[Aspirin resistance in patients taking small dose of aspirin].
OBJECTIVE
To investigate the phenomenon and influencing factors of aspirin resistance (AR) in patients taking small dose of aspirin.


METHODS
Three hundred and twenty-eight patients with stable cardiac and cerebral vascular diseases, diabetes mellitus, et al taking aspirin 100 mg/d for > or =14 days, and then their blood samples were collected for determination of optical platelet aggregation index using arachidonic acid (AA) and adenosine diphosphate (ADP). AR was defined as a state in which aggregation of > or =20% with AA and that > or =70% with ADP was found. Aspirin semi-resistance (ASR) was defined as meeting one of the above criteria. If both above criteria were not met, the condition was defined as aspirin sensitive. The difference in clinical characteristics among the groups and independent risk factors associated with AR and ASR were analyzed.


RESULTS
Of 328 patients, 4.9% were AR, 27.4% were ASR. Among AR+ASR group, female, elderly, diabetic and hypertensive patients were predominant, but less common in smokers. Logistic regression analysis showed that diabetes mellitus was an independent risk factor of AR and ASR [odds ratio (OR)=0.953, 95% confidence interval (CI) 0.323-0.876, P=0.013], and hypertension was independently associated with AR and ASR (OR=0.610, 95%CI 0.376-0.991, P=0.046). The risk of AR and ASR was increased in non-smokers (OR=2.231, 95%CI 1.182-4.210, P=0.013).


CONCLUSIONS
The incidence rate of AR in patients taking small dose of aspirin was 4.9%. Diabetes mellitus and hypertension are relative risk factors of AR and ASR. The risk of AR and ASR in the no-smoking patients is increased.
Wang
Chun-bo
CB
Cardiovascular Center, Beijing Tongren Hospital, Affiliated Hospital of Capital University of Medicine Sciences, Beijing 100730, China. bzcat@263.net
Hu
Da-yi
DY
Shi
Xu-bo
XB
Zhu
Zheng-yan
ZY
Zhu
Jing-yan
JY
Yang
Jin-gang
JG
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001241:Aspirin / Q000008:administration & dosage* / Q000627:therapeutic use; D002318:Cardiovascular Diseases / Q000097:blood / Q000188:drug therapy; D002561:Cerebrovascular Disorders / Q000097:blood / Q000188:drug therapy; D004305:Dose-Response Relationship, Drug; D004361:Drug Tolerance; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010974:Platelet Aggregation / Q000187:drug effects; D010975:Platelet Aggregation Inhibitors / Q000008:administration & dosage* / Q000627:therapeutic use; D012307:Risk Factors
D010975:Platelet Aggregation Inhibitors; D001241:Aspirin