ORIGINAL ARTICLES   

International Angiology 2003 September;22(3):239-42

Copyright © 2003 EDIZIONI MINERVA MEDICA

lingua: Inglese

Increased sensitivity to ADP-aggregation in aspirin treated patients with recurrent ischemic stroke?

Mattiasson I. ¹, Lethagen S. ², Hillarp A. ³

¹ Department of Vascular Diseases, University Hospital, Malmö, Sweden 2 Department of Coagulation Disorders, University Hospital, Malmö, Sweden 3 Department of Clinical Chemistry, University Hospital, Malmö, Sweden

Aim. Anti­plate­let ther­a­py in order to ­reduce the plate­let aggreg­abil­ity is wide­ly used to pre­vent recur­rent ­stroke ­events. Data from sev­er­al stud­ies indi­cates that the inter-indi­vid­u­al vari­a­tion con­cern­ing the abil­ity of stan­dard doses of aspi­rin to inhib­it plate­let aggre­ga­tion is sub­stan­tial. The ratio­nale of the ­present study was to test wheth­er plate­let aggre­ga­tion in whole blood was ­enhanced in sub­jects that had suf­fered an ischem­ic ­stroke event under aspi­rin treat­ment.
Meth­ods. Two ­groups of ­patients were includ­ed: 1) ­patients that have suf­fered 1 ­stroke event and were there­af­ter under con­tin­u­ous treat­ment with aspi­rin 75-160 mg once daily (n=17); 2) ­patients that have suf­fered at least 2 ­stroke ­events, and aspi­rin 75-160 mg was pre­scribed after the 1st event (n=17). Plate­let aggre­ga­tion was test­ed in whole blood with col­la­gen (5 μg/mL and 1 μg/mL), ADP (5 μMol/L) and arach­i­don­ic acid (0.5 μg/mL). Aggre­ga­tion was record­ed as ­change in impe­dance and ­release of ATP after the addi­tion of a lucif­e­rin-lucif­e­rase ­reagent.
­Results. The inhib­i­to­ry ­effect of aspi­rin test­ed with arach­i­don­ic acid as an ago­nist was com­plete in all the test­ed sub­jects. Aggre­ga­tion ­induced by ADP 5 μmol/L was sig­nif­i­cant­ly high­er in the sub­jects with recur­rent ­stroke com­pared to those with a sin­gle stroke, when test­ed as impe­dance ­change. ATP ­release with ADP as an ago­nist was the same in both ­groups.
Con­clu­sion. The ­present study gives some indi­ca­tion that dif­fer­enc­es in ADP-­induced aggre­ga­tion, with a high­er remain­ing aggre­gat­ing abil­ity after ASA treat­ment, might be of impor­tance for the risk of ­stroke recur­rence.