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 in Indian patients with coronary artery disease and cardiovascular events.
BACKGROUND Aspirin resistance is a major problem and its incidence and clinical significance in Indian patients with documented coronary artery disease are not known . AIM We sought to study the incidence of aspirin resistance and its clinical significance in a cohort of Indian patients with coronary heart disease on therapy with aspirin  using urinary 11-Dehydrothromboxane B2 levels as a surrogate marker for antiplatelet efficacy . SETTING AND DESIGN Non r and omized single center prospect i ve study in cohort of patients with stable cardiovascular disease on chronic aspirin therapy attending the cardiology outpatient clinic of a tertiary care hospital . MATERIAL S AND METHODS Urinary dehydrothromboxane levels were analyzed in a cohort of 63 patients with stable documented coronary artery disease and in 21 healthy volunteers . The cases were followed up prospect ively for a median period of 36 ( 1 - 53 ) months . The clinical endpoint was a composite of acute coronary syndrome , stroke , revascularization and death . STATISTICAL ANALYSIS Comparison of urinary dehydrothromboxane concentration values between various risk factors was done using Mann Whitney U test , a non parametric alternative of independent t test . All statistical analyses were done using SPSS 11.0 ( Chicago , USA ) software . RESULTS The median ( range ) absolute values of urinary11- dehydrothromboxane B2 levels for the healthy volunteers and cases were 440 ( 286 - 2050 ) pg/ml and 320 ( 72 - 2600 ) pg/ml ( P=0.007 ) . The corresponding normalized values were 87.3 ( 43 - 143 ) and 60.8 ( 16.7 - 943 ) ng/mmol of creatinine ( P=0.131 ) . Among the various vascular risk factors , patients who were overweight had higher absolute levels of 11- urinary dehydrothomboxane B2 levels ( P=0.016 ) . There were significantly more clinical events in patients with absolute urinary 11-dehydrothromboxane B2 levels in the upper two quartiles compared to the lower two quartiles ( P=0.04 ) . CONCLUSION The incidence of aspirin resistance in the cohort of patients with documented heart disease was 38.1 % . Patients with elevated absolute urinary dehydrothomboxane levels ( > 320 pg/ml ) on chronic aspirin therapy constitute a high risk subset for recurrent vascular 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 .