Prognostic value of the pre-transplant diastolic pulmonary artery pressure-to-pulmonary capillary wedge pressure gradient in cardiac transplant recipients with pulmonary hypertension.

BACKGROUND: Although the transpulmonary gradient (TPG) and pulmonary vascular resistance (PVR) are commonly used to differentiate heart failure patients with pulmonary vascular disease from those with passive pulmonary hypertension (PH), elevations in TPG and PVR may not always reflect pre-capillary PH. Recently, it has been suggested an elevated diastolic pulmonary artery pressure-to-pulmonary capillary wedge pressure gradient (DPG) may be a better indicator of pulmonary vascular remodeling, and therefore, may be of added prognostic value in patients with PH being considered for cardiac transplantation.
METHODS: Using the United Network for Organ Sharing (UNOS) database, we retrospectively reviewed all primary adult (age > 17 years) orthotropic heart transplant recipients between 1998 and 2011. All patients with available pre-transplant hemodynamic data and PH (mean pulmonary artery pressure ≥ 25 mm Hg) were included (n = 16,811). We assessed the prognostic value of DPG on post-transplant survival in patients with PH and an elevated TPG and PVR.
RESULTS: In patients with PH and a TPG > 12 mm Hg (n = 5,827), there was no difference in survival at up to 5 years post-transplant between high DPG (defined as ≥3, ≥5, ≥7, or ≥10 mm Hg) and low DPG (<3, <5, <7, or <10 mm Hg) groups. Similarly, there was no difference in survival between high and low DPG groups in those with a PVR > 3 Wood units (n = 6,270). Defining an elevated TPG as > 15 mm Hg (n = 3,065) or an elevated PVR > 5 (n = 1,783) yielded similar results.
CONCLUSIONS: This large analysis investigating the prognostic value of DPG found an elevated DPG had no effect on post-transplant survival in patients with PH and an elevated TPG and PVR.