Mechanical circulatory support is effective to treat pulmonary hypertension in heart transplant candidates disqualified due to unacceptable pulmonary vascular resistance

Introduction
High pulmonary vascular resistance (PVR) in orthotopic heart transplantation (OHT) candidates is a risk factor of right ventricle failure after the procedure. However, the increase of PVR may be a consequence of the life-threatening deterioration of the left ventricle function. The use of mechanical circulatory support (MCS) seems to be the best solution, but it is reimbursed only in active OHT candidates.

Aim
We performed a retrospective analysis of MCS effectiveness in maintaining PVR at values accepted for OHT.

Material and methods
Starting from the year 2008 we identified 6 patients (all males, 42.8 ±17 years old) with dilated (n = 3), ischemic (n = 2), and restrictive cardiomyopathy (n = 1) in whom MCS – pulsatile left ventricle assist device (LVAD, n = 4), continuous flow LVAD (n = 1), and pulsatile biventricular assist device (BIVAD, n = 1) – was used at a time when PVR was unacceptable for OHT, and the reversibility test with nitroprusside was negative. After an average time of support of 261 ±129 days they were all transplanted.

Results
Right heart catheterization (RHC) results before MCS implantation were as follows: pulmonary artery systolic, diastolic, and mean pressure (PAPs/d/m) 60 ±20/28 ±7/40 ±11 mm Hg, pulmonary capillary wedge pressure (PCWP) 21 ±7 mm Hg, transpulmonary gradient (TPG) 19 ±7 mm Hg, cardiac output (CO) 3.6 ±0.8 l/min, PVR 5.7 ±2.1 Wood units (WU). Right heart catheterization results during MCS therapy were as follows: PAPs/d/s 27 ±11/12 ±4/17 ±6 mm Hg, PCWP 10 ±4 mm Hg, TPG 7 ±4 mm Hg, CO 5.1 ±0.7 l/min, PVR 1.4 ±0.6 WU. None of the patients experienced right ventricle failure after OHT with only one early loss due to multiorgan failure.

Conclusions
Mechanical circulatory support is an effective method of pulmonary hypertension treatment for patients disqualified for OHT due to high PVR.