aim to examine the clinical significance of the new PH definitions with regards to lung transplant waitlist mortality amongst patients with COPD-PH.MethodsThis was a retrospective cohort study of adult patients with COPD-PH listed for lung transplantation. Kaplan–Meier survival analyses were performed comparing patients with newly defined pre-capillary PH to those without pre-capillary PH and comparing patients with severe PH, defined as pulmonary vascular resistance (PVR) > 5 WU, to those without severe PH. Both mean pulmonary artery pressure (mPAP) and PVR were analyzed for potential cut-off points associated with increased waitlist mortality. Predictors of waitlist mortality were identified via Cox regression.ResultsAmong 6495 patients with COPD-PH listed for lung transplantation, pre-capillary PH was not associated with increased waitlist mortality (logrank p = 0.43), while severe PH was (logrank p < 0.001). Both severe PH (HR 1.79, 95% CI 1.22–2.60, p = 0.003) and PVR > 3.9 WU (HR 1.49, 95% CI 1.14–1.95, p = 0.004) were independently and significantly associated with increased waitlist mortality.ConclusionsPVR may serve as a strong predictor of lung transplant waitlist mortality among patients with COPD-PH as compared to other pulmonary hemodynamic parameters when predicting transplant waitlist mortality.