Platelet function after cardiac surgery and its association with severe postoperative bleeding: the PLATFORM study.

Area of Science:

• Cardiovascular Surgery
• Hematology
• Anesthesiology

Background:

• Platelet dysfunction is a key factor in postoperative bleeding following cardiac surgery.
• Current guidelines lack specific platelet activity cut-off values for managing bleeding patients.
• Predicting severe bleeding risk requires better understanding of platelet function post-bypass.

Purpose of the Study:

• To determine the relationship between platelet function after cardiopulmonary bypass and severe postoperative bleeding.
• To identify predictive values of platelet function tests for severe bleeding.
• To establish cut-off values for platelet activity to guide clinical interventions.

Main Methods:

• Prospective cohort study (PLATFORM) involving 490 adult patients undergoing cardiac surgery with cardiopulmonary bypass.
• Platelet function tests (ADPtest, TRAPtest) and routine coagulation tests were performed pre- and post-bypass.
• Multivariable analysis was used to assess the association between platelet function and severe bleeding.

Main Results:

• Post-bypass ADPtest and TRAPtest were significantly associated with severe bleeding (P=0.001).
• ADPtest (OR 0.962) and activated partial thromboplastin time (OR 1.097) were independently associated with severe bleeding.
• The post-bypass ADPtest showed the best discrimination (AUC 0.712), with a positive predictive value of 42% at a cut-off ≤8 U.

Conclusions:

• Platelet function tests after cardiopulmonary bypass are significantly linked to postoperative bleeding.
• While informative, platelet function alone does not offer a high positive predictive value for severe bleeding.
• Postoperative bleeding is multifactorial, necessitating a comprehensive assessment beyond platelet function.