Platelet function tests predict bleeding and thrombotic events after off-pump coronary bypass grafting

• Published in: European journal of cardio-thoracic surgery Vol. 27; no. 4; pp. 584 - 591
• Main Authors: Poston, Robert, Gu, Junyan, Manchio, Jeffrey, Lee, Andrew, Brown, James, Gammie, James, White, Charles, Griffith, Bartley P.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier Science B.V 01.04.2005; Elsevier Science
• Subjects: Aged; Biological and medical sciences; Blood Coagulation Tests - methods; Blood Platelets - physiology; Cardiology. Vascular system; Coronary artery bypass grafting; Coronary Artery Bypass, Off-Pump - adverse effects; Coronary Artery Bypass, Off-Pump - methods; Coronary heart disease; Female; Graft Occlusion, Vascular - diagnostic imaging; Graft Rejection; Heart; Humans; Male; Medical sciences; Middle Aged; Perioperative Care - methods; Platelet; Platelet Function Tests - methods; Postoperative Hemorrhage - etiology; Prospective Studies; Risk Assessment - methods; Saphenous vein; Thrombosis; Thrombosis - diagnostic imaging; Thrombosis - etiology; Tomography, X-Ray Computed; Vascular Patency; Platelet; Saphenous vein; Thrombosis; Coronary artery bypass grafting; Coronary artery; Prediction; Cardiovascular disease; Coronary heart disease; Hemorrhage; Vascular disease; Treatment; Aortocoronary; Bypass; Surgery; Platelet function; Graft
• ISSN: 1010-7940; 1873-734X
• DOI: 10.1016/j.ejcts.2004.12.061

Objective: A balanced coagulation system after cardiac surgery minimizes bleeding and thrombotic events. However, the best method to monitor this balance has not been established. We used a series of tests of coagulation and platelet function to define the risk of bleeding and thrombotic events after OPCAB. Methods: In 76 patients, routine coagulation tests (i.e. prothrombin time, fibrinogen level, d-dimer, and platelet count), thrombelastography, and whole blood aggregometry were obtained perioperatively and on days 1 and 3 after OPCAB. Intra- and postoperative blood loss was determined. Early patency of venous bypass grafts was determined using CT angiography (Philips Medical, Corp.). Results: Chest tube output and red cell volume loss at 24h were 952±475 and 190±115ml, respectively. Early graft failure developed in eight patients. Perioperative changes in routine coagulation tests showed no correlation with either bleeding or thrombosis. However, perioperative decline in platelet function as assessed by the area under the impedance curve for whole blood aggregometry correlated with intraoperative blood loss (R=0.42, P≪0.05). A perioperative decline in the maximum amplitude of the thrombelastography trace showed a significant correlation with 24h hemoglobin loss (R=0.45, P≪0.05). Compared to those with all patent grafts, patients with early graft failure demonstrated a reduction in platelet sensitivity to aspirin by both thrombelastography and aggregometry on day 3. Conclusions: In contrast to standard coagulation testing, platelet function predicted both bleeding and thrombosis after OPCAB. Titration of perioperative platelet function according to these tests may minimize thrombosis without increasing bleeding.