A comparison of Plateletworks and platelet aggregometry for the assessment of aspirin-related platelet dysfunction in cardiac surgical patients.

Objective: To compare the assessment of aspirin-related platelet dysfunction using Plateletworks (Helena Laboratories, Beaumont, TX), a new point-of-care platelet function analyzer, with turbidometric platelet aggregometry, in cardiac surgical patients.

Design: Prospective observational study.

Setting: University-affiliated teaching hospital.

Participants: Fifty consecutive adult patients undergoing elective cardiac surgery for coronary artery bypass grafting or cardiac valve replacement.

Interventions: None.

Measurements And Main Results: Platelet function was assessed by Plateletworks and turbidometric platelet aggregometry before the commencement of anesthesia. Collagen, 10 microg/mL, was used as the agonist for both techniques. The area under the receiver-operator curve for the identification of recent aspirin ingestion (or=72 hours) using Plateletworks was 0.58 (95% confidence interval [CI] 0.42-0.75) versus 0.77 (95% CI 0.61-0.95) for turbidometric platelet aggregometry. The Spearman correlation coefficient (rho) between preoperative Plateletworks trade mark and postoperative mediastinal blood loss was 0.07 (p = 0.58), and between preoperative turbidometric platelet aggregometry and postoperative mediastinal blood loss was -0.31 (p = 0.03). On completion of surgery, the correlation coefficients were 0.14 (p = 0.34) and -0.29 (p = 0.08), respectively.

Conclusion: These findings suggest that Plateletworks is of limited use for the detection of aspirin-related platelet defects in cardiac surgical patients.