At what hemoglobin level would you transfuse blood in a patient with a history of cerebrovascular accident (CVA), myocardial infarction (MI), and chronic kidney disease (CKD)?

Transfusion Threshold in Patients with Stroke, MI, and CKD

In a patient with stroke, myocardial infarction, and chronic kidney disease, transfuse when hemoglobin falls below 8 g/dL, or immediately if the patient develops symptoms of cardiac ischemia (chest pain, orthostatic hypotension unresponsive to fluids, tachycardia, or heart failure) regardless of hemoglobin level. 1, 2

Rationale for the 8 g/dL Threshold

The presence of cardiovascular disease (both stroke and MI) elevates this patient's transfusion threshold above the standard 7 g/dL used for most hospitalized patients. Multiple guidelines converge on this recommendation:

• The American Association of Blood Banks recommends a threshold of 8 g/dL for patients with preexisting cardiovascular disease 2, 3
• The European Society of Cardiology recommends considering transfusion when hemoglobin falls below 8 g/dL in patients with acute myocardial infarction 1
• The American College of Physicians specifically recommends 8 g/dL for patients with cardiovascular disease or those undergoing cardiac/orthopedic surgery 2, 3

Symptom-Based Transfusion Takes Priority

Transfuse immediately if any of the following symptoms develop, even if hemoglobin is above 8 g/dL: 1, 2

• Cardiac-related chest pain
• Orthostatic hypotension unresponsive to fluid resuscitation
• Tachycardia refractory to fluids
• Signs of congestive heart failure
• Evidence of end-organ ischemia

Transfusion Protocol

• Administer one unit of packed red blood cells at a time 2, 3
• Reassess clinical status and recheck hemoglobin after each unit before giving additional units 2, 3
• Target a post-transfusion hemoglobin of 8-9 g/dL; do not transfuse to levels above 10 g/dL 1, 2

Special Consideration for CKD

The chronic kidney disease component does not change the acute transfusion threshold. While CKD patients may have target hemoglobin goals of 11-12 g/dL when managed chronically with erythropoiesis-stimulating agents, the acute transfusion threshold remains 8 g/dL given the concurrent cardiovascular disease 4, 5. Attempting to correct hemoglobin to higher levels (>13 g/dL) with erythropoietin in CKD patients has been associated with increased cardiovascular events and mortality 5.

Critical Pitfalls to Avoid

• Do not use a liberal transfusion strategy (transfusing to hemoglobin >10 g/dL), as this increases risks of nosocomial infections, transfusion-related acute lung injury (TRALI), transfusion-associated circulatory overload (TACO), and potentially worse clinical outcomes without providing benefit 1, 2
• Do not wait for hemoglobin to drop below 8 g/dL if the patient is symptomatic - symptoms of ischemia mandate immediate transfusion 1, 2
• Do not rely solely on hemoglobin levels - always assess for signs of inadequate oxygen delivery, hemodynamic instability, and ongoing blood loss 2, 4

Evidence Quality

This recommendation is supported by high-quality evidence from multiple large randomized controlled trials showing that restrictive transfusion strategies (7-8 g/dL thresholds) do not increase mortality, myocardial infarction, stroke, or other complications compared to liberal strategies (9-10 g/dL), while reducing transfusion exposure by approximately 40% 6, 7, 3. The 2023 AABB International Guidelines provide a strong recommendation for the 8 g/dL threshold in patients with cardiovascular disease based on moderate certainty evidence 3.