Peek behind the paper – Durable left ventricular assist devices as a bridge to transplantation: what to expect along the way?
Andrea Fernandez Valledor completed her Cardiology Fellowship at the Hospital Clinic of Barcelona (Spain), where she subsequently joined the Advanced Heart Failure and Heart Transplantation team. In 2022, she became a member of the Research Team at Columbia University Irving Medical Center (NY, USA). Her primary research at Columbia has been dedicated to studying post-heart transplant rejection, with a particular focus on utilizing molecular diagnostics to advance the understanding and management of transplant rejection.
Read the full article in Expert Review of Medical Devices here>>
Please provide a short summary of your paper: ‘Durable left ventricular assist devices as a bridge to transplantation: what to expect along the way?’
The limited availability of heart donors, combined with significant advancements in left ventricular assist device (LVAD) technology, has led to the increased adoption of LVADs as a bridge to transplant (BTT) for patients with end-stage heart failure. This approach provides a vital alternative to immediate heart transplantation by stabilizing patients while they await a suitable donor heart. However, in 2018, the United Network for Organ Sharing (UNOS) updated its organ allocation policy, resulting in a significant decrease in the use of LVADs for BTT in the United States. Under the new system, stable patients on LVAD support were reclassified as status 4 (out of 6 status levels) and were no longer prioritized on the transplant list. This contrasts with the previous allocation system, where they were classified as status 1B (2 out of 3 status levels). To address this decline, experts suggest that further adjustments to the allocation policy may be necessary. Potential modifications could consider factors such as the duration of time a patient has been on device support, their age and the types of complications they have experienced. This review provides a comprehensive analysis of the current state of LVAD use as a BTT, covering essential topics such as patient selection criteria, strategies for optimizing patients prior to implantation and the outcomes observed following transplantation.
Why is the topic of LVADs in the context of heart transplantation important right now?
The topic of LVADs in the context of heart transplantation is particularly important right now due to ongoing challenges and changes in the United States heart transplant system. Although the use of LVADs as a BTT has declined in recent years due to changes in the organ allocation policy, they still offer a crucial solution for patients who experience deterioration while on temporary mechanical support. With current waiting times for certain blood types extending up to 8−12 weeks, there is growing concern about the risks associated with prolonged stays on temporary support, such as complications from intensive care, limited mobility and device-related issues. This situation raises the question of whether early LVAD implantation, after achieving hemodynamic stability and restoring end-organ function, might be a more advantageous option. Additionally, the difficulty of transplanting patients on stable, durable LVAD support within the current system complicates decision-making. While anticipated changes to the allocation system may eventually increase the incentive for using LVADs as BTT, these changes are not expected for several years, making this an urgent and evolving issue.
Do you have any tips for best practice for clinicians interested in this procedure/approach?
The current allocation system is shaped by both physician and programmatic decisions. Up to 50% of transplants involve exception requests, which bypass the prioritization system meant for the most critically ill patients. While some exceptions address cases not fully covered by the system, many result from physicians advocating for particular patients. The broad criteria for status 2 further complicate the allocation process. Grouping patients with diverse profiles under status 2 requires careful evaluation, as combining those with adverse hemodynamics but preserved perfusion with those experiencing cardiogenic shock and end-organ damage makes it challenging to prioritize the most critically ill patients. To address these issues, the United States allocation policy could be adjusted — such as redefining status 2 profiles and incorporating factors like days on device support, age and type of complications after LVAD implantation. In the end, a well-developed continuous scoring system could offer the best solution for patients awaiting heart transplantation. A crucial component to consider is how to factor in the length of time on LVAD support. Much like how end-stage renal patients receive a status boost based on their years on dialysis, it would be reasonable to create a system where LVAD patients with longer support durations receive a similar boost, thereby providing them a clearer pathway to transplantation after an extended period on LVAD support.
First patient receives artificial heart in bridge-to-heart transplant procedure
An artificial heart aims to become a long-term treatment option for patients with heart failure.
What ongoing research / upcoming research and activities do you planned in this space?
Due to the current allocation policy, wait times for high-urgency patients (status 2−3) have increased, leading to more complications from prolonged use of temporary mechanical circulatory support and extended ICU stays. These trends may prompt a reevaluation of the LVAD BTT approach, especially for populations at higher risk of adverse outcomes during the wait. To address this, our center has initiated a registry to assess the relative complications and outcomes of BTT versus direct-to-transplant approaches in patients over 70 years old (or 65+ with comorbidities). While a randomized trial would provide the most robust answers, it is currently uncertain whether there is enough equipoise to support such a trial.
The opinions expressed in this article are those of the author and do not necessarily reflect the views of Medical Devices Zone or Taylor & Francis Group.