Addition of clopidogrel to aspirin in 45,852 patients with acute myocardial infarction: randomised placebo-controlled trial

Relation between duration of dual antiplatelet therapy and risk of ischemic stroke after stent-assisted treatment of cerebral aneurysm (DAPTS ACE-registry)

BACKGROUND

The optimal duration of dual antiplatelet therapy (DAPT) in patients with cerebral aneurysm who undergo stent-assisted coil embolization (SACE) has not been established. We aimed to clarify the association between duration of DAPT and incidence of ischemic stroke in patients with cerebral aneurysm.

METHODS

We registered patients with cerebral aneurysm who underwent SACE in 27 hospitals in Japan. Those treated with DAPT (aspirin and clopidogrel) were eligible for inclusion in a previously reported randomized control trial (RCT). Patients who were ineligible or refused to participate to the RCT were followed-up for 15 months after SACE as the non-RCT cohort. Our study examined both the RCT and non-RCT cohorts. The primary and secondary outcomes were ischemic stroke and hemorrhagic events.

RESULTS

Among the 313 patients registered, 296 were included for analysis (of these, 136 were RCT patients and 160 were non-RCT patients). Patients who were treated with DAPT for more than 6 months (n=191) were classified as the long-term DAPT group. Those treated less than 6 months (n=105) were classified as the short-term group. The incidence of ischemic stroke did not significantly differ between the long-term group (2.5 per 100 person-years) and the short-term group (3.2 per 100 person-years); nor did incidence of hemorrhagic events (0.8 and 3.2 per 100 person-years, respectively). The period of DAPT was not significantly associated with incidence rates of ischemic stroke or hemorrhagic events.

CONCLUSIONS

Duration of DAPT was not associated with the incidence of ischemic stroke in the first 15 months after SACE.

Association of genetic variations of 3'-UTR in clopidogrel pharmacokinetic-relevant genes with clopidogrel response in Han Chinese patients with coronary artery disease

Dual antiplatelet therapy with aspirin and clopidogrel has reduced ischemic vascular events significantly. Genetic influence, especially those in clopidogrel pharmacokinetic-relevant genes partially accounts for interindividual pharmacodynamic variability of clopidogrel. However, most studies have concentrated on the genetic variations in introns, exons, or promoters of the candidate genes, and the association between genetic variations in 3'-UTR in clopidogrel pharmacokinetic-relevant genes and clopidogrel response is unknown. In our study, ten different algorithms were applied to pick potential miRNAs targeting the clopidogrel pharmacokinetic-relevant genes. Furthermore, the correlation between miRNA expression profiles and mRNA expression of corresponding clopidogrel pharmacokinetic-relevant genes was analyzed. Through comprehensive analysis, including bioinformatics prediction and correlation analysis of miRNA and mRNA expression profiles, miR-218-5p and miR-506-5p were supposed to regulate the expression of PON1 via binding with its 3'-UTR. Moreover, PON1 rs854551 and rs854552 were located in miRNA recognizing sequences and may serve as potential miRSNPs possibly affecting PON1 expression. The rs854552 polymorphism was genotyped and platelet reactivity index (PRI) indicative of clopidogrel response was measured in 341 Chinese coronary artery disease (CAD) patients 24 h after administration of 300 mg clopidogrel. Our results showed that PON1 rs854552 had a significant influence on PRI in CAD patients, especially in patients with CYP2C19 extensive metabolic phenotype. In conclusion, PON1 rs854552 polymorphisms may affect clopidogrel response. Bioinformatics prediction followed by functional validation could aid in decoding the contribution of unexplained variations in the 3'-UTR in drug-metabolizing enzymes on clopidogrel response.

Antiplatelet therapy for treatment of coronary artery disease in older patients

Coronary artery disease in older patients is more frequently diffuse and complex, and is often treated by percutaneous coronary intervention on top of medical therapy. There are currently no specific recommendations for antiplatelet therapy in patients aged≥75 years. Aspirin remains pivotal, and is still indicated as a long-term treatment after percutaneous coronary intervention. In addition, a P2Y12 inhibitor is administered for 6-12 months according to clinical presentation. Age is a minor bleeding risk factor, but because older patients often have several co-morbidities, they are considered as having a high bleeding risk according to different scoring systems. This increased bleeding risk has resulted in different therapeutic strategies for antithrombotic treatment after percutaneous coronary intervention; these include short dual antiplatelet therapy, a switch from potent to less potent antiplatelet therapy or single antiplatelet therapy with a P2Y12 inhibitor instead of aspirin, among others. A patient-centred approach, taking into account health status, functional ability, frailty, cognitive skills, bleeding and ischaemic risks and patient preference, is essential when caring for older adults with coronary artery disease. The present review focuses on the knowledge base, specificities of antiplatelet therapies, a balance between haemorrhagic and ischaemic risk, strategies for antiplatelet therapy and directions for future investigation pertaining to coronary artery disease in older patients.

Comprehensive comparative efficacy and safety of potent P2Y12 inhibitors in patients undergoing coronary intervention: A systematic review and meta-analysis

Potent P2Y12 receptor antagonists have been used widely for patients undergoing percutaneous coronary intervention with different results. Benefits from different regimens various between trials. Randomized controlled trials (RCTs) have restrictive inclusion and exclusion criteria; thus, they may limit the generalizability of the findings to a broader population. This study was aimed to comprehensively investigate the outcomes of potent P2Y12 inhibitors in patients undergoing PCI, including RCTs and real-world evidence (RWE) studies. Multiple electronic databases were systemically reviewed and searched on compared potent P2Y12 inhibitors with clopidogrel. The primary efficacy end point was composite ischemic cardiovascular event and primary safety endpoint was major bleeding. Overall estimates of proportions and incidence rates with 95 % confidence intervals (CI) were calculated using fixed-effects models. Total 24 studies (140,986 patients) underwent coronary intervention were included in this meta-analysis, including 18 RCTs and 6 large cohort studies with propensity score matching. The potent P2Y12 inhibitors including cangrelor, prasugrel, and ticagrelor, significantly decreased the risk of composite adverse cardiovascular ischemic events (95 % CI 0.89-0.96, p < 0.001), but increased major bleeding (95 % CI 1.15-1.33, p < 0.001) or any bleeding (95 % CI 1.21-1.33, p < 0.001) compared with Clopidogrel. This meta-analysis merges RCTs and RWE studies and comprehensively evidences newer potent P2Y12 inhibitors are significantly more effective than clopidogrel in reduction of composite adverse thrombotic events, but the incidence of major or any bleeding was higher compared with clopidogrel.

One Endothelium-Targeted Combined Nucleic Acid Delivery System for Myocardial Infarction Therapy

Acute myocardial infarction (MI) and ischemic heart disease are the leading causes of heart failure and mortality. Currently, research on MI treatment is focused on angiogenic and anti-inflammatory therapies. Although endothelial cells (ECs) are critical for triggering inflammation and angiogenesis, no approach has targeted them for the treatment of MI. In this study, we proposed a nonviral combined nucleic acid delivery system consisting of an EC-specific polycation (CRPPR-grafted ethanolamine-modified poly(glycidyl methacrylate), CPC) that can efficiently codeliver siR-ICAM1 and pCXCL12 for the treatment of MI. Animals treated with the combination therapy exhibited better cardiac function than those treated with each nucleic acid alone. In particular, the combination therapy of CPC/siR-ICAM1 and CPC/pCXCL12 significantly improved cardiac systolic function, anti-inflammatory responses, and angiogenesis compared to the control group. In conclusion, CPC-based combined gene delivery systems show impressive performance in the treatment of MI and provide a programmed strategy for the development of codelivery systems for various EC-related diseases.

The role of platelet P2Y12 receptors in inflammation

Inflammation is a complex pathophysiological process underlying many clinical conditions. Platelets contribute to the thrombo-inflammatory response. Platelet P2Y12 receptors amplify platelet activation, potentiating platelet aggregation, degranulation and shape change. The contents of platelet alpha granules, in particular, act directly on leucocytes, including mediating platelet-leucocyte aggregation and activation via platelet P-selectin. Much evidence for the role of platelet P2Y12 receptors in inflammation comes from studies using antagonists of these receptors, such as the thienopyridines clopidogrel and prasugrel, and the cyclopentyltriazolopyrimidine ticagrelor, in animal and human experimental models. These suggest that antagonism of P2Y12 receptors decreases markers of inflammation with some evidence that this reduces incidence of adverse clinical sequelae during inflammatory conditions. Interpretation is complicated by pleiotropic effects such as those of the thienopyridines on circulating leucocyte numbers and of ticagrelor on adenosine reuptake. The available evidence suggests that P2Y12 receptors are prominent mediators of inflammation and P2Y12 receptor antagonism as a potentially powerful strategy in a broad range of inflammatory conditions. 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.

