Does retrograde autologous priming during coronary artery bypass grafting reduce blood transfusions?

Coronary artery bypass grafting is associated with a significant risk of blood transfusion. The clinical efficacy of retrograde autologous priming, a potential blood conservation strategy, lacks consensus. We aim to evaluate the effect of retrograde autologous priming on transfusion requirements and clinical outcomes in patients undergoing coronary artery bypass grafting.

A retrospective review was conducted on all patients undergoing on-pump, isolated coronary artery bypass grafting between October 2018 and March 2023 at a single institution. Those undergoing retrograde autologous priming were identified and compared with non-retrograde autologous priming cases. Wilcoxon rank-sum and chi-square analyses were used to analyze continuous and categorical outcomes, respectively. Risk-adjusted multivariable logistic regression was performed.

A total of 1109 patients met inclusion criteria, with 332 (29.9%) receiving retrograde autologous priming. At baseline, patients in the retrograde autologous priming group had higher preoperative hemoglobin (14.0 g/dL vs 13.7 g/dL, P = .03), higher nadir intraoperative hemoglobin (10.2 g/dL vs 9.7 g/dL, P < .0), and less total crystalloid use (900 mL vs 110 0 mL, P < .01) in the operating room. On risk-adjusted analysis, including adjustment for preoperative hemoglobin levels, retrograde autologous priming was found to significantly reduce the risk of postoperative blood transfusion (odds ratio, 0.54, P < .01) and postoperative prolonged ventilation (odds ratio, 0.47, P = .02).

Use of retrograde autologous priming may result in fewer transfusions and thus potentially prevent transfusion-associated risks such as prolonged ventilation. Potential mechanisms include avoidance of volume overload and transfusion-related acute lung injury. Retrograde autologous priming should be considered in appropriately selected patients undergoing cardiac surgery.