What is the target hemoglobin level in a patient with a history of Coronary Artery Bypass Graft (CABG)?

From the Guidelines

For patients with a history of coronary artery bypass grafting (CABG), the recommended hemoglobin goal is to consider transfusion at a concentration of 8 g/dL or less, or for symptoms such as chest pain, orthostatic hypotension, or congestive heart failure, as suggested by the AABB guidelines. This approach is based on the recommendations from the AABB, which suggests adhering to a restrictive transfusion strategy in hospitalized, hemodynamically stable patients with preexisting cardiovascular disease 1. The evidence from clinical trials, such as the FOCUS trial, supports the use of a restrictive transfusion strategy, with no significant difference in outcomes between liberal and restrictive strategies in patients with cardiovascular disease 1.

Key Considerations

• The decision to transfuse should be individualized based on the patient's specific comorbidities, age, and functional status.
• Regular monitoring of hemoglobin levels, cardiac symptoms, and oxygen saturation is essential for patients with a history of CABG.
• The risks of anemia, including worsened myocardial oxygen delivery, should be balanced against the risks of liberal transfusion strategies, including volume overload and transfusion reactions.
• In acute situations where a patient with CABG history is experiencing active cardiac symptoms, transfusion to maintain hemoglobin above 8 g/dL is often appropriate.

Evidence Summary

The AABB guidelines recommend a restrictive transfusion strategy, with transfusion considered at a hemoglobin concentration of 8 g/dL or less, or for symptoms such as chest pain, orthostatic hypotension, or congestive heart failure 1. The quality of evidence is moderate, and the strength of recommendation is weak. However, the available evidence supports the use of a restrictive transfusion strategy in patients with cardiovascular disease, including those with a history of CABG.

From the FDA Drug Label

Using ESAs to target a hemoglobin level of greater than 11 g/dL increases the risk of serious adverse cardiovascular reactions and has not been shown to provide additional benefit [see Clinical Studies (14.1)]. In controlled clinical trials, ESAs increased the risk of death in patients undergoing coronary artery bypass graft surgery (CABG) and the risk of deep venous thrombosis (DVT) in patients undergoing orthopedic procedures.

The recommended hemoglobin goal in a patient with a history of CABG is not to exceed 11 g/dL, as targeting a higher level may increase the risk of serious adverse cardiovascular reactions without providing additional benefit 2.

• Key points:
  • Target hemoglobin level should not exceed 11 g/dL
  • Higher targets increase the risk of adverse cardiovascular reactions
  • No additional benefit has been shown for higher targets 2

From the Research

Hemoglobin Goal in Patients with History of CABG

• The ideal hemoglobin goal in patients with a history of Coronary Artery Bypass Graft (CABG) is not explicitly stated in the provided studies, but we can infer some guidelines based on the available evidence.
• A study published in 2019 3 found that a discharge hemoglobin level below 8 g/dL was associated with a higher incidence of readmission, suggesting that a hemoglobin level above 8 g/dL may be a reasonable goal.
• Another study from 2013 4 found that predischarge hemoglobin concentration was not a significant independent predictor of 30-day readmission to the hospital due to all causes, readmission to the hospital due to cardiac causes, or 30-day mortality.
• However, a study from 2020 5 on preoperative anemic adults undergoing non-cardiac surgery found that preoperative recombinant human erythropoietin (rHuEPO) therapy with iron supplementation increased hemoglobin concentrations and reduced the need for allogeneic red blood cell transfusions.

Considerations for Hemoglobin Goal

• The studies suggest that the hemoglobin goal may depend on various factors, including the patient's underlying condition, comorbidities, and the type of surgery.
• A study from 2009 6 found that hemoglobin level variability in hemodialysis patients was common and was associated with comorbidity, intercurrent illness, and mortality risk.
• The American Journal of Nephrology study 6 also found that anemia management interventions, such as erythropoiesis-stimulating agents (ESAs), intravenous iron, and transfusions, can influence hemoglobin variability.

Implications for Clinical Practice

• Based on the available evidence, it is essential to consider individual patient factors when determining the hemoglobin goal in patients with a history of CABG.
• The studies suggest that a hemoglobin level above 8 g/dL may be a reasonable goal, but this may need to be adjusted based on the patient's underlying condition and comorbidities.
• Further research is needed to determine the optimal hemoglobin goal in patients with a history of CABG, as the current evidence is limited and inconclusive 3, 5, 4.