Thrombus remodelling by reversible and irreversible P2Y12 inhibitors

Pharmacological inhibition of the platelet ADP-receptor P2Y₁₂ is a cornerstone in the prevention of atherothrombotic events in adult patients with acute coronary syndrome (ACS). Thienopyridines such as clopidogrel and prasugrel exert their antithrombotic effect by means of active metabolites that irreversibly inhibit P2Y₁₂. Due to the short half-life of these metabolites, a subpopulation of ADP-responsive platelets will form in between dosing. With increased platelet turnover rate or poor patient compliance, the fraction of ADP-responsive platelets will increase, potentially increasing the risk for new thrombotic events. In contrast, the reversible P2Y₁₂ inhibition produced by direct-acting ADP blockers such as ticagrelor and cangrelor inhibit the entire platelet population. In this study, we evaluated the impact of these pharmacological differences on thrombus formation in an ex vivo flow chamber model. A customized image analysis pipeline was used for automatized, large-scale identification and tracking of single platelets incorporated into the thrombus, enabling quantitative analysis of the relative contribution of inhibited and uninhibited platelets to thrombus growth and consolidation. Comparative experiments were conducted using the irreversible and reversible P2Y₁₂ inhibitors prasugrel active metabolite (PAM) and ticagrelor, respectively. Our results show that PAM inhibited thrombus platelet recruitment more gradually than ticagrelor, with a slower onset of inhibition. Further, we show that the presence of a small fraction (<10%) of uninhibited platelets did not abrogate the antithrombotic effect of PAM to any significant extent. Finally, we demonstrate a gradual enrichment of inhibited platelets in the thrombus shell due to selective recruitment of inhibited platelets to the thrombus periphery.

The Role of Personalized Medicine in Companion Animal Cardiology

Cardiomyopathies remain one of the most common inherited cardiac diseases in both human and veterinary patients. To date, well over 100 mutated genes are known to cause cardiomyopathies in humans with only a handful known in cats and dogs. This review highlights the need and use of personalized one-health approaches to cardiovascular case management and advancement in pharmacogenetic-based therapy in veterinary medicine. Personalized medicine holds promise in understanding the molecular basis of disease and ultimately will unlock the next generation of targeted novel pharmaceuticals and aid in the reversal of detrimental effects at a molecular level.

A nightmare of clopidogrel resistance in a resource-limited setting: case report of subacute stent thrombosis

BACKGROUND

Stent thrombosis, a life-threatening complication of percutaneous coronary intervention (PCI) continues to occur despite effective antiplatelet regimens and improved stenting methods. Noncompliance with dual antiplatelet therapy is the most common etiology; however, in spite of timely and their optimum administration the rates of recurrent myocardial infarction (MI) and stent thrombosis remain high. Clopidogrel resistance is increasingly evoked with elevated risk of anterothrombotic events particularly in the setting of stent implantation. In this case report, we present a case of subacute stent thrombosis associated with clopidogrel resistance in a resource-constrained setting.

CASE PRESENTATION

A 60 year old man with a long standing history of hypertension presented with a 6-month history of progressive shortness of breath. Initial electrocardiogram (ECG) revealed T-wave inversion on lateral leads and echocardiogram revealed akinetic basal lateral wall and hypokinetic mid lateral wall with reduced systolic functions. An elective coronary angiography (CAG) revealed a 90% stenosis of mid left anterior descending (LAD) artery and an 80% stenosis on the proximal left circumflex artery. He underwent a successful PCI with a drug-eluting stent implantation to mid LAD. He was discharged in a stable state 48 h post revascularization with dual antiplatelet (clopidogrel and acetylsalicylic acid). Seven days later, he presented with a crushing substernal chest pain. Cardiac enzymes were elevated and ECG revealed anterior ST-elevation MI. An emergency CAG revealed a high thrombus burden with 100% occlusion of mid LAD. Following unsuccessful ballooning, intravenous and intracoronary thrombolysis with tenecteplase was given. A TIMI II flow was achieved and the patient was sent to the coronary care unit. However, 14 h later there was yet a new onset of severe chest pain. A 12-lead ECG previewed anterior ST-elevation MI and the cardiac enzymes were high. Urgent CAG revealed in-stent thrombotic total occlusion of mid LAD. A stent in stent was then implanted and TIMI III flow was restored. Clopidogrel resistance was suspected and the patient was transitioned to ticagrelol. There were no further ischemic events during the remainder of hospitalization and the patient was discharged in a hemodynamically stable state three days later. During follow-up after one and three months, he was fairly stable without any further cardiac events.

CONCLUSIONS

Owing to clopidogrel resistance, stent thrombosis in the setting of dual antiplatelet therapy compliance may occur. While in a situation of clopidogrel resistance newer and more potent antiplatelet drugs should be used, their availability and cost remains a significant barrier particularly in the developing world. Nonetheless, a high index of suspicion and timely revascularization is fundamental to restore patency of the thrombosed vessel and confer better risk-adjusted survival rates.

Diagnostic Puzzles and Cause-Targeted Treatment Strategies in Myocardial Infarction with Non-Obstructive Coronary Arteries: An Updated Review

Myocardial infarction with nonobstructive coronary arteries (MINOCA) is a distinct subtype of myocardial infarction (MI), occurring in about 8-10% of spontaneous MI cases referred for coronary angiography. Unlike MI with obstructive coronary artery disease, MINOCA's pathogenesis is more intricate and heterogeneous, involving mechanisms such as coronary thromboembolism, coronary vasospasm, microvascular dysfunction, dissection, or plaque rupture. Diagnosing MINOCA presents challenges and includes invasive and non-invasive strategies aiming to differentiate it from alternative diagnoses and confirm the criteria of elevated cardiac biomarkers, non-obstructive coronary arteries, and the absence of alternate explanations for the acute presentation. Tailored management strategies for MINOCA hinge on identifying the underlying cause of the infarction, necessitating systematic diagnostic approaches. Furthermore, determining the optimal post-MINOCA medication regimen remains uncertain. This review aims to comprehensively address the current state of knowledge, encompassing diagnostic and therapeutic approaches, in the context of MINOCA while also highlighting the evolving landscape and future directions for advancing our understanding and management of this intricate myocardial infarction subtype.

The contribution of genotype-guided selection of P2Y12 inhibitor on prognosis in ACS /CCS patients undergoing percutaneous coronary intervention: a retrospective cohort study

PURPOSE

We aimed to explore the contribution of genotype-guided selection of P2Y12 inhibitors on prognosis in Chinese patients with acute coronary syndromes (ACS) or chronic coronary syndromes (CCS) undergoing percutaneous coronary intervention (PCI).

METHODS

Totally, 2063 patients were included. They were divided into empiric treatment group (n = 1025) and individualized treatment group (n = 1038) depending on whether taken CYP2C19 genetic testing. The incidences of clinical endpoint events were compared in two groups at 1-year follow-up. The effective endpoint events were major adverse cardiovascular events (MACEs), including all-cause mortality, in-stent restenosis, nonfatal myocardial infarction, nonfatal stroke and severe recurrent ischemia. Meanwhile, the safe endpoint was bleeding events defined by the Bleeding Academic Research Consortium (BARC) criteria.

RESULTS

Finally, 66.83% patients were diagnosed with ACS and 33.17% patients were diagnosed with CCS in empiric group. 68.11% patients were diagnosed with ACS and 31.89% patients were diagnosed with CCS in individualized group. At 1-year follow-up, individualized group showed lower MACEs rate than empiric group (19.61% vs. 10.69%, HR: 1.915; 95% CI: 1.534 to 2.392; P < 0.0001, log-rank test; adjusted HR: 1.983; 95% CI: 1.573 to 2.501; P = 0.000, cox proportional hazards regression models), while bleeding events were significantly less common in empiric group than in individualized group (7.32% vs. 10.40%, HR: 0.693; 95% CI: 0.519 to 0.926; P = 0.0132, log-rank test; adjusted HR: 0.695; 95% CI: 0.518 to 0.933; P = 0.016, cox proportional hazards regression models). It was mainly manifested in BARC class 1 bleeding, which did not warrant the interruption of antiplatelet therapy (ITA). Further, subgroup analyses illustrated that no significant difference existed in cumulative MACEs-free survival rate between all treatment arms of individualized group (P = 0.6579 by log-rank test), and CYP2C19 intermediate metabolizer (IM) genetype appeared to be significantly associated with bleeding events for patients treated with ticagrelor (clopidogrel vs. ticagrelor: 6.80% vs. 14.88%; adjusted HR:0.440; 95% CI: 0.246 to 0.787; adjusted P = 0.006).

