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/).

Validation of Three Platelet Function Tests for Bleeding Risk Stratification During Dual Antiplatelet Therapy Following Coronary Interventions

“…Some evidence emerged lately assessing the risk of bleeding and specific cutoff values for its predictability in patients after acute coronary syndromes 8,9 and those undergoing heart surgery. 18,19 Overall, the available evidence suggests that mainstream use of platelet analyzers cannot reliably assess individual bleeding risk and should not be currently recommended, 20,21 which is in full agreement with the index data. Independent from the instrument type applied, predicting future bleeding in a particular individual patient usually fails.…”

“…The main objective of these studies was to define the incidence of thrombotic occlusions by linking such adverse events with high on‐treatment platelet reactivity. Some evidence emerged lately assessing the risk of bleeding and specific cutoff values for its predictability in patients after acute coronary syndromes and those undergoing heart surgery …”

Anti-platelet Therapy Resistance – Concept, Mechanisms and Platelet Function Tests in Intensive Care Facilities

“…In cardiac surgery, perioperative platelet functional assessment using point-of-care devices like Multiplate® or VerifyNow system, can predict blood loss and transfusion requirements in patients treated with anti-platelet drugs [87,88].…”

Isolated platelet concentrate transfusion during surgery: a single‐center observational cohort study

“…Alternatively, when available, impedance aggregometry has excellent reliability in determining antiplatelet drug effect . in vitro platelet aggregation is strongly associated with postoperative bleeding . In one study examining the dose of PC required to reverse clopidogrel, even five PC unit equivalents did not fully restore normal platelet aggregation under flow conditions .…”

“…22 in vitro platelet aggregation is strongly associated with postoperative bleeding. [23][24][25] In one study examining the dose of PC required to reverse clopidogrel, even five PC unit equivalents did not fully restore normal platelet aggregation under flow conditions. 26 Hence, it is likely that treatment with one PC unit is inadequate in many cases.…”