Static cold storage at 10 °C mitigates the influence of advanced donor age on heart transplant recipient outcomes

J Thorac Cardiovasc Surg. 2026 Jan 2:S0022-5223(25)01068-2. doi: 10.1016/j.jtcvs.2025.12.013. Online ahead of print.

Abstract

Objective: Advanced donor age has been associated with inferior outcomes after heart transplantation. Recent use of a 10 °C static cold storage has been shown to improve heart transplant recipient outcomes compared with traditional ice storage. This study evaluates the pertinence of donor age on posttransplant outcomes in cardiac allografts stored at 10 °C.

Methods: All adult heart transplant recipients, whose allografts were preserved with either 10 °C or ice static cold storage from a single institution from June 2023 to December 2024 were reviewed. Recipients receiving a multiorgan transplant or with congenital heart disease were excluded. Allografts from donor age younger than 18 years were also excluded. Patients were divided into 3 groups based on donor age: 18 to 30, 30 to 40, and older than 40 years. Outcomes included rates of severe primary graft dysfunction, and 30-, 90-, and 180-day mortality, and other clinical outcomes. A subgroup analysis was performed by comparing outcomes between donor ages 41 to 45 years versus older than 45 years.

Results: Four hundred eleven adult heart transplant recipients (10 °C static cold storage n = 135; ice n = 276; median age, 58.3 years [range, 48.6-64.9 years]; 25.1% women) were compared across donor-age strata of age younger than 30 years (n = 179), age 30 to 40 years (n = 137), and older than age 40 years (n = 95). Modeling donor age continuously, 10 °C attenuated the age-related risk versus ice for both outcomes: severe primary graft dysfunction odds ratio per year, 0.91 (95% CI, 0.83-0.97; P = .02) and 90-day mortality odds ratio per year, 0.89 (95% CI, 0.81-0.97; P = .006). After covariate balancing, 10 °C was associated with lower odds of severe primary graft dysfunction in donors aged 30 to 40 years (odds ratio, 0.15; 95% CI, 0.02-0.68; Holm-adjusted P = .03) and older than age 40 years (odds ratio, 0.20; 95% CI, 0.03-0.81; Holm-adjusted P = .04), with no difference for donor age younger than 30 years (odds ratio, 0.91; 95% CI, 0.36-2.32; Holm-adjusted P = .23). In a post hoc split of donor age older than 40 years (ie, 40-45 years vs 45 years and older), severe primary graft dysfunction was more frequent with ice in donor age older than 45 years (8.7% vs 0%); these exploratory findings were not multiplicity-adjusted.

Conclusions: The use of 10 °C static cold storage for cardiac allografts may mitigate the association between increased donor age and inferior posttransplant outcomes and possibly expand the donor pool.

Keywords: 10 °C cooler; donor age; heart transplant; static cold storage.