A Comparative Study In The Very Old Patients Treated With Different Antiplatelet Agents

BackgroundThe antiplatelet agents have been used widely in primary and secondary prevention and treatment in cardialvascular diseases at present. Aspirin and clopidogrel are the most common kinds among them. Although the current cardiovascular guidelines has emphasized the importance so much and given its recommend dosage as well as their possible adverse reactions, there is no convincing evidence in the very old people aged 75 or over related with using them up till now. There is still a dearth of information about the effects and adverse reactions of these kinds of medications in this specific aged group, so it is necessary to make further studies in order to get safe and effective antiplatelet agents and optimal antiplatelet treatment protocol.ObjectiveTo study the antiplatelet effects, side-effects comparatively of different kinds of antiplatelet agents such as the risk of gastrointestinal bleeding, thrombocytopenia and resistance rate in order to find out safe and effective antiplatlet agents, also to find out an optimal antiplatelet treatment protocol in the very old patients aged 75-year-old and over.Methods263 patients aged 75-year-old or over with cardiovascular diseases were included in the study. Those patients with blood disease, hepatic disfunction, active gastrointestinal ulcer, a history of recent surgery, allergic to aspirin or clopidogrel, and a history of injury or bleeding in recent two weeks were excluded. Patients were radomized to seven groups:aspirin 100mg, aspirin 100mg plus marzulene-s 0.67g, plavix 75mg, aspirin 100mg plus plavix 75mg, talcom 50mg, plavix 75mg plus PPIs, and the placebo group. The treatment was lasted for 16 weeks. Before and in the end of the study, gastroscopy was performed to detect gastrointestinal bleeding; Blood specimens were collected in all eligible patients to test blood routine values, prothrombin time (PT), prothrombin activity (PA), activated partial thromboplastin time (APTT), fibrinogen(FIB), and platelet aggregation rate(PAG). Statistic analysis was made by SPSS 13.0 and P<0.05 was significant.ResultBaseline information was paralleled among all groups. Platelet aggregation rate decreased significantly in all treatment groups compared with placebo group(P<0.05) after treatment. Athough there was a inclination that the platelet aggregation rate in aspirin plus plavix group was lower than that in aspirin or plavix alone group, the difference was not significant among them. The difference of platelet aggregation rate was not significant among PPIs added group and non-PPIs groups. The difference of the gastric bleeding occurrence was not significiant among all groups, also not among marzulene-s added group and non-marzulene-s groups. There was no significant difference in the number of blood platelet among all groups. Aspirin or Plavix resistance was similar to that in literatures.Conclusion①Common dosage of aspirin, clopidogrel or combination of them can inhibit platelet aggregation well in the very old patients, all of them could be used safely in this group.②The combination of aspirin and clopidogrel can inhibit platelet aggregation better by different ways, however, the side-effects didn't increase in the meantime.③The effect of platelet aggregation inhibition and the safety were similar between talcum group (50mg per day) and plavix group(75mg per day).④There was a similar rate of mucomembranous injury among aspirin or plavix alone group and the combination group, also among marzulene-s added group and non-marzulene-s groups, similarly among PPIs added group and non-PPIs groups.⑤PPIs doesn't decrease the inhibition effect of platelet aggregation compared with the non-PPIs groups.⑥Common use of aspirin or clopidogrel didn't influence the number of PLT in the very old patients.⑦There was a similar aspirin or clopidogrel resistance rate in the very old patients to non-elderly patients in literatures.