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 .
Prevalence of aspirin resistance in patients with an evolving acute myocardial infarction.
OBJECTIVE To study the prevalence and importance of aspirin resistance in patients with an evolving acute myocardial infa rct ion ( AMI ) by use of the Platelet Function Analyzer-100 . INTRODUCTION Previous studies have demonstrated the existence of aspirin resistance , but the clinical relevance of the phenomenon remains to be clarified . If aspirin resistant patients comprise a high-risk subgroup , it might be expected that the prevalence of aspirin resistance in patients with AMI would be higher than in patients without AMI . We hypothesized that the prevalence of aspirin resistance in patients with AMI was twice the prevalence in patients without AMI . METHODS We included 298 consecutive patients with known cardiovascular disease who were admitted to hospital with symptoms suggestive of an AMI . All had been taking aspirin 150 mg/day for at least 7 days prior to hospital admission .  Platelet function was measured immediately at admission , and aspirin resistance was defined as a collagen/epinephrine Closure Time ( CT(CEPI))<165 s. RESULTS We found that 70 ( 23.5 % ) patients were  aspirin resistant , and 70 ( 23.5 % ) patients ended up with the diagnosis of an AMI . The prevalence of aspirin resistance was significantly higher in patients with AMI as compared to patients without ( 36 % versus 20 % , OR 2.26 , CI 95 % 1.19 - 4.22 , p=0.0058 ) . The CT(CEPI ) measured at admission was an independent factor associated with an AMI . CONCLUSIONS  Aspirin resistance is present in almost one fourth of patients admitted to hospital with symptoms suggestive of an AMI , and aspirin resistance is significantly associated with the diagnosis of a definite AMI
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 .