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 .
The Effect of Aspirin Dosing on Platelet Function in Diabetic and Nondiabetic Patients
OBJECTIVE — Diabetic patients may have a higher prevalence of platelet aspirin resistance than nondiabetic patients . Our goal was to analyze platelet aspirin responsiveness to various aspirin doses in diabetic and nondiabetic patients . RESEARCH DESIGN AND METHODS — We examined the effect of aspirin ( 81 , 162 , and 325 mg/day for 4 weeks each ) on platelet aspirin responsiveness in 120 stable out patients ( 30 diabetic patients and 90 nondiabetic patients ) with coronary artery disease ( CAD ) using light transmittance aggregometry ( LTA ) , VerifyNow , platelet function analyzer (PFA)-100 , and levels of urinary 11-dehydro-thromboxane B2 ( 11-dh-TxB2 ) . RESULTS — In the total group , a low prevalence ( 0–2 % ) of aspirin resistance was observed with all aspirin doses as determined by arachidonic acid – induced LTA . Aspirin resistance was higher at the 81-mg dose in diabetic versus nondiabetic patients using collagen-induced LTA ( 27 vs. 4 % , P = 0.001 ) , VerifyNow ( 13 vs. 3 % , P = 0.05 ) , and urinary 11-dh-TxB2 ( 37 vs. 17 % , P = 0.03 ) . Diabetic patients treated with 81 mg exhibited higher platelet function measured by VerifyNow , collagen- and ADP-induced LTA , and 11-dh-TxB2 levels ( P ≤ 0.02 for all comparisons ) . Higher aspirin doses significantly inhibited platelet function and decreased aspirin resistance in diabetic patients ( P < 0.05 ) . CONCLUSIONS — Diabetic patients with CAD treated with 81 mg aspirin exhibit a higher prevalence of aspirin resistance and have significantly higher ADP- and collagen-induced platelet aggregation , 11-dh-TxB2 levels , and aspirin reaction units measured by VerifyNow than nondiabetic patients . Increased aspirin dosing result ed in similar rates of resistance and platelet function levels between groups . These findings indicate that diabetic patients exhibit a global high platelet reactivity phenotype that may be partially overcome by higher aspirin doses
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 .