NCT02058134.

Methods	Participants undergoing open‐heart surgery with cardiopulmonary bypass (CPB) with an increased risk of bleeding identified preoperatively were randomised to one of two groups. Randomisation was carried out with a 1:1 ratio and was stratified for the inclusion criteria. The method of allocation concealment is not described. The study was not blinded.
Participants	68 participants undergoing open‐heart surgery with CPB for coronary artery disease, aortic stenosis, aortic insufficiency, mitral insufficiency, or aortic aneurysm were randomised to one of two groups: Interventional group (Autotransfusion) Control group A total of 68 participants were recruited prior to study termination.
Interventions	Interventional group (Autotransfusion): underwent heart surgery with intra‐ and postoperative use of the CardioPAT cell saver. The CardioPAT cell saver collects blood from the operative site and from the chest tubes; it washes and concentrates the red blood cells prior to retransfusion to the patient. The group also received identical blood‐conserving strategies as the control group. Control group: underwent heart surgery with blood‐conserving strategies that are currently standard routine at the host institution.
Outcomes	Outcomes reported: rate of allogeneic transfusion with red blood cells during hospital admission
Notes	Transfusion protocol: a transfusion protocol is not described within the trial registration. Prospective registration status: the trial was registered retrospectively on clinicaltrials.gov. Ethical approval: it is not clear whether the study was approved by an ethics committee or institutional review board. Language: information available in the trial registration is published in English. Reason for awaiting classification status: the study was terminated prior to completion. The reason stated is 'due to other trials in the department'. Information available for this study is from the trial registration on clinicaltrials.gov. Insufficient information is available to determine whether the study meets eligibility criteria for inclusion.