Prognostic Implications of the Novel Pulmonary Hypertension Definition in Patients with Aortic Stenosis after Transcatheter Valve Replacement

Abstract

Introduction: Pulmonary hypertension (PH), traditionally defined as a mean pulmonary artery pressure (PAP) ≥ 25 mmHg, is associated with poor outcomes in patients undergoing a transcatheter aortic valve replacement (TAVR) for severe aortic stenosis (AS). Recently, a novel definition for PH has been proposed, placing the cut-off value of mean PAP at 20 mmHg, and introducing pulmonary vascular resistance as an exclusive indicator for the pre-capillary involvement. In light of the novel criteria, whether PH still preserves its prognostic significance remains unknown. Methods: The study population consisted of 380 patients with AS, who underwent a right heart catheterization before TAVR. The cohort was divided according to the presence of PH (n = 174, 45.7%) or not. Patients with PH were further divided into the following groups: (1) Pre-capillary PH ((Pre-capPH), n = 46, 12.1%); (2) Isolated post-capillary PH ((IpcPH), n = 78, 20.5%); (3) Combined pre and post-capillary PH ((CpcPH), n = 82, 21.6%). The primary endpoint was all-cause mortality at 1 year. Results: A total of 246 patients (64.7%) exhibited mean PAP > 20 mmHg. Overall, the presence of PH was associated with higher 1-year mortality rates (hazard ratio (HR) 2.8, 95% CI: 1.4−5.8, p = 0.004). Compared to patients with no PH, Pre-capPH and CpcPH (but not IpcPH) were related to higher 1-year mortality (HR 2.7, 95% CI: 1.0−7.2, p = 0.041 and HR 3.9, 95% CI: 1.8−8.5, p = 0.001, respectively). This remained significant even after the adjustment for baseline comorbidities. Conclusions: Pre-interventional PH according to the novel hemodynamic criteria, is linked with poor outcomes in patients undergoing TAVR for severe AS. However, this is mainly driven by patients with mean PAP ≥ 25 mmHg. Patients with a pre-capillary PH component as defined by increased PVR present an even worse prognosis as compared to patients with isolated post-capillary or no PH who present comparable 1-year mortality rates.

Keywords: aortic stenosis; pulmonary hypertension; transcatheter aortic valve replacement.

Figure 1

Study flow chart, and PH groups of the study population, according to the novel definition. Reclassification effect of PH groups as compared to the criteria proposed in the 2015 ESC guidelines on PH diagnosis and treatment. TAVR: Transcatheter aortic valve replacement; PA: Pulmonary artery pressure; PAWP: pulmonary arterial wedge pressure; PVR: pulmonary vascular resistance; WU: Wood Units; PH: pulmonary hypertension; Pre-cap: Pre-capillary; Ipc: Isolated post-capillary; Cpc: Combined pre and post-capillary.

Figure 2

Kaplan–Meier curves for all-cause mortality at 1 year. Population stratified according to (A) whether PH was present or not, (B) mPAP quartiles, (C) the presence of mean PAP between 21 and 24 mmHg and (D) hemodynamic type of PH. HR: hazard ratio; p values refer to unadjusted hazard ratios from Cox regression analysis. CI: confidence intervals; TAVR: Transcatheter Aortic Valve Replacement. PH: Pulmonary hypertension; AS: Aortic stenosis; PA; Pulmonary artery.

Figure 3

Kaplan–Meier curves for all-cause mortality at 1 year. Population stratified according to (A) PAWP, (B) PVR, (C) PAC, and (D) AS staging. HR: hazard ratio; p values refer to unadjusted hazard ratios from Cox regression analysis. CI: confidence intervals; TAVR: Transcatheter Aortic Valve Replacement; PAWP: Pulmonary artery wedge pressure; PVR: Pulmonary vascular resistance; PAC: Pulmonary artery compliance; AS: Aortic stenosis.