CHIPS Trial Comparing Cold and Room-Temperature Stored Platelets for Cardiac Surgery Patients

Over 50 years ago room-temperature stored platelets (RTPs) were shown to have increased platelet recovery and survival compared to cold-stored platelets (CSPs). However, about 10-20% of RTPs are outdated and wasted due to the short storage time. In 2023, the U.S. FDA approved CSPs up to 14 days to treat bleeding patients when RTPs are not feasible, but questions still remain about the hemostatic effectiveness of CSPs. The Chilled Platelet Study (CHIPS) was a phase 3 partially blinded noninferiority trial to compare CSPs stored up to 21 days to RTPs in patients at risk of bleeding undergoing cardiac bypass surgery; 1181 patients (mean age, 42 years; 68% male) were randomized 2:1 to receive either CSPs or RTPs at 27 hospitals in the U.S. and Australia. During the study, 650 patients were transfused CSPs and 339 standard RTPs. The primary outcome of hemostatic efficacy (a 5-point scale adapted from the universal perioperative bleeding score) was similar in both study arms—3.08 (95% C.I., 2.99 to 3.17) and 2.99 (95% C.I., 2.88 to 3.11) in the CSP and RTP arms, respectively. This suggests that CSPs may be hemostatically as effective as RTPs in cardiac surgery patients. However, re-exploration rates for bleeding and total volume of blood per kg transfused were higher for the CSP arm than for the RTP arm, and viscoelastic clot stiffness measures were lower in the group receiving CSPs. While CSPs may be useful for some patients, especially in locations where RTPs are not feasible to keep in inventory, more research is needed for other patient subgroups.

References:

1. Spinella PC, Zantek ND, VanBuren JM, Nicolson SC, et al; CHIPS Investigator Group. Cold and Room-Temperature Platelets in Cardiac Surgery: The CHIPS Randomized Clinical Trial. JAMA. 2026 Aug 17:e2613328. doi: 10.1001/jama.2026.13328. Epub ahead of print. PMID: 42606886; PMCID: PMC13482631.  
2. Hess AS. A World With Platelets Stored Cold for 21 Days: Chill and Tender. JAMA. 2026 Aug 17. doi: 10.1001/jama.2026.13885. Epub ahead of print. PMID: 42606881.
3. Estrera AL, Miller CC 3rd. A New Era for Cold-Stored Platelets in Cardiac Surgery. JAMA Surg. 2026 Aug 17. doi: 10.1001/jamasurg.2026.3888. Epub ahead of print. PMID: 42606878.
4. Cold and Room-Temperature Platelets in Cardiac Surgery: Research Summary. JAMA. 2026 Aug 17:e2613621. doi: 10.1001/jama.2026.13621. Epub ahead of print. PMID: 42606875.