Rivaroxaban with or without Aspirin in Stable Cardiovascular Disease

Antithrombotic treatment in peripheral artery disease

Abstract. This review treats antithrombotic use for peripheral arterial disease (PAD). In asymptomatic patients, there are no scientific data to support single antiplatelet therapy (SAPT) for primary prophylaxis. In symptomatic PAD, SAPT with aspirin or clopidogrel is indicated. The efficacy of aspirin is controversial. Clopidogrel may be preferred over aspirin. Ticagrelor is not superior to clopidogrel in reducing major adverse cardiovascular events and major adverse limb events, but lowers the risk of ischaemic stroke. In symptomatic PAD, dual antiplatelet therapy (DAPT) with clopidogrel and aspirin does not provide benefit over SAPT with aspirin alone and is associated with increased risk of major bleeding. DAPT with ticagrelor 60 mg b. i. d. and aspirin provides a significant major adverse cardiovascular events reduction in symptomatic PAD patients and may be considered in PAD patients with prior myocardial infarction. The use of a new thrombin receptor antagonist, vorapaxar, on top of SAPT or DAPT with aspirin and/or clopidogrel, reduces the risk of acute limb ischaemia and peripheral artery revascularization in patients with symptomatic PAD, at the cost of an increased risk for bleeding. Rivaroxaban (2.5 mg b. i. d.) plus aspirin (100 mg daily) is the first antithrombotic association that proved significant benefit for PAD patients, in terms of strong endpoints – total mortality and cardiovascular mortality. Therefore, this association shows the strongest evidence for secondary prevention of symptomatic PAD patients. In PAD patients undergoing percutaneous peripheral interventions, at least four weeks of DAPT with aspirin and clopidogrel is recommended after infrainguinal stent implantation. Stenting below-the-knee arteries is often followed by a longer period of DAPT, but no specific evidence is available. Anticoagulation is mandatory to prevent arterial occlusion during radial or brachial invasive procedures. The strategy includes use of unfractioned heparin, bivalirudin or enoxaparin. Vitamin K antagonists may be considered after autologous vein infrainguinal bypass.

Effects of gastroprotectant drugs for the prevention and treatment of peptic ulcer disease and its complications: a meta-analysis of randomised trials

Background

Gastroprotectant drugs are used for the prevention and treatment of peptic ulcer disease and might reduce its associated complications, but reliable estimates of the effects of gastroprotectants in different clinical settings are scarce. We aimed to examine the effects of proton-pump inhibitors (PPIs), prostaglandin analogues, and histamine-2 receptor antagonists (H2RAs) in different clinical circumstances by doing meta-analyses of tabular data from all relevant unconfounded randomised trials of gastroprotectant drugs.

Methods

We searched MEDLINE and Embase from Jan 1, 1950, to Dec 31, 2015, to identify unconfounded, randomised trials of a gastroprotectant drug (defined as a PPI, prostaglandin analogue, or H2RA) versus control, or versus another gastroprotectant. Two independent researchers reviewed the search results and extracted the prespecified outcomes and key characteristics for each trial. We did meta-analyses of the effects of gastroprotectant drugs on ulcer development, bleeding, and mortality overall, according to the class of gastroprotectant, and according to the individual drug within a gastroprotectant class.

Findings

We identified comparisons of gastroprotectant versus control in 849 trials (142 485 participants): 580 prevention trials (110 626 participants), 233 healing trials (24 033 participants), and 36 trials for the treatment of acute upper gastrointestinal bleeding (7826 participants). Comparisons of one gastroprotectant drug versus another were available in 345 trials (64 905 participants), comprising 160 prevention trials (32 959 participants), 167 healing trials (28 306 participants), and 18 trials for treatment of acute upper gastrointestinal bleeding (3640 participants). The median number of patients in each trial was 78 (IQR 44·0–210·5) and the median duration was 1·4 months (0·9–2·8). In prevention trials, gastroprotectant drugs reduced development of endoscopic ulcers (odds ratio [OR] 0·27, 95% CI 0·25–0·29; p<0·0001), symptomatic ulcers (0·25, 0·22–0·29; p<0·0001), and upper gastrointestinal bleeding (0·40, 0·32–0·50; p<0·0001), but did not significantly reduce mortality (0·85, 0·69–1·04; p=0·11). Larger proportional reductions in upper gastrointestinal bleeding were observed for PPIs than for other gastroprotectant drugs (PPIs 0·21, 99% CI 0·12–0·36; prostaglandin analogues 0·63, 0·35–1·12; H2RAs 0·49, 0·30–0·80; p_het=0·0005). Gastroprotectant drugs were effective in preventing bleeding irrespective of the use of non-steroidal anti-inflammatory drugs (p_het=0·56). In healing trials, gastroprotectants increased endoscopic ulcer healing (3·49, 95% CI 3·28–3·72; p<0·0001), with PPIs more effective (5·22, 99% CI 4·00–6·80) than prostaglandin analogues (2·27, 1·91–2·70) and H2RAs (3·80, 3·44–4·20; p_het<0·0001). In trials among patients with acute bleeding, gastroprotectants reduced further bleeding (OR 0·68, 95% CI 0·60–0·78; p<0·0001), blood transfusion (0·75, 0·65–0·88; p=0·0003), further endoscopic intervention (0·56, 0·45–0·70; p<0·0001), and surgery (0·72, 0·61–0·84; p<0·0001), but did not significantly reduce mortality (OR 0·90, 0·72–1·11; p=0·31). PPIs had larger protective effects than did H2RAs for further bleeding (p_het=0·0107) and blood transfusion (p_het=0·0130).

