Association of Intraoperative Red Blood Cell Transfusions With Venous Thromboembolism and Adverse Outcomes After Cardiac Surgery

Objective: We determined whether intraoperative packed red blood cell (PRBC) transfusion 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.