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Updated: May 2, 2026
Microfluidics in Assessing Platelet Function
Published on: November 8, 2024
P2Y12 platelet function assay for assessment of bleeding risk in coronary artery bypass grafting
Pey-Jen Yu1, Hugh A Cassiere, Sophia L Dellis
1North Shore University Hospital, Manhasset, New York.
Insights
Discontinuing P2Y12 inhibitors three days before coronary artery bypass grafting (CABG) surgery, not platelet function tests, predicts bleeding and transfusion needs. Relying solely on these tests for timing CABG in patients on P2Y12 inhibitors warrants caution.
Area of Science:
- Cardiology
- Transfusion Medicine
- Surgical Optimization
Background:
- Platelet function testing is used to guide P2Y12 inhibitor discontinuation before coronary artery bypass grafting (CABG).
- The reliability of point-of-care assays for predicting bleeding risk in patients on P2Y12 inhibitors undergoing CABG requires further validation.
Purpose of the Study:
- To evaluate the correlation between preoperative P2Y12 receptor blockade levels and postoperative bleeding outcomes in patients undergoing CABG.
- To determine if the VerifyNow P2Y12 assay can predict the need for packed red blood cell (pRBC) and platelet transfusions after CABG.
Main Methods:
- Eighty-one patients on P2Y12 inhibitors undergoing isolated CABG were studied.
- Preoperative P2Y12 receptor blockade was measured using the VerifyNow P2Y12 assay.
- Postoperative outcomes, including pRBC and platelet transfusions and chest tube output, were correlated with P2Y12 reaction units (PRUs) and timing of P2Y12 inhibitor discontinuation.
Main Results:
- Patients discontinuing P2Y12 inhibitors ≤3 days before surgery received significantly more platelet transfusions and had higher chest tube output compared to those stopping longer.
- No significant difference in transfusions or chest tube output was observed between patients with PRU values <250 versus ≥250.
- pRBC requirements correlated with hematocrit and age, but not with P2Y12 inhibitor timing or PRU levels.
Conclusions:
- Discontinuation of P2Y12 inhibitors three days prior to CABG surgery is a better predictor of postoperative bleeding and transfusion needs than VerifyNow PRU values.
- Sole reliance on platelet function testing to determine surgical timing for patients on P2Y12 inhibitors should be approached with caution.
Background:
The use of platelet function testing has been advocated to individualize the time needed between discontinuation of P2Y12 inhibitors and coronary artery bypass grafting (CABG). However, the use of specific point-of-care assays to predict bleeding risk in patients on P2Y12 inhibitors prior to CABG has not been fully validated.
Methods:
From September 2012 to May 2013, 81 patients on P2Y12 inhibitors underwent isolated CABG. Preoperative level of P2Y12 receptor blockade was measured using the VerifyNow P2Y12 assay. Packed red blood cell (pRBC) and platelet transfusions and postoperative chest tube output were correlated with preoperative P2Y12 reaction units (PRUs).
Results:
Patients who stopped P2Y12 inhibitors for ≤3 days received significantly more platelet transfusions as compared to those whose inhibitors were stopped for longer (0.71 ± 1.05 units vs. 0.20 ± 0.71 units, p = 0.01). They also had increased postoperative chest tube output (552.5 ± 325.5 mL vs. 399.8 ± 146.5 mL, p = 0.03). There was no significant difference in platelet transfusions and chest tube output between patients whose preoperative PRU value was <250 compared to those whose values were ≥250. pRBC requirements were correlated with preoperative hematocrit and age but not with timing of discontinuation of P2Y12 inhibitors or with PRU levels.
Conclusions:
In patients on P2Y12 inhibitors undergoing CABG surgery, discontinuation of P2Y12 inhibitors three days prior to surgery rather than VerifyNow PRU values predicts postoperative bleeding and the need for platelet transfusions. Sole reliance on platelet function testing to determine the timing of surgery for patients on P2Y12 inhibitors should therefore be done with caution.
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