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 to both aspirin and clopidogrel is associated with the highest risk of adverse events following percutaneous coronary intervention
Aim High on-clopidogrel platelet reactivity ( HCPR ) and high on-aspirin platelet reactivity ( HAPR ) are associated with atherothrombotic events following coronary stenting . There are , however , few data concerning high on-treatment platelet reactivity to both aspirin and clopidogrel simultaneously . The aim of the present study was to determine the incidence of dual high on-treatment platelet reactivity ( DAPR ) and its impact on clinical outcome . Methods On-treatment platelet reactivity was measured in parallel by ADP- and arachidonic acid-induced light transmittance aggregometry ( LTA )  ( n=921 ) and the point-of-care VerifyNow system ( P2Y12 and aspirin ) ( n=422 ) in patients on dual antiplatelet therapy undergoing elective stent implantation . HCPR and HAPR were established by receiver-operator characteristic curve analysis . The primary endpoint was a composite of all-cause death , non-fatal acute myocardial infa rct ion , stent thrombosis and ischaemic stroke at 1-year follow-up . Results The incidence of DAPR varied between 14.7 % and 26.9 % depending on the platelet function test used . DAPR , assessed by LTA and the VerifyNow system , was highly associated with an adverse clinical outcome . At 1-year follow-up the primary endpoint occurred more frequently in patients with isolated HCPR ( 11.7 % ) , isolated HAPR ( 9.6 % ) or DAPR ( 10.7 % ) compared with patients without high on-treatment platelet reactivity ( 4.2 % , all p<0.01 ) when platelet function was evaluated with LTA . Using the VerifyNow system , patients exhibiting DAPR had the highest risk for the primary endpoint ( 17.7 % vs 4.1 % in patients without high on-treatment platelet reactivity , p=0.001 ) . Conclusions In patients undergoing elective percutaneous coronary intervention , DAPR to aspirin and clopidogrel is present in one in five patients and is associated with a high risk for atherothrombotic events . DAPR measured by the point-of-care VerifyNow system has a higher predictability for atherothrombotic events than LTA . Clinical Trial Registration Information www . clinical trials.gov : NCT00352014
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 .