Low Fibrinogen Is Associated with Increased Bleeding-Related Re-exploration after Cardiac Surgery

Background: Re-exploration after cardiac surgery remains a relatively frequent complication associated with adverse effects on outcome. We aimed to identify risk factors for re-exploration.

Methods: We retrospectively reviewed 2,403 patients having undergone cardiac surgical procedure between January 2013 and December 2014. Re-exploration was required in 114 patients (4.7%). Patients with oral anticoagulation, infective endocarditis, or a clearly identified bleeding source were excluded. Therefore, 42 patients remained for analysis. A matched cohort was selected for age, sex, ejection fraction, creatinine, and procedure out of the non-re-explored patients.

Results: Demographic data were similar in both groups, except for a higher prevalence of diabetes (45 vs. 21%; p = 0.036) in the non-re-explored patients. Surgery was elective in two-thirds and preoperative plasma fibrinogen concentration was lower in patients requiring re-exploration (2.8 ± 0.9 vs. 3.6 ± 0.9 g/L; p = 0.002). During the initial operation, re-explored patients received more packed red blood cells (1.5 ± 3 vs. 0 ± 1 units; p < 0.001), Postoperatively, re-explored patients had higher lactate levels (1.7 ± 1.4 vs. 1.3 ± 0.6 mmol/L, p = 0.044), more chest tube drainage (1,245 ± 948 vs. 685 ± 413 mL; p < 0.001), higher hospital mortality (19 vs. 7%; p = 0.19), and longer intensive care unit (ICU) stays (8 ± 8 vs. 4 ± 7 days; p = 0.010). In addition, more fibrinogen was administrated during the initial surgery. Plasma fibrinogen concentration upon arrival at the ICU was lower in patients requiring re-exploration (2 ± 0.6 vs. 2.7 ± 0.7 g; p < 0.001). Multivariable linear regression analysis identified fibrinogen upon arrival at the ICU as an independent predictor of postoperative bleeding.

Conclusion: Cardiac surgery patients with low perioperative plasma fibrinogen concentration appear to be more susceptible to bleeding and re-exploration. Re-exploration in this group of patients is associated with increased morbidity and mortality.