Platelet function measured using a whole blood aggregometer can predict bleeding events

We hypothesized that excessive suppression of platelet function due to antiplatelet therapy can increase the incidence of bleeding complications. The aim of the present study was to find whether we could predict bleeding events by measuring platelet function.

We enrolled 743 subjects whose platelet function was measured using a whole blood aggregometer based on a screen filtration pressure method. Of these subjects, 551 (74.2%) were treated with some type of antiplatelet agent. The endpoints were bleeding or ischemic events requiring hospitalization or extension of hospital stay. We prospectively compared the platelet function of subjects with and without bleeding or ischemic events.

During 556 ± 207 days of follow-up, 52 (7.0%) bleeding events and 20 (2.7%) ischemic events were observed. Kaplan-Meier analysis using the log-rank test revealed that an aggregation rate of < 20% induced by 8 µ M adenosine diphosphate (ADP) was significantly associated with a greater number of bleeding events (11.9% vs. 5.2%; p = 0.0007). Cox proportional hazards model showed that age > 75 years (hazard ratio [HR], 1.78; 95% confidence interval [CI], 1.03-3.10; p = 0.039), estimated glomerular filtration rate < 60 ml/min/1.73 m(2) (HR, 1.82; 95% CI, 1.06-3.18; p = 0.031) and aggregation rate < 20% induced by 8 µ M ADP (HR, 2.18; 95% CI, 1.24-3.80; p = 0.0071) were independent predictors of bleeding events.

Low platelet function demonstrated using a whole blood aggregometer was an independent predictor of bleeding complications.