Optical platelet aggregation versus thromboxane metabolites in healthy individuals and patients with stable coronary artery disease after low-dose aspirin administration

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• 作者：Sofie S. Hedegaard ; Anne-Mette Hvas ; Erik L. Grove ; Jens Refsgaard ; Bianca Rocca ; Giovanni Daví ; Steen D. Kristensen
• 关键词：Aspirin ; Drug resistance ; 11-dehydro-thromboxane B₂ ; Patient compliance ; Platelet aggregation ; Thromboxane B₂
• 刊名：Thrombosis Research
• 出版年：2009
• 出版时间：May 2009
• 年：2009
• 卷：124
• 期：1
• 页码：96-100
• 全文大小：216 K

文摘

Introduction

Aspirin reduces cardiovascular events in patients with coronary artery disease (CAD), but studies report a highly variable response to aspirin, often referred to as ‘aspirin low-responsiveness’. We investigated whether 75 mg of daily non-enteric coated aspirin would completely inhibit the platelet cyclooxygenase-1 activity to a comparable extent in healthy individuals and stable CAD patients.

Methods

We assessed serum thromboxane B₂ (S-TxB₂), urinary 11-dehydro-TxB₂ (U-TxM) and arachidonic acid-induced optical platelet aggregometry (OPA) in 44 CAD patients on aspirin and in 22 healthy individuals before and after aspirin. OPA was performed in duplicate for four consecutive days during aspirin treatment after one week of treatment. Compliance was optimized by face-to-face interviews and pill counting and confirmed by S-TxB₂ measurements.

Results

Aspirin inhibited S-TxB₂ > 99 % in healthy individuals (median 1.1 ng/mL, interquartile range (IQR) = 0.8;1.9 after aspirin) and in patients, S-TxB₂ was reduced to a similar level (0.9 ng/mL (0.7;1.5)). Healthy individuals had a median U-TxM of 278.5 pg/mg creatinine (229.5;380.0) before aspirin and 68.5 pg/mg creatinine (59.0;99.7) on aspirin corresponding to an average 74 % inhibition of the endogenous TxA₂ biosynthesis. In patients median U-TxM was 67.5 pg/mg creatinine (54.0;85.5). Seven study participants (11 % ) were aspirin low-responders according to OPA, but none had S-TxB₂ in the highest quartile.

Conclusions

Low-dose aspirin suppressed S-TxB₂ to comparable levels in CAD patients and healthy individuals. Despite an almost complete inhibition of S-TxB₂, some participants were low-responders according to OPA. Thorough compliance control and use of thromboxane-specific assays are important when measuring platelet response to aspirin.