Prevalence and biologic profile of aspirin resistance in patients with angiographically proven coronary artery disease.
BACKGROUND
Aspirin protects from cardiovascular events. However, a number of patients who take this drug suffer events, probably due to aspirin resistance. The role of certain biologic variables that may affect resistance is still uncertain.


OBJECTIVE
To determine the prevalence of aspirin resistance in patients taking this drug and to test if resistance is related to haemostatic, inflammatory and lipidic variables.


METHODS
Platelet function measured with PFA-100 was studied in 268 patients (185 men) with stable coronary disease who took aspirin (100 to 300 mg/day). Aspirin resistance was defined when epinephrine closure time <174 s. Results of lipoprotein(a) are expressed in median (interquartile range).


RESULTS
Aspirin resistance was found in 16% of cases. Patients with aspirin resistance had higher levels of Apolipoprotein B (109.27+/-27.65 vs 100.92+/-23.77 mg/dl; p<0.05), lipoprotein(a) [20.37 (4.83-36.72) vs 10.02 (1.88-25.41); p<0.01], Platelet Count (241.42+/-75.35 vs 213.94+/-56.74 mm(3); p<0.05) and fibrinogen (388.93+/-107.27 vs 354.33+/-89.35 mg/dl; p<0.05). We used the logistic regression analysis to detect the independent predictors of aspirin resistance. Lipoprotein(a) was found to be the only independent risk factor to identify aspirin resistance (p<0.05; OR: 1.302; CI 95%: 1.003-1.688).


CONCLUSIONS
Although the potential mechanisms of aspirin resistance still remains uncertain, we found that platelet responsiveness to aspirin is reduced in patients with high levels of Apolipoprotein B and lipoprotein(a). Our work demonstrate that lipoprotein(a) is an independent risk factor for aspirin resistance possibly due to the interaction of Apolipoprotein(a) with human platelets.
Narvaez
Idoia
I
FIDEC, Department of Atherosclesosis and Thrombosis, Gurtubay s/n, 48012, Bilbao, Vizcaya, Spain. nfpirezj@lg.ehu.eh
Sagastagoitia
Jose Domingo
JD
Vacas
Marta
M
Saez
Yolanda
Y
Lafita
Manolo
M
Monica
Santos
S
de Lafuente
Jesus Pablo Saez
JP
Molinero
Enrique
E
Iriarte
Jose Antonio
JA
D000368:Aged; D001055:Apolipoproteins B / Q000378:metabolism; D001241:Aspirin / Q000627:therapeutic use*; D001792:Blood Platelets / Q000187:drug effects / Q000378:metabolism; D003324:Coronary Artery Disease / Q000188:drug therapy / Q000453:epidemiology / Q000473:pathology*; D004351:Drug Resistance; D004837:Epinephrine / Q000627:therapeutic use; D005260:Female; D006487:Hemostasis; D006801:Humans; D007249:Inflammation; D017270:Lipoprotein(a) / Q000737:chemistry; D008297:Male; D008875:Middle Aged; D009389:Neovascularization, Pathologic; D010975:Platelet Aggregation Inhibitors / Q000627:therapeutic use; D010979:Platelet Function Tests; D015995:Prevalence
D001055:Apolipoproteins B; D017270:Lipoprotein(a); D010975:Platelet Aggregation Inhibitors; D001241:Aspirin; D004837:Epinephrine