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 .
Thrombotic events in high risk patients are predicted by evaluating different pathways of platelet function.
A higher rate of clinical events in poor clopidogrel and /or aspirin responders was documented by using different methods to measure platelet function , but no conclusive data about the appropriate methodology to explore platelet reactivity are available . A total of 746 patients included in the cohort of the RECLOSE trial who had successful drug-eluting stent implantation were assessed for post-treatment residual platelet reactivity ( RPR ) in platelet-rich plasma by 10 microM adenosine 5'-diphosphate ( ADP ) , 1 mM arachidonic acid ( AA ) and 2 microg/ml collagen-induced platelet aggregation and in whole blood by the PFA-100 system . At six-month follow-up , RPR by two stimuli ( ADP and AA or ADP and collagen ) and by three stimuli ( ADP , AA and collagen ) is significantly associated with higher percentage of primary ( definite or probable stent thrombosis ) and secondary ( cardiac mortality and stent thrombosis ) end-points than RPR by ADP , AA , collagen and PFA-100 system . According to the primary and secondary end points , the specificity values for RPR identified by two ( ADP and AA:94 % ; ADP and collagen:97 % ) and three stimuli were higher with respect to RPR by ADP ( 88 % ) , or RPR by AA ( 83 % ) or RPR by collagen ( 90 % ) . The positive likelihood ratio values of RPR by three stimuli ( 9.55 ) or of RPR by ADP and collagen ( 8.08 ) were higher than those of RPR by ADP ( 2.59 ) , by AA ( 2.05 ) , by collagen ( 4.73 ) , or by PFA-100 ( 2.63 ) . This prospect i ve study documents that the evaluation of platelet reactivity addressed to identify patients at risk of thrombotic events on dual antiplatelet treatment has to be carried out by methods able to explore different pathways
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 .