Outcomes in Older Heart Transplant Recipients: A Subgroup Analysis of the GUARDIAN Heart Registry

10131 

Abstract Submission 

Dan Meyer (1), Andreas Zuckermann (2), Jacob Schroder (3), Andrea Eixeres Esteve (4), Rajamiyer Venkateswaran (5), Heinrich Maechler (6), Yasuhiro Shudo (7), Juan bustamante-Munguira (8), Koji Takeda (9), David D'Alessandro (10)

(1) Baylor Scott and White Health, Dallas, TX, (2) Department of Cardiac Surgery, Medical University of Vienna, Vienna, Vienna, (3) Duke University Medical Center, Durham, NC, (4) N/A, N/A, (5) Department of cardiothoracic surgery, Manchester University NHS Foundation Trust, Manchester, UK, Manchester, Manchester, (6) Medical University of Graz, Graz, NA, (7) Stanford University, Stanford, CA, (8) Hospital Clínico Universitario, Valladolid, Spain, (9) Columbia University, New York, NY, (10) Harvard University Medical School, Weston, MA

*Dan Meyer    -  Contact Me
Baylor Scott and White Health

Andreas Zuckermann    -  Contact Me
Department of Cardiac Surgery, Medical University of Vienna

Jacob Schroder    -  Contact Me
Duke University Medical Center

Andrea Eixeres Esteve    -  Contact Me
N/A

Rajamiyer Venkateswaran    -  Contact Me
Department of cardiothoracic surgery, Manchester University NHS Foundation Trust, Manchester, UK

Heinrich Maechler    -  Contact Me
Medical University of Graz

Yasuhiro Shudo    -  Contact Me
Stanford University

Juan bustamante-Munguira    -  Contact Me
Hospital Clínico Universitario

*Koji Takeda    -  Contact Me
Columbia University

*David D'Alessandro    -  Contact Me
Harvard University Medical School

*Dan Meyer    -  Contact Me
Baylor Scott and White Health

Objectives: Historically, older recipients have been considered to have poorer-post-transplant outcomes; however, the relationship between organ preservation quality and outcomes in older recipients has not been well-studied. Use of a controlled, moderate hypothermic cardiac transport system (CTS) is an organ preservation technology designed to maintain donor heart temperatures continuously between 4°C - 8°C, potentially mitigating tissue damage due to freezing temperatures in organs transported using traditional ice cooler methods, in addition to minimizing mechanical insult through a hermetically sealed chamber. We seek to investigate whether improved preservation of the donor heart prior to transplantation has an impact on post-transplant outcomes in older heart transplant recipients. This is especially important to European transplant programs, who typically have an older recipient population.

Methods: The GUARDIAN Heart Registry is an international, multicenter real-world registry comparing post heart transplant outcomes using CTS and traditional ice cooler methods for organ preservation and transport. Review of global data from the subset of recipients over 55 years old (N=347 Ice cooler, N=447 CTS) were evaluated and compared using summary statistics. Propensity-matching was also performed using criteria of donor age, recipient age, total ischemic time, site, recipient durable left ventricular assist device (LVAD) bridge, and transplant era (referencing the pre- and post-October 2018 UNOS organ allocation changes.

Results: Despite significantly longer average ischemic time by 24 minutes, there was a significant 32% reduction (p=0.01) in the rate of any primary graft dysfunction (PGD) and a 51% reduction (p=0.004) in the overall subset of patients >55 years old who received a heart preserved using the CTS compared to ice coolers (see Table). A significantly greater proportion of recipients in the CTS cohort also exhibited normal right ventricular (RV) function post-transplant, as well as a trending reduction in total hospital length of stay (p=0.08). Following propensity matching, the baseline variables were similar, and there remained significant reductions of 49% in PGD, 74% in severe PGD, as well as a 39% reduction in moderate to severe RV dysfunction (RVD) along with a trending reduction in RV-PGD (p=0.06) in those receiving hearts preserved using the CTS. Survival was statistically similar between cohorts in both analyses.

Conclusions: Use of controlled moderate hypothermic organ preservation was associated with meaningful improvements in post-transplant outcomes in older recipients, despite significantly longer ischemic times. Propensity matching of the data resulted in maintenance of these advantages, including significant improvements in PGD, severe PGD, moderate to severe RVD, and shorter time to weaning. These data add to the growing evidence supporting use of the moderate hypothermic CTS to optimize post-transplant outcomes, including in the subgroup of older recipients.

Heart Transplant