Interpretation

Gastroprotectants, in particular PPIs, reduce the risk of peptic ulcer disease and its complications and promote healing of peptic ulcers in a wide range of clinical circumstances. However, this meta-analysis might have overestimated the benefits owing to small study bias.

Funding

UK Medical Research Council and the British Heart Foundation.

Network analysis of coronary artery disease risk genes elucidates disease mechanisms and druggable targets

Genome-wide association studies (GWAS) have identified over two hundred chromosomal loci that modulate risk of coronary artery disease (CAD). The genes affected by variants at these loci are largely unknown and an untapped resource to improve our understanding of CAD pathophysiology and identify potential therapeutic targets. Here, we prioritized 68 genes as the most likely causal genes at genome-wide significant loci identified by GWAS of CAD and examined their regulatory roles in 286 metabolic and vascular tissue gene-protein sub-networks (“modules”). The modules and genes within were scored for CAD druggability potential. The scoring enriched for targets of cardiometabolic drugs currently in clinical use and in-depth analysis of the top-scoring modules validated established and revealed novel target tissues, biological processes, and druggable targets. This study provides an unprecedented resource of tissue-defined gene–protein interactions directly affected by genetic variance in CAD risk loci.

Novel Direct Anticoagulants and Atherosclerosis

Coagulation factors can affect cellular processes that include inflammatory signaling by acting on endothelial protease activated receptors, vascular smooth muscle and inflammatory cells beyond the coagulation cascade. This is important in the pathogenesis of atherosclerosis. Accordingly, experimental data points to beneficial effects of coagulation protease inhibitors on the attenuation of atherosclerosis progression in animal models. However, available clinical data do not support the use of anticoagulants as an add-on treatment of atherosclerosis. New clinical studies are needed with a better selection of patients to clarify the role of novel direct anticoagulants in the management of atherosclerosis.

Fibrin Clot Strength in Patients with Diabetes Mellitus Measured by Thrombelastography

BACKGROUND

Patients with diabetes mellitus (DM) exhibit increased risk of recurrent myocardial infarction. Maximal clot strength measured by thrombelastography (TEG) is a risk factor for recurrent ischemic events. We hypothesized that diabetic subjects exhibit increased fibrin clot strength in platelet-poor plasma and that glycemic control correlates with maximal fibrin clot strength.

METHODS

We collected plasma samples from subjects with known or suspected coronary artery disease undergoing cardiac catheterization (n = 354). We measured kaolin-activated TEG in platelet-poor citrate plasma. Time to fibrin formation (R), clot formation time (K), and maximal fibrin clot strength (MA) were recorded.

RESULTS

Plasma fibrin MA was increased among subjects with DM (n = 152) as compared to non-DM (n = 202) (37.0 ± 8 versus 34.1 ± 8 mm; p < 0.001). Hemoglobin A1c (HbA1c) (ρ = 0.22; p = 0.001) and fibrinogen (ρ = 0.29; p < 0.001) correlated with fibrin MA. In multivariable regression analysis, DM remained significantly associated with plasma MA after adjustment for fibrinogen level (p = 0.003).

CONCLUSIONS

Subjects with diabetes mellitus exhibit increased maximal fibrin clot strength measured by TEG in platelet-poor plasma.

Biomarkers in stable coronary artery disease

Coronary artery disease (CAD) remains a significant cause of morbidity and mortality around the world. Patients with stable CAD can have an unpredictable clinical trajectory; thus, additional tools to prognosticate risk in this cohort are warranted. In recent years, a wide range of biomarkers has been recognized for their diagnostic capabilities in patients with stable CAD, identifying those with obstructive disease who may require more intensive preventive therapies or even consideration of percutaneous coronary intervention in some circumstances. In addition, a multiple-biomarker approach may identify stable CAD patients at highest risk for future major adverse cardiac events. Thus, randomized controlled trials to assess biomarker-guided preventive therapy in this cohort appear warranted.

