Efficacy and safety of clopidogrel versus aspirin monotherapy for secondary prevention in patients with coronary artery disease: a meta-analysis

Background

The benefits and risks of aspirin verse clopidogrel monotherapy in patients with coronary artery disease (CAD) remain controversial. This meta-analysis evaluated the efficacy and safety of aspirin verse clopidogrel monotherapy for long-term treatment in patients with CAD.

Methods

Literature was searched in the Pubmed, the Cochrane Library, and the Embase databases until March 2023. The Cochrane Risk of Bias Tool was used to assess the risk of bias in included studies. Data were extracted from the included studies, heterogeneity analysis, and pooled analysis conducted by RevMan 5.3 software.

Results

A total of five trials were included, involving 11, 766 patients with CAD. Compared with the aspirin group, the clopidogrel group was associated with reduced risk of major adverse cardiac and cerebrovascular events (MACCE) [risk ratio (RR) = 0.68, P = 0.0007], myocardial infarction (MI, RR = 0.66, P = 0.01), stroke (RR = 0.58, P = 0.003), and BARC major bleeding (RR = 0.63, P = 0.02). There were no significant differences in death from any cause (RR = 1.06, P = 0.59) and vascular death (RR = 0.92, P = 0.62) between the two groups.

Conclusions

Patients with CAD use clopidogrel could further reduce the risk of MACCE, MI, stroke, and BARC major bleeding, compared with the use of aspirin. This finding supported the use of clopidogrel rather than aspirin in patients with CAD who required long-term antiplatelet monotherapy for preventing ischemic events.

Prophylactic Efficacy and Safety of Antithrombotic Regimens in Patients with Stable Atherosclerotic Cardiovascular Disease (S-ASCVD): A Bayesian Network Meta-Regression Analysis

OBJECTIVE

The aim of this study was to evaluate the efficacy and safety of antithrombotic regimens and their combinations in preventing thrombotic incidents in patients with stable atherosclerotic cardiovascular disease (S-ASCVD).

METHODS

A systematic literature search was conducted in the PubMed, Embase, Cochrane Library, Scopus, and Google Scholar databases. The primary comprehensive endpoint was a major adverse cardiovascular event (MACE) composite of cardiovascular death, stroke, or myocardial infarction, while the secondary endpoints were cardiovascular death, all-cause stroke, ischemic stroke, myocardial infarction, and all-cause death. The safety endpoint was major bleeding. Bayesian network meta-regression analysis in R software was used to calculate the final effect size and to correct for the effect of follow-up time on the outcome effect size.

RESULTS

Twelve studies reporting 122,190 patients with eight antithrombotic regimens were included in this systematic review. For the primary composite endpoint, low-dose aspirin plus clopidogrel 75 mg (hazard ratio [HR] 0.53, 95% confidence interval [CI] 0.33-0.87) and low-dose aspirin plus rivaroxaban 2.5 mg twice daily (HR 0.53, 95% CI 0.34-0.82) showed significantly better efficacy than clopidogrel monotherapy, and the efficacy was comparable among the first two regimens. Unfortunately, none of the active regimens significantly decreased all-cause death, cardiovascular death branch, and all-cause stroke as part of the secondary endpoints. Low-dose aspirin plus ticagrelor 90 mg twice daily (HR 0.81, 95% CI 0.69-0.94) and low-dose aspirin plus ticagrelor 60 mg twice daily (HR 0.84, 95% CI 0.74-0.95) had a significant advantage in myocardial infarction compared with low-dose aspirin monotherapy, while low-dose aspirin plus 2.5 mg rivaroxaban twice daily (HR 0.62, 95% CI 0.41-0.94) was better than low-dose aspirin in the treatment of ischemic stroke. In the major bleeding branch, low-dose aspirin plus ticagrelor 90 mg twice daily (HR 2.2, 95% CI 1.70-2.90), low-dose aspirin plus ticagrelor 60 mg twice daily (HR 2.1, 95% CI 1.70-2.60), low-dose aspirin plus rivaroxaban 2.5 mg twice daily (HR 1.7, 95% CI 1.30-2.00), and rivaroxaban 5 mg twice daily (HR 1.5, 95% CI 1.20-1.90) showed higher major bleeding risk compared with low-dose aspirin.

