A pharmacodynamic comparison of a personalized strategy for anti-platelet therapy versus ticagrelor in achieving a therapeutic window

Pharmacogenetic considerations in therapy with novel antiplatelet and anticoagulant agents

Antiplatelets and anticoagulants are extensively used in cardiovascular medicine for the prevention and treatment of thrombosis in the venous and arterial circulations. Wide inter-individual variability has been observed in response to antiplatelets and anticoagulants, which triggered researchers to investigate the genetic basis of this variability. Data from extensive pharmacogenetic studies pointed to strong evidence of association between polymorphisms in candidate genes and the pharmacokinetics and pharmacodynamic action and clinical response of the antiplatelets clopidogrel and the anticoagulant warfarin. In this review, we conducted an extensive search on Medline for the time period of 2009-2023. We also searched the PharmGKB website for levels of evidence of variant-drug combinations and for drug labels and clinical guidelines. We focus on the pharmacogenetics of novel antiplatelets and anticoagulants while excluding acetylsalicylic acid, warfarin and heparins, and discuss the current knowledge with emphasis on the level of evidence.

Genotype-guided antiplatelet treatment versus conventional therapy: A systematic review and meta-analysis

AIM

This meta-analysis was carried out to explore if a personalized antiplatelet strategy based on genotyping is superior to conventional therapy.

METHODS

PubMed, Web of Science, EMBASE and the Cochrane Library were searched from the inception of each database to 5 May 2020. Studies reporting endpoints in genotype-guided treatment group and conventional treatment group were included. The endpoint results were presented as the risk ratio (RR), with 95% confidence interval (CI).

RESULTS

A total of 10 561 patients from 16 studies (eight randomized controlled trials [RCT] and eight cohort studies) were included in the meta-analysis. The rates of major adverse cardiovascular events (MACE), stent thrombosis and myocardial infarction (MI) were significantly lower in the genotype-guided group than in the conventional treatment group (RR 0.56, 95% CI 0.44-0.73, P < .0001; RR 0.40, 95% CI 0.24-0.67, P = .0005; RR 0.45, 95% CI 0.35-0.58, P < .00001, respectively). A significant difference was found between the two groups in major bleeding (RR 0.73, 95% CI 0.55-0.98, P = .04), which was not robust after sensitivity analysis.

CONCLUSION

Genotype-guided antiplatelet treatment could decrease the risk of MACE, stent thrombosis and MI in patients with coronary artery disease or undergoing percutaneous coronary intervention, without increasing the risk of bleeding over a long follow-up period. The decreased risk of efficacy outcomes was more obvious in cohort studies. Well-organized RCTs and clinical trials are required to verify the benefit of genotype-guided therapy.

Nano-scaled MTCA-KKV: for targeting thrombus, releasing pharmacophores, inhibiting thrombosis and dissolving blood clots in vivo

BACKGROUND

In vitro (1R,3S)-1-methyl-1,2,3,4-tetrahydro-β-carboline-3-carboxyl-Lys(Pro-Ala-Lys)-Arg-Gly-Asp-Val (MTCA-KKV) adheres activated platelets, targets P-selectin and GPIIb/IIIa. This led to the development of MTCA-KKV as thrombus targeting nano-medicine.

METHODS

MTCA-KKV was characterized by nano-feature, anti-thrombotic activity, thrombolytic activity, thrombus target and targeting release.

RESULTS

In vivo 0.01 μmol/kg of MTCA-KKV formed nano-particles less than 100 nm in diameter, targeted thrombus, released anti-thrombotic and thrombolytic pharmacophores, prevented thrombosis and dissolved blood clots.

CONCLUSION

Based on the profiles of targeting thrombus, targeting release, inhibiting thrombosis and dissolving blood clots MTCA-KKV is a promising nano-medicine.

