Objective: We determined whether intraoperative packed red blood cell transfusion (PRBC) was associated with a higher incidence of hospital-acquired venous thromboembolic (HA-VTE) complications and adverse outcomes after isolated coronary artery bypass grafting (CABG) surgery.

Background: Intraoperative PRBC has been associated with increased risk for postoperative deep venous thrombosis after cardiac surgery, but validation of these findings in a large, multi-institutional, national cohort of cardiac surgery patients has been lacking.

Methods: A registry-based cohort study of 751,893 patients with isolated CABG between January 1, 2015, to December 31, 2019. Using propensity-score-weighted regression analysis, we analyzed the effect of intraoperative PRBC on the incidence of HA-VTE and adverse outcomes.

Results: Administration of 1, 2, 3 and ≥4 units of PRBC transfusion was associated with increased odds for HA-VTE [odds ratios (ORs) 1.27 (1.22-1.32), 1.21 (1.16-1.26), 1.93 (1.85-2.00), 1.82 (1.75-1.89)], deep venous thrombosis [ORs 1.39 (1.33-1.46), 1.38 (1.32-1.44), 2.18 (2.09-2.28), 1.82 (1.74-1.91], operative mortality [ORs 1.11 (1.08-1.14), 1.16 (1.13-1.19), 1.29 (1.26-1.32), 1.47 (1.43-1.50)], readmission within 30 days [ORs 1.05 (1.04-1.06), 1.16 (1.13-1.19), 1.29 (1.26-1.32), 1.47 (1.43-1.50)], and a prolonged postoperative length of stay [mean difference in days, 0.23 (0.19-0.27), 0.34 (0.30-0.39), 0.69 (0.64-0.74), 0.77 (0.72-0.820]. The odds of pulmonary venous thromboembolism were lower for patients transfused with 1 or 2 units [ORs 0.98 (0.91-1.06), 0.75 (0.68-0.81)] of PRBC but remained significantly elevated for those receiving 3 and ≥4 units [ORs 1.19 (1.09-1.29), 1.35 (1.25-1.48)].

Conclusions: Intraoperative PRBC transfusion was associated with HA-VTE and adverse outcomes after isolated CABG surgery.