CONCLUSIONS

Considering MACEs, myocardial infarction, all kinds of stroke, ischemic stroke, and major bleeding, low-dose aspirin plus rivaroxaban 2.5 mg twice daily should be considered the preferred regimen for S-ASCVD patients with low bleeding risk.

Aspirin versus clopidogrel for chronic maintenance monotherapy after percutaneous coronary intervention (HOST-EXAM): an investigator-initiated, prospective, randomised, open-label, multicentre trial

BACKGROUND

Optimal antiplatelet monotherapy during the chronic maintenance period in patients who undergo coronary stenting is unknown. We aimed to compare head to head the efficacy and safety of aspirin and clopidogrel monotherapy in this population.

METHODS

We did an investigator-initiated, prospective, randomised, open-label, multicentre trial at 37 study sites in South Korea. We enrolled patients aged at least 20 years who maintained dual antiplatelet therapy without clinical events for 6-18 months after percutaneous coronary intervention with drug-eluting stents (DES). We excluded patients with any ischaemic and major bleeding complications. Patients were randomly assigned (1:1) to receive a monotherapy agent of clopidogrel 75 mg once daily or aspirin 100 mg once daily for 24 months. The primary endpoint was a composite of all-cause death, non-fatal myocardial infarction, stroke, readmission due to acute coronary syndrome, and Bleeding Academic Research Consortium (BARC) bleeding type 3 or greater, in the intention-to-treat population. This trial is registered with ClinicalTrials.gov, NCT02044250.

FINDINGS

Between March 26, 2014, and May 29, 2018, we enrolled 5530 patients. 5438 (98·3%) patients were randomly assigned to either the clopidogrel group (2710 [49·8%]) or to the aspirin group (2728 [50·2%]). Ascertainment of the primary endpoint was completed in 5338 (98·2%) patients. During 24-month follow-up, the primary outcome occurred in 152 (5·7%) patients in the clopidogrel group and 207 (7·7%) in the aspirin group (hazard ratio 0·73 [95% CI 0·59-0·90]; p=0·0035).

INTERPRETATION

Clopidogrel monotherapy, compared with aspirin monotherapy during the chronic maintenance period after percutaneous coronary intervention with DES significantly reduced the risk of the composite of all-cause death, non-fatal myocardial infarction, stroke, readmission due to acute coronary syndrome, and BARC bleeding type 3 or greater. In patients requiring indefinite antiplatelet monotherapy after percutaneous coronary intervention, clopidogrel monotherapy was superior to aspirin monotherapy in preventing future adverse clinical events.

FUNDING

ChongKunDang, SamJin, HanMi, DaeWoong, and the South Korea Ministry of Health and Welfare.

Adverse Drug Reactions in the Emergency Department: Is There a Role for Pharmacogenomic Profiles at Risk?-Results from the ADRED Study

Individual differences in required drug dosages exist based on the pharmacogenomic (PGx) profiles. This study aimed to assess associations between PGx profiles and adverse drug reactions (ADR) that lead to admissions to the emergency department (ED). ADR cases of the prospective multi-center observational trial in EDs (ADRED study) were analyzed (n = 776) together with the relevant PGx phenotypes of the enzymes CYP2D6, CYP2C19, CYP2C9, and VKORC1. Overall, the allele frequency distribution in this cohort did not differ from the population frequencies. We compared the frequencies of phenotypes in the subgroups with the drugs suspected of certain ADR, in the remaining cases. The frequency distribution of CYP2C19 differed for the ADR bleeding cases suspected of clopidogrel (p = 0.020). In a logistic regression analysis, higher CYP2C19 activity (OR (95% CI): 4.97 (1.73−14.27)), together with age (1.05 (1.02−1.08)), showed an impact on the clopidogrel-suspecting ADRs, when adjusting for the clinical parameters. There was a trend for an association of phenprocoumon-risk profiles (low VKORC1 or CYP2C9 activity) with phenprocoumon-suspecting ADRs (p = 0.052). The PGx impact on serious ADRs might be highest in drugs that cannot be easily monitored or those that do not provoke mild ADR symptoms very quickly. Therefore, patients that require the intake of those drugs with PGx variability such as clopidogrel, might benefit from PGx testing.

