Association Between Adverse Clinical Outcomes After Coronary Artery Bypass Grafting and Perioperative Blood Transfusions

The Relationship Between Transfusion in Cardiac Surgery Patients and Adverse Outcomes

OBJECTIVES

To understand if red blood cell (RBC) transfusions are independently associated with a risk of mortality, prolonged intubation, or infectious, cardiac, or renal morbid outcomes.

DESIGN

A retrospective review.

SETTING

A single-institution university hospital.

PARTICIPANTS

A total of 2,458 patients undergoing coronary bypass artery graft and/or valvular surgery from July 2014 through January 2018.

INTERVENTIONS

No interventions were done.

MEASUREMENTS AND MAIN RESULTS

The primary outcome was the occurrence of an adverse event or prolonged intubation. Infectious, cardiac, and renal composite outcomes were also defined. These composites, along with mortality, were analyzed individually and then combined to form the "any adverse events" composite. Preoperative demographic and intraoperative parameters were analyzed as univariate risk factors for adverse outcomes. Logistic regression was used to screen variables, with a p value criterion of p < 0.05 for entry into the model selection procedure. A backward selection algorithm was used with variable entry and retention criteria of p < 0.05 to select the final multivariate model. Multivariate logistic regression models were used to determine whether there was an association between the volume of RBC transfusion and the defined adverse event after adjusting for covariates. A p value < 0.01 was considered statistically significant in the final model of each aim to adjust for multiple comparisons. The final logistic models for each of the following outcomes indicate an increased risk of that outcome per each additional unit of RBC transfused. For prolonged intubation, the odds ratio (OR) was 1.493 (p < 0.0001), OR = 1.358 (p < 0.0001) for infectious composite outcomes, OR = 1.247 (p < 0.0001) for adverse renal outcomes, and OR = 1.467 (p < 0.0001) for any adverse event.

CONCLUSIONS

The authors demonstrated a strong independent association between RBC transfusion volume and adverse outcomes after cardiac surgery. Efforts should be undertaken, such as preoperative anemia management and control of coagulopathy, in order to minimize the need for RBC transfusion.

Implementation of a Short-term Treatment Protocol in Anemic Patients before Cardiac Surgery

BACKGROUND

 We assessed whether implementation of an immediate preoperative treatment in anemic patients could result in fewer perioperative packed red blood cell (PRBC) transfusions and improved outcomes in a real-world setting.

METHODS

 From January 1, 2020, to November 31, 2022, we implemented a perioperative protocol for anemic patients (hemoglobin (Hb) level in women <11.5 g/dL, men <12.5 g/dL), which included subcutaneous erythropoietin α, intravenous Iron, and intramuscular vitamin B12 (all given preoperatively) and per os iron and folic acid given once a day postoperatively. We retrospectively compared all patients receiving the protocol to all eligible patients who were operated upon in the 4 years prior to implementation of the protocol. Primary outcome was amount of PRBC transfusions during surgery and index admission.

RESULTS

 In the months after protocol implementation, 114 patients who received the treatment protocol were compared with 236 anemic patients in the 4 years prior to who did not receive the protocol. The treatment reduced total PRBC use (control group median 4 [2-7] units vs. treatment 2 [1-3] units, p < 0.0001) and the incidence of postoperative blood products transfusions (treatment group 58 patients, 50.88% vs. control group 177 patients, 75%, p < 0.0001). Hb prior to discharge was higher among the protocol group (treatment median 9 g/dL [8.3-9.5 g/dL] vs. control 8.6 g/dL [8.1-9.1 g/dL], p = 0.0081).

CONCLUSION

 Despite some differences compared with previously described protocols, the implementation of a perioperative treatment protocol for anemic patients was associated with a reduction in PRBC transfusion in a real-world setting.

Clinical impact of red blood cell transfusion on adverse clinical events in acute heart failure patients with anemia

BACKGROUND

Anemia has been recognized as an important comorbidity in patients with acute heart failure (AHF) and is associated with adverse clinical events. However, the clinical impact of red blood cell (RBC) transfusion in such patients is unclear.

METHOD

This study was a retrospective single-center registry including AHF patients admitted to Kyorin University Hospital between 2007 and 2014. Anemia was defined as a hemoglobin level < 130 g/L in males or < 120 g/L in females. Those with major bleeding with a fall in hemoglobin concentration of >20 g/L were excluded. AHF readmission at 3 months and in-hospital and 2-year all-cause mortality were evaluated.

RESULTS

Of 501 AHF patients, 38 were excluded owing to major bleeding; finally, 463 (age, 77 ± 11 years; males, 58%) were evaluated. RBC transfusion during hospitalization was performed in 112 patients (24%). Hemoglobin level on admission was 105 ± 16 g/L (transfusion, 89 ± 17 g/L; no transfusion, 110 ± 12 g/L; p < 0.001). AHF readmission at 3 months and in-hospital and 2-year all-cause mortality were observed in 46 (10%), 16 (3%), and 121 (26%) patients, respectively. Univariate Cox regression analysis demonstrated that RBC transfusion was not associated with AHF readmission at 3 months (hazard ratio: 0.80; 95% confidence interval: 0.39-1.66) The association did not differ at any hemoglobin concentration or left ventricular ejection fraction value. Multivariate Cox regression analysis revealed similar results. Furthermore, RBC transfusion was not correlated with in-hospital and 2-year all-cause mortality.

CONCLUSIONS

RBC transfusion was not associated with AHF readmission or all-cause mortality.