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 .
Comparison of 2 point-of-care platelet function tests, VerifyNow Assay and Multiple Electrode Platelet Aggregometry, for predicting early clinical outcomes in patients undergoing percutaneous coronary intervention.
BACKGROUND Various platelet function tests are currently used to measure responsiveness to antiplatelet therapy . We sought to compare 2 point-of-care platelet function tests , VerifyNow Assay ( Accumetrics , San Diego , CA ) and Multiple Electrode Platelet Aggregometry ( MEA ) ( Dynabyte , Munich , Germany ) , for predicting early clinical outcomes after percutaneous coronary intervention . METHODS Platelet reactivity in the arachidonic acid-induced and adenosine diphosphate (ADP)-induced platelet aggregation was measured simultaneously with the VerifyNow Assay and MEA in 222 patients undergoing percutaneous coronary intervention between August and October 2009 . We investigated the correlations between the 2 tests and performed receiver operating characteristic curve analysis for major adverse cardiovascular events ( MACE ) , a composite of death , myocardial infa rct ion ( MI ) , stroke , and target vessel revascularization , at 30 days . RESULTS Major adverse cardiovascular events occurred in 19 patients ( 8.6 % ) , including 14 patients with periprocedural MI and 5 patients with stroke . Correlations were weak between the 2 tests in the arachidonic acid-induced ( Spearman r = 0.189 , P = .006 ) and ADP-induced platelet reactivity ( Spearman r = 0.390 , P < .001 ) . Although the VerifyNow P2Y12 Assay ( Accumetrics ) was able to predict periprocedural MI ( area under the aggregation curve 0.680 , P = .024 ) and 30-day MACE ( area under the aggregation curve 0.649 , P = .032 ) , VerifyNow Aspirin Assay ( Accumetrics ) , MEA ASPI test , and MEA ADP test failed to predict such clinical events . Hyporesponsiveness to clopidogrel based on the VerifyNow Assay was associated with about a 6-fold increased risk of MACE at 30 days . CONCLUSIONS Hyporesponsiveness to clopidogrel measured by VerifyNow Assay was able to identify patients with dual antiplatelet therapy who were at higher risk for periprocedural MI and MACE at 30 days . Further r and omized studies are required to vali date the effectiveness of different platelet function tests for predicting long-term clinical outcomes
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 .