A Pilot Trial of Platelets Stored Cold versus at Room Temperature for Complex Cardiothoracic Surgery

Abstract

Background This pilot trial focused on feasibility and safety to provide preliminary data to evaluate the hemostatic potential of cold-stored platelets (2° to 6°C) compared with standard room temperature–stored platelets (20° to 24°C) in adult patients undergoing complex cardiothoracic surgery. This study aimed to assess feasibility and to provide information for future pivotal trials. Methods A single center two-stage exploratory pilot study was performed on adult patients undergoing elective or semiurgent complex cardiothoracic surgery. In stage I, a two-armed randomized trial, platelets stored up to 7 days in the cold were compared with those stored at room temperature. In the subsequent single-arm stage II, cold storage time was extended to 8 to 14 days. The primary outcome was clinical effect measured by chest drain output. Secondary outcomes were platelet function measured by multiple electrode impedance aggregometry, total blood usage, immediate and long-term (28 days) adverse events, length of stay in intensive care, and mortality. Results In stage I, the median chest drain output was 720 ml (quartiles 485 to 1,170, n = 25) in patients transfused with room temperature–stored platelets and 645 ml (quartiles 460 to 800, n = 25) in patients transfused with cold-stored platelets. No significant difference was observed. The difference in medians between the room temperature– and cold-stored up to 7 days arm was 75 ml (95% CI, −220, 425). In stage II, the median chest drain output was 690 ml (500 to 1,880, n = 15). The difference in medians between the room temperature arm and the nonconcurrent cold-stored 8 to 14 days arm was 30 ml (95% CI, −1,040, 355). Platelet aggregation in vitro increased after transfusion in both the room temperature– and cold-stored platelet study arms. Total blood usage, number of adverse events, length of stay in intensive care, and mortality were comparable among patients receiving cold-stored and room temperature–stored platelets. Conclusions This pilot trial supports the feasibility of platelets stored cold for up to 14 days and provides critical guidance for future pivotal trials in high-risk cardiothoracic bleeding patients. Editor’s Perspective What We Already Know about This Topic What This Article Tells Us That Is New

Refrigeration of apheresis platelets in platelet additive solution (PAS‐E) supports in vitro platelet quality to maximize the shelf‐life

“…12 Importantly, the first contemporary clinical trial of coldstored platelets transfused units supplemented with PAS (PAS-C and PAS-E), and reported that they performed similarly to RT platelets for the treatment of bleeding in cardiac surgical patients. 44 While these studies provide essential insight, they also highlight the need for a greater understanding of the impact of storage solution on platelet quality during cold-storage.…”

Platelet Transfusion—Insights from Current Practice to Future Development

“…Both studies agree that CSPs are a useful alternative to RT platelets and could be even more effective in a post-traumatic context, where speed and strength of clot formation has priority. A recent pilot trial supports the feasibility of platelets stored cold for up to 14 days and provides critical guidance for future pivotal trials in high-risk cardiothoracic bleeding patients [ 77 ].…”

Lessons Learned From the Battlefield and Applicability to Veterinary Medicine – Part 2: Transfusion Advances

“…Similarly, Torres and colleagues demonstrated in a rat hemorrhage model that CSP participated equally in clot formation when compared to room temperature platelets (79). A randomized clinical trial in Norway demonstrated that 7 day CSP transfusion is at least equally as effective as room temperature platelets in treating post-operative bleeding after cardiac surgery in people (80). When paired with the logistical superiority of prolonged storage life and decreased risk of bacterial contamination, the functional equivalence of CSP prompted the military to request an FDA variance allowing 14 day cold storage of platelets.…”