A pilot trial of long‐distance shipped, extended‐ and cold‐stored platelets in 100% plasma for cardiothoracic surgical bleeding

BACKGROUND: In this pilot trial, we tested the feasibility of conducting a randomized controlled trial in cardiac surgery patients using extended-, 100% plasma-, cold-stored, and long-distance-shipped platelets (CSPs). STUDY DESIGN AND METHODS: We conducted a single center, controlled, double-blind pilot study in adult patients undergoing elective redo or complex cardiothoracic surgery. Patients were allocated in a week-based block randomization scheme to receive either room temperature-stored platelets (RTPs) or CSPs shipped from a Texas-based blood center and stored between 10 and 14 days. The primary outcome was defined as the feasibility of recruitment and accrual. Several other secondary endpoints were assessed. All platelet units were screened for aggregates using RTP release criteria. RESULTS: In a post-hoc "as treated" analysis, 15 patients received RTPs, and 9 received CSPs (including 3 who received both). We found that most CSPs (58%) were not usable for transfusion due to the presence of aggregates. This resulted in an excess of subjects receiving RTPs; consequently, the final nine transfused participants were allocated to receive CSPs without randomization. We accrued 0.7 evaluable subjects/month of active enrollment, which was below our desired primary outcome feasibility target of ≥1.2. One death within 28 days occurred in the RTP transfusion group, while none occurred in the CSPs group. In vitro testing yielded contradictory results. CONCLUSION: Due to slow recruitment and the abundance of aggregates in CSPs, this pilot trial does not support the feasibility of the study protocol.