Efficacy and safety comparing prasugrel/ticagrelor and clopidogrel in Hong Kong post-acute coronary syndrome patients-A 10-year cohort study

Comparative Efficacy and Safety of Novel Antiplatelets and Standard Therapy in Patients With Coronary Artery Disease

Coronary artery disease (CAD) is a significant health concern that has affected approximately 110 million people worldwide. CAD is defined as persistent narrowing of the coronary arteries as a result of atherosclerotic plaque build-up. Acute coronary syndrome (ACS), which encompasses ST-elevation myocardial infarction (STEMI), non-ST-elevation myocardial infarction (NSTEMI), and unstable angina, often results from plaque ruptures. Platelets are crucial for atherogenesis, vascular inflammation, and oxidative stress. Antiplatelet therapy aimed at reducing thrombotic events is vital for ACS treatment. Clinical guidelines advise the use of dual antiplatelet therapy (DAPT) that combines aspirin and a P2Y12 receptor inhibitor (clopidogrel, prasugrel, or ticagrelor) in ACS patients undergoing percutaneous intervention (PCI). This study aimed to assess comprehensively the effectiveness and safety of ticagrelor and prasugrel in comparison to clopidogrel in patients with ACS. An extensive literature search was conducted using PubMed, PubMed Central (PMC), ScienceDirect, and EBSCO databases. The search revealed studies that compared ticagrelor and prasugrel to clopidogrel in ACS patients, and we selected these studies based on specific inclusion and exclusion criteria, which included observational studies, clinical trials, literature reviews, and meta-analyses involving adult ACS patients treated with ticagrelor, prasugrel, or clopidogrel. The efficacy outcomes were defined as major adverse cardiovascular events (MACE) and thrombotic events, whereas the safety outcomes were measured by major and minor bleeding and hemorrhagic stroke. After a rigorous quality assessment to minimize bias, 23 studies were selected for analysis. The findings indicated that novel antiplatelets reduced MACE but increased bleeding complications, with ticagrelor consistently associated with dyspnea. In conclusion, novel P2Y12 inhibitors provide cardiovascular benefits but require careful patient selection and monitoring due to gastrointestinal bleeding (GIB) risks. Future research should standardize bleeding definitions and assess long-term outcomes. Ticagrelor and prasugrel may be more effective and safer than clopidogrel in ACS patients. Given the high risk of GIB, especially among older individuals or those with a past stroke, it is advisable to suggest a lower prasugrel dose without raising the bleeding rates. Since fewer patients use the novel antiplatelet regimen compared to clopidogrel, future clinical trials should include a broader patient population and compare these regimens.

Platelet P2Y12 signalling pathway in the dysregulated immune response during sepsis

Sepsis is a complicated pathological condition in response to severe infection. It is characterized by a strong systemic inflammatory response, where multiple components of the immune system are involved. Currently, there is no treatment for sepsis. Blood platelets are known for their role in haemostasis, but they also participate in inflammation through cell-cell interaction and the secretion of inflammatory mediators. Interestingly, an increase in platelet activation, secretion, and aggregation with other immune cells (such as monocytes, T-lymphocytes and neutrophils) has been detected in septic patients. Therefore, antiplatelet therapy in terms of P2Y12 antagonists has been evaluated as a possible treatment for sepis. It was found that blocking P2Y12 receptors decreased platelet marker expression and limited attachment to immune cells in some studies, but not in others. This review addresses the role of platelets in sepsis and discusses whether antagonizing P2Y12 signalling pathways can alter the disease outcome. Challenges in studying P2Y12 antagonists in sepsis also are discussed. LINKED ARTICLES: This article is part of a themed issue on Platelet purinergic receptor and non-thrombotic disease. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v181.4/issuetoc.

Thrombotic risk in patients with acute coronary syndromes discharged on prasugrel or clopidogrel: results from the PROMETHEUS study

AIMS

Based on recent clinical data, the 2020 ESC guidelines on non-ST-elevation acute coronary syndrome (NSTE-ACS) suggest to tailor antithrombotic strategy on individual thrombotic risk. Nonetheless, prevalence and prognostic impact of the high thrombotic risk (HTR) criteria proposed are yet to be described. In this analysis from the PROMETHEUS registry, we assessed prevalence and prognostic impact of HTR, defined according to the 2020 ESC NSTE-ACS guidelines, and if the benefits associated with prasugrel vs. clopidogrel vary with thrombotic risk.

