Platelet transfusions are essential in managing bleeding, particularly during cardiac surgeries, but are often hindered by supply shortages and logistical challenges. Traditional room-temperature platelets (RTP), stored at 20–24°C, have a shelf life of seven days to preserve post-transfusion survival, but this approach leads to significant wastage—up to 30%—and supply chain difficulties. Cold-stored platelets (CSP), kept at 1–6°C, present an alternative, offering extended shelf life and enhanced hemostatic activity. However, their use has been limited due to concerns about reduced post-transfusion circulation time and regulatory restrictions.
The PLTS-1 study examines a promising approach: delayed cold-stored platelets (DCSP). This strategy involves storing platelets at room temperature for the initial four days to maintain quality and then refrigerating them for up to 14 days. By bridging the benefits of both storage methods, DCSP aims to optimize platelet availability and efficacy while addressing logistical challenges. The study hypothesizes that DCSP offers non-inferior safety and hemostatic effectiveness compared to RTP, making it a viable solution for addressing platelet shortages.
The pilot study is a multicentre, randomized, active-control, blinded trial involving 50 adult cardiac surgery patients from two Canadian centers. Patients undergoing at least moderately complex cardiac surgery with cardiopulmonary bypass and requiring platelet transfusion will be randomized to receive either RTP or DCSP. The intervention group will receive DCSP—pathogen-reduced platelets stored at room temperature for four days, then refrigerated for at least 24 hours—while the control group will receive standard RTP, stored and transfused within seven days.
The study’s feasibility objectives focus on three critical metrics: achieving recruitment rates of at least 15% of eligible patients per center per month, ensuring that 90% of DCSP recipients have appropriate product availability, and maintaining clinician adherence to treatment assignments in over 90% of cases. Success in these areas will inform the design of a larger, definitive randomized controlled trial (RCT) to evaluate DCSP’s hemostatic effectiveness and safety.
Secondary outcomes aim to assess the intervention’s impact on bleeding management, measured through the number of allogeneic blood components transfused within 24 hours post-surgery, severity of bleeding, chest tube output, and coagulation parameters. Safety endpoints include the incidence of adverse events (AEs), thromboembolic complications, mortality, and patient-reported quality of life. Additionally, the study evaluates practical outcomes like the logistical feasibility of DCSP delivery and clinician adherence to blinding protocols.
The trial methodology incorporates robust randomization and blinding techniques to ensure unbiased results. Platelet products will be blinded using tamper-proof, temperature-controlled containers, with insulated gloves provided to prevent clinicians from distinguishing between RTP and DCSP during transfusion. Clinicians, patients, and outcome assessors will remain blinded to the treatment assignments, minimizing potential biases.
Cold-stored platelets have shown promise in preclinical and small pilot studies, demonstrating at least comparable hemostatic efficacy with no increased risk of adverse outcomes. CSP’s reduced metabolic activity and enhanced hemostatic properties make them particularly suited for acute bleeding scenarios, such as those encountered in cardiac surgery. By introducing delayed cold storage, DCSP provides a middle ground, balancing quality preservation with supply optimization. However, large-scale clinical trials are needed to confirm their efficacy and safety, as well as their logistical feasibility in real-world settings.
The PLTS-1 study’s outcomes could have far-reaching implications. If successful, DCSP could revolutionize platelet transfusion practices by extending shelf life, improving supply chains, and enabling the storage of platelets in smaller hospitals without specialized equipment like agitators. This approach could enhance access to platelets in remote or underserved areas, ensuring timely transfusion for critical patients. Additionally, the study’s findings could pave the way for regulatory approval and global adoption of DCSP as a standard practice in transfusion medicine.
The trial, funded by Canadian Blood Services, has been designed with scalability in mind. By identifying and addressing potential barriers during this pilot phase, the researchers aim to streamline the procedures for a larger definitive trial. Ultimately, the study could provide the evidence needed to establish DCSP as a safe, effective, and logistically superior option for managing bleeding in cardiac surgery and beyond.
