CRITICAL JOURNAL REVIEW
Will your ACS patient bleed excessively during CABG?
Tello-Montoliu A, Albaladejo P, Hernández-Romero D, Taboada R, Albacete CL, Arribas JM, et al. Bleeding Risk Prediction in Patients With Dual Antiplatelet Therapy Undergoing Coronary Artery Bypass Grafting Surgery Using a Rapid Point-of-Care Platelet Function Test. Circ Cardiovasc Interv. 2018 Dec;11(12):e007264
The cutoff point separating patients with high bleeding risk versus low risk was P2Y12 reaction units (PRU) <204 with the risk of suffering major bleeding being 5-fold higher in such patients as compared to patients with PRU>204.
In this prospective, observational study, 118 patients with acute coronary syndrome undergoing coronary artery bypass grafting (CABG) surgery under dual antiplatelet therapy with aspirin and a P2Y12 receptor inhibitor were evaluated by using one fasting blood sample obtained between 8:00 and 9:00 am in the morning of the surgery.
Platelet function testing was performed by VerifyNow P2Y12 assay, and results were reported as P2Y12 reaction units (PRU). The primary end point was the occurrence of major bleeding defined as any of the following (1) reoperation after closure of sternotomy for controlling bleeding; (2) transfusion of ≥5 units of packed red bloods cells or ≥2 units of packed platelet concentrate within a 48-hour period; (3) hemoglobin drop ≥5 g/dL; or (4) chest tube output ≥1000 mL within a 24-hour period.
Mean platelet reactivity of all patients as assessed with VerifyNow P2Y12 was PRU 239.2±58.1. Major bleeding was reported in 17 (14.4%) patients. Number of antiplatelet discontinuation days (6 [interquartile range, 4–10.5] days versus 5 [interquartile range, 4–8] days; P=0.824 did not impact the degree of bleeding. However, lower platelet reactivity was found in patients presenting with major bleeding (no major bleeding: PRU 245.8±52.4 versus major bleeding: PRU 197.1±75; P=0.002). Decreasing values of PRU were associated with a higher risk of major bleeding (C index: 0.707 [95% CI, 0.617–0.787], P=0.003), and the cutoff point showing the best results was PRU <204 (sensitivity of 58.8%, specificity of 79.2%, positive predictive value of 32.3%, and negative predictive value of 92.0%). In fact, a higher proportion of patients with PRU <204 suffered a major bleeding (58.8% versus 41.2%, P=0.001). The risk of suffering major bleeding in patients presenting with PRU <204 was 5-fold higher (odds ratio, 5.44; 95% CI, 1.85–16.01; P=0.002).
Conclusion: A PRU >204 might allow clinicians to rule out those patients who are not at high risk of bleeding and, therefore, it is safer to perform the surgery.
Comments and Clinical relevance:
Although the main limitation of the present study is the small sample size, use of VerifyNow P2Y12 assay allows for a really easy and quick management by using cutoff points in daily practice for predicting safety of surgery. It is in line with the Society of Thoracic Surgeons guidelines to recommend the use of platelet function tests in this setting.
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