TOPLINE:

Cryopreserved platelets with a 2-year shelf life did not demonstrate noninferiority to conventional liquid-stored platelets in controlling bleeding after cardiac surgery, with the upper bound of the 95% CI indicating a potential increase in blood loss of up to 34%. Patients who received cryopreserved platelets experienced 42% higher intraoperative blood loss, with a greater proportion of these patients requiring transfusions of blood products.

METHODOLOGY:

• Platelets are vital for hemorrhage control, but storage at room temperature is limited to 5-7 days, causing 25%-33% wastage and restricted availability for smaller or remote hospitals. Cryopreservation with dimethyl sulfoxide extends the shelf life to 2 years and is operationally feasible, but clinical evidence of its safety and effectiveness remains limited.
• Researchers conducted a multicenter, randomized, double-blind, parallel-group noninferiority trial (CLIP-II) involving adults who underwent cardiac surgery and were at a high risk of requiring a platelet transfusion; participants were randomly assigned to receive up to three units of either group O cryopreserved platelets or conventional liquid-stored platelets, commencing intraoperatively or within 24 hours of ICU admission.
• Of 388 randomly assigned patients, 202 received platelet transfusions; of these, 104 received cryopreserved platelets (mean age, 65.5 years) and 98 received liquid-stored platelets (mean age, 63.2 years).
• The primary outcome was postsurgical chest drain bleeding within the first 24 hours following ICU admission, with noninferiority defined as less than 20% greater bleeding.
• More patients in the cryopreserved group received open-label platelets after the first study unit but before all three study units were transfused (25% vs 3.1%), and the total number of study platelets plus open-label platelet units was higher (median, 2 vs 1 units); despite this, the 24-hour platelet nadir was lower in the cryopreserved group than in the liquid-stored group (median, 103 vs 140 × 10³/μL).

TAKEAWAY:

• The volume of chest drain bleeding over the first 24 hours in the ICU was 605 mL with cryopreserved platelets vs 535 mL with liquid‑stored platelets (ratio of geometric means, 1.13; 95% CI, 0.96-1.34; P = .07). The upper bound of the 95% CI indicated a “potential increase in blood loss of up to 34%,” the authors of the study wrote. As the CI extended beyond the noninferiority threshold, noninferiority of cryopreserved platelets was not established.
• Volumes of intraoperative and total perioperative blood loss were significantly higher in the cryopreserved group (ratio of geometric means, 1.42; 95% CI, 1.12-1.80 and 1.31; 95% CI, 1.07-1.60, respectively), as was the volume of chest drains at ICU admission (ratio of geometric means, 2.48; 95% CI, 1.40-4.38).
• More patients in the cryopreserved group than in the liquid‑stored group were transfused red cells (74.0% vs 59.2%; absolute difference, 14.9%), fresh frozen plasma, and cryoprecipitate. Although the time to initiation of aspirin and heparin was similar between groups, clinicians removed surgical drains at or before 24 hours more often in the liquid-stored group.
• Rates of prespecified adverse events did not differ significantly, although mortality was numerically higher in the cryopreserved group (12.5% vs 5.1% by day 90). The clinical course was prolonged with cryopreserved platelets: median duration of ventilation, 25.5 vs 23.6 hours; median length of ICU stay, 3.8 vs 3.0 days; and median length of hospital stay, 10.9 vs 9.1 days.

IN PRACTICE:

“Cryopreserved platelets did not meet criterion for noninferiority to liquid-stored platelets in treating bleeding during and after cardiac surgery,” the authors of the study wrote.

SOURCE:

The study, led by Michael C. Reade, MBBS, DPhil, Medical School, University of Queensland, Brisbane, Australia, was published online in JAMA.

LIMITATIONS:

The findings were specific to high-risk cardiac surgery and may not be generalized to trauma, obstetric, or gastrointestinal hemorrhage. Cryopreserved platelets were reconstituted in fresh frozen plasma, while many liquid units were in platelet additive solution, which could have confounded comparisons. Additionally, a higher proportion of patients in the cryopreserved group received open-label liquid platelets before completing all study units, which may have reflected clinician perception or imperfect blinding.

DISCLOSURES:

The study received funding from the Australian National Health and Medical Research Council, Australian Red Cross Lifeblood, and the Australian Defence Force through its 2011-2022 relationship with the University of Queensland. Two authors disclosed being employed with the Australian Defence Force, and three authors disclosed being employed with Australian Red Cross Lifeblood. Full disclosures are noted in the original article.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.