Abstract 4367893: Growing Use, Evolving Risk: A Contemporary Profile of Heart-Liver Transplantation

Background: Combined heart–liver transplantation (CHLT) offers long-term survival comparable with isolated heart transplantation. National use keeps rising, and 2019 was the first year adults with congenital heart disease (ACHD) represented > 50 % of all CHLTs. Whether these modern ACHD candidates reach transplant in poorer condition—and how their increasing complexity affects outcomes—remains uncertain. Methods: UNOS STAR files captured every adult CHLT (2000-2024). A Pre-modern era (2000-2018) was contrasted with a Modern era (2019-2024). Wilcoxon and Chi-squared tests compared characteristics; Kaplan–Meier curves and multivariable Cox models—including a prespecified Modern era × ACHD interaction—evaluated 90-day and 1-year mortality. Thirty-day conditional survival localised excess risk. Results: Among 586 heart-liver transplants from 2000–2024, annual volume more than doubled after 2019, rising from ~30 to over 70 per year (Image 1) . ACHD recipients also increased from 28% to 55% in 2019. Modern recipients were younger (median 43 vs 48 y) yet markedly sicker: ventricular-assist device 8.1 % vs 3.8 %, extracorporeal membrane oxygenation 2.7 % vs 0 %, prior sternotomy 60 % vs 36 % (all P < 0.05). Procurement distance quadrupled (198 vs 51 nm) and cold-ischemic time lengthened (3.7 vs 3.0 h; P < 0.001). Kaplan–Meier curves (Image 2) showed higher Modern-era mortality for the full cohort at 90 days (13.5 % vs 6.2 %) and 1 year (17.5 % vs 12.1 %; both P ≤ 0.007); ACHD-only curves revealed an even wider Modern-era deficit at 90 days (P = 0.003) and 1 year (P = 0.007). Each additional ischemic hour increased 1-year hazard 22 % (HR 1.22, P = 0.007). The Modern era × ACHD term was strong (HR 3.9, P = 0.009), indicating nearly four-fold excess risk for Modern-era ACHD recipients. Conditional curves equalised beyond day 30 (P = 0.36) ( Image 3). Deaths shifted toward cerebrovascular events (15 % vs 3 %), organ failure (23% vs 15% and primary graft failure (11 % vs 3 %) Conclusions: Survival has declined in the Modern era for CHLT overall and—most strikingly—for ACHD recipients, likely driven by greater physiologic and surgical complexity and longer cold ischemia. Because deaths cluster within the peri-operative window, earlier ACHD referral, cold-ischemia reduction, and ACHD-focused peri-operative pathways are essential. Allocation policies that broadened sharing expanded access but now require refinement to safeguard this vulnerable ACHD CHLT population.