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 .
Abnormal PFA-100 closure time is associated with increased platelet aggregation in patients presenting with chest pain
Background Antiplatelet therapy has been proven to be effective for both primary and secondary prevention of myocardial infa rct ion , stroke , and cardiovascular death . However , a significant proportion of patients treated  with aspirin  experience ischemic events . A number of prospect i ve studies have demonstrated that decreased responsiveness to antiplatelet therapy as measured by various methods , is strongly associated with an increase in clinical events . Our objective was to characterize platelet function in patients presenting with chest pain using a point-of-care assay , PFA-100 ® and correlating results to traditional platelet aggregometry to determine if patients with aspirin non-responsiveness have increased clinical sequelae . Methods Platelet function was assessed using PFA-100 ® , flow cytometry , and optical aggregometry in 94 patients presenting to the emergency department with chest pain . All patients were on aspirin 81–325 mg daily . Clinical events occurring during the index hospitalization were documented . Results Forty-seven patients ( 50 % ) were defined as aspirin non-responders by PFA-100 ® ( collagen-epinephrine closure time ≤ 193 ) . Compared to aspirin responders , aspirin non-responders had higher levels of mean platelet aggregation to adenosine diphosphate ( ADP ) ( P = 0.004 ) and high dose epinephrine ( P = 0.03 ) . Furthermore , expression of PAC-1 was significantly increased in patients with aspirin nonresponse as compared to aspirin responders ( P = 0.003 and P = 0.0006 respectively ) . No significant difference in clinical events during the index hospitalization was noted between aspirin non-responders and aspirin responders . Conclusion Patients presenting with chest pain who have abnormal PFA-100 closure times have increased platelet aggregation and activation however this aspirin non-responsiveness does not correlate with increased clinical events in the index hospitalization
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 .