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 .
Incidence and clinical impact of dual nonresponsiveness to aspirin and clopidogrel in patients with drug-eluting stents.
OBJECTIVES This study sought to determine the incidence of aspirin nonresponsiveness in addition to clopidogrel nonresponsiveness and whether this association identifies patients at an increased risk of drug-eluting stent ( DES ) thrombosis . BACKGROUND Nonresponsiveness to clopidogrel is a predictor of DES thrombosis . No prospect i ve data exist about the possible association of dual nonresponsiveness to clopidogrel and aspirin with DES thrombosis . METHODS Platelet function was assessed after a loading dose of 600 mg clopidogrel in 746 patients who had successful DES implantation followed by 6-month dual-antiplatelet therapy .  Platelet reactivity was assessed by light transmittance aggregometry using adenosine 5'-diphosphate , arachidonic acid , and collagen . The primary end point was definite/probable DES thrombosis at 6 months . The secondary end point was the composite of cardiac mortality and DES thrombosis . RESULTS The incidence of dual nonresponsiveness to aspirin and clopidogrel was 6 % . Definite/probable DES thrombosis was significantly higher in dual aspirin and clopidogrel nonresponders ( 11.1 % ) than in clopidogrel and aspirin responders ( 2.1 % , p < 0.001 ) , isolated clopidogrel nonresponders ( 2.2 % , p < 0.05 ) , or aspirin nonresponders ( 2.3 % , p < 0.05 ) . The incidence of the secondary end point was 4.4 % in isolated clopidogrel nonresponders , 2.3 % in isolated aspirin nonresponders , and 13.3 % in dual aspirin and clopidogrel nonresponders . Dual clopidogrel and aspirin nonresponsiveness was an independent predictor of DES thrombosis ( hazard ratio : 3.18 , 95 % confidence interval : 1.14 to 8.83 , p = 0.027 ) and the composite of cardiac mortality and DES thrombosis ( hazard ratio : 2.94 , 95 % confidence interval : 1.16 to 7.41 , p = 0.022 ) . CONCLUSIONS Dual nonresponsiveness to aspirin and clopidogrel is a relatively infrequent condition that identifies patients at a very high risk of DES thrombosis or death
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 .