Effect of antiplatelet drugs in patients with prosthetic heart valves under warfarin treatment

Abstract

In order to evaluate the effect of small dose of aspirin (40mg/day) with or without dilazep (300mg/day) and ticlopidine (200mg/day) with dilazep for 4 weeks in patients with prosthetic heart valves under warfarin treatment, platelet survival time by malondialdehyde (MDA) method, platelet functions and some coagulation parameters were examined before and after the treatment.
Following results were obtained;
1) There was a negative linear correlation between platelet count and the recovery rate of platelet MDA production on the fifth day.
2) Although the platelet aggregability was suppressed significantly after administration of aspirin with or without dilazep, the suppression of the platelet aggregability was not found after administration of ticlopidine with dilazep.
3) Platelet count increased after aspirin with dilazep and after ticlopidine with dilazep as compared with that observed before treatment.
4) Platelet survival time was also prolonged after 4-weeks' administraton of aspirin with dilazep as compared with that observed before treatment.
These results suggest that the MDA recovery rate on the third and the fifth day may be useful parameter to evaluate the platelet survival time. The increase in platelet count and the prolongation of platelet survival time suggest that small dose of aspirin with dilazep may prevent thrombo-embolic complications in these patients with prosthetic heart valves under warfarin treatment.