Importance  Platelet transfusion is critical in managing major bleeding, but access to liquid-stored platelets is limited by their 5- to 7-day shelf life. Cryopreserved platelets last up to 2 years and may improve availability, although their cost-effectiveness remains uncertain.

Objective  To evaluate the cost-effectiveness of cryopreserved platelets vs liquid-stored platelets for managing surgical bleeding.

Design, Setting, and Participants  An economic evaluation was conducted from the Australian government funder perspective alongside the CLIP-II randomized clinical trial, following intention-to-treat principles. Adult patients (age ≥18 years) undergoing cardiac surgery at 11 Australian tertiary hospitals between August 2021 and April 2024 were screened for eligibility. Eligible patients were those at high risk for platelet transfusion, identified by risk prediction score or clinician judgment, excluding female patients aged 18 to 55 years who were rhesus D (RhD) negative or with unknown RhD status and patients with coagulopathy or prior thromboembolism. Data were analyzed between January and April 2025.

Interventions  Participants received at least 3 units of either cryopreserved or liquid-stored platelets intraoperatively or within 24 hours postsurgery.

Main Outcomes and Measures  Costs were estimated in 2023 Australian dollars (A$) by assigning unit costs to patient-level resource use in each trial group, including intensive care unit (ICU) admissions, hospitalizations, and blood products. Effectiveness measures included postoperative bleeding volume (first 24 hours post-ICU admission and total), 90-day mortality, type 4 bleeding (based on the Bleeding Academic Research Consortium criteria), and serious adverse events. Given the 90-day follow-up period, discounting was not applied.

Results  Among 202 participants (median [IQR] age, 66 [57-74] years, 153 [75.7%] male), 104 received cryopreserved platelets and 98 received liquid-stored platelets. The mean difference in per-patient cost was A$15 035 (95% CI, −A$1878 to A$31 949) with cryopreserved platelets vs liquid-stored platelets. Mean blood loss within 24 hours following ICU admission was 121 (95% CI, 5 to 237) mL higher, total postoperative blood loss was 504 (95% CI, 145 to 862) mL higher, and type 4 bleeding was 12.3% (95% CI, 1% to 23.6%) higher with cryopreserved platelets compared with liquid-stored platelets. The difference in 90-day mortality between cryopreserved platelet and liquid-stored platelet groups was not statistically significant (7.4% [95% CI, −0.3% to 15.1%]). Only 1 serious adverse event was observed in each group.

Conclusions and Relevance  In this economic evaluation, cryopreserved platelets were dominated by liquid-stored platelets for managing bleeding in cardiac surgery. Further research is needed to assess the potential economic benefits of cryopreserved platelets in broader populations, particularly in regional and remote hospitals where platelet availability is limited.