title: [Long term effects of 50 mg acetylsalicylic acid alone and in combination with dipyridamole on platelet function after coronary bypass surgery].
abstract: In a prospective randomized trial in 42 patients undergoing coronary artery bypass surgery, we analyzed the long term platelet inhibiting effects of 50 mg acetylsalicylic acid (ASA) by itself and in combination with dipyridamole (2 x 200 mg), in comparison with phenprocoumon. Three and six months therapy led to significant inhibition of maximum aggregation induced by collagen 1 microgram/ml in platelet rich plasma (PRP) by more than 50% (p < or = 0.05). In PRP stimulated with 5 micrograms/ml collagen maximum inhibition amounted to nearly 20% (n.s.). The groups treated with ASA/ASA + dipyridamole showed an ADP threshold concentration 2.5 times higher than the group treated with phenprocoumon (p < or = 0.05). After stimulation with collagen 1 microgram/ml and 5 micrograms/ml thromboxane B2 synthesis in vitro in both groups treated with ASA was reduced to 1% of the base line values (p < or = 0.01). Inhibition of aggregation in whole blood appeared evident, but was not statistically significant due to considerable fluctuation of measurement. An additional effect of dipyridamole was not detectable. In conclusion, treatment with 50 mg ADA/d results in a lasting, effective inhibition of aggregation of platelets in patients with coronary artery bypass surgery. There is no synergistic effect of additional dose of 400 mg dipyridamole/d.
authors.affiliation: Abteilung für Kardiologie Medizinische Klinik Universitäts-Krankenhaus Eppendorf, Hamburg.
authors.forename: M W
authors.initials: MW
authors.lastname: Hoffmann
authors.forename: C
authors.initials: C
authors.lastname: Rauhöft
authors.forename: W
authors.initials: W
authors.lastname: Terres
mesh_terms: D000925:Anticoagulants / Q000627:therapeutic use*; D001241:Aspirin / Q000627:therapeutic use*; D001792:Blood Platelets / Q000187:drug effects* / Q000502:physiology; D001026:Coronary Artery Bypass; D003327:Coronary Disease / Q000188:drug therapy / Q000601:surgery; D004176:Dipyridamole / Q000627:therapeutic use*; D004359:Drug Therapy, Combination; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010644:Phenprocoumon / Q000627:therapeutic use; D010974:Platelet Aggregation / Q000187:drug effects; D010975:Platelet Aggregation Inhibitors / Q000627:therapeutic use*; D010979:Platelet Function Tests; D011446:Prospective Studies; D013929:Thromboxane B2 / Q000096:biosynthesis; D013997:Time Factors
chemical_list: D000925:Anticoagulants; D010975:Platelet Aggregation Inhibitors; D013929:Thromboxane B2; D004176:Dipyridamole; D010644:Phenprocoumon; D001241:Aspirin