METHODS AND RESULTS

PROMETHEUS was a multicentre prospective study comparing prasugrel vs. clopidogrel in ACS patients undergoing percutaneous coronary intervention (PCI). Patients were at HTR if presenting with one clinical plus one procedural risk feature. The primary endpoint was major adverse cardiac events (MACE), composite of death, myocardial infarction, stroke, or unplanned revascularization, at 1 year. Adjusted hazard ratio (adjHR) and 95% confidence intervals (CIs) were calculated with propensity score stratification and multivariable Cox regression. Among 16 065 patients, 4293 (26.7%) were at HTR and 11 772 (73.3%) at low-to-moderate thrombotic risk. The HTR conferred increased incidence of MACE (23.3 vs. 13.6%, HR 1.85, 95% CI 1.71-2.00, P < 0.001) and its single components. Prasugrel was prescribed in patients with less comorbidities and risk factors and was associated with reduced risk of MACE (HTR: adjHR 0.83, 95% CI 0.68-1.02; low-to-moderate risk: adjHR 0.75, 95% CI 0.64-0.88; pinteraction = 0.32).

CONCLUSION

High thrombotic risk, as defined by the 2020 ESC NSTE-ACS guidelines, is highly prevalent among ACS patients undergoing PCI. The HTR definition had a strong prognostic impact, as it successfully identified patients at increased 1 year risk of ischaemic events.

The Signaling Pathway of the ADP Receptor P2Y12 in the Immune System: Recent Discoveries and New Challenges

P2Y12 is a G-protein-coupled receptor that is activated upon ADP binding. Considering its well-established role in platelet activation, blocking P2Y12 has been used as a therapeutic strategy for antiplatelet aggregation in cardiovascular disease patients. However, receptor studies have shown that P2Y12 is functionally expressed not only in platelets and the microglia but also in other cells of the immune system, such as in monocytes, dendritic cells, and T lymphocytes. As a result, studies were carried out investigating whether therapies targeting P2Y12 could also ameliorate inflammatory conditions, such as sepsis, rheumatoid arthritis, neuroinflammation, cancer, COVID-19, atherosclerosis, and diabetes-associated inflammation in animal models and human subjects. This review reports what is known about the expression of P2Y12 in the cells of the immune system and the effect of P2Y12 activation and/or inhibition in inflammatory conditions. Lastly, we will discuss the major problems and challenges in studying this receptor and provide insights on how they can be overcome.

Efficacy and safety comparing prasugrel/ticagrelor and clopidogrel in Hong Kong post-acute coronary syndrome patients-A 10-year cohort study

BACKGROUND

Clinical evidence of prasugrel/ticagrelor in dual antiplatelet therapy (DAPT) in Asian acute coronary syndrome (ACS) population remains inconclusive. We aimed to compare the clinical efficacy and safety of prasugrel/ticagrelor compared to clopidogrel as part of DAPT in Hong Kong ACS population for 10 years.

HYPOTHESIS

Prasugrel/ticagrelor, compared to clopidogrel, reduces risk of major adverse cardiovascular event (MACE) in Hong Kong ACS population.

METHODS

The retrospective observational cohort study included patients admitted to seven institutions under Hospital Authority Hong Kong with diagnosis of ACS during 2008-2017. Risk of MACE, defined as composite of cardiovascular (CV) death, non-fatal myocardial infarction (MI) and non-fatal stroke, and risk of any bleeding leading to hospitalization were examined. Baseline characteristics difference was adjusted by propensity score (PS) matching. Adjusted Cox regression model was used to estimate hazard ratio of interested outcome.

RESULTS

In PS matched cohort including 944 patients in each group, MACE risk reduction of 40% from 1 year to 5 years after index ACS event was observed in prasugrel/ticagrelor group (HR 0.60, 95% CI 0.39-0.91, p = .015). The risk reduction was highly driven by MI reduction (HR 0.54, 95% CI 0.33-0.91, p = .019). Lower bleeding risk was observed in prasugrel/ticagrelor group compared to clopidogrel from 1 year to 5 years (HR 0.46, 95% CI 0.21-1.00, p = .051).

CONCLUSIONS

Prasugrel/ticagrelor showed MACE risk reduction over clopidogrel as part of DAPT up to 5 years after index event, while prasugrel/ticagrelor was not associated with increased bleeding risk.