2017 Scientific Sessions Sol Sherry Distinguished Lecture in Thrombosis: Factor XI as a Target for New Anticoagulants

The goal of anticoagulant therapy is to attenuate thrombosis without compromising hemostasis. Although the direct oral anticoagulants are associated with less intracranial hemorrhage than vitamin K antagonists, bleeding remains their major side effect. Factor XI has emerged as a promising target for anticoagulants that may be safer than those currently available. The focus on factor XI stems from epidemiological evidence of its role in thrombosis, the observation of attenuated thrombosis in factor XI-deficient mice, identification of novel activators, and the fact that factor XI deficiency is associated with only a mild bleeding diathesis. Proof-of-concept comes from the demonstration that compared with enoxaparin, factor XI knockdown reduces venous thromboembolism without increasing bleeding after elective knee arthroplasty. This article rationalizes the selection of factor XI as a target for new anticoagulants, reviews the agents under development, and outlines a potential path forward for their development.

Meta-Analysis of the Safety and Efficacy of the Oral Anticoagulant Agents (Apixaban, Rivaroxaban, Dabigatran) in Patients With Acute Coronary Syndrome

The significance of adding new oral anticoagulants (NOACs) to antiplatelet therapy in patients with acute coronary syndrome (ACS) is unclear. We conducted a meta-analysis to assess the safety and efficacy of adding NOACs (apixaban, rivaroxaban, and dabigatran) to single antiplatelet agent (SAP) or dual antiplatelet therapy (DAPT) in patients with ACS. Seven randomized controlled trials were selected using PubMed or MEDLINE, Scopus, and Cochrane library (inception to August 2017). The summary measure was random effects hazard ratio (HR) with 95% confidence interval (CI). The primary safety outcome was clinically significant bleeding. The secondary efficacy outcome was major adverse cardiovascular events (MACE; composite of myocardial infarction, stroke, and all-cause mortality). In 31,574 patients, addition of NOAC to SAP did not increase the risk of clinically significant bleeding (HR 0.82, 95% CI 0.56 to 1.20, p = 0.31); however, the risk of clinically significant bleeding was significantly increased with NOAC plus DAPT (HR 2.24, 95% CI 1.75 to 2.87, p < 0.001). NOACs had no statistically beneficial effect on MACE when used with SAP (HR 0.82, 95% CI 0.66 to 1.04, p = 0.10); however, a modest reduction in MACE was observed when NOACs were combined with DAPT (HR 0.86, 95% CI 0.78 to 0.93, p < 0.001). In conclusion, in patients with ACS, the addition of NOAC to DAPT resulted in increased risk of clinically significant bleeding, whereas only a modest reduction in MACE was achieved. The addition of NOACs to SAP did not result in significant reduction of MACE or increase in clinically significant bleeding.

Anticoagulant and antiplatelet therapy choices for patients with atrial fibrillation one year after coronary stenting or acute coronary syndrome

INTRODUCTION

Guidelines recommend a combined anticoagulant and antiplatelet approach for patients with atrial fibrillation (AF) after coronary stenting (CS) or acute coronary syndrome (ACS). Finding the optimal balance of reducing ischemic risk and minimizing bleeding risk is challenging. Recent trials have evaluated a variety of regimens for up to one year for AF patients after CS/ACS. Little empiric evidence exists about the best antithrombotic strategy beyond one year.

AREAS COVERED

In this review two key areas are covered. First, a summary of the overall risk and benefits of anticoagulant and antiplatelet therapy in patients with AF and CS or ACS is provided. Second, despite limited empiric evidence to guide therapeutic decisions for combined anticoagulant and antiplatelet therapy in patients with AF one year after CS/ACS we provide guidance for shared patient-physician decision making.

EXPERT OPINION

The evidence is limited. For all patients with AF and stable CAD (≥1 year after CS or ACS) the risk for thromboembolism, cardiovascular events and bleeding should be assessed individually. For patients with low bleeding risk and high risk for cardiovascular events, antiplatelet therapy might be added to anticoagulant therapy.

Recent Approaches to Improve Medication Adherence in Patients with Coronary Heart Disease: Progress Towards a Learning Healthcare System

PURPOSE OF REVIEW

Non-adherence to medications for the secondary prevention of myocardial infarction (MI) is a major contributor to morbidity and mortality in these patients. This review describes recent advances in promoting adherence to therapies for coronary artery disease (CAD).

