For Jehovah’s Witness (JW) patients requiring cardiac surgery, various strategies such as preoperative use of erythropoietin stimulating agents (ESAs), intravenous iron (IVI), and non-pharmacologic interventions have emerged to prevent complications from blood loss given transfusion is not acceptable in this population.

Retrospective case-control of cardiac surgeries performed by the same surgeon between 1/1/2011 and 8/30/2021. JW patients were matched to non-JW who received blood products and non-JW who did not receive blood products on a 1:2:2 basis. Patients were matched on procedure, age, gender, and Society of Thoracic Surgeons morbidity score. Eligible patients were aged >18 years and had a sternotomy procedure. The primary efficacy and safety outcomes included mean hematocrit values perioperatively and thrombotic events.

A total of 27 JW, 52 non-JW transfused, and 53 non-JW not transfused patients were included in the analysis. JW patients had significantly higher mean hematocrits at every time point when compared to non-JW transfused patients and at all time points except clinic and the last recorded operating room value when compared to non-JW not transfused patients. No significant differences in thrombotic rates were found between groups, however there was a numerically higher incidence in the JW population (JW: 7.4%; non-JW transfused: 0%; non-JW not transfused: 1.9%; p = .106).

A blood conservation protocol in a JW population was associated with higher perioperative hematocrit values when compared to matched controls. Further prospective study is warranted before applying similar protocols to other populations given the possibility for an increased rate of venous thromboembolism.