Aspirin is widely considered the best practice for antiplatelet therapy in cardiovascular diseases (CVD) management. It is a cornerstone in preventing myocardial infarction by inhibiting platelets from forming blood clots.
However, the prevalence of aspirin resistance differs greatly across various groups of people based on factors such as gender, age, underlying health conditions, and aspirin resistance testing methodologies.
A systematic review found that aspirin resistance could be higher in women (26.9%) than men (23.5%)[1], and elderly patients with coronary artery disease had 9.3% to 24.8% aspirin resistance[1].
These findings underscore the need for accurate aspirin resistance testing to enhance personalized medicine and improve patient outcomes.
How Does Aspirin Inhibit Platelet Aggregation?
Aspirin, also known as acetylsalicylic acid, stops platelets from sticking together and forming clots by irreversibly blocking the enzyme cyclooxygenase (COX-1). Platelets need this enzyme to make thromboxane A2, a potent platelet activator, which induces platelet aggregation.
Without thromboxane A2, platelets can't clump together to form harmful blood clots. Moreover, they have no nucleus and DNA, so no new COX-1 can be produced. Hence, the effect of aspirin on platelets persists until new platelets are made, which takes about 7 to 10 days.
Even after stopping aspirin, the body may still take some time to resume normal blood clotting. Aspirin also changes a specific enzyme called COX-2. It is required in the prostaglandin pathway to reduce inflammation in the body. This is how aspirin helps decrease pain and swelling when taken in higher doses.
Mechanisms Behind Aspirin Resistance and Its Clinical Consequences
However, this drug can fail to hit its pharmacological target (COX-1), not effectively inhibiting platelet function and clot formation in a certain kind of group. In clinics, it is known as aspirin resistance.
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1. Mechanisms of Aspirin Resistance
To optimize patient management, it's important to understand these mechanisms. Various reasons could cause the occurrence of aspirin resistance, including:
Reduced Bioavailability
Aspirin works best when it is absorbed well in the stomach. Factors like pH level and meal intake can affect its absorption rate. Variability in absorption can result in varying plasma concentration levels, which might make it less effective.
Increased Platelet Turnover
In some inflammatory processes, such as atherosclerosis and other complications, the body makes new platelets faster than normal. This reduces aspirin's ability to block COX-1, which results in less efficacy of the drug over time.
Negative Drug Interactions
Taking other drugs such as NSAIDs (non-steroidal anti-inflammatory drugs) along with aspirin can interfere with its binding to COX-1, diminishing its effectiveness in preventing blood clots.
2. Clinical Consequences of Aspirin Resistance
A research study has shown that aspirin resistance can raise heart events to 13 times higher in cardiovascular patients[2]. Generally, factors can result in severe clinical consequences:
High risk of myocardial infarction and stroke
Alternative antiplatelet agents
Difficulty in patient management
Need for precise aspirin resistance testing
Methods of Aspirin Resistance Testing
Accurate aspirin resistance testing is essential for optimizing patient outcomes, as it enables healthcare professionals to personalize aspirin therapy. The following aspirin resistance testing methods are widely used to check its effectiveness:
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1. Platelet Function Tests
Platelet function test is one of the methods to undergo aspirin resistance testing in labs and clinical settings, such as:
Light Transmission Aggregometry (LTA)
Platelet Function Analyzer 100/200 (PFA 100/200)
Thromboelastography (TEG)
Thromboxane B2 (TXB2) Testing
These aspirin resistance tests can be used to measure the efficacy of aspirin in preventing platelet aggregation. However, in a study of 201 patients with stable coronary artery disease, researchers found unclear results in these different tests[3]. Yield significantly varied results when detecting aspirin resistance. It suggests that these tests may not reliably assess aspirin's antiplatelet effects.
Besides, the study found poor correlation and agreement among the different testing methods as well[3]. This indicates that even when multiple aspirin resistance tests are employed, the conclusions might be inconsistent, complicating clinical decision-making.
2. Genetic Tests
Genetic testing for aspirin resistance is an emerging area of research that aims to enhance the effectiveness of aspirin therapy in preventing cardiovascular diseases. Several studies have identified specific genetic variants associated with aspirin resistance, notably including[4]:
ITGB3
ITGA2
PTGS1
PTGS2
Similarly, a study reviewed various laboratory genetic tests for aspirin resistance, showing a strong link between the particular genetic variant “P1A1/A2” in the GPIIIa receptor gene (ITGB3) and aspirin resistance[5].
Consequently, genetic testing is a more reliable way to identify patients likely to benefit from alternative therapies or adjusted dosages, thereby improving precision medicine and treatment outcomes
Tianlong’s Aspirin Personalized Medication Solutions
This association is especially noted in healthy individuals, but it can only be identified if the results are accurate. To ensure error-free results, Tialong’s ligation sequencing kit, the Aspirin Personalized Medication Solution, is specifically designed for precision in aspirin resistance testing and subsequent medication use. The features include:
99% accuracy in detection results
70 minutes process to determine the presence of TGB3 (c.176 T>C), LTC4S (c.-444 A>C), PEAR1 (C.-9-3996 G>A), PTGS1 (c.-842 A>G) and GP1BA (c.482 C>T)
Pre-filled reagents without sample extraction
Conclusion
Aspirin resistance poses a significant challenge for cardiovascular patients. Accurate aspirin resistance testing methods are required for precision medicine. Using accurate and efficient testing reagents like Tianlong’s ligation sequencing kits on aspirin resistance, doctors can offer customized treatments for better safety and aspirin efficacy.
At Tianlong, we are a trusted name in genetic testing and molecular diagnostics. With 100+ independent intellectual property rights and 200 international certifications, our solutions have made significant contributions to disease prevention and control. For any inquiries or further information, please feel free to contact us directly.
Reference
[1] Available at: https://pmc.ncbi.nlm.nih.gov/articles/PMC7265510/
[2] Available at: https://pubmed.ncbi.nlm.nih.gov/18766252/
[3] Available at: https://academic.oup.com/eurheartj/article/28/14/1702/2887650
[4] Available at: https://pmc.ncbi.nlm.nih.gov/articles/PMC10014202/
[5] Available at: https://pmc.ncbi.nlm.nih.gov/articles/PMC2492913/