RECENT FINDINGS

Two large randomized controlled trials to "incentivize" adherence were somewhat disappointing; neither financial incentives nor "peer pressure" successfully increased rates of adherence in the post-MI population. Patient education and provider engagement appear to be critical aspects of improving adherence to CAD therapies, where the provider is a physician, pharmacist, or nurse and follow-up is performed in person or by telephone. Fixed-dose combinations of CAD medications, formulated as a so-called "polypill," have shown some early efficacy in increasing adherence. Technological advances that automate monitoring and/or encouragement of adherence are promising but seem universally dependent on patient engagement. For example, medication reminders via text message perform better if patients are required to respond. Multifaceted interventions, in which these and other interventions are combined together, appear to be most effective. There are several available types of proven interventions through which providers, and the health system at large, can advance patient adherence to CAD therapies. No single intervention to promote adherence will be successful in all patients. Further study of multifaceted interventions and the interactions between different interventions will be important to advancing the field. The goal is a learning healthcare system in which a network of interventions responds and adapts to patients' needs over time.

P2Y12 receptor inhibitors: an evolution in drug design to prevent arterial thrombosis

INTRODUCTION

P2Y12 inhibitors are a critical component of dual antiplatelet therapy (DAPT), which is the superior strategy to prevent arterialthrombosis in patients with acute coronary syndromes (ACS) and undergoing stent implantation.. Areas covered: Basic science articles, clinical studies, and reviews from 1992-2017 were searched using Pubmed library to collet impactful literature. After an introduction to the purinergic receptor biology, this review summarizes current knowledge on P2Y12 receptor inhibitors. Furthermore, we describe the subsequent improvements of next-generation P2Y12 receptor inhibitors facing the ambivalent problem of bleeding events versus prevention of arterial thrombosis in a variety of clinical settings. Therefore, we summarize data from relevant preclinical and clinical trials of currently approved P2Y12 receptor inhibitors (clopidogrel, prasugrel, ticagrelor, cangrelor) and provide strategies of drug switching and management of bleeding events. Expert opinion: An enormous amount of pharmacologic and clinical data is available for the application of P2Y12 receptor inhibitors. Today prasugrel, ticagrelor and clopidogrel are the standard of care drugs during dual antiplatelet therapy for ACS patients, but have considerable rates of bleeding. Recent and future clinical trials will provide evidence for subsequent escalation and de-escalation strategies of P2Y12 receptor inhibition. These data may pave the way for an evidence-based, individualized P2Y12 receptor inhibitor therapy.

Rivaroxaban with or without aspirin in patients with stable peripheral or carotid artery disease: an international, randomised, double-blind, placebo-controlled trial

BACKGROUND

Patients with peripheral artery disease have an increased risk of cardiovascular morbidity and mortality. Antiplatelet agents are widely used to reduce these complications.

METHODS

This was a multicentre, double-blind, randomised placebo-controlled trial for which patients were recruited at 602 hospitals, clinics, or community practices from 33 countries across six continents. Eligible patients had a history of peripheral artery disease of the lower extremities (previous peripheral bypass surgery or angioplasty, limb or foot amputation, intermittent claudication with objective evidence of peripheral artery disease), of the carotid arteries (previous carotid artery revascularisation or asymptomatic carotid artery stenosis of at least 50%), or coronary artery disease with an ankle-brachial index of less than 0·90. After a 30-day run-in period, patients were randomly assigned (1:1:1) to receive oral rivaroxaban (2·5 mg twice a day) plus aspirin (100 mg once a day), rivaroxaban twice a day (5 mg with aspirin placebo once a day), or to aspirin once a day (100 mg and rivaroxaban placebo twice a day). Randomisation was computer generated. Each treatment group was double dummy, and the patient, investigators, and central study staff were masked to treatment allocation. The primary outcome was cardiovascular death, myocardial infarction or stroke; the primary peripheral artery disease outcome was major adverse limb events including major amputation. This trial is registered with ClinicalTrials.gov, number NCT01776424, and is closed to new participants.

FINDINGS

Between March 12, 2013, and May 10, 2016, we enrolled 7470 patients with peripheral artery disease from 558 centres. The combination of rivaroxaban plus aspirin compared with aspirin alone reduced the composite endpoint of cardiovascular death, myocardial infarction, or stroke (126 [5%] of 2492 vs 174 [7%] of 2504; hazard ratio [HR] 0·72, 95% CI 0·57-0·90, p=0·0047), and major adverse limb events including major amputation (32 [1%] vs 60 [2%]; HR 0·54 95% CI 0·35-0·82, p=0·0037). Rivaroxaban 5 mg twice a day compared with aspirin alone did not significantly reduce the composite endpoint (149 [6%] of 2474 vs 174 [7%] of 2504; HR 0·86, 95% CI 0·69-1·08, p=0·19), but reduced major adverse limb events including major amputation (40 [2%] vs 60 [2%]; HR 0·67, 95% CI 0·45-1·00, p=0·05). The median duration of treatment was 21 months. The use of the rivaroxaban plus aspirin combination increased major bleeding compared with the aspirin alone group (77 [3%] of 2492 vs 48 [2%] of 2504; HR 1·61, 95% CI 1·12-2·31, p=0·0089), which was mainly gastrointestinal. Similarly, major bleeding occurred in 79 (3%) of 2474 patients with rivaroxaban 5 mg, and in 48 (2%) of 2504 in the aspirin alone group (HR 1·68, 95% CI 1·17-2·40; p=0·0043).

