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.
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.
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.
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.
- Platelets are stored at room temperature (20° to 24°C) with constant agitation for 5 to 7 days to maximize recovery and survival in vivo after transfusion
- Cold storage of platelets at 2° to 6°C would provide extended shelf life, and laboratory investigations indicate improved hemostatic function, which may be beneficial for treatment of bleeding
- No significant difference was observed between cold-stored and room temperature–stored platelets for hemostatic function assessed by chest drainage, total blood usage, platelet function, and clinical outcomes
- This pilot trial supports the potential feasibility of cold-stored platelets for clinical use and provides potential guidance for future pivotal trials