CONCLUSIONS

Genotype-guided selection of P2Y12 inhibitor made a very positive contribution on the prognosis in Chinese ACS/CCS patients undergoing PCI. Instead of intensifying antiplatelet strategies, conventional-dose clopidogrel could be recommended as P2Y12 inhibitor after weighing MACEs and bleeding events in CYP2C19 IM patients.

CYP2C19 Genotype Prevalence and Association With Recurrent Myocardial Infarction in British-South Asians Treated With Clopidogrel

Background

Cytochrome P450 family 2 subfamily C member 19 (CYP2C19) is a hepatic enzyme involved in the metabolism of clopidogrel from a prodrug to its active metabolite. Prior studies of genetic polymorphisms in CYP2C19 and their relationship with clinical efficacy have not included South Asian populations.

Objectives

The objective of this study was to assess prevalence of common CYP2C19 genotype polymorphisms in a British-South Asian population and correlate these with recurrent myocardial infarction risk in participants prescribed clopidogrel.

Methods

The Genes & Health cohort of British Bangladeshi and Pakistani ancestry participants were studied. CYP2C19 diplotypes were assessed using array data. Multivariable logistic regression was used to test for association between genetically inferred CYP2C19 metabolizer status and recurrent myocardial infarction, controlling for known cardiovascular disease risk factors, percutaneous coronary intervention, age, sex, and population stratification.

Results

Genes & Health cohort participants (N = 44,396) have a high prevalence (57%) of intermediate or poor CYP2C19 metabolizers, with at least 1 loss-of-function CYP2C19 allele. The prevalence of poor metabolizers carrying 2 CYP2C19 loss-of-function alleles is 13%, which is higher than that in previously studied European (2.4%) and Central/South Asian populations (8.2%). Sixty-nine percent of the cohort who were diagnosed with an acute myocardial infarction were prescribed clopidogrel. Poor metabolizers were significantly more likely to have a recurrent myocardial infarction (OR: 3.1; P = 0.019).

Conclusions

A pharmacogenomic-driven approach to clopidogrel prescribing has the potential to impact significantly on clinical management and outcomes in individuals of Bangladeshi and Pakistani ancestry.

The 2023 Taiwan Stroke Society Guidelines for the management of patients with intracranial atherosclerotic disease

Intracranial atherosclerotic disease (ICAD) is a major cause of ischemic stroke, especially in Asian populations, which has a high risk of recurrent stroke and cardiovascular comorbidities. The present guidelines aim to provide updated evidence-based recommendations for diagnosis and management of patients with ICAD. Taiwan Stroke Society guideline consensus group developed recommendations for management of patients with ICAD via consensus meetings based on updated evidences. Each proposed class of recommendation and level of evidence was approved by all members of the group. The guidelines cover six topics, including (1) epidemiology and diagnostic evaluation of ICAD, (2) nonpharmacological management of ICAD, (3) medical therapy for symptomatic ICAD, (4) endovascular thrombectomy and rescue therapy for acute ischemic stroke with underlying ICAD, (5) endovascular interventional therapy for postacute symptomatic intracranial arterial stenosis, and (6) surgical treatment of chronic symptomatic intracranial arterial stenosis. Intensive medical treatment including antiplatelet therapy, risk factor control, and life style modification are essential for patients with ICAD.

Long-term risk, clinical management, and healthcare resource utilization of stable patients with coronary artery disease and post-myocardial infarction in Greece - TIGREECE study

BACKGROUND

In light of the scarcity of evidence, TIGREECE evaluated the clinical management and long-term outcomes of patients at high risk for an atherothrombotic event who have suffered a myocardial infarction (MI), managed by cardiologists/internists in routine hospital and private office settings in Greece.

METHODS

TIGREECE, a multicenter, 3-year prospective cohort study, enrolled patients ≥50 years old, with a history of MI 1-3 years before enrollment and with at least one of the following risk factors: age ≥65 years, diabetes mellitus requiring medication, second prior MI, multivessel coronary artery disease, and creatinine clearance 15-60 mL/min. The primary outcome was a composite of MI, unstable angina with urgent revascularization, stroke, or all-cause death.

RESULTS

Between 5 June 2014 and 25 July 2015, 305 eligible consented patients (median age: 67.3 years; 81.3% males; 14.8% active smokers; 80.7% overweight/obese) were enrolled; 52.5% had ≥2 qualifying risk factors. The median time from the index MI [ST-segment elevation myocardial infarction (STEMI) in 51.1%, non-STEMI in 33.1%] to enrollment was 1.7 years. Of the patients, 65.9% had been discharged on dual antiplatelet therapy. At enrollment, 94.4% were receiving antiplatelets: 60.0% single [acetylsalicylic acid (ASA): 43.3%; clopidogrel: 15.7%] and 34.4% dual (ASA + clopidogrel: 31.8%) therapy. The Kaplan-Meier estimated 3-year primary composite event rate was 9.3% [95% confidence interval (CI): 6.4-13.0), and the ischemic composite event rate was 6.7% (95% CI: 4.2-9.9).

CONCLUSIONS

Study results indicate that in the routine care of Greece one in ten patients experience a recurring cardiovascular event or death, mainly of ischemic origin, 1-3 years post-MI.

A Comparative Study on Ticagrelor and Clopidogrel in Patients With Acute Coronary Syndrome Treated With Primary Percutaneous Coronary Intervention

This study was conducted to compare the efficacy and safety of ticagrelor and clopidogrel in patients with acute coronary syndrome (ACS) treated with primary percutaneous coronary intervention (PPCI). A total of 3528 consecutive patients with ACS treated with PPCI were divided into the ticagrelor and clopidogrel groups based on their dual antiplatelet therapy regimen at hospital discharge. Patient follow-up visits were completed 1, 6, and 12 months after PPCI treatment. Major adverse cardiac events (MACEs) and Bleeding Academic Research Consortium (BARC) bleeding events were assessed in both groups. In total, 2501 cases were included in the ticagrelor group, and 817 cases were included in the clopidogrel group. The incidence of MACEs was lower in the ticagrelor group than in the clopidogrel group (P < .05). The ticagrelor group had lower incidence of all-cause death and cardiac death compared with the clopidogrel group, and the difference was significant (P < .05). The incidences of study end points, including recurrent myocardial infarction and repeat revascularization, were not significantly different between the groups (P > .05). The incidences of BARC total and major bleeding events were not significantly different between the groups (P > .05). However, the incidences of BARC type 1 and 2 bleeding events were lower in the ticagrelor group than in the clopidogrel group (P < .05). The multivariate Cox regression analysis suggested that ticagrelor could decrease all-cause death compared with clopidogrel (P = .021). In patients with ACS treated with PPCI, ticagrelor could significantly reduce the risk of MACEs compared with clopidogrel, without increasing the risk of bleeding.

Is It Really Safe to Discontinue Antiplatelet Therapy 12 Months After Percutaneous Coronary Intervention in Patients with Atrial Fibrillation?

The prevalence of AF in patients with coronary artery disease is high. The guidelines from many professional groups, including the European Society of Cardiology, American College of Cardiology/American Heart Association and Heart Rhythm Society, recommend a maximum duration of 12 months of combination single antiplatelet and anticoagulation therapy in patients who undergo percutaneous coronary intervention and who have concurrent AF, followed by anticoagulation alone beyond 1 year. However, the evidence that anticoagulation alone without antiplatelet therapy adequately reduces the well-documented attritional risk of stent thrombosis after coronary stent implantation is relatively sparse, particularly given that very late stent thrombosis (>1 year from stent implantation) is the commonest type. By contrast, the elevated risk of bleeding from combined anticoagulation and antiplatelet therapy is clinically important. The aim of this review is to assess the evidence for long-term anticoagulation alone without antiplatelet therapy 1 year post-percutaneous coronary intervention in patients with AF.

Treatment effect modification due to comorbidity: Individual participant data meta-analyses of 120 randomised controlled trials

BACKGROUND

People with comorbidities are underrepresented in clinical trials. Empirical estimates of treatment effect modification by comorbidity are lacking, leading to uncertainty in treatment recommendations. We aimed to produce estimates of treatment effect modification by comorbidity using individual participant data (IPD).

