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 .
Aspirin resistance measured by cationic propyl gallate platelet aggregometry and recurrent cardiovascular events during 4 years of follow-up.
BACKGROUND Aspirin resistance appears to be an important prognostic factor in patients with coronary artery disease , yet there is no st and ardized method to measure it and limited data on its correlation to clinical outcomes . METHODS In a prospect i ve study we followed 103 patients ( mean age 64 years ) with acute coronary syndrome ( ACS ) without ST segment elevation who were treated with 100 mg of aspirin ( ASA ) daily . Optical platelet aggregometry using cationic propyl gallate ( CPG ) as an inductor was measured at ACS onset and after 3 , 12 , 24 , 36 , and 48 months . ASA responsiveness was defined both by the slope of the aggregation curve ( < 53%/min ) and by spontaneous aggregation ( < 5 % ) . The primary outcomes were the recurrence of ACS or stroke . RESULTS Patients with ACS exhibited a greater prevalence of  ASA resistance ( 55 % ) than healthy volunteers ( 4 % ; p<0.01 ) . ASA resistance occurred more often in patients with type 2 diabetes , hypertriacylglycerolemia , and decreased HDL levels , and in smokers ( p<0.05 ) . A single assessment of platelet aggregometry was sufficient to identify ASA-resistant patients . During the 4-year follow-up , the patients with ASA resistance had an 88 % incidence of recurrent cardiovascular events versus 46 % for the patients without ASA resistance ( p<0.01 ) . In the subgroup with recurrent cardiovascular ( CV ) events , significantly more patients were ASA-resistant than in the subgroup without recurrent CV events ( 72 % vs. 8 % , p<0.01 ) . CONCLUSION ASA resistance measured by CPG-induced platelet aggregometry is more common among patients with ACS and some metabolic risk factors , and ASA-resistant patients have a significantly higher recurrence of cardiovascular 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 .