This is a pilot trial to discover the feasibility of recruiting 50 pts over the course of 12 months. The trial is testing the efficacy of using cold-stored vs. room temperature stored (current standard of care) platelets to treat bleeding in persons with hematological disorders and thrombocytopenia.

Patients with hematologic malignancies or marrow aplasia are at increased risk of bleeding. While prophylactic platelet transfusions reduce the risk of bleeding compared with no prophylaxis, a significant risk of bleeding remains, with 43-54% of patients with a hematologic malignancy or marrow aplasia receiving chemotherapy, immunotherapy, or hematopoietic stem cell transplant (HSCT) experiencing WHO grade 2 or higher bleeding [Stanworth et al. NEJM 2013; Gernsheimer et al, Blood 2020]. Improved efficacy of therapeutic platelet transfusions would benefit this patient population. In vitro data suggests that cold-stored platelets have greater hemostatic responsiveness than those stored at room temperature.

This study will evaluate the feasibility of a randomized clinical trial comparing cold- and room temperature storage in patients admitted to hospital with a hematologic malignancy or marrow aplasia. Results will inform estimates of transfusion requirements and changes in bleeding severity for power calculations, inform management of a cold-stored platelet inventory, and will provide data on the use of cold-stored platelets in the Canadian health-care setting.

Inclusion Criteria:

1. Adult patients (age ≥ 18) admitted to Malignant Hematology ward with hematologic malignancy or marrow aplasia, this may include patients undergoing chemotherapy, immunotherapy, or hematopoietic stem cell transplant or patients admitted for symptom management.
2. Moderate thrombocytopenia, platelet concentration 10-100 x109/L
3. Platelet transfusion ordered to treat bleeding

Exclusion Criteria:

1. Severe thrombocytopenia (platelet concentration <10 x 109/L)
2. Known platelet refractoriness requiring HLA or HPA selected platelet concentrates
3. International normalized ratio (INR) >2.0
4. Activated partial thromboplastin time (aPTT) >40 seconds
5. Therapeutic anticoagulation (unfractionated heparin, low molecular weight heparin, warfarin, direct oral anticoagulant)
6. Known congenital bleeding disorder
7. History of unprovoked venous thromboembolic disease
8. Transfusion of platelet concentrate for >grade 2 bleeding in preceding 24 hours
9. Order for multiple platelet transfusion at once
10. Refusal of blood transfusion
11. Prior participation in CoVeRTS-HM trial
12. Participation in other clinical trials with interventions that may affect CoVeRTS-HM treatment or outcome
13. Unable or unwilling to provide informed consent

The investigator and participant will both be blinded to the study treatment (whether they receive cold stored vs. room temperature stored platelets). The clinical staff who will administer the platelets and complete the bleeding assessment tool will not be informed of the group assignment. The outcome assessors/adjudication committee will be blinded.