Evidence in Guidelines for Treatment of Coronary Artery Disease

In this chapter, we focus on evidences in current guidelines for treatment of coronary artery disease (CAD). In Part 1, diet and lifestyle management is discussed, which plays an important role in CAD risk control, including forming healthy dietary pattern, maintaining proper body weight, physical exercise, smoking cessation, and so on. Part 2 elaborated on revascularization strategies and medical treatments in patients presenting with acute coronary syndrome (ACS), including specific AHA and ESC guidelines on ST elevation myocardial infarction (STEMI) and non-ST elevation ACS (NSTE-ACS). Part 3 discussed chronic stable coronary artery disease (SCAD), the treatment objective of which is a combination of both symptomatic and prognostic improvement. Yet many of the recommendations for SCAD are expert-based rather than evidence-based. Initial medical treatment is safe and beneficial for most patients. While cumulating studies have focused on optimizing pharmacological therapy (referring to nitrates, beta-blockers, calcium channel blockers, antiplatelet agents, ACEI/ARB, statins, etc.), education, habitual modification, and social support matters a lot for reducing cardiac morbidity and mortality. Patients with moderate-to-severe symptoms and complex lesions should be considered for revascularization. But practical management of revascularization shall take individual characteristics, preference, and compliance into consideration as well.

Medical Therapy for Long-Term Prevention of Atherothrombosis Following an Acute Coronary Syndrome: JACC State-of-the-Art Review

Following an acute coronary syndrome (ACS), heightened predisposition to atherothrombotic events may persist for years. Advances in understanding the pathobiology that underlies this elevated risk furnish a mechanistic basis for devising long-term secondary prevention strategies. Recent progress in ACS pathophysiology has challenged the focus on single "vulnerable plaques" and shifted toward a more holistic consideration of the "vulnerable patient," thus highlighting the primacy of medical therapy in secondary prevention. Despite current guideline-directed medical therapy, a consistent proportion of post-ACS patients experience recurrent atherothrombosis due to unaddressed "residual risk": contemporary clinical trials underline the pivotal role of platelets, coagulation, cholesterol, and systemic inflammation and provide a perspective on a personalized, targeted approach. Emerging data sheds new light on heretofore unrecognized residual risk factors. This review aims to summarize evolving evidence relative to secondary prevention of atherothrombosis, with a focus on recent advances that promise to transform the management of the post-ACS patient.

Aspirin Versus Clopidogrel Monotherapy for the Treatment of Patients with Stable Coronary Artery Disease: A Systematic Review and Meta-Analysis

Introduction

Although aspirin (ASA) is the mainstay of treatment for the prevention of recurrent ischemic stroke, the Clopidogrel versus Aspirin in Patients at Risk of Ischemic Events (CAPRIE) trial showed ASA monotherapy to be inferior to clopidogrel in preventing recurrent adverse cardiovascular outcomes in patients with high cardiac risks. Here, we aimed to systematically compare ASA versus clopidogrel monotherapy for the treatment of patients with stable coronary artery disease (CAD).

Methods

Electronic databases were searched and studies were included if they compared ASA versus clopidogrel monotherapy for the treatment of patients with CAD and they reported adverse clinical outcomes. The latest version of RevMan software (version 5.3) was used as the statistical tool for the data analysis. Odds ratios (OR) and 95% confidence intervals (CI) were generated to interpret the data.

Results

A total number of 5497 patients (from years 2003 to 2011) were treated with ASA monotherapy, whereas 2544 patients were treated with clopidogrel monotherapy. Results of this analysis showed no significant difference in composite endpoints (cardiovascular death, myocardial infarction, and stroke) (OR 0.99, 95% CI 0.47–2.10; P = 0.98), all-cause mortality (OR 1.05, 95% CI 0.82–1.33; P = 0.71), cardiac death (OR 0.89, 95% CI 0.17–4.74; P = 0.89, myocardial infarction (OR 0.84, 95% CI 0.52–1.36; P = 0.48), stroke (OR 1.26, 95% CI 0.39–4.06; P = 0.70), and bleeding defined by the Bleeding Academic Research Consortium (BARC [grade 3 or above]) (OR 1.28, 95% CI 0.78–2.12; P = 0.33).

Conclusion

This analysis did not show any significant difference in all-cause mortality, cardiac death, myocardial infarction, stroke, and BARC grade 3 or above among CAD patients who were treated with either ASA or clopidogrel monotherapy. However, as a result of the limited data, this hypothesis should be confirmed in other major trials.