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 .
Prediction of the excessive perioperative bleeding in patients undergoing coronary artery bypass grafting: role of aspirin and platelet glycoprotein IIIa polymorphism.
OBJECTIVE The presence of the glycoprotein IIIa allele PlA2 is associated with enhanced thrombin formation and an impaired antithrombotic action of aspirin , which could favor coronary thrombosis . We wondered whether PlA1/A2 genetic polymorphism could affect the postoperative bleeding in patients undergoing coronary artery bypass grafting .  We also aim ed to assess the effects of aspirin pretreatment and to ascertain the value of platelet function studies as predictors of postoperative bleeding . METHODS In a r and omized , double-blind study , patients undergoing coronary artery bypass grafting were pretreated with a 150-mg dose of aspirin orally 12 and 3 hours before surgery ( n = 51 , 41 elective ) or with placebo ( n = 51 , 43 elective ) . The hemostasis was monitored by Simplate ( bioMérieux , Inc , Durham , NC ) bleeding time and capillary closure time ( platelet function analyzer PFA 100 ; Sysmex UK Ltd , Milton Keynes , United Kingdom ) . Postoperative bleeding and blood products transfusions were recorded . The glycoprotein IIIa polymorphism was analyzed . RESULTS Bleeding was significantly greater in PlA1 homozygotes from control group . Blood loss was significantly greater ( by 25 % ) in aspirin group . The volume of blood products transfusions in aspirin patients was significantly larger ( by 137 % ) . When subjects were stratified accordingly to blood platelet glycoprotein IIb/IIIa genotype , in the aspirin group PlA2 carriers had greater blood loss than PlA1 homozygotes ( 1858 + /- 932 mL vs 1216 + /- 525 mL , P < .05 ) . CONCLUSION PlA1 homozygotes normally had a greater risk of perioperative bleeding . Capillary closure time had no advantage relative to Simplate bleeding time in predicting postoperative blood loss . Aspirin pretreatment revealed no beneficial effects and result ed in increased postoperative bleeding and requirement for blood product transfusions after coronary artery bypass grafting in patients with stable angina . It was most unfavorable for PlA2 carriers
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 .