TY - JOUR
T1 - Inhibition of platelet aggregation by aspirin progressively decreases in long-term treated patients
AU - Pulcinelli, Fabio M.
AU - Pignatelli, Pasquale
AU - Celestini, Andrea
AU - Riondino, Silvia
AU - Gazzaniga, Pier Paolo
AU - Violi, Francesco
PY - 2004/3/17
Y1 - 2004/3/17
N2 - Objectives We sought to investigate, during a two-year follow-up period, the effects of aspirin on platelet aggregation. Background The platelets of patients given aspirin may be less sensitive to antiplatelet treatment, although the extent of such phenomenon over long-term follow-up is unclear. Methods Adenosine diphosphate (ADP) and collagen-induced platelet aggregation was periodically monitored before and after 2, 6, 12, and 24 months of treatment with aspirin (n = 150) or ticlopidine (n = 80) in patients matched for gender, age, and risk factors for atherothrombosis. Results Compared with baseline values, two months of aspirin treatment significantly inhibited platelet aggregation; thereafter, this inhibitory effect progressively decreased. At 24-month follow-up, collagen-induced platelet aggregation was significantly higher than that observed at two months (p <0.05); a more pronounced difference was observed when collagen-induced lag phase was considered (p <0.01). Restoration of platelet aggregation was less evident when ADP was used as an agonist. Conversely, the inhibition induced by ticlopidine was constant throughout follow-up with both agonists. Conclusions The study demonstrates that a long-term treatment with aspirin is associated with a progressive reduction in platelet sensitivity to this drug.
AB - Objectives We sought to investigate, during a two-year follow-up period, the effects of aspirin on platelet aggregation. Background The platelets of patients given aspirin may be less sensitive to antiplatelet treatment, although the extent of such phenomenon over long-term follow-up is unclear. Methods Adenosine diphosphate (ADP) and collagen-induced platelet aggregation was periodically monitored before and after 2, 6, 12, and 24 months of treatment with aspirin (n = 150) or ticlopidine (n = 80) in patients matched for gender, age, and risk factors for atherothrombosis. Results Compared with baseline values, two months of aspirin treatment significantly inhibited platelet aggregation; thereafter, this inhibitory effect progressively decreased. At 24-month follow-up, collagen-induced platelet aggregation was significantly higher than that observed at two months (p <0.05); a more pronounced difference was observed when collagen-induced lag phase was considered (p <0.01). Restoration of platelet aggregation was less evident when ADP was used as an agonist. Conversely, the inhibition induced by ticlopidine was constant throughout follow-up with both agonists. Conclusions The study demonstrates that a long-term treatment with aspirin is associated with a progressive reduction in platelet sensitivity to this drug.
KW - Adenosine diphosphate
KW - ADP
KW - COX-1
KW - Cyclooxygenase-1
KW - Maximal percentage
KW - Mx%
KW - Thromboxane A
KW - Thromboxane B
KW - TXA
KW - TXB
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U2 - 10.1016/j.jacc.2003.08.062
DO - 10.1016/j.jacc.2003.08.062
M3 - Article
C2 - 15028353
AN - SCOPUS:1542604069
VL - 43
SP - 979
EP - 984
JO - Journal of the American College of Cardiology
JF - Journal of the American College of Cardiology
SN - 0735-1097
IS - 6
ER -