FT. LAUDERDALE, FLA. – Left ventricular assist devices were associated with a significant survival advantage compared with all other support pathways implemented before heart transplant in an analysis of more than 13,000 patients.
There are a variety of support pathways available to eventual heart transplant recipients, but there is little information concerning comparative outcomes of patients bridged with the various treatments. Such information could provide valuable insight for clinical decision making and organ allocation policy, according to Dr. Tara Karamlou.
Dr. Tara Karamlou
A large database study was conducted using the United Network Organ Sharing Dataset to track outcomes of status 1 heart transplant recipients from 2000 to 2010. Dr. Karamlou of Seattle Children’s Hospital, and her colleagues, grouped transplant recipients based on the use of support pathways prior to transplant, including patients transitioning from one support pathway to another.
Dr. Karamlou reported her group’s results using Kaplan-Meir plots to compare time-related mortality among the different support-pathway groups. The study sought to uncover multivariable factors for time-related death using hazard regression models, she said at the annual meeting of the Society of Thoracic Surgeons.
There were six initial support pathways used in the 13,250 status 1 heart transplant patients identified in the database. These comprised inotropes (7,607); left ventricular assist devices (LVAD, 4,034); intra-aortic balloon pump (IABP, 729); biventricular assist devices (BIVAD, 521); extracorporeal circulation membrane oxygenation (ECMO, 316); and right ventricular assist devices (RVAD, 43).
"Multivariable analysis showed that LVAD use conferred a significant survival advantage compared with all other support pathways [hazard ratio, 0.71; P greater than .001]," said Dr. Karamlou. All other support treatments showed significantly increased risk of posttransplant death compared with LVAD treatment, including inotropes (HR, 1.1); RVAD (HR, 1.9); and ECMO (HR, 2.2).
There were 2,175 patients in the analysis who transitioned (either escalation or reduction) from one support pathway to another: no support to LVAD; LVAD to BIVAD; inotropes to LVAD; LVAD to inotropes; BIVAD to LVAD; and ECMO to LVAD. Among these patients, those who began with ECMO or BIVAD support followed by LVAD had improved posttransplant survival comparable to that of patients who began on LVAD and continued it throughout their course of pretransplant support.
LVAD support, especially in the setting of bridge to transplant, has clearly undergone several modifications that have made it safer and easier to implant and maintain, she added. Implantation of an LVAD in the current era, based on these findings, has survival superior to all other mechanical circulatory support pathways, and is equivalent to inotropic therapy. Additionally, in patients who are able to be weaned from biventricular support (ECMO and BIVAD therapy), LVAD implantation allows recovery of posttransplant survival to levels equivalent to primary LVAD–only therapy. This finding gives surgeons and cardiologists critical prognostic information regarding triage to pretransplant support pathways.
"Several key issues remain unresolved and, based on our results, will require further investigation. For example, the timing and clinical status of the patient surrounding both initial support and transition (either escalation or de-escalation) could not be determined from our data. In my mind, this is a crucial issue because delayed institution of mechanical support can have serious repercussions and, given the significantly increased risk of death with ECMO and BIVAD, a delay in de-escalation of therapy to LVAD could also confer an important survival disadvantage," she said.
"Organ allocation policy development and clinical decision making might benefit by considering these results in order to maximize the societal benefits of heart transplants," Dr. Karamlou concluded.
Dr. Karamlou reported having no financial disclosures.