METHODS AND FINDINGS

We obtained IPD for 120 industry-sponsored phase 3/4 trials across 22 index conditions (n = 128,331). Trials had to be registered between 1990 and 2017 and have recruited ≥300 people. Included trials were multicentre and international. For each index condition, we analysed the outcome most frequently reported in the included trials. We performed a two-stage IPD meta-analysis to estimate modification of treatment effect by comorbidity. First, for each trial, we modelled the interaction between comorbidity and treatment arm adjusted for age and sex. Second, for each treatment within each index condition, we meta-analysed the comorbidity-treatment interaction terms from each trial. We estimated the effect of comorbidity measured in 3 ways: (i) the number of comorbidities (in addition to the index condition); (ii) presence or absence of the 6 commonest comorbid diseases for each index condition; and (iii) using continuous markers of underlying conditions (e.g., estimated glomerular filtration rate (eGFR)). Treatment effects were modelled on the usual scale for the type of outcome (absolute scale for numerical outcomes, relative scale for binary outcomes). Mean age in the trials ranged from 37.1 (allergic rhinitis trials) to 73.0 (dementia trials) and percentage of male participants range from 4.4% (osteoporosis trials) to 100% (benign prostatic hypertrophy trials). The percentage of participants with 3 or more comorbidities ranged from 2.3% (allergic rhinitis trials) to 57% (systemic lupus erythematosus trials). We found no evidence of modification of treatment efficacy by comorbidity, for any of the 3 measures of comorbidity. This was the case for 20 conditions for which the outcome variable was continuous (e.g., change in glycosylated haemoglobin in diabetes) and for 3 conditions in which the outcomes were discrete events (e.g., number of headaches in migraine). Although all were null, estimates of treatment effect modification were more precise in some cases (e.g., sodium-glucose co-transporter-2 (SGLT2) inhibitors for type 2 diabetes-interaction term for comorbidity count 0.004, 95% CI -0.01 to 0.02) while for others credible intervals were wide (e.g., corticosteroids for asthma-interaction term -0.22, 95% CI -1.07 to 0.54). The main limitation is that these trials were not designed or powered to assess variation in treatment effect by comorbidity, and relatively few trial participants had >3 comorbidities.

CONCLUSIONS

Assessments of treatment effect modification rarely consider comorbidity. Our findings demonstrate that for trials included in this analysis, there was no empirical evidence of treatment effect modification by comorbidity. The standard assumption used in evidence syntheses is that efficacy is constant across subgroups, although this is often criticised. Our findings suggest that for modest levels of comorbidities, this assumption is reasonable. Thus, trial efficacy findings can be combined with data on natural history and competing risks to assess the likely overall benefit of treatments in the context of comorbidity.

Effects of morphine and P2Y inhibitor amongst patients with acute coronary syndrome: A meta-analysis of comparative studies

BACKGROUND

P2Y inhibitor and morphine are widely used in caring for patients with the acute coronary syndrome (ACS), but there are some concerns about the combination use due to interaction in metabolism. Therefore, this study aimed to examine whether using morphine with antiplatelets in patients with ACS affects the clinical outcomes based on currently available evidence.

METHODS

Three databases were searched for comparative studies on this topic by using relevant keywords of ACS and morphine. Two authors independently extracted study information, mortality, major adverse cardiac event (MACE), major bleeding, and length of hospital stay. Then, they evaluated the quality of evidence independently. Meta-analysis was planned to be conducted in random-effects model. Risk ratio (RR) was used for most outcomes except hospital stay, and Peto odds ratio (POR) was used if there were any zero cells. Pooled estimate was presented with 95% confidence interval (CI).

RESULTS

Fourteen studies (n = 73,033) met eligibility criteria, and there was non-significant difference in mortality between antiplatelet with and without morphine (RR = 1.13, 95%CI: 0.78 to 1.64). Antiplatelet therapy without morphine significantly reduced the risk of MACE (RR = 0.78, 95%CI: 0.67 to 0.89; I-square = 0%), but increased the odds of major bleeding (POR = 1.87, 95%CI: 1.04 to 3.35; I-square = 0%) as compared with the combined use of antiplatelet therapy and morphine.

CONCLUSION

In conclusion, there is no statistically significant difference in mortality in patients with ACS using morphine or not, but clinicians ought to make a trade-off between a lower risk of MACE and a higher risk of major bleeding before adding morphine to antiplatelet therapy.

Bleeding risk in patients prescribed dual antiplatelet therapy and triple therapy after coronary interventions: the ADAPTT retrospective population-based cohort studies

Background

Bleeding among populations undergoing percutaneous coronary intervention or coronary artery bypass grafting and among conservatively managed patients with acute coronary syndrome exposed to different dual antiplatelet therapy and triple therapy (i.e. dual antiplatelet therapy plus an anticoagulant) has not been previously quantified.

Objectives

The objectives were to estimate hazard ratios for bleeding for different antiplatelet and triple therapy regimens, estimate resources and the associated costs of treating bleeding events, and to extend existing economic models of the cost-effectiveness of dual antiplatelet therapy.

Design

The study was designed as three retrospective population-based cohort studies emulating target randomised controlled trials.

Setting

The study was set in primary and secondary care in England from 2010 to 2017.

Participants

Participants were patients aged ≥ 18 years undergoing coronary artery bypass grafting or emergency percutaneous coronary intervention (for acute coronary syndrome), or conservatively managed patients with acute coronary syndrome.

Data sources

Data were sourced from linked Clinical Practice Research Datalink and Hospital Episode Statistics.

Interventions

Coronary artery bypass grafting and conservatively managed acute coronary syndrome: aspirin (reference) compared with aspirin and clopidogrel. Percutaneous coronary intervention: aspirin and clopidogrel (reference) compared with aspirin and prasugrel (ST elevation myocardial infarction only) or aspirin and ticagrelor.

Main outcome measures

Primary outcome: any bleeding events up to 12 months after the index event. Secondary outcomes: major or minor bleeding, all-cause and cardiovascular mortality, mortality from bleeding, myocardial infarction, stroke, additional coronary intervention and major adverse cardiovascular events.

Results

The incidence of any bleeding was 5% among coronary artery bypass graft patients, 10% among conservatively managed acute coronary syndrome patients and 9% among emergency percutaneous coronary intervention patients, compared with 18% among patients prescribed triple therapy. Among coronary artery bypass grafting and conservatively managed acute coronary syndrome patients, dual antiplatelet therapy, compared with aspirin, increased the hazards of any bleeding (coronary artery bypass grafting: hazard ratio 1.43, 95% confidence interval 1.21 to 1.69; conservatively-managed acute coronary syndrome: hazard ratio 1.72, 95% confidence interval 1.15 to 2.57) and major adverse cardiovascular events (coronary artery bypass grafting: hazard ratio 2.06, 95% confidence interval 1.23 to 3.46; conservatively-managed acute coronary syndrome: hazard ratio 1.57, 95% confidence interval 1.38 to 1.78). Among emergency percutaneous coronary intervention patients, dual antiplatelet therapy with ticagrelor, compared with dual antiplatelet therapy with clopidogrel, increased the hazard of any bleeding (hazard ratio 1.47, 95% confidence interval 1.19 to 1.82), but did not reduce the incidence of major adverse cardiovascular events (hazard ratio 1.06, 95% confidence interval 0.89 to 1.27). Among ST elevation myocardial infarction percutaneous coronary intervention patients, dual antiplatelet therapy with prasugrel, compared with dual antiplatelet therapy with clopidogrel, increased the hazard of any bleeding (hazard ratio 1.48, 95% confidence interval 1.02 to 2.12), but did not reduce the incidence of major adverse cardiovascular events (hazard ratio 1.10, 95% confidence interval 0.80 to 1.51). Health-care costs in the first year did not differ between dual antiplatelet therapy with clopidogrel and aspirin monotherapy among either coronary artery bypass grafting patients (mean difference £94, 95% confidence interval -£155 to £763) or conservatively managed acute coronary syndrome patients (mean difference £610, 95% confidence interval -£626 to £1516), but among emergency percutaneous coronary intervention patients were higher for those receiving dual antiplatelet therapy with ticagrelor than for those receiving dual antiplatelet therapy with clopidogrel, although for only patients on concurrent proton pump inhibitors (mean difference £1145, 95% confidence interval £269 to £2195).

Conclusions

This study suggests that more potent dual antiplatelet therapy may increase the risk of bleeding without reducing the incidence of major adverse cardiovascular events. These results should be carefully considered by clinicians and decision-makers alongside randomised controlled trial evidence when making recommendations about dual antiplatelet therapy.

Limitations

The estimates for bleeding and major adverse cardiovascular events may be biased from unmeasured confounding and the exclusion of an eligible subgroup of patients who could not be assigned an intervention. Because of these limitations, a formal cost-effectiveness analysis could not be conducted.

Future work

Future work should explore the feasibility of using other UK data sets of routinely collected data, less susceptible to bias, to estimate the benefit and harm of antiplatelet interventions.

Trial registration

This trial is registered as ISRCTN76607611.

Funding

This project was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 27, No. 8. See the NIHR Journals Library website for further project information.

