Effect of Group 2 Pulmonary Hypertension Subgroups on Outcomes: Impact of the Updated Definition of Pulmonary Hypertension

Abstract

Background: Pulmonary hypertension (PH) is a common complication of end-stage heart failure (ESHF) and associated with increased mortality. The definition of PH has recently been changed from a mean pulmonary arterial pressure (PAPm) ≥25 mmHg to a PAPm >20 mmHg. Since this change, there are no data evaluating group 2 PH subgroups on outcomes. The purpose of this study was to determine the impact of updated group 2 PH subgroups on outcomes, as well as to evaluate the clinical, echocardiographic, and haemodynamic characteristics of subgroups, and determine predictors of PH in patients with ESHF.

Method: A total of 416 patients with ESHF with left ventricular ejection fraction (LVEF) ≤25% were divided into three groups. Pulmonary hypertension was defined as PAPm >20 mmHg. Primary outcome was defined as left ventricular assist device (LVAD) implantation, urgent heart transplantation (HT), or death. Secondary outcome was defined as LVAD implantation and HT.

Results: Over a median follow-up of 503.5 days, combined pre- and postcapillary PH (Cpc-PH) displayed greater risk of primary outcome than those with isolated postcapillary (Ipc-PH) (hazard ratio [HR], 1.57; 95% confidence interval [CI], 1.29-1.91; p<0.001) and those with no PH (HR, 2.47; 95% CI, 1.68-3.63; p<0.001). Patients with Ipc-PH demonstrated greater risk than those with no PH (HR, 1.57; 95% CI, 1.57-1.90; p<0.001). Likelihood ratios of updated PH criteria and old PH criteria (PAPm ≥25 mmHg) in identifying primary outcome were 75.6 (R²=0.179) and 72.09 (R²=0.164). Patients with PAPm 21-24 mmHg had a higher primary outcome than those with PAPm ≤20 mmHg. Severe mitral regurgitation, LVEF, grade 3 diastolic dysfunction, diabetes, and cardiac output were predictors of PH.

Conclusions: Pulmonary hypertension increases the risk of LVAD, urgent HT, or death, and Cpc-PH further increases risk in patients with ESHF. Compared to the previous definition, a new PH definition better discriminates death, going to urgent HT, or LVAD implantation for PH subgroups.

Keywords: Combined pre-and postcapillary pulmonary hypertension; End-stage heart failure; Isolated postcapillary pulmonary hypertension; Outcomes; Updated pulmonary hypertension definition.