To describe perioperative transfusion rates, hospital variability, temporal trends, and the association between red blood cell (RBC) transfusion and predefined risk factors in Dutch cardiac surgery.

Nationwide retrospective cohort study.

All 16 cardiac surgery centers in the Netherlands, 2016-2023.

Adults undergoing cardiac surgery recorded in the mandatory Netherlands Heart Registration (NHR), between 2016 and 2023 (N = 110,366).

None.

The primary outcome were transfusion rates of RBCs, plasma, platelets, prothrombin complex concentrate, fibrinogen concentrate, and recombinant factor VIIa. Secondary outcomes included interhospital variability and temporal trends. Transfusion rates among patients with available data were 30.6% for RBCs, 11.0% for plasma, 20.3% for platelets, 7.4% for prothrombin complex concentrate, 13.5% for fibrinogen concentrate, and 0.5% for recombinant factor VIIa. Significant variability existed between centers. Annual transfusion rates increased for almost all products: RBCs (odds ratio [OR] 1.02, 95% confidence interval [CI] 1.02-1.03), plasma (OR 1.08, 95% CI 1.07-1.09), platelets (OR 1.09, 95% CI 1.08-1.10), PCC (OR 1.10, 95% CI 1.09-1.11), fibrinogen (OR 1.15, 95% CI 1.14-1.16). In exploratory analyses, adjustment for patient and procedural characteristics showed a similar temporal trend in RBC transfusion (adjusted OR 1.03, 95% CI 1.02-1.04) per year.

Perioperative transfusion rates in Dutch cardiac surgery have increased and have substantial intercenter variability. The observed increase in RBC transfusions was not fully reflected by changes in measured patient and procedural characteristics. These findings highlight the importance of continuous monitoring of transfusion practices to better understand temporal trends and variation in clinical practice.