Myocardial infarction with nonobstructive coronary arteries: from pathophysiology to therapeutic strategies

Myocardial infarction with nonobstructive coronary arteries (MINOCA) is a heterogeneous group of clinical entities characterized by clinical evidence of acute myocardial infarction (AMI) with normal or near-normal coronary arteries on coronary angiography (stenosis < 50%) and without an over the alternative diagnosis for the acute presentation. Its prevalence ranges from 6% to 11% among all patients with AMI, with a predominance of young, nonwhite females with fewer traditional risks than those with an obstructive coronary artery disease (MI-CAD). MINOCA can be due to either epicardial causes such as rupture or fissuring of unstable nonobstructive atherosclerotic plaque, coronary artery spasm, spontaneous coronary dissection and cardioembolism in-situ or microvascular causes. Besides, also type-2 AMI due to supply-demand mismatch and Takotsubo syndrome must be considered as a possible MINOCA cause. Because of the complex etiology and a limited amount of evidence, there is still some confusion around the management and treatment of these patients. Therefore, the key focus of this condition is to identify the underlying individual mechanisms to achieve patient-specific treatments. Clinical history, electrocardiogram, echocardiography, and coronary angiography represent the first-level diagnostic investigations, but coronary imaging with intravascular ultrasound and optical coherent tomography, coronary physiology testing, and cardiac magnetic resonance imaging offer additional information to understand the underlying cause of MINOCA. Although the prognosis is slightly better compared with MI-CAD patients, MINOCA is not always benign and depends on the etiopathology. This review analyzes all possible pathophysiological mechanisms that could lead to MINOCA and provides the most specific and appropriate therapeutic approach in each scenario.

Antiplatelet Therapy in Coronary Artery Disease: Now and Then

Cardiovascular disease, particularly coronary artery disease (CAD), remains the leading cause of mortality and morbidity in industrialized countries. Platelet activation and aggregation at the site of endothelial injury play a key role in the processes ultimately resulting in thrombus formation with vessel occlusion and subsequent end-organ damage. Consequently, antiplatelet therapy has become a mainstay in the pharmacological treatment of CAD. Several drug classes have been developed over the last decades and a broad armamentarium of antiplatelet agents is currently available. This review portrays the evolution of antiplatelet therapy, and provides an overview on previous and current antiplatelet drugs and strategies.

Novel Aspects Targeting Platelets in Atherosclerotic Cardiovascular Disease—A Translational Perspective

Platelets are important cellular targets in cardiovascular disease. Based on insights from basic science, translational approaches and clinical studies, a distinguished anti-platelet drug treatment regimen for cardiovascular patients could be established. Furthermore, platelets are increasingly considered as cells mediating effects “beyond thrombosis”, including vascular inflammation, tissue remodeling and healing of vascular and tissue lesions. This review has its focus on the functions and interactions of platelets with potential translational and clinical relevance. The role of platelets for the development of atherosclerosis and therapeutic modalities for primary and secondary prevention of atherosclerotic disease are addressed. Furthermore, novel therapeutic options for inhibiting platelet function and the use of platelets in regenerative medicine are considered.

Negative findings but positive contributions in cardiovascular research

Researchers have always concluded that results that do not support the hypothesis as unimportant, unworthy, or simply not good enough for publication. However, negative findings are essential for the progress of science and its self-correcting nature. We also believe in the importance and indispensability of negative results. Therefore, in this review, we discussed the factors contributing to the publication bias of negative results and the problems to assess the factuality and validity of negative results. Moreover, we emphasized the importance of reporting negative results in cardiovascular research, including treatments, and suggest that the negative results could clarify previously controversial topics in the treatment of cardiovascular diseases and prompt the translation of research on precision cardiovascular disease prevention and treatment.

miR-6076 rs1463411 polymorphisms are associated with bleeding during clopidogrel treatment in patients with acute coronary syndrome

Bleeding is a major adverse event during clopidogrel treatment in patients with acute coronary syndrome (ACS). However, the potential mechanism affecting bleeding among individuals is unclear. Herein, we investigated the involvement of CYP2C19*2 and CYP2C19*3, as well as 10 miRNA polymorphisms, in bleeding in Chinese patients with ACS during the first year of clopidogrel treatment. The miR-6076 rs1463411 G polymorphism was significantly associated with the risk of bleeding (P < 0.001), and the rs1463411 GT + GG genotype significantly increased the risk of bleeding (adjusted odds ratio, 6.09; 95% confidence interval, 1.09-34.0; P < 0.001). Dual luciferase assay showed that miR-6076 significantly decreased the mRNA expression of P2RY12 (P < 0.05). P2RY12 mRNA and protein levels were significantly lower in cells transfected with miR-6076-G than in cells transfected with miR-6076-T (P < 0.05). The findings indicate that miR-6076 targets P2RY12 mRNA and that miR-6076 rs1463411 T/G polymorphisms differentially regulate P2RY12 mRNA and protein levels in cells. rs1463411 G polymorphism may increase the risk of bleeding during clopidogrel treatment in patients with ACS.

The Increased Ischemic Risk During the Early Period After Clopidogrel Noncompliance in Patients with Acute Coronary Syndrome: A Meta-Analysis

Although dual antiplatelet therapy for secondary prevention in acute coronary syndrome (ACS) is highly recommended by current guidelines, P2Y12 inhibitor non-adherence often occurs and devastates prognosis. To evaluate whether the ischemic risk during the early period of clopidogrel noncompliance was increased among ACS patients, a comprehensive search of PubMed, Embase, and Web of Science was conducted to identify studies reporting early ischemic risk after clopidogrel noncompliance in ACS patients. The primary endpoint was a composite of death or myocardial infarction (MI). Effect sizes were synthesized in patients with or without revascularization. A total of 7 observational studies focusing on clopidogrel noncompliance were included in this meta-analysis, whereas no studies involving ticagrelor or prasugrel were retrieved. A significantly increased risk of death or MI 0 to 90 days after clopidogrel noncompliance was found compared with that during 90 to 180 or 90 to 360 days regardless of revascularization (incidence rate ratio [IRR]: 2.01, 95% confidence interval (CI): 1.62-2.49, P < .001, I2 = 9%) or not (IRR: 1.61, 95% CI: 1.05-2.48, P < .001, I2 = 74%). Patients undergoing percutaneous coronary intervention had a higher risk of death or MI 0 to 90 days after clopidogrel noncompliance compared with 90-180 or 90-360 days irrespective of drug-eluting stent or bare metal stent implantation (P < .05 for both). The early ischemic risk after clopidogrel noncompliance is significantly higher than the late risk in ACS patients. Antiplatelet noncompliance remains a serious concern.

CYP2C19 genotype-guided antithrombotic treatment versus conventional clopidogrel therapy in peripheral arterial disease: study design of a randomized controlled trial (GENPAD)

BACKGROUND

Clopidogrel is recommended in international guidelines to prevent arterial thrombotic events in patients with peripheral arterial disease (PAD). Clopidogrel itself is inactive and metabolism is dependent on the CYP2C19 enzyme. About 30% of Caucasian PAD patients receiving clopidogrel carry 1 or 2 CYP2C19 loss-of-function allele(s) and do not or to a limited extent convert the prodrug into its active metabolite. As a result, platelet inhibition may be inadequate which could lead to an increased risk of adverse clinical events related to arterial thrombosis. A CYP2C19 genotype-guided antithrombotic treatment might be beneficial for PAD patients.

METHODS

GENPAD is a multicenter randomized controlled trial involving 2,276 PAD patients with an indication for clopidogrel monotherapy. Patients with a separate indication for dual antiplatelet therapy or stronger antithrombotic therapy are not eligible for study participation. Patients randomized to the control group will receive clopidogrel 75 mg once daily without pharmacogenetic guidance. Patients randomized to the intervention group will be tested for carriage of CYP2C19 *2 and *3 loss-of-function alleles, followed by a genotype-guided antithrombotic treatment with either clopidogrel 75 mg once daily for normal metabolizers, clopidogrel 150 mg once daily for intermediate metabolizers, or acetylsalicylic acid 80 mg once daily plus rivaroxaban 2.5 mg twice daily for poor metabolizers. The primary outcome is a composite of myocardial infarction, ischemic stroke, cardiovascular death, acute or chronic limb ischemia, peripheral vascular interventions, or death. The secondary outcomes are the individual elements of the primary composite outcome and clinically relevant bleeding complications.

CONCLUSION

The aim of the GENPAD study is to evaluate the efficacy, safety, and cost-effectiveness of a genotype-guided antithrombotic treatment strategy compared to conventional clopidogrel treatment in PAD patients.

Only Acute but Not Chronic Thrombocytopenia Protects Mice against Left Ventricular Dysfunction after Acute Myocardial Infarction

BACKGROUND

Platelets are major players of thrombosis and inflammation after acute myocardial infarction (AMI). The impact of thrombocytopenia on platelet-induced cellular processes post AMI is not well defined.

