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 .
High on-treatment platelet reactivity by more than one agonist predicts 12-month follow-up cardiovascular death and non-fatal myocardial infarction in acute coronary syndrome patients receiving coronary stenting.
There is some data available on the role of high on-treatment platelet reactivity by ADP whereas , as regards arachidonic acid or other agonists , there is no proof of the best cut-off for identifying population s with a different cardiovascular outcome by the construction of appropriate receiver-operator characteristics ( ROC ) curves . We enrolled 1,108 acute coronary syndrome patients undergoing percutaneous coronary intervention ( PCI ) with stent implantation  and followed them up for 12 months . Platelet reactivity was assessed by light transmission aggregometry ( LTA ) using 10 microM ADP , 1 mM arachidonic acid ( AA ) and 2 microg/ml collagen . At a 12-month follow-up , we found 37 cardiovascular deaths ( 3.3 % ) , 54 non-fatal myocardial infa rct ions ( MI ) ( 4.8 % ) and 154 target vessel revascularisations ( TVR ) ( 13.8 % ) . ROC analysis demonstrated that 10 microM ADP LTA , 1 mM AA and 2 microg/ml collagen LTA were able to distinguish between patients with and without subsequent cardiovascular death and non-fatal MI ( area under the curve for 10 microM ADP 0.63 ( 0.55 - 0.71 ) , p<0.001 ; for 1 mM AA 0.68 ( 0.61 - 0.76 ) , p<0.0001 ; for 2 microg/ml collagen 0.62 ( 0.52 - 0.73 ) , p<0.0111 ) , whereas no association was demonstrated with the occurrence of TVR . Ten microM ADP LTA > or=55 % , 1 mM AA LTA > or=15 % and 2 microg/ml collagen LTA > or=31 % were identified as the optimal cut-off to predict cardiovascular death and non-fatal MI at 12-month follow-up . The contemporary platelet hyperreactivity to more than one agonist was associated with a higher risk of 12-month cardiovascular death and MI , whereas isolated platelet hyperreactivity to only one agonist had not a predictive value [ 10 microM ADP LTA > or=55 % + 1 mM AA LTA > or=15 % : odds ratio [OR]=3.6(2.4 - 6.1 ) , p<0.0001 ; ADP LTA > or=55 % + 1 mM AA LTA > or=15 % + 2 microg/ml collagen LTA > or=31 % : OR=4.7(2.9 - 7.7 ) , p<0.0001 ] . In this prospect i ve study on a large number of acute coronary syndrome patients undergoing stent implantation  , we have found that high on-treatment platelet reactivity measured by LTA induced by more than one agonist -- AA , ADP , collagen -- is an independent risk factor for 12-month cardiovascular death and non-fatal MI . Isolated platelet hyperreactivity to only one agonist has not a predictive value for clinical recurrences
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 .