The current state of simultaneous heart-liver transplantation in the United States.

Simultaneous heart-liver transplantation (SHLT) has expanded in recent years, bolstered by increases in congenital heart disease (CHD) indications and improvements in organ preservation. We performed a contemporary analysis of patients undergoing SHLT for CHD vs non-CHD, further exploring the impact of machine perfusion (MP). Patients undergoing SHLT between 2010-2024 were retrospectively identified using the United Network for Organ Sharing database, assessing the primary outcome of patient survival and the secondary outcome of MP utilization. Five hundred thirty-five patients underwent SHLT, 224 (41.9%) with CHD indication and 311 (58.1%) with non-CHD. CHD recipients had significantly lower 1-year (72.9% vs 89.4%, P < .01) and 5-year survival (66.1% vs 81.4%, P < .01) compared to non-CHD recipients. CHD indication was independently associated with a 2-fold increased mortality risk, compared to a non-CHD diagnosis (Hazard Ratio: 2.31, 95% CI: [1.53, 3.47]). Decision tree boosting demonstrated a 2.9% higher relative mortality likelihood after SHLT for recipients with CHD. From 2022-2024, SHLT MP utilization for CHD increased; among 111 patients, 18.0% received an MP liver, 8.1% an MP heart, and 10.8% MP heart and MP liver. In this analysis of modern SHLT cases, patients with CHD had suboptimal outcomes; several donor and recipient factors also impacted mortality. Awareness of these factors can guide pretransplant optimization, donor/recipient matching, and strategic MP use to improve survival.