METHODS

The left anterior descending artery was ligated in C57/Bl6 mice and in two thrombocytopenic mouse models to induce AMI.

RESULTS

Platelets from STEMI patients and from C57/Bl6 mice displayed enhanced platelet activation after AMI. This allows platelets to migrate into the infarct but not into the remote zone of the left ventricle. Acute thrombocytopenia by antibody-induced platelet depletion resulted in reduced infarct size and improved cardiac function 24 h and 21 days post AMI. This was due to reduced platelet-mediated inflammation after 24 h and reduced scar formation after 21 days post AMI. The collagen composition and interstitial collagen content in the left ventricle were altered due to platelet interaction with cardiac fibroblasts. Acute inflammation was also significantly reduced in Mpl-/- mice with chronic thrombocytopenia, but cardiac remodeling was unaltered. Consequently, left ventricular function, infarct size and scar formation in Mpl-/- mice were comparable to controls.

CONCLUSION

This study discovers a novel role for platelets in cardiac remodeling and reveals that acute but not chronic thrombocytopenia protects left ventricular function post AMI.

Current and Future Insights for Optimizing Antithrombotic Therapy to Reduce the Burden of Cardiovascular Ischemic Events in Patients with Acute Coronary Syndrome

The pharmacological treatment strategies for acute coronary syndrome (ACS) in recent years are constantly evolving to develop more potent antithrombotic agents, as reflected by the introduction of more novel P2Y₁₂ receptor inhibitors and anticoagulants to reduce the ischemic risk among ACS patients. Despite the substantial improvements in the current antithrombotic regimen, a noticeable number of ACS patients continue to experience ischemic events. Providing effective ischemic risk reduction while balancing bleeding risk remains a clinical challenge. This updated review discusses the currently approved and widely used antithrombotic agents and explores newer antithrombotic treatment strategies under development for the initial phase of ACS.

Dual vs. mono antiplatelet therapy for acute ischemic stroke or transient ischemic attack with evidence of large artery atherosclerosis

Background and purpose

Current pieces of evidence support the short-term use of dual antiplatelet (DAPT) in minor ischemic stroke or transient ischemic attack (TIA) based on the studies performed in patients with a broad range of non-cardioembolic stroke mechanisms. However, the efficacy and safety of DAPT use in ischemic stroke patients with large artery atherosclerosis (LAA) are still uncertain. We undertook a systemic search and formal meta-analysis to compare DAPT vs. mono-antiplatelet therapy (MAPT) in patients with etiology specifically presumed to be symptomatic LAA.

Methods

We conducted a systemic online search for completed randomized controlled trials that (1) compared DAPT vs. MAPT in patients with acute ischemic stroke or TIA, and (2) were confined to or had available subgroup data regarding population with symptomatic extra- or intracranial artery stenosis. Study-level meta-analysis was performed for outcomes, including ischemic stroke (IS) recurrence, intracranial hemorrhage (ICH), and major bleeding with the Mantel-Haenszel method and random effect models, and was described as risk difference (RD) and 95% CI.

Results

A total of 10 trials including 5,004 patients were pooled. Comparing to MAPT, DAPT significantly reduced IS recurrence (5.99 vs. 9.55%, RD: −3%, 95% CI: −5–0%). Across all agents, out of 100 treated patients, 3 fewer had a recurrent ischemic stroke with DAPT. The safety endpoints including ICH (0.28 vs. 0.32%, RD: 0%, 95% CI: −0–0%) and major bleeding (0.73 vs. 0.51%, RD: 0%, 95% CI: −0–0%) did not differ significantly.

Conclusion

In patients with symptomatic large artery extracranial or intracranial atherosclerosis, DAPT was superior to MAPT in preventing IS recurrence without increasing bleeding risks. The optimal DAPT regimens and duration of treatment in this population need to be clarified in further studies.

Ideal P2Y12 Inhibitor in Acute Coronary Syndrome: A Review and Current Status

Dual antiplatelet therapy (DAPT) has remained the cornerstone for management of acute coronary syndrome (ACS) over the years. Clopidogrel has been the quintessential P2Y12 receptor (platelet receptor for Adenosine 5′ diphosphate) inhibitor for the past two decades. With the demonstration of unequivocal superior efficacy of prasugrel/ticagrelor over clopidogrel, guidelines now recommend these agents in priority over clopidogrel in current management of ACS. Cangrelor has revived the interest in injectable antiplatelet therapy too. Albeit the increased efficacy of these newer agents comes at the cost of increased bleeding and this becomes more of a concern when combined with aspirin. Which P2Y12i is superior over another has been intensely debated over last few years after the ISAR-REACT 5 study with inconclusive data. Three novel antiplatelet agents are already in the pipeline for ACS with all of them succeeding in phase II studies. The search for an ideal antiplatelet remains a need of the hour for optimal reduction of ischemic events in ACS.

Effect of CYP2C19 genetic variants on bleeding and major adverse cardiovascular events in a cohort of Arab patients undergoing percutaneous coronary intervention and stent implantation

INTRODUCTION

One-third of patients have clopidogrel resistance that may lead to major adverse cardiac events (MACEs). By contrast, it was found that some clopidogrel-treated patients have hyperresponsive platelets that are associated with higher bleeding risk. Several studies have shown that polymorphisms in the gene encoding the CYP2C19 contribute to the variability in response to clopidogrel. Data on genetic and nongenetic factors affecting clopidogrel response in the Arab population are scarce. In this prospective cohort study, we sought to assess the association between the increased function allele (CYP2C19*17) and bleeding events, and validate the effect of the CYP2C19 genetic variants and nongenetic factors on the incidence of MACEs.

METHODS

Blood samples were collected from patients that were undergoing percutaneous coronary intervention and receiving clopidogrel at the Heart Hospital, a specialist tertiary hospital in Doha, Qatar. Patients were followed for 12 months. Genotyping was performed for CYP2C19*2, *3, and *17 using TaqMan assays.

RESULTS

In 254 patients, the minor allele frequencies were 0.13, 0.004, and 0.21 for *2, *3, and *17, respectively. Over a 12-month follow-up period, there were 21 bleeding events (8.5 events/100 patient-year). CYP2C19*17 carriers were found to be associated with increased risk of bleeding (OR, 21.6; 95% CI, 4.8-96.8; P < 0.0001). CYP2C19*2 or *3 carriers were found to be associated with increased risk of baseline and incident MACE combined (OR, 8.4; 95% CI, 3.2-23.9; P < 0.0001).

CONCLUSION

This study showed a significant association between CYP2C19*17 allele and the increased risk of bleeding, and CYP2C19*2 or *3 with MACE outcomes.

Best Practices in Pharmacotherapy for Acute Coronary Syndromes

Numerous advances have been made in the therapy of acute coronary syndromes. Despite these advances, acute coronary syndromes still cause significant morbidity and mortality. Decisions as to the best therapy vary depending on other patient factors, such as age, need for chronic anticoagulation, tolerability of medications, and the degree of myocardial damage. Recent evidence suggests that a shorter duration of therapy may be beneficial in decreasing bleeding events without compromising benefits of preventing ischemic complications. For those who have an indication for chronic anticoagulation, less intensive therapy may also be beneficial, again without increasing ischemic complications. Data regarding agents that inhibit the renin–angiotensin–aldosterone system are available and these data are reviewed. Knowledge of the pharmacology, potency, and pharmacokinetics of drugs, as well as adverse drug events, may direct clinicians in choosing the optimal pharmacotherapy strategy for their patients.

Pathogenetic Link of Cardiac Rupture and Left Ventricular Thrombus Following Acute Myocardial Infarction: A Joint Preclinical and Clinical Study

Background

Cardiac rupture (CR) and left ventricular thrombus (LVT) remain important complications of acute myocardial infarction (MI), and they are currently regarded as independent events. We explored the pathogenetic link between CR and LVT by investigating a murine model of MI with a high frequency of CR and in patients with acute MI.

Methods

MI was induced in mice, the onset of CR was monitored, and the hearts of mice with or without fatal CR were histologically examined. Between 2015 and 2022, from patients admitted due to acute MI, the data of patients with CR or LVT were retrospectively collected and compared to uncomplicated patients (control).

Results

A total of 75% of mice (n = 65) with MI developed CR 2–4 days after MI. A histological examination of CR hearts revealed the existence of platelet-rich intramural thrombi in the rupture tunnel, which was connected at the endocardial site to platelet-fibrin thrombi within an LVT. In CR or non-CR mouse hearts, LV blood clots often contained a portion of platelet-fibrin thrombi that adhered to the infarct wall. In non-CR hearts, sites of incomplete CR or erosion of the infarct wall were typically coated with platelet thrombi and dense inflammatory cells. Of 8,936 patients with acute MI, CR and LVT occurred in 102 (1.14%) and 130 (1.45%) patients, respectively, with three cases having both complications. CR accounted for 32.8% of in-hospital deaths. The majority of CR (95%) or LVT (63%, early LVT) occurred within 7 days. In comparison to the control or LVT-late groups, patients with CR or early LVT reported increased levels of cellular and biochemical markers for inflammation or cardiac injury.

