Do Patients Supported With Continuous-flow Left Ventricular Assist Device Have a Sufficient Risk of Death to Justify a Priority Allocation? A Propensity Score Matched Analysis of Patients Listed in UNOS Status 2

Impact of duration of mechanical support on heart transplantation: Hasty transplantation may not have a good long-term outcome

BACKGROUND

Mechanical circulatory support (MCS) has been widely utilized in critically ill cardiac transplant candidates. Few studies have investigated the impact of duration of MCS before heart transplantation (HTx) on long-term patient survival.

METHODS

A retrospective HTx database was reviewed between 2009 and 2019. Patients who did not or did undergo MCS before HTx were categorized into two groups: (1) A (did not) and (2) B (did), respectively. A receiver operating characteristic (ROC) curve was plotted to assess the cutoff level of MCS duration before HTx in evaluating 5-year survival.

RESULT

A total of 270 HTx patients (group A: 120, group B: 150) were analyzed. Group B patients had a higher percentage of blood type O, a higher incidence of resuscitation, a shorter listing duration, and a higher likelihood of having United Network for Organ Sharing (UNOS) 1A status than group A. The ROC curve revealed 24 days as a good cut-off level for determining the best MCS before HTx timing. Group B was categorized into two subgroups: (1) B1 (MCS < 24 days, n = 65) and (2) B2 (MCS > 24 days, n = 85). B2 had a higher incidence of cardiopulmonary resuscitation (CPR), hemodialysis, longer waiting time after MCS, and better ventricular assist device implantation than B1. However, the survival curves showed that B1 outcomes were significantly worse than in groups A and B2. Groups A and B2 had similar survival curves without an increased incidence of infection.

CONCLUSION

The preliminary data demonstrated that a longer duration of MCS may be associated with better outcomes than urgent HTx.

Decreased frequency of transplantation and lower post-transplant survival free of re-transplantation in LVAD patients with the new heart transplant allocation system

PURPOSE

To evaluate the effect of the new heart transplant (HT) allocation system in left ventricular assist device (LVAD) supported patients listed as bridge to transplantation (BTT).

METHODS

Adult patients who were listed for HT between October 18, 2016 and October 17, 2019, and were supported with an LVAD, enrolled in the UNOS database were included in this study. Patients were classified in the old or new system if they were listed or transplanted before or after October 18, 2018, respectively.

RESULTS

A total of 3261 LVAD patients were listed for transplant. Of these, 2257 were classified in the old and 1004 in the new system. The cumulative incidence of death or removal from the transplant list due to worsening clinical status at 360-days after listing was lower in the new system (4% vs. 7%, P = .011). LVAD Patients listed in the new system had a lower frequency of transplantation within 360-days of listing (52% vs. 61%, P < .001). A total of 1843 LVAD patients were transplanted, 1004 patients in the old system and 839 patients in the new system. The post-transplant survival at 360 days was similar between old and new systems (92.3% vs. 90%, P = .08). However, LVAD patients transplanted in the new system had lower frequency of the combined endpoint, freedom of death or re-transplantation at 360 days (92.2% vs. 89.6%, P = .046).

CONCLUSION

The new HT allocation system has affected the LVAD-BTT population significantly. On the waitlist, LVAD patients have a decreased cumulative frequency of transplantation and a concomitant decrease in death or delisting due to worsening status. In the new system, LVAD patients have a decreased survival free of re-transplantation at 360 days post-transplant.