Dr Fardad Esmailian (Los Angeles, Calif)
. This is an important retrospective study of the UNOS database from 2006 to 2015 that demonstrates survival of the patients bridged to cardiac retransplantation with current contemporary MCS devices has significantly improved compared with previous studies. Furthermore, overall survival for patients requiring ECMO as a bridge to retransplantation continues to be poor, findings that are similar to previous studies with respect to primary cardiac transplantation and is confirmed by the International Society for Heart and Lung Transplantation registry.
I have 4 questions. In the article, you have 10 patients in the MCS group and 14 patients in the non-MCS group who have IABPs. In my opinion, IABP is considered a temporary MCS. Therefore, this group of patients really should be categorized under the MCS group as opposed to 2 separate groups. This might change some of the data and will be a more accurate presentation of the MCS group. I would like to hear your thoughts.
Dr Koji Takeda (New York, NY)
. This is an issue of the UNOS database. We don't know exactly when the balloon pump was placed. Even if the patient has an MCS, the balloon pump should be removed at the time. There are some patients in the MCS group with concomitant balloon pump, for example, with ECMO and on a balloon pump. These are concomitant. So I don't know if this is data management alone. But in our institution, we don't call a balloon pump an MCS anymore. In each institution, perhaps it is different.
Dr Esmailian. Furthermore, in the article you had 30 patients in the MCS group and 13 patients in the non-MCS group who received retransplants in 1 year or less. In the ECMO group, 15 patients, or 50% of the ECMO group, received retransplants in 1 year or less of their primary transplant, with 14 of those 15 patients receiving transplants in 3 months or less for a retransplant.
Knowing that the patients who receive retransplants within 1 year of primary transplantation have significantly worse survival, do you think the conclusion about the ECMO could be skewed when you have such a large number of patients with ECMO who receive retransplants in a short time in the database?
Dr Takeda. Generally, patients who require ECMO or who require in the acute phase retransplant are a very sick population, maybe cardiogenic shock status rescued by ECMO. In my opinion, those patients, unless the patient will recover from shock status, perhaps will be extubated to contemporary ECMO management; if those were managed ECMO patients, in my mind, the outcome may improve. But in general, this ECMO cohort included patients in shock. If we operate on these patients in shock on ECMO, as you can see, the outcome is not good. So those patients should not receive retransplant.
Dr Esmailian. As a follow-up to that question, there were 15 patients in the ECMO group who received transplant after 1 year of their initial transplant. Do you have the information on that subgroup of patients in terms of their outcome?
Dr Takeda. Actually, no.
Dr Esmailian. I think it will be important to look at those 2 subgroups in the ECMO cohort and try to separate them, because, as you know, the patients receiving transplant at less than 1 year have significantly poor survival. Finally, although the numbers are small, in the article you had 10 patients who were bridged to more than 1 device before retransplantion. Do you know if they are bridged from ECMO to a durable device and then to transplant, and if they were, what were the timing and results?
Dr Takeda. Actually, there are no detailed data. This is a limitation of the UNOS database.
Published online: May 13, 2019
© 2019 Published by Elsevier Inc. on behalf of The American Association for Thoracic Surgery