Conclusion

CR and LVT after MI are potentially linked in their pathogenesis. LVT occurring early after MI may be triggered by a thrombo-inflammatory response following wall rupture or endocardial erosion.

Antiplatelet Agents in Acute ST Elevation Myocardial Infarction

Platelet aggregation and thrombus formation represent the basic mechanism for clinical, electrocardiographic, and biomarker changes consistent with acute coronary syndrome. Various oral and intravenous formulations of platelet function inhibitors have been developed to help decrease platelet aggregation due to acute atherosclerotic plaque rupture. In this article, we review the various mechanisms, pharmacokinetics/pharmacodynamics, and the key clinical trials related to the platelet inhibitors that form the basis for current recommendations of their use in the ST elevation myocardial infarction guidelines by the American College of Cardiology/American Heart Association.

Comparison of P2Y12 Inhibitors in Acute Coronary Syndromes in the Australian Population

BACKGROUND

Clopidogrel in combination with aspirin after acute coronary syndromes (ACS) reduces recurrent ischaemic events compared to aspirin alone. Further reductions in events have been demonstrated when clopidogrel is replaced by ticagrelor or prasugrel albeit with increases in bleeding. There are few studies documenting the patterns of use of P2Y12 inhibitors or their association with outcomes in the Australian population.

AIMS

To describe the patterns of use of each P2Y12 inhibitor and to determine the associations between initial P2Y12 inhibitor use and outcomes.

METHODS

Data were extracted from Cooperative National Registry of ACS, Guideline Adherence and Clinical Events (CONCORDANCE)-a prospective database of patients presenting to 43 sites across Australia with ACS. Patients were stratified based on first antiplatelet agent received. Baseline clinical characteristics were compared between these patient groups and hospital investigations, management as well as in-hospital and 12 months outcomes (death, a composite of cardiac-related death, myocardial infarction, and stroke, and major bleeding) were compared between the three treatment cohorts after adjustment for differences in baseline characteristics.

RESULTS

Mean ages of the clopidogrel (n=7,537), ticagrelor (n=1,878), and prasugrel (n=347) cohorts were 65, 63, and 58 yrs respectively (p<0.0001), the mean Global Registry of Acute Coronary Events (GRACE) risk scores were 107, 104, and 102 (p=0.0016). The ticagrelor and prasugrel cohorts were more likely to receive percutaneous coronary intervention (PCI) (clopidogrel 52%, ticagrelor 66%, prasugrel 88%, p<0.0001), and evidence based medications (≥4 guideline indicated medications: clopidogrel 76%, ticagrelor 82%, prasugrel 93%, p<0.0001). Patients treated with ticagrelor and prasugrel were less likely to experience in-hospital death (clopidogrel 2.5%, ticagrelor 1.4%, prasugrel 1.2%, p=0.05), major adverse cardiac events (MACE) (clopidogrel 5.1%, ticagrelor 3.0%, prasugrel 3.5% [p=0.01]), or bleeding (clopidogrel 8.4%, ticagrelor 4.6%, prasugrel 7.5% [p<0.001]) compared to clopidogrel. These differences were no longer apparent after multivariable adjustment. There was no difference in outcomes between cohorts at 12 months.

CONCLUSIONS

In Australia, ticagrelor and prasugrel are used in younger patients who are more likely to undergo percutaneous coronary intervention (PCI) and receive evidence based therapy. Patients receiving clopidogrel were more likely to experience in hospital ischaemic or bleeding events but this was explained by their higher baseline risk. Selection of therapy was not associated with any difference in outcomes at 12-month follow-up, but our findings suggest there is room for improvement towards guideline-driven usage of P2Y12 inhibitors.

Phosphoinositide 3-Kinases as Potential Targets for Thrombosis Prevention

As integral parts of pathological arterial thrombi, platelets are the targets of pharmacological regimens designed to treat and prevent thrombosis. A detailed understanding of platelet biology and function is thus key to design treatments that prevent thrombotic cardiovascular disease without significant disruption of the haemostatic balance. Phosphoinositide 3-kinases (PI3Ks) are a group of lipid kinases critical to various aspects of platelet biology. There are eight PI3K isoforms, grouped into three classes. Our understanding of PI3K biology has recently progressed with the targeting of specific isoforms emerging as an attractive therapeutic strategy in various human diseases, including for thrombosis. This review will focus on the role of PI3K subtypes in platelet function and subsequent thrombus formation. Understanding the mechanisms by which platelet function is regulated by the various PI3Ks edges us closer toward targeting specific PI3K isoforms for anti-thrombotic therapy.

Antiplatelet Therapy in Patients Undergoing Elective Percutaneous Coronary Intervention

PURPOSE OF REVIEW

The evidence for use of dual antiplatelet therapy (DAPT) for patients undergoing percutaneous coronary intervention (PCI) in the elective setting is relatively sparse and is based on data from more than two decades ago. We will review the evidence supporting the use of DAPT with focus on stable patients undergoing elective PCI, including the role of potent P₂Y₁₂ inhibitors, modified DAPT durations, and more recently, aspirin discontinuation.

RECENT FINDINGS

Clopidogrel is the recommended P₂Y₁₂ inhibitor in the elective PCI setting. The benefit of more potent P₂Y₁₂ inhibitors such as ticagrelor or prasugrel in stable patients is unproven, but their use might be reasonable in those with high clinical or angiographic features of increased ischemic risk without increased risk of bleeding. Moreover, extending DAPT beyond 12 months is associated with a reduction in ischemic events but also increased bleeding. In contrast, shortening DAPT (3-6 months) reduces bleeding compared with 1 year of treatment, but it is also probably associated with increased ischemic events, mainly in higher-risk patients undergoing complex PCI. Recently, early aspirin discontinuation at 3 months (and perhaps as early as 1 month) following PCI reduces bleeding, with no evidence to suggest an increase in ischemic events. Clopidogrel is the P₂Y₁₂ inhibitor of choice, while more data are required to support the use of more potent P₂Y₁₂ inhibitors in stable patients. The duration of DAPT should be tailored to individual patient ischemic and bleeding risks. New strategies, such as early aspirin discontinuation, are promising to reduce bleeding risk without increase in ischemic risk.

Towards personalized antithrombotic management with drugs and devices across the cardiovascular spectrum

Intravascular thrombus formation and embolization are among the most frequent events leading to a number of cardiovascular conditions with high morbidity and mortality. The underlying causes are stasis of the circulating blood, genetic and acquired coagulation disorders, and reduced antithrombotic or prothrombotic properties of the vascular wall (Virchow's triad). In the venous system, intravascular thrombi can cause venous thrombosis and pulmonary and even peripheral embolism including ischaemic stroke [through a patent foramen ovale (PFO)]. Thrombi in the left atrium and its appendage or ventricle form in the context of atrial fibrillation and infarction, respectively. Furthermore, thrombi can form on native or prosthetic aortic valves, within the aorta (in particular at sites of ulcers, aortic dissection, and abdominal aneurysms), and in cerebral and peripheral arteries causing stroke and critical limb ischaemia, respectively. Finally, thrombotic occlusion may occur in arteries supplying vital organs such the heart, brain, kidney, and extremities. Thrombus formation and embolization can be managed with anticoagulants and devices depending on where they form and embolize and on patient characteristics. Vitamin K antagonists are preferred in patients with mechanical valves, while novel oral anticoagulants are first choice in most other cardiovascular conditions, in particular venous thromboembolism and atrial fibrillation. As anticoagulants are associated with a risk of bleeding, devices such as occluders of a PFO or the left atrial appendage are preferred in patients with an increased bleeding risk. Platelet inhibitors such as aspirin and/or P2Y12 antagonists are preferred in the secondary prevention of coronary artery disease, stroke, and peripheral artery disease either alone or in combination depending on the clinical condition. A differential and personalized use of anticoagulants, platelet inhibitors, and devices is recommended and reviewed in this article.

