Acute and delayed antithrombotic effects of alcohol in humans

Alcohol intake, especially in the form of red wine, has been:shown to inhib it platelet function. However, whether alcohol in spirits may inhibit plate let-dependent thrombosis in humans up to 6 hours after ingestion is unknown and was assessed in this study. Platelet thrombus that is formed on exposu re of an aortic media (simulating deep arterial injury or plaque rupture) t o flowing blood was assessed in an ex vivo Badimon's superfusion chamber at shear rates of 754 or 2,546 seconds(-1) (simulating flow in normal or sten osed arteries). Twelve healthy subjects were studied before and at 20 minut es and 6 hours after consumption of 2 ounces of 40% alcohol. Blood alcohol level was 1.1 +/- 0.1, 8.2 +/- 0.7, and 1.3 +/- 0.2 mmol/L at baseline, 20 minutes and 6 hours, respectively, after alcohol consumption (analysis of v ariance [ANOVA] p = 0.0001). Compared with baseline, platelet thrombus form ation at the low shear rate flow was significantly decreased by 57% and 61% at 20 minutes and 6 hours, respectively, after alcohol intake (ANOVA p = 0 .0001). Platelet thrombus deposition at the high shear rate was similarly i nhibited to 68% and 64% of baseline values at 20 minutes and 6 hours, respe ctively (ANOVA p = 0.003). Men and women showed equal benefit. Thus, modera te alcohol intake in humans significantly inhibited platelet thrombus depos ition under low and high shear rates of arterial flow conditions. This anti thrombotic effect of a single alcohol drink, persisting for 6 hours and eve n after blood alcohol level has returned to baseline, may be clinically rel evant to the cardioprotective effects of alcohol in men and women. (C) 2001 by Excerpta Medica, Inc.