Dual antiplatelet therapy in ACS: time-dependent variability in platelet aggregation during the first week.

ABSTRACT

AIMS AND OBJECTIVES: Platelets play an important role in the pathogenesis of Acute Coronary Syndrome (ACS). Most of the complications of ACS occur during the initial hours of presentation. We tried to gain an insight into the platelet function during the initial phase of ACS in patients on dual antiplatelet therapy. MATERIALS AND METHODS: Platelet aggregation study was performed by light transmittance aggregometry in 64 ACS patients 48 hour and 7 days after initiation of dual antiplatelet therapy with aspirin and clopidogrel. RESULTS: Epinephrine, ADP and collagen induced platelet aggregation was significantly higher at 48 hours, following initiation of dual antiplatelet therapy, in comparison to the profile observed on the 7th day. Diabetics demonstrated a significantly higher aggregation at both the time points and aggregation was also somewhat higher in smokers though it did not reach statistical significance. CONCLUSION: This study conceptualizes the hypothetical role of alpha-2 adrenoreceptor blockers during the early hours following ACS and also warrants further investigations exploring the optimum loading dose of antiplatelet agents, especially clopidogrel in patients with ACS.