MILD PULMONARY HYPERTENSION IN ADVANCED HEART FAILURE PATIENTS IS ASSOCIATED WITH BOTH ABNORMAL RESISTIVE AND PULSATILE LOAD AND LOWER 3-YEAR SURVIVAL

BACKGROUND Current guidelines require patients with heart failure (HF) being evaluated for advanced therapies such as heart transplantation or left ventricular assist device (LVAD) implantation to undergo right heart catheterization to identify the presence of pulmonary hypertension (PH). PH that is irreversible is a relative contraindication to heart transplantation and associated with poor prognosis. Based on the International Society for Heart and Lung Transplantation guidelines, reversibility is assessed with a vasodilator challenge if pulmonary artery systolic pressure (PASP) is > 50 mmHg, and either transpulmonary gradient (TPG) is > 15 mmHg or pulmonary vascular resistance (PVR) is > 3 WU. However, the most updated 6th World Symposium on Pulmonary Hypertension defined PH more broadly as to mean pulmonary artery pressure (mPAP) > 20 mmHg. As such, there is an intermediate group of patients with mild PH not meeting the threshold to receive a vasodilator challenge to determine whether mild PH is reversible. Our aim was to assess the hemodynamic characteristics of this group and determine whether they are at risk of worse clinical outcomes. METHODS AND RESULTS A retrospective analysis was performed of 175 patients with heart failure who were referred to our centre for right heart catheterization as part of evaluation for candidacy for advanced heart failure therapies. Patients were divided into three groups based on initial hemodynamics: patients with mPAP 20 mmHg that did not meet the threshold for vasodilator challenge (PH-V, n=77). Compared to the No-PH group, the PH-V group did not have a significantly different stroke volume index or cardiac index, however, they had a significantly higher PVR, indicating greater resistive load, and lower pulmonary artery compliance (PAC), indicating higher pulsatile load (Table). The PH-V group also had significantly higher mean right atrial pressure (mRAP) compared to the No-PH group, suggesting right ventricular decompensation. Composite pre-and post-intervention three-year survival after catheterization appeared lower in both PH+V and PH-V patients compared to the No-PH group (Figure). CONCLUSION HF patients assessed for advanced therapies identified as having mild PH have increased pulmonary pulsatile and resistive load, along with elevated right-sided filling pressures, and have increased mortality. Currently, this group does not undergo vasodilator testing to determine PH reversibility. Whether mild PH is modifiable, and its relationship to outcomes after heart transplantation or LVAD implant requires further study.