Genetics in the Clinical Decision of Antiplatelet Treatment

A systematic study to evaluate the safety of ticagrelor combined with aspirin in the treatment of PCI patients in Chinese population: A single nucleotide polymorphisms study

The aim of this study was to identify genes and their associated loci related to ticagrelor pharmacokinetics and pharmacodynamics in Chinese patients with acute coronary syndrome (ACS) after percutaneous coronary intervention (PCI). The study included 1115 patients with ACS who received a drug-eluting stent implantation between October 2019 and January 2021. Among them, 98 cases of adverse reactions were observed; thus, 97 cases without adverse reactions were selected as the comparison group. The steady-state serum drug concentration was determined via high-performance liquid chromatography-mass spectrometry, and 15 single nucleotide polymorphism (SNP) loci were genotyped using the SNaPshot SNP Multiplex System. Our results showed that age and sex may affect ticagrelor serum concentration in patients with ACS. In particular, the SNPs CYP3A4∗1 (rs2242480 C > T), IGT2B (rs5911 A > C), P2Y12 (rs6787801) and CYP3A5 (rs776746 C > T) may affect the steady-state blood concentration of ticagrelor after PCI in ACS patients, and CYP3A4∗1 may also be related to adverse events. In addition, we found that the SNPs PEAR1 (rs4661012 T > G) and P2Y12 (rs6787801 A > G) may be associated with dyspnea. These findings can provide a useful reference to establish guidelines for future clinical individualized dosage regimens of ticagrelor after PCI.

Cardiovascular Pharmacogenomics: An Update on Clinical Studies of Antithrombotic Drugs in Brazilian Patients

Anticoagulant and antiplatelet drugs effectively prevent thrombotic events in patients with cardiovascular diseases, ischemic stroke, peripheral vascular diseases, and other thromboembolic diseases. However, genetic and non-genetic factors affect the response to antithrombotic therapy and can increase the risk of adverse events. This narrative review discusses pharmacogenomic studies on antithrombotic drugs commonly prescribed in Brazil. Multiple Brazilian studies assessed the impact of pharmacokinetic (PK) and pharmacodynamic (PD) gene variants on warfarin response. The reduced function alleles CYP2C9*2 and CYP2C9*3, and VKORC1 rs9923231 (c.-1639G>A) are associated with increased sensitivity to warfarin and a low dose requirement to prevent bleeding episodes, whereas CYP4F2 rs2108622 (p.Val433Met) carriers have higher dose requirements (warfarin resistance). These deleterious variants and non-genetic factors (age, gender, body weight, co-administered drugs, food interactions, and others) account for up to 63% of the warfarin dose variability. Few pharmacogenomics studies have explored antiplatelet drugs in Brazilian cohorts, finding associations between CYP2C19*2, PON1 rs662 and ABCC3 rs757421 genotypes and platelet responsiveness or clopidogrel PK in subjects with coronary artery disease (CAD) or acute coronary syndrome (ACS), whereas ITGB3 contributes to aspirin PK but not platelet responsiveness in diabetic patients. Brazilian guidelines on anticoagulants and antiplatelets recommend the use of a platelet aggregation test or genotyping only in selected cases of ACS subjects without ST-segment elevation taking clopidogrel, and also suggest CYP2C9 and VKORC1 genotyping before starting warfarin therapy to assess the risk of bleeding episodes or warfarin resistance.

Risk of infections in patients treated with ticagrelor vs. clopidogrel: a systematic review and meta-analysis

AIMS

Ticagrelor has been shown to reduce the risk of pneumonia and improve lung function, but the findings across studies were inconsistent. The objective is to investigate the relative safety of ticagrelor vs. clopidogrel on infection outcomes in patients with cardiovascular diseases.

METHODS AND RESULTS

We searched MEDLINE, Embase, Cochrane Library, and ClinicalTrials.gov up to 15 October 2019. Randomized controlled trials comparing ticagrelor and clopidogrel that reported infection outcomes were included. The primary outcome was pneumonia. Secondary outcomes were upper respiratory tract infection (URTI), urinary tract infection (UTI), and sepsis. Study quality was assessed using the Cochrane Risk of Bias tool. Study selection, data extraction, and quality assessment were conducted by independent authors. Random-effects model was used for data synthesis. Relative risks (RRs) and 95% confidence intervals (CIs) were pooled with a random-effects model. Out of 5231 citations, 10 trials with altogether 37 514 patients were included. Ticagrelor was associated with a lower risk of pneumonia (RR 0.80, 95% CI 0.67-0.95) compared to clopidogrel. There were no statistically significant differences for URTI (RR 0.71, 95% CI 0.34-1.48), UTI (RR 1.06, 95% CI 0.73-1.64), or sepsis (RR 0.79, 95% CI 0.50-1.26).

CONCLUSION

Compared to clopidogrel, ticagrelor reduces the risk of pneumonia, but not URTI, UTI, or sepsis. Our study provides further evidence for recommending ticagrelor to patients with acute coronary syndrome at risk of pneumonia, although the mechanism by which ticagrelor reduces the risk of pneumonia merits further research.