INTERPRETATION

Low-dose rivaroxaban taken twice a day plus aspirin once a day reduced major adverse cardiovascular and limb events when compared with aspirin alone. Although major bleeding was increased, fatal or critical organ bleeding was not. This combination therapy represents an important advance in the management of patients with peripheral artery disease. Rivaroxaban alone did not significantly reduce major adverse cardiovascular events compared with asprin alone, but reduced major adverse limb events and increased major bleeding.

FUNDING

Bayer AG.

Rivaroxaban with or without aspirin in patients with stable coronary artery disease: an international, randomised, double-blind, placebo-controlled trial

BACKGROUND

Coronary artery disease is a major cause of morbidity and mortality worldwide, and is a consequence of acute thrombotic events involving activation of platelets and coagulation proteins. Factor Xa inhibitors and aspirin each reduce thrombotic events but have not yet been tested in combination or against each other in patients with stable coronary artery disease.

METHODS

In this multicentre, double-blind, randomised, placebo-controlled, outpatient trial, patients with stable coronary artery disease or peripheral artery disease were recruited at 602 hospitals, clinics, or community centres in 33 countries. This paper reports on patients with coronary artery disease. Eligible patients with coronary artery disease had to have had a myocardial infarction in the past 20 years, multi-vessel coronary artery disease, history of stable or unstable angina, previous multi-vessel percutaneous coronary intervention, or previous multi-vessel coronary artery bypass graft surgery. After a 30-day run in period, patients were randomly assigned (1:1:1) to receive rivaroxaban (2·5 mg orally twice a day) plus aspirin (100 mg once a day), rivaroxaban alone (5 mg orally twice a day), or aspirin alone (100 mg orally once a day). Randomisation was computer generated. Each treatment group was double dummy, and the patients, investigators, and central study staff were masked to treatment allocation. The primary outcome of the COMPASS trial was the occurrence of myocardial infarction, stroke, or cardiovascular death. This trial is registered with ClinicalTrials.gov, number NCT01776424, and is closed to new participants.

FINDINGS

Between March 12, 2013, and May 10, 2016, 27 395 patients were enrolled to the COMPASS trial, of whom 24 824 patients had stable coronary artery disease from 558 centres. The combination of rivaroxaban plus aspirin reduced the primary outcome more than aspirin alone (347 [4%] of 8313 vs 460 [6%] of 8261; hazard ratio [HR] 0·74, 95% CI 0·65-0·86, p<0·0001). By comparison, treatment with rivaroxaban alone did not significantly improve the primary outcome when compared with treatment with aspirin alone (411 [5%] of 8250 vs 460 [6%] of 8261; HR 0·89, 95% CI 0·78-1·02, p=0·094). Combined rivaroxaban plus aspirin treatment resulted in more major bleeds than treatment with aspirin alone (263 [3%] of 8313 vs 158 [2%] of 8261; HR 1·66, 95% CI 1·37-2·03, p<0·0001), and similarly, more bleeds were seen in the rivaroxaban alone group than in the aspirin alone group (236 [3%] of 8250 vs 158 [2%] of 8261; HR 1·51, 95% CI 1·23-1·84, p<0·0001). The most common site of major bleeding was gastrointestinal, occurring in 130 [2%] patients who received combined rivaroxaban plus aspirin, in 84 [1%] patients who received rivaroxaban alone, and in 61 [1%] patients who received aspirin alone. Rivaroxaban plus aspirin reduced mortality when compared with aspirin alone (262 [3%] of 8313 vs 339 [4%] of 8261; HR 0·77, 95% CI 0·65-0·90, p=0·0012).

INTERPRETATION

In patients with stable coronary artery disease, addition of rivaroxaban to aspirin lowered major vascular events, but increased major bleeding. There was no significant increase in intracranial bleeding or other critical organ bleeding. There was also a significant net benefit in favour of rivaroxaban plus aspirin and deaths were reduced by 23%. Thus, addition of rivaroxaban to aspirin has the potential to substantially reduce morbidity and mortality from coronary artery disease worldwide.

FUNDING

Bayer AG.

