rs5911 and rs3842788 Genetic Polymorphism, Blood Stasis Syndrome, and Plasma TXB2 and hs-CRP Levels Are Associated with Aspirin Resistance in Chinese Chronic Stable Angina Patients

Genetic factors related to aspirin resistance using the Multiplate® device in Hong Kong Chinese patients with stable coronary heart disease

Objective

Associations between single nucleotide polymorphisms (SNPs) and aspirin resistance (AR) have been studied with variable results. The associations of genetic variants with AR may be helpful to explain why some individuals demonstrate aspirin insensitivity with this anti-platelet therapy. The purpose of this research was to investigate the effect of different genotypes in candidate genes on aspirin response in patients taking long-term aspirin therapy by measuring the serum thromboxane B2 (TXB2) and platelet function using the Multiplate® analyser.

Methods

A total of 266 patients with stable coronary heart disease (CHD) taking low-dose aspirin for long periods of time and without any other anti-platelet drugs medications were enrolled into the study. They were required to take 80 mg of aspirin every morning for a week including the day before blood tests. Blood samples were collected 24 h after the last dose. The 80 mg dose of aspirin was taken orally and blood samples were collected again 1 h later. The serum TXB2 levels were measured in samples at 24 h post-dose and 1 h post-dose using the EIA kit and platelet activity was determined using the Multiplate® Impedance Platelet Aggregometry (ASPI) assay. Genotyping assays were performed by the TaqMan SNP genotyping technique.

Results

Of the 266 patients, only 251 patients were enrolled in the present study. The PTGS1/COX1-1676 A > G (rs1330344) and the PTGS2/COX2-765 G > C (rs20417) SNPs showed significant associations with the ASPI measurements in samples taken at 24 h post-dose, but not with the values at 1 h post-dose or with the TXB2 levels (P < 0.05).

Conclusions

Our results suggest that polymorphisms in the PTGS1/COX1 and the PTGS2/COX2 genes may be associated with reduced anti-aggregatory effects and increased the risk of AR, but future larger-scale cohort studies are necessary for further validation.

DNA methylation profile in the whole blood of acute coronary syndrome patients with aspirin resistance

BACKGROUND

Aspirin resistance (AR) results in major adverse cardiovascular events, and DNA methylation might participate in the regulation of this pathological process.

METHODS

In present study, a sum of 35 patients with AR and 35 non-AR (NAR) controls were enrolled. Samples from 5 AR and 5 NAR were evaluated in an 850 BeadChip DNA methylation assay, and another 30 AR versus 30 NAR were evaluated to validate the differentially methylated CpG loci (DML). Then, qRT-PCR was used to investigate the target mRNA expression of genes at CpG loci. Finally, Gene Ontology (GO) as well as Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were performed to reveal the enriched pathways.

RESULTS

The AR and NAR groups displayed significant differences in DNA methylation at 7707 positions, with 270 hypermethylated sites (e.g., cg09555818 located in APOC2) and 7437 sites hypomethylated sites (e.g., cg26828689 located in SLC12A5). Six DML were validated by pyrosequencing, and it was confirmed that DNA methylation (cg16391727, cg21008208, cg21293749, and cg13945576) was related to the increasing risk of AR. The relative mRNA expression of the ROR1 gene was also associated with AR (p = 0.007), suggesting that the change of cg21293749 in DNA methylation might lead to differential ROR1 mRNA expression, ultimately resulting in AR. Furthermore, the identified differentially methylated sites were associated with the molecular pathways such as circadian rhythms and insulin secretion.

CONCLUSION

Hence, the distinct DNA methylation might play a vital role in the biological regulation of AR through the pathways such as circadian rhythms.

Mechanism of Improving Aspirin Resistance: Blood-Activating Herbs Combined With Aspirin in Treating Atherosclerotic Cardiovascular Diseases

Atherosclerotic thrombotic disease continues to maintain a high morbidity and mortality rate worldwide at present. Aspirin, which is reckoned as the cornerstone of primary and secondary prevention of atherosclerotic cardiovascular diseases (ASCVDs), has been applied in clinics extensively. However, cardiovascular events continue to occur even though people utilize aspirin appropriately. Therefore, the concept of aspirin resistance (AR) was put forward by scholars, which is of great significance for the prediction of the clinical outcome of diseases. The pathogenesis of AR may be incorporated with low patient compliance, insufficient dose, genetic polymorphism, increased platelet transformation, inflammation, and the degenerative changes and calcification of platelets. The improvement of AR in the treatment of ASCVDs has gradually become a research hot spot in recent years. Traditional Chinese medicine (TCM) regards individuals as a whole and treats them from a holistic view, which has been found to have advantages in clinical studies on the treatment of AR. Many kinds of blood-activating TCM have the effect of improving AR. The potential mechanism for the improvement of AR by blood-activating herbs combined with aspirin was explored. The combination of blood-activating herbs and aspirin to improve AR is likely to turn into a hot topic of research in the future.

Multiplate® evaluation of acetylsalicylic acid efficacy in carotid surgery: routine and genetic influencing factors

Essentials Acetylsalicylic acid (ASA) is prescribed to patients scheduled for carotid endarterectomy (CEA). We measured ASA efficacy during CEA by Multiplate® and searched for influencing factors. Most patients scheduled for CEA and treated by ASA are sensitive to this therapy. Influencing genomic factors are involved in ASA metabolism and in platelet function modulations.

SUMMARY

Background Acetylsalicylic acid (ASA) is recommended before, during and after carotid endarterectomy (CEA). The efficacy of ASA is influenced by numerous biological and genotypic factors. Objectives To determine the biological efficacy of ASA by using the Multiplate® method, and to explore the biological parameters and genomic factors influencing this efficacy. Methods This descriptive cross-sectional study included all patients scheduled for CEA between January 2012 and April 2013. Multiplate® tests were performed at day 0 and day 30. A set of 66 single-nucleotide polymorphisms (SNPs) from 38 genes or DNA regions were selected and studied along with phenotypic parameters by the use of hierarchical clustering (HC) for multidimensional data management. Results Fifty-five patients receiving ASA were analyzed. Of the patients, 95% were found to be sensitive to ASA, with values under the threshold of normality (400 AU min-1 ). However, there were notable differences in residual aggregation among subjects over a wide range. HC revealed four subclusters comprising three categories of parameters: (i) routine and functional parameters - in ASA-treated patients, the ASPItest was highly linked to the ADPtest, to platelet count, and, to a lesser extent, to fibrinogen and hematocrit; (ii) polymorphisms in genes involved in ASA absorption and in the arachidonic acid pathway (ABCB1 and COX-1); and (iii) polymorphisms in genes modulating basal platelet function, i.e. TBXA2R, ADRA2A, PEAR1, ITGA2 and ITGB1. Conclusion Most patients treated with ASA before CEA were sensitive to it, according to Multiplate® ASPItest results. Genomic factors influencing this efficacy are SNPs involved in ASA absorption and metabolic pathway, and in modulations in basal platelet function.