Influence of CYP2C19 Phenotype on the Effect of Clopidogrel in Patients Undergoing a Percutaneous Neurointervention Procedure

This observational retrospective study assessed the antiplatelet response and clinical events after clopidogrel treatment in patients who underwent percutaneous neurointervention, related to CYP2C19 metabolizer status (normal (NM), intermediate/poor (IM-PM), and ultrarapid (UM); inferred from *2, *3, and *17 allele determination). From 123 patients, IM-PM had a higher aggregation value (201.1 vs. 137.6 NM, 149.4 UM, P < 0.05) and lower response rate (37.5% vs. 69.8% NM, 61.1% UM), along with higher treatment change rate (25% vs. 5.7% NM, 10.5% UM). The highest ischemic events incidence occurred in NM (11.3% vs. 6.3% IM, 10.5% UM) and hemorrhagic events in UM (13.2% vs. 0% IM and 3.8% NM). No differences were found regarding ischemic event onset time, while hemorrhagic event frequency in UM was higher with shorter onset time (P = 0.047). CYP2C19 no-function and increased function alleles defined the clopidogrel response. UM patients had increased bleeding risk. Therapeutic recommendations should include dose reduction or treatment change in UM.

Ischemic and bleeding outcomes after coronary artery bypass grafting among patients initially treated with a P2Y12 receptor antagonist for acute coronary syndromes: Insights on timing of discontinuation of ticagrelor and clopidogrel prior to surgery

BACKGROUND

Clinical outcomes in acute coronary syndrome patients treated with P2Y₁₂ inhibitors who require urgent coronary artery bypass grafting (CABG) have not been well studied.

METHODS

We examined clinical outcomes in acute coronary syndrome patients in relation to the timing of CABG following P2Y₁₂ inhibitor discontinuation (<72 h, 72 h to five days, >5 days). The primary ischemic outcome was a composite of death, reinfarction, need for revascularization, or stroke. The primary safety outcome was bleeding of at least moderate severity as defined by a Universal Definition of Perioperative Bleeding class ≥2.

RESULTS

Among 508 patients (95 ticagrelor, 413 clopidogrel), the timing of CABG following P2Y₁₂ inhibitor discontinuation was <72 h in 32.1%, 72 h to five days in 23.2% and >5 days in 44.7%. Compared with CABG within 72 h, CABG 72 h to five days (adjusted odds ratio (OR) 0.35; 95% confidence interval (CI) 0.14-0.85; p=0.02) but not >5 days (adjusted OR 0.62; 95% CI 0.33-1.16; p=0.14) after P2Y₁₂ inhibitor discontinuation was associated with lower odds of the primary ischemic outcome. Compared with CABG within 72 h, CABG 72 h to five days (adjusted OR 0.38; 95% CI 0.22-0.66; p=0.001) and >5 days (adjusted OR 0.33; 95% CI 0.20-0.53; p<0.001) after P2Y₁₂ inhibitor discontinuation were associated with lower rates of Universal Definition of Perioperative Bleeding class ≥2 bleeding.

CONCLUSIONS

CABG within 72 h after P2Y₁₂ inhibitor discontinuation is associated with excess ischemia and bleeding. The rates of ischemic and bleeding events were comparable in patients undergoing CABG 72 h to five days compared with >5 days after P2Y₁₂ inhibitor discontinuation.

Platelet function testing as a biomarker for efficacy of antiplatelet drugs

Despite the overwhelming evidence in support of the efficacy of dual antiplatelet therapy with aspirin and clopidogrel, it is also obvious that not all patients benefit from these drugs to the same extent. This interindividual variability in platelet responses may underlie clinical differences in drug efficacy, with potential for optimization of antiplatelet therapy to prevent ischemic events without excessively increasing bleeding risk. This review presents the current evidence regarding platelet function testing for monitoring of antiplatelet therapy, with emphasis on the prognostic value of platelet function testing to predict ischemic and bleeding events. The potential of platelet function testing to provide personalized antiplatelet therapy is also discussed, with an outlook toward the future of platelet function testing in high-risk individuals.