Safety profile and bleeding risk of ticagrelor compared with clopidogrel

Clopidogrel versus ticagrelor in the treatment of Chinese patients undergoing percutaneous coronary intervention: effects on platelet function assessed by platelet function tests and mean platelet volume

Background

Knowledge on the pharmacodynamic effects of antiplatelet drugs including clopidogrel and ticagrelor on Asian patients is scarce. We aim to evaluate the effects of the two drugs on platelet reactivity in the treatment of Chinese patients who underwent percutaneous coronary intervention (PCI), using two platelet function tests (PFT). Meanwhile, the relationship between mean platelet volume (MPV), a routine index of platelet size, and high on-treatment platelet reactivity (HPR) is also investigated.

Methods

Patients receiving dual antiplatelet therapy (DAPT) were scheduled for the assessment of platelet reactivity at 2–3 days after PCI. Two PFTs, light transmission aggregometry (LTA) and vasodilator-stimulated phosphoprotein (VASP)-FCM assay, were applied in the evaluation of platelet reactivity. The MPV was measured simultaneously with EDTA plasma using a Sysmex XN 2000 automated hematology analyzer.

Results

The final study population included the aspirin + clopidogrel group (n = 46) and the aspirin + ticagrelor group (n = 66). In the aspirin + ticagrelor group, the maximal light transmittance (LT) changes in response to 5 μM ADP assessed by LTA was obviously lower than that in the aspirin + clopidogrel group (P <  0.001). The platelet reactivity index (PRI) level in the VASP test was also markedly lower in the group given aspirin and ticagrelor (P <  0.001). There was a significant difference in HPR between the two groups. MPV showed a potent ability to predict the presence of HPR at VASP assay (AUC = 0.788, 95% CI: 0.701–0.875, P <  0.001) in receiver-operating characteristic curve analysis.

Conclusions

Compared with clopidogrel, ticagrelor has dramatically greater antiplatelet effect, with a superiority in suppressing platelet function and a lower HPR rate. In addition, there existed a significant independent association between MPV and high prevalence of HPR in the VASP assay.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12959-021-00350-2.

Risk of bleeding with ticagrelor in elderly patients over 75 years old: A systematic review and meta-analysis

BACKGROUND

Bleeding is an untoward outcome in the management of elderly patients with acute coronary syndrome (ACS). Although the potent oral P2Y12 inhibitor, ticagrelor is clinically beneficial, its association with bleeding events in elderly ACS patients (≥75 years) is poorly understood.

METHODS

We conducted a systematic search of 7 databases up to May 20, 2020 to identify studies which examined the risk of bleeding (defined according to each study) among elderly ACS patients (≥75 years) receiving ticagrelor compared to clopidogrel. Summary risk ratios (RR) were estimated using the random effects model.

RESULTS

Eight studies consisting of 5 observational studies and 3 randomized controlled trials involving 7032 elderly patients met the eligibility criteria. The mean age of the patients was 77.8 years, and the mean follow-up duration was 12 months. Overall, the pooled RRs showed higher risk of a bleeding event with ticagrelor compared to clopidogrel (RR 1.20, 95% confidence interval [95% CI] 1.03-1.40; P = .017). No statistically significant heterogeneity was observed among the studies (Q = 6.93; P = .44; I2 = 0). Also, pooled RRs did not show a higher risk of major bleeding (RR 1.32, 95% CI 0.91-1.92; P = .15) or minor bleeding (RR 1.09, 95% CI 0.76-1.58; P = .64) when comparing the ticagrelor to the clopidogrel group.

CONCLUSIONS

There is a 20% increased risk of a bleeding event in elderly ACS patients treated with ticagrelor compared to clopidogrel; for such patients, clopidogrel may be considered as an alternative agent to ticagrelor due to its lower risk of bleeding.

Application of Feedback System Control Optimization Technique in Combined Use of Dual Antiplatelet Therapy and Herbal Medicines

Aim: Combined use of herbal medicines in patients underwent dual antiplatelet therapy (DAPT) might cause bleeding or thrombosis because herbal medicines with anti-platelet activities may exhibit interactions with DAPT. In this study, we tried to use a feedback system control (FSC) optimization technique to optimize dose strategy and clarify possible interactions in combined use of DAPT and herbal medicines.