Thrombosis and Vascular Inflammation in Diabetes: Mechanisms and Potential Therapeutic Targets

Cardiovascular disease remains the main cause of morbidity and mortality in patients with diabetes. The risk of vascular ischemia is increased in this population and outcome following an event is inferior compared to individuals with normal glucose metabolism. The reasons for the adverse vascular profile in diabetes are related to a combination of more extensive atherosclerotic disease coupled with an enhanced thrombotic environment. Long-term measures to halt the accelerated atherosclerotic process in diabetes have only partially addressed vascular pathology, while long-term antithrombotic management remains largely similar to individuals without diabetes. We address in this review the pathophysiological mechanisms responsible for atherosclerosis with special emphasis on diabetes-related pathways. We also cover the enhanced thrombotic milieu, characterized by increased platelet activation, raised activity of procoagulant proteins together with compromised function of the fibrinolytic system. Potential new therapeutic targets to reduce the risk of atherothrombosis in diabetes are explored, including alternative use of existing therapies. Special emphasis is placed on diabetes-specific therapeutic targets that have the potential to reduce vascular risk while keeping an acceptable clinical side effect profile. It is now generally acknowledged that diabetes is not a single clinical entity but a continuum of various stages of the condition with each having a different vascular risk. Therefore, we propose that future therapies aiming to reduce vascular risk in diabetes require a stratified approach with each group having a "stage-specific" vascular management strategy. This "individualized care" in diabetes may prove to be essential to improve vascular outcome in this high risk population.

Comparison of Anticoagulant Therapy for Atrial Fibrillation - Novel Oral Anticoagulants Versus Vitamin K Antagonists

In patients with non-valvular atrial fibrillation (NVAF), oral anticoagulation is important for prevention of stroke and systemic embolism (SE). While Vitamin K antagonists (VKAs) have historically been the standard of care, these medications are limited by numerous food and drug interactions with onerous requirements for frequent monitoring and dose adjustments. Over the past decade, several novel oral anticoagulants (NOACs) have been developed to directly inhibit factor IIa/thrombin (dabigatran) or activated factor X (apixaban, rivaroxaban, edoxaban). These medications have been shown to be at least as effective as warfarin for stroke prevention in NVAF with more favorable safety profiles. However, their advantages are underscored by a lack of specific antidotes and assays quantifying their anticoagulant effects. This paper addresses the use of NOACs compared to VKAs in patients with NVAF, with a special focus on high-risk populations, including the elderly, those with renal disease, diabetes mellitus, coronary artery disease, and previous stroke. The current literature surrounding special clinical scenarios including the treatment of bleeding, perioperative management, and the use of NOACs in cardioversion and catheter ablation will be also discussed.

Current and future antiplatelet therapies: emphasis on preserving haemostasis

Antiplatelet drugs, such as aspirin, P2Y₁₂ antagonists, and glycoprotein (GP) IIb/IIIa inhibitors, have proved to be successful in reducing the morbidity and mortality associated with arterial thrombosis. These agents are, therefore, the cornerstone of therapy for patients with acute coronary syndromes. However, these drugs all carry an inherent risk of bleeding, which is associated with adverse cardiovascular outcomes and mortality. Thus, the potential benefits of more potent, conventional antiplatelet drugs are likely be offset by the increased risk of bleeding. Data from experiments in vivo have highlighted potentially important differences between haemostasis and thrombosis, raising the prospect of developing new antiplatelet drugs that are not associated with bleeding. Indeed, in preclinical studies, several novel antiplatelet therapies that seem to inhibit thrombosis while maintaining haemostasis have been identified. These agents include inhibitors of phosphatidylinositol 3-kinase-β (PI3Kβ), protein disulfide-isomerase, activated GPIIb/IIIa, GPIIb/IIIa outside-in signalling, protease-activated receptors, and platelet GPVI-mediated adhesion pathways. In this Review, we discuss how a therapeutic ceiling has been reached with existing antiplatelet drugs, whereby increased potency is offset by elevated bleeding risk. The latest advances in our understanding of thrombus formation have informed the development of new antiplatelet drugs that are potentially safer than currently available therapies.

Implementation of smart technology to improve medication adherence in patients with cardiovascular disease: is it effective?

INTRODUCTION

Medication adherence is of key importance in the treatment of cardiovascular disease. Studies consistently show that a substantial proportion of patients is non-adherent.

AREAS COVERED

For this review, telemedicine solutions that can potentially improve medication adherence in patients with cardiovascular disease were reviewed. A total of 475 PubMed papers were reviewed, of which 74 were assessed.

EXPERT COMMENTARY

Papers showed that evidence regarding telemedicine solutions is mostly conflictive. Simple SMS reminders might work for patients who do not take their medication because of forgetfulness. Educational interventions and coaching interventions, primarily delivered by telephone or via a web-based platform can be effective tools to enhance medication adherence. Finally, it should be noted that current developments in software engineering may dramatically change the way non-adherence is addressed in the nearby future.

