Prasugrel switching from clopidogrel after percutaneous coronary intervention for acute coronary syndrome in Taiwanese patients: an analysis of safety and efficacy

What is the current optimal antithrombotic therapy after transcatheter aortic valve implantation? Current evidence from Japan and the world

Aortic stenosis (AS) is a major valvular disease that can have a negative impact on patients' prognosis, and its prevalence is increasing due to an aging population worldwide. Transcatheter aortic valve implantation (TAVI) is a well-established therapy for symptomatic severe AS utilized across the entire surgical risk spectrum. Based on the recently published evidence of large, randomized controlled trials (RCTs), the number of patients undergoing TAVI is increasing worldwide. Ischemic and bleeding events are common after TAVI and can have serious consequences both immediately after the procedure and in the long-term. Antiplatelet therapy has been traditionally recommended to prevent thromboembolic events after TAVI. The situation regarding the optimal antithrombotic regimen following TAVI is rapidly changing because many game-changing RCTs have been published. This report provides an overview of the current status and remaining issues in the field of optimal antithrombotic therapy following TAVI, including its possible effect on leaflet thrombosis.

Ticagrelor versus Adjusted-Dose Prasugrel in Acute Coronary Syndrome with Percutaneous Coronary Intervention

Dual antiplatelet therapy (DAPT) with ticagrelor or adjusted-dose prasugrel has been used for acute coronary syndrome (ACS). However, few studies have directly compared these two drugs. In this study, we compared the real-world applications and outcomes of these two drugs in patients with ACS who had undergone percutaneous coronary intervention (PCI). This retrospective cohort study was conducted using the data of eligible patients with ACS who had undergone PCI at Chang Gung Memorial Hospital System between June 2019 and December 2021. The primary efficacy-related outcome was the occurrence of major adverse cardiovascular events (MACEs), and the primary safety-related outcome was major bleeding. Inverse probability of treatment weighting based on propensity score was performed to reduce confounding effects. The study included 2,636 patients; of them, 429 received prasugrel and 2,207 received ticagrelor. No significant between-group difference was observed in the risk of MACE (13.1 vs. 13.1 events per 100 person-years, respectively, hazard ratio (HR): 1.01, 95% confidence interval (CI): 0.71-1.43). Both groups exhibited similar rates of major bleeding (3.9 vs. 4.1 events per 100 person-years, respectively, subdistribution HR: 0.96, 95% CI: 0.68-1.35). In real-world settings, adjusted-dose prasugrel and ticagrelor exhibit comparable safety and efficacy profiles in East Asian patients with ACS after PCI. Our findings offer valuable insights for future clinical decision making and patient management strategies.

Dual Antithrombotic Therapy with Oral Anticoagulant and P2Y12 inhibitors in Patients with Atrial Fibrillation After Percutaneous Coronary Intervention

BACKGROUND

The efficacy and safety of dual antithrombotic therapy (DAT) with oral anticoagulant and P2Y12 inhibitors (P2Y12i) in patients with atrial fibrillation (AF) undergoing percutaneous coronary intervention (PCI) have not been well investigated. The purpose of this study was first to evaluate clinical outcomes of DAT with P2Y12i compared with triple antithrombotic therapy (TAT), and then to compare DAT with low-dose prasugrel and DAT with clopidogrel, in patients with AF undergoing PCI.

METHODS

This study was a multicenter, non-interventional, prospective and retrospective registry. A total of 710 patients with AF undergoing PCI between January 2015 and March 2021 at 15 institutions were analyzed. Clinical outcomes within 1 year, including major adverse cardiovascular events (MACE) and major bleeding events (BARC 3 or 5) were compared between patients receiving DAT (n = 239) and TAT (n = 471), and then, compared among prasugrel-DAT (n = 82), clopidogrel-DAT (n = 157), and TAT.

RESULTS

The DAT group showed significantly lower incidence of MACE and major bleeding events compared with the TAT group (log-rank p = 0.013 and 0.047). In the multivariable Cox regression analyses, DAT (p = 0.028), acute coronary syndrome (p = 0.025), and anemia (p = 0.015) were independently associated with MACE. In addition, anemia (p = 0.022) was independently associated with, and DAT (p = 0.056) and thrombocytopenia (p = 0.051) tended to be associated with, major bleeding events. When analyzed among the prasugrel-DAT, clopidogrel-DAT, and TAT groups, there were no significant differences in clinical outcomes between the prasugrel-DAT and clopidogrel-DAT groups, and similar trends were observed for both 2 groups in comparison with the TAT group.

CONCLUSIONS

In AF patients undergoing PCI, DAT was associated with lower incidence of MACE and major bleeding events compared with TAT. In comparison of P2Y12i, there might be no significant difference in the incidence of MACE and bleeding events between prasugrel-based DAT and clopidogrel-based DAT.

Assessment of Nonfatal Bleeding Events as a Surrogate for Mortality in Coronary Artery Disease

Background

Bleeding events are frequently applied as safety end points for randomized controlled trials (RCTs) investigating the effect of antithrombotic agents in patients with coronary artery disease. However, whether a bleeding event is a valid surrogate for death remain uncertain.

