Plasma Transfusion for INR 1.4 Before CABG
No, a patient with an INR of 1.4 undergoing coronary artery bypass grafting does not require plasma transfusion. This INR value is only minimally elevated and plasma transfusion at this level lacks both efficacy and biological plausibility while exposing the patient to unnecessary transfusion-related risks.
Evidence Against Plasma Transfusion at INR 1.4
Lack of Efficacy and Biological Plausibility
Plasma infusion does not meaningfully change INR values below 1.5 and only minimally impacts values below 2.0, with no evidence that such minimal changes reduce bleeding risk 1.
There is no high-quality evidence that plasma transfusions reduce bleeding when administered to nonbleeding patients with incidentally abnormal INRs 1.
A pilot randomized trial found that even in patients with INR 1.5-2.5 undergoing invasive procedures, plasma transfusion resulted in no difference in hemoglobin drop (the primary bleeding outcome) compared to no transfusion 2.
Emerging evidence demonstrates that transfusing plasma for an INR ≤1.5 does not confer hemostatic benefit while unnecessarily exposing patients to transfusion risks 3.
Guideline-Based INR Thresholds
Fresh frozen plasma transfusion is indicated only when INR is greater than 1.5 times normal (approximately >1.5) or INR >2.0 in the presence of excessive microvascular bleeding 1.
The American Society of Anesthesiologists guidelines specify that FFP transfusion is not indicated if PT, INR, and aPTT are normal, and correction is only warranted for INR >2.0 in bleeding patients 1.
Recent guidelines and consensus statements recommend against plasma transfusion for mildly abnormal INR values in patients not on vitamin K antagonist therapy 1.
Risks of Unnecessary Plasma Transfusion
Large doses of plasma (20 mL/kg, or 1.4 liters in a 70 kg patient) are required to achieve even modest 20% factor repletion, exposing patients to volumetric and immunologic risks 1.
Plasma transfusion carries risks of transfusion-associated circulatory overload (TACO), transfusion-related acute lung injury (TRALI), transfusion-related immunomodulation (TRIM), and allergic reactions 4.
Studies suggest that 30-90% of plasma transfused for prophylactic correction of laboratory abnormalities is unnecessary and puts patients at risk 4.
Clinical Approach for CABG with INR 1.4
Proceed Without Plasma Transfusion
An INR of 1.4 is acceptable for proceeding with coronary artery bypass surgery without prophylactic plasma transfusion 1, 5.
The standard preoperative target is INR <1.5 for major surgical procedures, which this patient already meets 5.
Alternative Strategies to Minimize Transfusion
Consider blood conservation techniques such as acute normovolemic hemodilution, retrograde autologous priming, and integrated arterial filter oxygenator, which have been shown to avoid blood transfusions in 92% of CABG patients 6.
Use point-of-care viscoelastic testing (ROTEM or TEG) rather than relying solely on INR to guide intraoperative and postoperative transfusion decisions 1, 4.
Important Caveats
If the patient is on warfarin or other vitamin K antagonists, ensure these were stopped 5 days preoperatively to allow natural normalization 5.
Verify that the elevated INR is not due to underlying liver disease or inherited coagulation disorders, which would require different management considerations 1.
A normal INR has poor sensitivity for bleeding disorders and provides false reassurance—consider the clinical context and patient-specific bleeding risk factors beyond the laboratory value 1.
If unexpected bleeding occurs intraoperatively, use viscoelastic testing to guide targeted factor replacement rather than empiric plasma transfusion 1, 4.