Methods: Herbal medicines with reported anti-platelet activities were selected by searching related references in Pubmed. Experimental anti-platelet activities of representative compounds originated from these herbal medicines were investigated using in vitro assay, namely ADP-induced aggregation of rat platelet-rich-plasma. FSC scheme hybridized artificial intelligence calculation and bench experiments to iteratively optimize 4-drug combination and 2-drug combination from these drug candidates.

Results: Totally 68 herbal medicines were reported to have anti-platelet activities. In the present study, 7 representative compounds from these herbal medicines were selected to study combinatorial drug optimization together with DAPT, i.e., aspirin and ticagrelor. FSC technique first down-selected 9 drug candidates to the most significant 5 drugs. Then, FSC further secured 4 drugs in the optimal combination, including aspirin, ticagrelor, ferulic acid from DangGui, and forskolin from MaoHouQiaoRuiHua. Finally, FSC quantitatively estimated the possible interactions between aspirin:ticagrelor, aspirin:ferulic acid, ticagrelor:forskolin, and ferulic acid:forskolin. The estimation was further verified by experimentally determined Combination Index (CI) values.

Conclusion: Results of the present study suggested that FSC optimization technique could be used in optimization of anti-platelet drug combinations and might be helpful in designing personal anti-platelet therapy strategy. Furthermore, FSC analysis could also identify interactions between different drugs which might provide useful information for research of signal cascades in platelet.

Place of non-vitamin K antagonist oral anticoagulants in anticoagulant-antiplatelet combinations in peripheral artery disease

Non-vitamin K antagonist oral anticoagulants are becoming increasingly important in the prophylaxis and treatment of thrombosis in atrial fibrillation and venous thromboembolism. Antiplatelets are widely prescribed in the primary and secondary prevention of cardiac and vascular diseases. There are potentially numerous situations where anticoagulants and antiplatelets may be combined; these combinations have been explored in coronary artery disease, and some have been included in updated recommendations. Is it legitimate to transpose these recommendations to the management of peripheral artery disease? The specific characteristics of the treated vessels, the stents used, the respective frequencies of stent thrombosis and its effect on the target organ are probably different, and explain why opinions differ. However, because of a lack of evidence, empirical behaviours are being established without scientific validation. This review of the literature details the situations in which combinations of an anticoagulant and an antiplatelet have been explored in peripheral artery disease. We discuss the issue of antithrombotic combinations in stable peripheral artery disease and for vascular or endovascular surgery.

Ticagrelor: pharmacokinetics, pharmacodynamics, clinical efficacy, and safety

Dual antiplatelet therapy, composed of aspirin plus a P2Y₁₂-receptor antagonist, is the cornerstone of treatment for patients with acute coronary syndrome (ACS). A number of U.S. Food and Drug Administration–approved P2Y₁₂-receptor antagonists are available for treating patients with ACS, including the thienopyridine compounds clopidogrel and prasugrel. Ticagrelor, the first of a new class of antiplatelet agents, is a noncompetitive, direct-acting P2Y₁₂-receptor antagonist. Unlike the thienopyridine compounds, ticagrelor does not require metabolism for activity. Also, whereas clopidogrel and prasugrel are irreversible inhibitors of the P2Y₁₂ receptor, ticagrelor binds reversibly to inhibit receptor signaling and subsequent platelet activation. In pharmacodynamic studies, ticagrelor demonstrated faster onset and more potent inhibition of platelet aggregation than clopidogrel. These properties of ticagrelor may contribute to reduced rates of thrombotic outcomes compared with clopidogrel, as demonstrated in a phase III clinical trial. However, in addition to bleeding, distinctive adverse effects of this new chemical entity have not been reported with the thienopyridine P2Y₁₂-receptor inhibitors. Although ticagrelor represents an advancement in P2Y₁₂-receptor inhibition therapy, a thorough understanding of this compound as an antiplatelet therapy remains to be elucidated.