Commentary: Supporting a left ventricular assist device to transplant, the right way.

Mickey S. Ising, MD, ME, and J. Hunter Mehaffey, MD, MSc

Right ventricular failure after LVAD managed with inotropes or mechanical support does not affect long-term survival after heart transplantation after accounting for preoperative liver dysfunction.

See Article page 146.

Management of the right ventricle (RV) following left ventricular assist device (LVAD) placement continues to be a conundrum for clinicians. RV failure following LVAD support occurs in 4% to 6% of patients and is associated with increased postoperative complications and mortality up to 50%., A portion of these patients require more durable RV support (ie, total artificial heart, durable biventricular assist device) and can eventually progress to transplant. However, those patients have reduced long-term posttransplant survival.

An additional patient population, those requiring temporary right ventricular assist device (RVAD) or inotropic support, has less well-known outcomes after transplant. Using the United Network of Organ sharing database, Barac and colleagues described the posttransplant survival of patients with LVAD stratified by the requirement of temporary support for RV failure. The latter group was further divided by whether patients required either mechanical or inotropic support. Importantly, patients with total artificial hearts and durable biventricular assist devices were excluded, as were those patients who supported with venoarterial extracorporeal membrane oxygenation. Unadjusted posttransplant survival was lower in patients with LVAD requiring RV support, both inotropic and mechanical, at 1, 3, and 5 years. In the landmark analysis of long-term survival (the first 100 days and beyond), there was no difference between the groups. Moreover, Cox-proportional analyses showed RV support was not a risk factor for posttransplant survival. These statements can seem counterintuitive at first but suggest that risk factors like liver dysfunction rather than RVAD or inotrope support lead to the diminished short-term survival.

There are multiple options for mechanical support of the RV, including venoarterial extracorporeal membrane oxygenation and RVADs. A recent report from the Society of Thoracic Surgeons database favored RVAD use, as it was associated with lower renal failure, limb ischemia, and operative mortality. Options for temporary, percutaneous RVADs exist, including the ProtekDuo and Impella RP, which have the advantage of being easily and quickly inserted under fluoroscopic guidance. In addition, they allow for patient ambulation and can be removed at the bedside, eliminating an additional trip to the operating room. Furthermore, they have the potential to be used pre-emptively to prevent RV failure or support the RV to transplant. RV failure post-LVAD is difficult to predict, and early intervention improves survival. The present article suggests that there is subpopulation of these patients that has equivalent posttransplant survival as those not requiring RV support. As mechanical circulatory support technology improves and clinical experience increases, this population will hopefully reveal itself and expand the opportunity for transplant of patients suffering for RV failure.