Results indicated that some PFTs may have some prognostic utility , i.e. a trend for more clinical events to be associated with groups classified as ' aspirin resistant ' .
Study -level effect sizes were generally small and absolute outcome risk was not substantially different between ' aspirin resistant ' and ' aspirin sensitive ' design ations .
Based on assumptions of PFTs being able to accurately identify patients at high risk of clinical events and such patients benefiting from treatment modification , the economic model found that a test-treat strategy was likely to be cost-effective .
However , neither assumption is currently evidence based .
BACKGROUND The use of aspirin is well established for secondary prevention of cardiovascular disease .
However , a proportion of patients suffer repeat cardiovascular events despite being prescribed aspirin treatment .
It is uncertain whether or not this is due to an inherent inability of aspirin to sufficiently modify platelet activity .
This report aims to investigate whether or not insufficient platelet function inhibition by aspirin ( ' aspirin resistance ' ) , as defined using platelet function tests ( PFTs ) , is linked to the occurrence of adverse clinical outcomes , and further , whether or not patients at risk of future adverse clinical events can be identified through PFTs .
OBJECTIVES To review systematic ally the clinical effectiveness and cost-effectiveness evidence regarding the association between PFT design ation of ' aspirin resistance ' and the risk of adverse clinical outcome ( s ) in patients prescribed aspirin therapy .
To undertake exploratory model-based cost-effectiveness analysis on the use of PFTs .
The effect of acetylsalicylic acid resistance on prognosis of patients who have developed acute coronary syndrome during acetylsalicylic acid therapy.
AIM The relationships between clinical events and acetylsalicylic acid resistance ( AR ) , as well as its frequency , have been established in stable patients with coronary artery disease ( CAD ) . Although acute coronary syndrome ( ACS ) patients taking  acetylsalicylic acid  have been accepted as a high-risk population , the role of AR has not been investigated in these patient groups . Thus , in the present study , the impact of AR was investigated in patients with ACS who were taking acetylsalicylic acid .  METHODS Between January 2001 and February 2003 , 140 ACS patients were included in the present prospect i ve study . All patients had ACS while taking acetylsalicylic acid .  Coronary angiographic scores for severity and extent of CAD were determined for all patients . The effect of acetylsalicylic acid on platelet function was assessed by the platelet function analyzer PFA-100 ( Dade Behring , USA ) . The primary end point was the composite of death , myocardial infa rct ion , cerebrovascular accident and revascularization . The mean follow-up period was 20 months . RESULTS Patients with AR were  older  than patients without AR ( 63.8+/-10.8 years versus 58.3+/-11.2 years ; P=0.005 ) . Moreover , myocardial damage was higher in patients with AR according to cardiac troponin T values ( 1.11+/-1.3 mug/L versus 0.41+/-0.5 mug/L ; P=0.01 ) . The composite end point of death , myocardial infa rct ion , cerebrovascular accident or revascularization was present in 16 of 45 patients ( 35 % ) with AR and in 13 of 79 patients ( 16 % ) without AR ( hazard ratio 2.46 , 95 % CI 1.18 to 5.13 ; P=0.016 ) . After adjustment for age , platelet count , cardiac troponin T value and CAD severity score , AR remained an independent predictor for long-term adverse events ( hazard ratio 3.03 , 95 % CI 1.06 to 8.62 ; P=0.038 ) . CONCLUSIONS The clinical event rate was found to be higher in ACS patients with AR than in those without AR . Thus , it may be concluded that there is a strong correlation between a worse prognosis and AR in these patients
Results indicated that some PFTs may have some prognostic utility , i.e. a trend for more clinical events to be associated with groups classified as ' aspirin resistant ' .
Study -level effect sizes were generally small and absolute outcome risk was not substantially different between ' aspirin resistant ' and ' aspirin sensitive ' design ations .
Based on assumptions of PFTs being able to accurately identify patients at high risk of clinical events and such patients benefiting from treatment modification , the economic model found that a test-treat strategy was likely to be cost-effective .
However , neither assumption is currently evidence based .
BACKGROUND The use of aspirin is well established for secondary prevention of cardiovascular disease .
However , a proportion of patients suffer repeat cardiovascular events despite being prescribed aspirin treatment .
It is uncertain whether or not this is due to an inherent inability of aspirin to sufficiently modify platelet activity .
This report aims to investigate whether or not insufficient platelet function inhibition by aspirin ( ' aspirin resistance ' ) , as defined using platelet function tests ( PFTs ) , is linked to the occurrence of adverse clinical outcomes , and further , whether or not patients at risk of future adverse clinical events can be identified through PFTs .
OBJECTIVES To review systematic ally the clinical effectiveness and cost-effectiveness evidence regarding the association between PFT design ation of ' aspirin resistance ' and the risk of adverse clinical outcome ( s ) in patients prescribed aspirin therapy .
To undertake exploratory model-based cost-effectiveness analysis on the use of PFTs .