Objectives

This study aimed to assess the correlation between the treatment effect on bleeding events and mortality.

Methods

Multiple databases were searched to identify RCTs studying antithrombotic agents for patients with coronary artery disease through August 2022. Major and minor bleeding events were defined in included trials, mostly defined with BARC (Bleeding Academic Research Consortium) or TIMI (Thrombolysis In Myocardial Infarction) criteria. Trial-level correlations between nonfatal bleeding events and mortality were assessed. We performed subgroup analyses by the definitions of bleeding (BARC vs TIMI criteria), study year, and follow-up duration. We used a cutoff with a lower limit of 95% confidence interval of R2 >0.72 as a strong correlation and with an upper limit of 95% confidence interval of R2 <0.50 as a weak correlation.

Results

A total of 48 RCTs with 181,951 participants were analyzed. Overall, trial-level R2 for major and minor bleeding were 0.09 (95% CI: 0.00-0.26) and 0.09 (95% CI: 0.00-0.27) for all-cause or cardiovascular death, respectively. When confined to major bleeding, R2 were 0.03 (95% CI: 0.00-0.13) and 0.01 (95% CI: 0.00-0.05), respectively. All of the subgroup analyses did not show any significant correlations.

Conclusions

We demonstrated a trial-defined bleeding event may not be a valid surrogate for mortality in RCTs investigating the effect of antithrombotic agents for coronary artery disease.

Treatment strategies of acute myocardial infarction: updates on revascularization, pharmacological therapy, and beyond

Owing to recent advances in early reperfusion strategies, pharmacological therapy, standardized care, and the identification of vulnerable patient subsets, the prognosis of acute myocardial infarction has improved. However, there is still considerable room for improvement. This review article summarizes the latest evidence concerning clinical diagnosis and treatment of acute myocardial infarction.

2023 Guidelines of the Taiwan Society of Cardiology on the Diagnosis and Management of Chronic Coronary Syndrome

Coronary artery disease (CAD) covers a wide spectrum from persons who are asymptomatic to those presenting with acute coronary syndromes (ACS) and sudden cardiac death. Coronary atherosclerotic disease is a chronic, progressive process that leads to atherosclerotic plaque development and progression within the epicardial coronary arteries. Being a dynamic process, CAD generally presents with a prolonged stable phase, which may then suddenly become unstable and lead to an acute coronary event. Thus, the concept of "stable CAD" may be misleading, as the risk for acute events continues to exist, despite the use of pharmacological therapies and revascularization. Many advances in coronary care have been made, and guidelines from other international societies have been updated. The 2023 guidelines of the Taiwan Society of Cardiology for CAD introduce a new concept that categorizes the disease entity according to its clinical presentation into acute or chronic coronary syndromes (ACS and CCS, respectively). Previously defined as stable CAD, CCS include a heterogeneous population with or without chest pain, with or without prior ACS, and with or without previous coronary revascularization procedures. As cardiologists, we now face the complexity of CAD, which involves not only the epicardial but also the microcirculatory domains of the coronary circulation and the myocardium. New findings about the development and progression of coronary atherosclerosis have changed the clinical landscape. After a nearly 50-year ischemia-centric paradigm of coronary stenosis, growing evidence indicates that coronary atherosclerosis and its features are both diagnostic and therapeutic targets beyond obstructive CAD. Taken together, these factors have shifted the clinicians' focus from the functional evaluation of coronary ischemia to the anatomic burden of disease. Research over the past decades has strengthened the case for prevention and optimal medical therapy as central interventions in patients with CCS. Even though functional capacity has clear prognostic implications, it does not include the evaluation of non-obstructive lesions, plaque burden or additional risk-modifying factors beyond epicardial coronary stenosis-driven ischemia. The recommended first-line diagnostic tests for CCS now include coronary computed tomographic angiography, an increasingly used anatomic imaging modality capable of detecting not only obstructive but also non-obstructive coronary plaques that may be missed with stress testing. This non-invasive anatomical modality improves risk assessment and potentially allows for the appropriate allocation of preventive therapies. Initial invasive strategies cannot improve mortality or the risk of myocardial infarction. Emphasis should be placed on optimizing the control of risk factors through preventive measures, and invasive strategies should be reserved for highly selected patients with refractory symptoms, high ischemic burden, high-risk anatomies, and hemodynamically significant lesions. These guidelines provide current evidence-based diagnosis and treatment recommendations. However, the guidelines are not mandatory, and members of the Task Force fully realize that the treatment of CCS should be individualized to address each patient's circumstances. Ultimately, the decision of healthcare professionals is most important in clinical practice.

Antithrombotic therapy after transcatheter aortic valve replacement

Aortic stenosis is a major valvular disease, which affects prognosis, and its prevalence is increasing due to an aging population. Transcatheter aortic valve replacement (TAVR) is a well-established therapy for symptomatic severe aortic stenosis across the entire risk spectrum, and the number of patients who undergo TAVR is increasing worldwide. Generally, ischemic and bleeding events after TAVR are not rare and can be devastating. Thus, antithrombotic therapy is recommended to prevent thromboembolic events after TAVR. Recently, a lot of randomized control trials have been published on antithrombotic therapy following TAVR, and the situation regarding the optimal antithrombotic regiment following TAVR is dramatically changing. This report reviews the current status and remaining issues in the field of optimal antithrombotic therapy following TAVR and leaflet thrombosis.

