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 .
Aprotinin shows both hemostatic and antithrombotic effects during off-pump coronary artery bypass grafting.
BACKGROUND Hemostatic drugs are widely thought to be unnecessary and potentially detrimental in off-pump coronary artery bypass graft surgery ( OPCABG ) , despite well-established use in on-pump surgery . In a r and omized , prospect i ve OPCABG trial , we assessed efficacy and safety of aprotinin through a comprehensive assessment of graft patency and hematologic function . METHODS Sixty patients were r and omly assigned to full-dose aprotinin or placebo . Heparin was titrated to a kaolin-based activated clotting time of greater than 300 seconds . Exclusionary criteria included creatinine greater than 2 mg/dL , conversion to on-pump CABG , and preoperative GPIIb/IIIa inhibition .  Hematologic assessment s were obtained preoperatively , at the end of surgery , and on days 1 and 3 : mean platelet volume , thrombin generation ( prothrombin fragment 1.2 assay ) , and aspirin resistance using a modified thrombelastography , whole blood aggregometry , 11-dehydro-thromboxane B2 levels , and flow cytometry . Thrombotic events were defined as postoperative myocardial infa rct ion by electrocardiography or elevated troponin I , clinical stroke by examination and head computed tomography , and bypass graft failure by multichannel computed tomography angiography on day 5 . RESULTS Aprotinin was associated with a significant reduction in intraoperative and postoperative blood loss compared with placebo but had no effect on transfusion rates . Patients treated with aprotinin had significantly fewer thrombotic events ( 3 % versus 23 % , p < 0.05 , Fisher 's exact test ) and less postoperative aspirin resistance ( 20 % versus 46 % , respectively , p < 0.05 , Fisher 's exact test ) . Postoperative prothrombin fragment 1.2 level was reduced by aprotinin use . CONCLUSIONS Aprotinin reduced perioperative bleeding after OPCABG . Preserved aspirin sensitivity in the aprotinin group may explain the observed reduction in thrombotic events and might be related to the suppression of perioperative and transmyocardial thrombin formation
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 .