Non-vitamin K Antagonist Oral Anticoagulant After Acute Coronary Syndrome: Is There a Role?

Despite dual antiplatelet therapy (DAPT) including potent P2Y12 inhibitors, recurrent ischaemic events occur in a significant number of patients after acute coronary syndrome (ACS), warranting new antithrombotic strategies. Combinations of non-vitamin K antagonist oral anticoagulant (NOAC) with antiplatelet therapy have been tested in several large phases II and III randomised trials. Overall, current evidence suggests that the use of NOACs on top of DAPT after ACS reduces the rate of recurrent ischaemic events, albeit at the price of increased risk for major bleeding. In the particular field of patients with ACS and atrial fibrillation, NOACs may be associated with reduced bleeding complications compared with vitamin K antagonist. Further randomised trials evaluating low-dose NOAC combined with single antiplatelet therapy are warranted.

Anticoagulation in Patients with Ischaemic Heart Disease and Peripheral Arterial Disease: Clinical Implications of COMPASS Study

Patients with established cardiovascular disease may suffer further cardiovascular events, despite receiving optimal medical treatment. Although platelet inhibition plays a central role in the prevention of new events, the use of anticoagulant therapies to reduce events in atheromatous disease has, until recently, been overlooked. The recent Rivaroxaban for the Prevention of Major Cardiovascular Events in Coronary or Peripheral Artery Disease (COMPASS) study showed an important reduction in cardiovascular events without increasing the risk of fatal and intracranial bleeding when using rivaroxaban, a novel oral anticoagulant, combined with aspirin. This article reviews the available evidence regarding the use of anticoagulant therapies for prevention of cardiovascular events, the results of the COMPASS study and how these results may affect patient management in everyday clinical practice.

Direct oral anticoagulants: An update

Vitamin K antagonists were the only choice for chronic oral anticoagulation for more than half a century. Over the past few years, direct oral anticoagulants have emerged, including one direct thrombin inhibitor (dabigatran etexilate) and three factor Xa inhibitors (apixaban, edoxaban and rivaroxaban). In randomised controlled trials comparing direct oral anticoagulants with traditional vitamin K antagonists, the direct oral anticoagulants all showed a favourable benefit-risk balance in their safety and efficacy profile, in prevention of thromboembolic events in patients with atrial fibrillation and in the prevention and treatment of venous thromboembolism and acute coronary syndrome. In 2008, dabigatran was the first direct oral anticoagulant approved by the European Medicine Agency. Subsequently, rivaroxaban, apixaban and edoxaban were also authorised. This article reviews the evidence related to the use of these drugs.

2018 Canadian Cardiovascular Society/Canadian Association of Interventional Cardiology Focused Update of the Guidelines for the Use of Antiplatelet Therapy

Antiplatelet therapy (APT) has become an important tool in the treatment and prevention of atherosclerotic events, particularly those associated with coronary artery disease. A large evidence base has evolved regarding the relationship between APT prescription in various clinical contexts and risk/benefit relationships. The Guidelines Committee of the Canadian Cardiovascular Society and Canadian Association of Interventional Cardiology publishes regular updates of its recommendations, taking into consideration the most recent clinical evidence. The present update to the 2011 and 2013 Canadian Cardiovascular Society APT guidelines incorporates new evidence on how to optimize APT use, particularly in situations in which few to no data were previously available. The recommendations update focuses on the following primary topics: (1) the duration of dual APT (DAPT) in patients who undergo percutaneous coronary intervention (PCI) for acute coronary syndrome and non-acute coronary syndrome indications; (2) management of DAPT in patients who undergo noncardiac surgery; (3) management of DAPT in patients who undergo elective and semiurgent coronary artery bypass graft surgery; (4) when and how to switch between different oral antiplatelet therapies; and (5) management of antiplatelet and anticoagulant therapy in patients who undergo PCI. For PCI patients, we specifically analyze the particular considerations in patients with atrial fibrillation, mechanical or bioprosthetic valves (including transcatheter aortic valve replacement), venous thromboembolic disease, and established left ventricular thrombus or possible left ventricular thrombus with reduced ejection fraction after ST-segment elevation myocardial infarction. In addition to specific recommendations, we provide values and preferences and practical tips to aid the practicing clinician in the day to day use of these important agents.

Safety and efficacy of rivaroxaban for the secondary prevention following acute coronary syndromes among biomarker-positive patients: Insights from the ATLAS ACS 2-TIMI 51 trial

BACKGROUND:

Despite dual antiplatelet therapy, persistent thrombin generation and thrombin-mediated platelet activation account in part for the residual risk of atherothrombotic disease among patients with prior acute coronary syndrome (ACS). Inhibition of thrombin generation among high-risk ACS patients (biomarker-positive ACS) with the factor Xa inhibitor rivaroxaban may limit ongoing thrombus formation and myocardial necrosis and thereby improve clinical outcomes.

