Prevalences widely differ between studies reporting on aspirin resistance .
BACKGROUND The absolute risk of recurrences among patients using aspirin for prevention of cardiovascular events remains high .
Persistent platelet reactivity despite aspirin therapy might explain this in part .
Reported prevalences of this so-called aspirin resistance vary widely , between 0 % and 57 % .
OBJECTIVES The aim of the study was to systematic ally review all available evidence on prevalence of aspirin resistance and to study determinants of reported prevalence .
Incidence of aspirin nonresponsiveness using the Ultegra Rapid Platelet Function Assay-ASA.
We report the incidence of  aspirin  nonresponsiveness  in a prospect i ve , multicenter registry ( n=422 patients ) to be 23 % using the Ultegra Rapid Platelet Function Assay-ASA , and determined a history of coronary artery disease to be associated with twice the odds of being an  aspirin nonresponder ( odds ratio 2.01 , 95 % confidence interval 1.189 to 3.411 , p=0.009 ) . Further prospect i ve studies are needed to correlate  aspirin nonresponsiveness to adverse clinical events
Prevalences widely differ between studies reporting on aspirin resistance .
BACKGROUND The absolute risk of recurrences among patients using aspirin for prevention of cardiovascular events remains high .
Persistent platelet reactivity despite aspirin therapy might explain this in part .
Reported prevalences of this so-called aspirin resistance vary widely , between 0 % and 57 % .
OBJECTIVES The aim of the study was to systematic ally review all available evidence on prevalence of aspirin resistance and to study determinants of reported prevalence .