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 .
Residual platelet activity is increased in clopidogrel- and ASA-treated patients with coronary stenting for acute coronary syndromes compared with stable coronary artery disease
Objective : To evaluate residual platelet activity in a consecutive cohort of patients treated with dual antiplatelet therapy after coronary stent implantation  Design : Prospect i ve single-centre cohort study . Setting : University hospital in Germany . Patients : 480 patients with symptomatic coronary artery disease ( n = 221 ( 46 % ) or acute coronary syndrome ( ACS ; n = 259 ( 54 % ) stable angina ) were studied . Platelet activity was measured by collagen- ( 5 µg/ml ) and adenosine diphosphate- ( ADP ; 20 µmol/l ) induced platelet aggregation to assess post-treatment activity in patients treated with acetylsalicylic acid ( 500 mg bolus intravenously followed by 100 mg once a day ) and clopidogrel ( 600 mg loading dose followed by 75 mg once a day ) Main outcome measures : Increased residual platelet activity ( IRPA ) was defined if platelet aggregation was in the upper tertile of values in the patient collective . Association of epidemiological factors with IRPA was evaluated in a multivariate logistic regression analysis . Results : IRPA-ADP was found in 53 patients ( 11.0 % ) and IRPA-collagen in 42 patients ( 8.8 % ) . ACS was associated with IRPA independently from other factors ( for IRPA-collagen : odds ratio ( OR ) = 2.3 , 95 % confidence interval ( CI ) 1.2 to 4.5 , p<0.05 ; for IRPA-ADP : OR = 2.4 ; 95 % CI 1.3 to 4.4 , p<0.01 ; for IRPA-ADP/collagen : OR = 4.5 , 95 % CI 1.2 to 16.9 , p<0.05 ) . Conclusions : The data suggest that ACS is independently associated with IRPA despite conventional antiplatelet therapy . Further studies are warranted to demonstrate the effects of intensified antiplatelet therapy for patients with acute coronary events
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 .