Introduction and objective: Acetylsalicylic acid (ASA) is one of the basic preparations which are used in the treatment of cardiovascular diseases. ASA administration leads to irreversible restriction of platelet aggregation. The objective of our work was to test possibilities of monitoring the effectiveness of ASA therapy by measuring the platelet aggregability in vitro after induction with cationic propyl gallate (CPG) which is considered a very potent aggregation inductor.
Method: We examined a group of 27 healthy volunteers divided into two sub-groups (n = 19, n = 8). In the first sub-group the platelet aggregation was examined before and after 24 hours following ingestion of 400 mg ASA after induction with ADP, collagen, adrenaline and CPG. In the second sub-group the platelet aggregation was examined before and after three-day administration of ASA--100 mg/day.
Results and conclusion: In a group of 27 volunteers we assessed normal values of aggregation after different inductors. A low stability of the methods used was proved (low stability or insignificant correlation of results of the same method before and after ASA ingestion. The most useful parameter by means of which it was possible to monitor the effectiveness of administration of 400 or 100 mg ASA was the C/G slope (paired t-test, p < 0.0000002, and p < 0.001 resp.). In parameter CPG slope we were able to assess in both groups the cut-off value (< 53%/min.) by means of which it is possible to discriminate probands according to ASA therapy (contrary to the other commonly used inductors). From the results ensues that when assessing the thrombocyte aggregation after CPG induction we find a significantly lower percentage of so-called ASA non-respondents than after other inductors. We consider the use of assessment of thrombocyte aggregation after CPG induction when monitoring antiaggregation therapy a very promising procedure.