The developmental journey of therapies targeting purine receptors: from basic science to clinical trials

Since the discovery of ATP as an extracellular signalling molecule in 1972, purinergic signalling, mediated by extracellular purines and pyrimidines has been identified in virtually all mammalian tissues and is implicated in regulating fundamental cellular processes. In recent years, there has been an increasing focus on the pathophysiology and potential therapeutic interventions based on purinergic signalling. A vast range of compounds targeting purine receptors are in clinical development, and many more are in preclinical studies, which highlights the fast growth in this research field. As a tribute to Professor Geoffrey Burnstock's legacy in purinergic signalling, we present here a brief review of compounds targeting purine receptors that are in different stages of clinical trials. The review highlights the 50-year journey from basic research on purinergic receptors to clinical applications of therapies targeting purine receptors.

A HANC Risk Stratification Score for Antiplatelet Therapy Optimization with Low-Dose Prasugrel in Taiwanese Acute Coronary Syndrome Patients from the Switch Study

BACKGROUND

A significant proportion of acute coronary syndrome (ACS) patients experience high on-treatment platelet reactivity (HPR) on clopidogrel-based dual antiplatelet therapy (DAPT) after percutaneous coronary intervention (PCI).

OBJECTIVES

This study assessed key independent risk factors associated with significant HPR risk on clopidogrel, but not prasugrel, in the Switch Study cohort of 200 Taiwanese ACS patients who switched from clopidogrel to low-dose prasugrel for maintenance DAPT after PCI.

METHODS

Univariate analysis and stepwise multivariate logistic regression analysis were conducted to identify key independent risk factors for HPR on clopidogrel, but not prasugrel.

RESULTS

A HANC [H: low hemoglobin (< 13 g/dL for men and < 12 g/dL for women); A: age ≥ 65 years; N: non-ST elevation myocardial infarction; C: chronic kidney disease as defined by estimated glomerular filtration rate < 60 mL/min] risk stratification score was developed, and demonstrated optimal sensitivity and specificity at a cutoff score of ≥ 2. The HANC score compared favorably against the recently validated ABCD score in the full Switch Study cohort (n = 200), and the ABCD-GENE score in a genotyped cohort (n = 102).

CONCLUSIONS

The HANC score may serve to alert clinicians to patients at potentially higher HPR risk on clopidogrel, but not prasugrel. Further research to validate this score and assess its correlation with clinical outcomes is warranted.

Comparison of short-term clinical outcomes between low-dose prasugrel and clopidogrel as part of triple antithrombotic therapy in patients requiring oral anticoagulant therapy and percutaneous coronary intervention

BACKGROUND

Triple antithrombotic therapy, including dual antiplatelet therapy and oral anticoagulant (OAC), is recommended for a short-term period after percutaneous coronary intervention (PCI) in patients requiring anticoagulation therapy. The purpose of this study was to compare in-hospital clinical outcomes between low-dose prasugrel (3.75 mg/day) and clopidogrel, as part of triple antithrombotic therapy, using a large database in Japan.

METHODS

Patients with ischemic heart disease who underwent PCI between January 2015 and December 2019, and were prescribed triple therapy with aspirin, a P2Y12 inhibitor (clopidogrel or low-dose prasugrel), and OAC (direct oral anticoagulant: DOAC or vitamin K antagonist: VKA), were selected from the Diagnosis Procedure Combination database. The primary outcome was in-hospital mortality. The secondary outcomes were myocardial infarction, ischemic stroke, bleeding stroke, gastrointestinal bleeding, and blood transfusion.

RESULTS

Overall, 5,777 patients were eligible in this analysis. The patients were divided into 4 subgroups according to the type of P2Y12 inhibitor and OAC: clopidogrel/DOAC (n = 1,628), clopidogrel/VKA (n = 1,334), prasugrel/DOAC (n = 1,607), and prasugrel/VKA (n = 1,208). There was no significant difference in the incidence of death and gastrointestinal bleeding among the 4 subgroups. The prasugrel/DOAC group had significantly lower incidence of MI (OR 0.566, 95% CI 0.348-0.921). The incidence of ischemic stroke was significantly lower in the prasugrel/DOAC group (OR 0.701, 95% CI 0.502-0.979), and significantly higher in the clopidogrel/VKA group (OR 1.680, 95% CI 1.273-2.216). Need for blood transfusion was less frequent in the prasugrel/DOAC group (OR 0.729, 95% CI 0.598-0.890), and more frequent in both the clopidogrel/VKA group (OR 1.424, 95% CI 1.187-1.708) and the prasugrel/VKA group (OR 1.633, 95% CI 1.367-1.950).

CONCLUSIONS

Combination of low-dose prasugrel and DOAC was associated with lower incidence of MI, ischemic stroke, and blood transfusion. Low-dose prasugrel may be feasible as part of triple therapy in patients undergoing PCI.