The role of point-of-care assessment of platelet function in predicting postoperative bleeding and transfusion requirements after coronary artery bypass grafting.

ABSTRACT

Objective: Objective platelet function assessment after cardiac surgery can predict postoperative blood loss, guide transfusion requirements and discriminate the need for surgical re‑exploration. We conducted this study to assess the predictive value of point‑of‑care testing platelet function using the Multiplate® device. Methods: Patients undergoing isolated coronary artery bypass grafting were prospectively recruited (n = 84). Group A (n = 42) patients were on anti‑platelet therapy until surgery; patients in Group B (n = 42) stopped anti‑platelet treatment at least 5 days preoperatively. Multiplate® and thromboelastography (TEG) tests were performed in the perioperative period. Primary end‑point was excessive bleeding (>2.5 ml/kg/h) within first 3 h postoperative. Secondary end‑points included transfusion requirements, re‑exploration rates, intensive care unit and in‑hospital stays. Results: Patients in Group A had excessive bleeding (59% vs. 33%, P = 0.02), higher re‑exploration rates (14% vs. 0%, P < 0.01) and higher rate of blood (41% vs. 14%, P < 0.01) and platelet (14% vs. 2%, P = 0.05) transfusions. On multivariate analysis, preoperative platelet function testing was the most significant predictor of excessive bleeding (odds ratio [OR] 2.3, P = 0.08), need for blood (OR 5.5, P < 0.01) and platelet transfusion (OR 15.1, P < 0.01). Postoperative “ASPI test” best predicted the need for transfusion (sensitivity ‑ 0.86) and excessive blood loss (sensitivity ‑ 0.81). TEG results did not correlate well with any of these outcome measures. Conclusions: Peri‑operative platelet functional assessment with Multiplate® was the strongest predictor for bleeding and transfusion requirements in patients on anti‑platelet therapy until the time of surgery. Study registration ISRCTN43298975 (http// www.controlled‑trials.com/ISRCTN43298975/).