Antithrombotic Properties of Nitroglycerin in Patients with Coronary Artery Diease

This study was desingned to test the effects of nitroglycerin on platelet activation and aggregation in 11 patients with unstable angina pectoris and 14 patients with acute myocardial infarction. Intravenous infusion of nitroglycerin was begun at 0.25 ug/kg/min., and was incresed to 1 ug/kg/min. by controlling blood pressure. Blood samples fo determination of platelet aggregation, (ß-TG) and platelet factor-4 (TF-4) before infusion, after 45 minutes and 24 hours. The levels obtained before nitroglycerin infusion were compared with the measurements of 10 healthy persons. These three parameters were high in the patient group (p=0,0001; p=0,0001). Platelet aggregation was reduced to 80.4±7.5% (p=0,0001) and 85.1±4.9% (p=0,0001) from baseline (97.7±3.3%) at 45 minutes and 24 hours, respectively; ß-TG declined from 54±8 IU/ml to 46±8 IU/ml at 45 minutes of infusion (p<0,0001) and to 42±8 IU/ml at 24 hours (p<0,0001); PF-4 decreased from 13.7±3.1 IU/ml to 10.8±2.7 IU/ml (p=0,0001) and to 9.4±2.3 IU/ml (p=0,0001), respectively. These data suggest that therapeutic doses of nitroglycerin can inhibit platelet functions significantly in patients with acute ischemic syndrome. This beneficial effect of nitrovasodilators in acute ischemic syndromes may contribute to the therapeutic value of these agents.