Does pretransplant left ventricular assist device therapy improve results after heart transplantation in patients with elevated pulmonary vascular resistance?

Abstract

Objective: Pulmonary hypertension (PH), defined as a pulmonary vascular resistance (PVR) >2.5 Wood units (WU) and (or) a transpulmonary gradient (TPG) >12 mmHg, is an established risk factor for mortality in heart transplantation. Elevated PVR in heart transplant candidates can be reduced using a left ventricular assist device (LVAD), and LVAD is proposed to be the treatment of choice for candidates with PH. We analyzed the effect on PVR of pretransplant LVAD therapy in patients with PH and compared posttransplant outcome with matched controls. Long-term survival was compared between heart transplant recipients with mild, moderate or severe PH and patients with no PH.

Methods: Heart transplant recipients 1988-2007 (n=405) were reviewed and divided into two groups with respect to pretransplant PVR: <2.5 WU (n=148) and >2.5 WU (n=158). From the group with PH, patients subjected to pretransplant LVAD therapy (n=11) were analyzed with respect to PVR at implant and at transplant and, with respect to outcome, compared to matched historical controls (n=22). Patients with PH without LVAD treatment (n=147) were stratified into three subgroups: mild, moderate and severe PH and survival according to Kaplan-Meier was analyzed and compared to patients with no PH.

Results: LVAD therapy reduced PVR from 4.3+/-1.6 to 2.0+/-0.6 WU, p<0.05. Three cases of perioperative heart failure required mechanical support whereas one control patient developed perioperative right heart failure requiring mechanical support. The incidence of other perioperative complications was comparable between groups. There was no difference in survival between LVAD patients and controls, 30-day survival was 82% and 91%, respectively and 4-year survival was 64% and 82%, respectively.

Conclusions: Pretransplant LVAD therapy reduces an elevated PVR in heart transplant recipients, but there was no statistically significant difference in posttransplant survival in patients with PH with, or without LVAD therapy. The study revealed no differences in survival in patients regardless of the severity of the PH.