Antiplatelet therapy in cardiovascular disease: current status and future directions

Antiplatelet medications remain a cornerstone of therapy for atherosclerotic cardiovascular and cerebrovascular diseases. In primary prevention (patients with cardiovascular risk factors but no documented events, symptoms or angiographic disease), there is little evidence of benefit of any antiplatelet therapy, and such therapy carries the risk of excess bleeding. Where there is documented disease (secondary prevention), stable patients benefit from long-term antiplatelet monotherapy, aspirin being first choice in those with coronary heart disease and clopidogrel in those with cerebrovascular disease; moreover, recent evidence shows that low-dose rivaroxaban in combination with aspirin confers added benefit, in patients with stable cardiovascular and peripheral arterial disease. In patients with acute cerebrovascular disease, aspirin combined with clopidogrel reduces subsequent risk, while in acute coronary syndrome, dual antiplatelet therapy comprising aspirin and a P2Y₁₂ inhibitor (clopidogrel, prasugrel or ticagrelor) confers greater protection than aspirin monotherapy, with prasugrel and ticagrelor offering greater antiplatelet efficacy with faster onset of action than clopidogrel. Although greater antiplatelet efficacy is advantageous in preventing thrombotic events, this must be tempered by increased risk of bleeding which may be a particular issue in certain patient groups, as will be discussed. We will also discuss possible future approaches to personalisation of antiplatelet therapy.

Use of Optical Coherence Tomography in MI with Non-obstructive Coronary Arteries

MI with non-obstructive coronary arteries (MINOCA) comprises an important minority of cases of acute MI. Many different causes have been implicated in the pathogenetic mechanism of MINOCA. Optical coherence tomography (OCT) is an indispensable tool for recognising the underlying pathogenetic mechanism when epicardial pathology is suspected. OCT can reliably identify coronary lesions not apparent on conventional coronary angiography and discriminate the various phenotypes. Plaque rupture and plaque erosion are the most frequently found atherosclerotic causes of MINOCA. Furthermore, OCT can contribute to the identification of ischaemic non-atherosclerotic causes of MINOCA, such as spontaneous coronary artery dissection, coronary spasm and lone thrombus. Recognition of the exact cause will enable therapeutic management to be tailored accordingly. The combination of OCT with cardiac magnetic resonance can set a definite diagnosis in the vast majority of MINOCA patients.

Pharmacological Approaches to Limit Ischemic and Reperfusion Injuries of the Heart. Analysis of Experimental and Clinical Data on P2Y12 Receptor Antagonists

High mortality among people with acute myocardial infarction is one of the most urgent problems of modern cardiology. And in recent years, much attention has been paid to the search for pharmacological approaches to prevent heart damage. In this review, we tried to analyze data on the effect of P2Y₁₂ receptor antagonists on the ischemia/reperfusion tolerance of the heart.

Ischemic and reperfusion injuries of the heart underlie the pathogenesis of acute myocardial infarction (AMI) and sudden cardiac death. The mortality rate is still high and is 5–7% in patients with ST-segment elevation myocardial infarction. The review is devoted to pharmacological approaches to limitation of ischemic and reperfusion injuries of the heart. The article analyzes experimental evidence and the clinical data on the effects of P2Y₁₂ receptor antagonists on the heart’s tolerance to ischemia/reperfusion in animals with coronary artery occlusion and reperfusion and also in patients with AMI. Chronic administration of ticagrelor prevented adverse remodeling of the heart. There is evidence that sphingosine-1-phosphate is the molecule that mediates the infarct-reducing effect of P2Y₁₂ receptor antagonists. It was discussed a role of adenosine in the cardioprotective effect of ticagrelor.

Dual antiplatelet therapy before coronary artery bypass grafting in patients with myocardial infarction: a prospective cohort study

BACKGROUND

Dual antiplatelet therapy (DAPT) in patients with MI who are candidates for early coronary artery bypass grafting (CABG) can affect intraoperative and postoperative outcomes. Therefore, the aim of this study was to evaluate the effect of DAPT up to the day before CABG on the outcomes during and after surgery in patients with MI.

METHODS

In this prospective cohort study, 224 CABG candidate patients with and without MI were divided into two groups: (A) patients without MI who were treated with aspirin 80 mg/day before surgery (noMI-aspirin group; n = 124) and (B) patients with MI who were treated with aspirin 80 mg/day before surgery and clopidogrel (Plavix brand) at a dose of 75 mg/day (MI-DAPT group; n = 120). Dual or mono-antiplatelet therapy continued until the day before surgery. Patients were followed to assess in-hospital and 6-months outcomes.

RESULTS

The in-hospital mortality in MI-DAPT group was similar with noMI-aspirin group (OR 4.2; 95% CI 0.9-20.5; p = 0.071). The prevalence of CVA (p = 0.098), duration of hospital stay (p = 0.109), postoperative ejection fraction level (p = 0.693), diastolic dysfunction grade (p = 0.651) and postoperative PAP level (p = 0.0364) did not show difference between two groups. No mild or severe bleeding was observed in the patients. Six-month follow up showed that number of readmissions (p = 0.801), number of cases requiring angiography (p = 0.100), cases requiring re-PCI (p = 0.156), need for re-CABG (p > 0.999) and CVA (p > 0.999) did not differ between the two groups. During the 6-month follow-up, out-hospital mortality did not differ significantly between the two groups (p = 0.446).

CONCLUSIONS

A 6-month follow-up showed that DAPT with aspirin and clopidogrel before CABG in patients with MI has no effect on postoperative outcomes more than mono-APT with aspirin. Therefore, DAPT is recommended in the preoperative period for these patients.

Effectiveness and Safety of P2Y12 Inhibitors Pretreatment in Primary Percutaneous Coronary Intervention with Long Transfer Times

BACKGROUND

Early initiation of a new P2Y12 inhibitor in ST-elevation myocardial infarction (STEMI) patients prior to primary percutaneous coronary intervention (PCI) is recommended over clopidogrel. However, comparative data remain limited, especially in semi-rural regions with subsequent longer transfer times.

OBJECTIVES

We aimed to assess the determinants, effectiveness, and safety of pretreatment with new P2Y12 inhibitors compared with clopidogrel in a primary PCI regional network.

METHODS

Outcomes of 1235 primary PCI patients pretreated with new P2Y12 inhibitors (n = 1050) or clopidogrel (n = 185) were evaluated using a prospective registry. Primary effectiveness endpoint was the composite of death, recurrent myocardial infarction, stroke, or new revascularization. Serious bleedings were defined as Bleeding Academic Research Consortium ≥ 2.

RESULTS

Clopidogrel was more likely to be used in older and female patients with more comorbidities. Mean transfer time was longer in the clopidogrel group (123.3 ± 67.3 vs. 102.3 ± 57.2 min; p < 0.01). The primary endpoint was less frequent with new P2Y12 inhibitors compared with clopidogrel (14.9 vs. 30.3%; odds ratio 0.58, 95% confidence interval [CI] 0.39-0.87; p < 0.01), mostly driven by a reduced rate of death (4.5 vs. 26% respectively; hazard ratio 0.25, 95% CI 0.16-0.38; p < 0.01). Bleeding rates did not differ between groups (1 vs. 0.5%, respectively; p = 0.96).

CONCLUSION

Compared with clopidogrel, pretreatment with new P2Y12 inhibitors seems to be associated with lower risks of mortality and ischemic outcomes, and similar risks of bleeding in a real-world registry. Our results are in line with the guidelines recommending the preferential pre-PCI administration of new P2Y12 inhibitors in STEMI patients referred for primary PCI.

Early- and Middle-Phase Angioscopic Assessment of Arterial Healing Following Current Drug-Eluting Stent Implantation in Patients With Acute Coronary Syndrome

Background: Drug-eluting stents (DESs) have been widely used for the treatment of acute coronary syndrome (ACS). However, there are few reports on early- and middle-phase arterial repair after DES implantation in ACS patients. Methods and Results: Coronary angioscopy (CAS) findings covering the early and middle phases (mean [±SD] 4±1 and 10±2 months, respectively) of arterial healing after second- and later-generation DES placement between May 2009 and January 2020 were extracted from the Kansai Rosai Hospital Cardiovascular Center database. Neointimal coverage (NIC), yellow color intensity, and the incidence of thrombus adhesion were compared between ACS and chronic coronary syndrome (CCS) in the early (54 stents of 47 lesions, 38 ACS patients; 86 stents of 70 lesions, 52 CCS patients) and middle (179 stents of 154 lesions from 136 ACS patients; 459 stents of 374 lesions from 287 CCS patients) phases. In the early phase, NIC, the incidence of thrombus adhesion (ACS, 39.1%; CCS, 38.0%), and maximum yellow color grade were similar between the 2 groups. In the middle phase, although the maximum yellow color grade was significantly higher in the ACS group (P=0.013), NIC and the incidence of thrombus adhesion (ACS, 24.6%; CCS, 23.4%) were similar in the 2 groups. Conclusions: Arterial healing assessment with CAS showed that NIC and the incidence of thrombus adhesion after DES implantation were similar between ACS and CCS patients.