OBJECTIVES AND METHODS:

ATLAS ACS 2-TIMI 51 was a double-blind, placebo-controlled clinical trial that randomized ACS patients to either rivaroxaban 2.5 mg b.i.d., rivaroxaban 5 mg b.i.d., or placebo plus standard-of-care antiplatelet therapy for a mean of 13.1 months and up to 31 months ( N=15,526). This post-hoc analysis evaluates the safety and efficacy of rivaroxaban among biomarker-positive ACS patients with and without a history of prior stroke of transient ischemic attack in the ATLAS ACS 2-TIMI 51 trial.

RESULTS:

A total of 12,626 biomarker-positive ACS patients were included in this analysis. Among biomarker-positive patients without a prior history of stroke or transient ischemic attack, rivaroxaban 2.5 b.i.d. was associated with a reduction in the primary efficacy endpoint (composite of cardiovascular death, myocardial infarction, or stroke) as compared with placebo (hazard ratio=0.80, 95% confidence interval (0.68-0.94), p=0.007) at the expense of an increase in non-coronary-artery-bypass-graft-related Thrombolysis in Myocardial Infarction major bleeding (1.9% vs. 0.7%, p<0.0001), but not a significant increase in either intracranial hemorrhage (0.4% vs. 0.2%, p=0.11) or fatal bleeding (0.1% vs. 0.3%, p=0.16).

CONCLUSION:

Rivaroxaban 2.5 mg b.i.d. was associated with a significant reduction in the composite of cardiovascular death, myocardial infarction, or stroke with no increase in fatal bleeding. Biomarker-positive patients with no prior history of stroke or transient ischemic attack may be a optimal target population to receive "dual pathway" therapy with rivaroxaban plus dual antiplatelet therapy for secondary prevention following ACS.

Inhibition of activated factor X by rivaroxaban attenuates neointima formation after wire-mediated vascular injury

Accumulating evidence suggests that activated factor X (FXa), a key coagulation factor, plays an important role in the development of vascular inflammation through activation of many cell types. Here, we investigated whether pharmacological blockade of FXa attenuates neointima formation after wire-mediated vascular injury. Transluminal femoral artery injury was induced in C57BL/6 mice by inserting a straight wire. Rivaroxaban (5mg/kg/day), a direct FXa inhibitor, was administered from one week before surgery until killed. At four weeks after surgery, rivaroxaban significantly attenuated neointima formation in the injured arteries compared with control (P<0.01). Plasma lipid levels and blood pressure were similar between the rivaroxaban-treated group and non-treated group. Quantitative RT-PCR analyses demonstrated that rivaroxaban reduced the expression of inflammatory molecules (e.g., IL-1β and TNF-α) in injured arteries at seven days after surgery (P<0.05, respectively). In vitro experiments using mouse peritoneal macrophages demonstrated that FXa increased the expression of inflammatory molecules (e.g., IL-1β and TNF-α), which was blocked in the presence of rivaroxaban (P<0.05). Also, in vitro experiments using rat vascular smooth muscle cells (VSMC) demonstrated that FXa promoted both proliferation and migration of this cell type (P<0.05), which were blocked in the presence of rivaroxaban. Inhibition of FXa by rivaroxaban attenuates neointima formation after wire-mediated vascular injury through inhibition of inflammatory activation of macrophages and VSMC.

Rationale and design of the long-Term rIsk, clinical manaGement, and healthcare Resource utilization of stable coronary artery dISease in post-myocardial infarction patients (TIGRIS) study

The long-term progression of coronary artery disease as defined by the natural disease course years after a myocardial infarction (MI) is an important but poorly studied area of clinical research. The long-Term rIsk, clinical manaGement, and healthcare Resource utilization of stable coronary artery dISease in post-myocardial infarction patients (TIGRIS) study was designed to address this knowledge gap by evaluating patient management and clinical outcomes following MI in different regions worldwide. TIGRIS (ClinicalTrials.gov Identifier: NCT01866904) is a multicenter, observational, prospective, longitudinal study enrolling patients with history of MI 1 to 3 years previously and high risk of developing atherothrombotic events in a general-practice setting. The primary objective of TIGRIS is to evaluate clinical events (time to first occurrence of any event from the composite cardiovascular endpoint of MI, unstable angina with urgent revascularization, stroke, or death from any cause), and healthcare resource utilization associated with hospitalization for these events (hospitalization duration and procedures) during follow-up. Overall, 9225 patients were enrolled between June 2013 and November 2014 and are being followed in 369 different centers worldwide. This will allow for the description of regional differences in patient characteristics, risk profiles, medical treatment patterns, clinical outcomes, and healthcare resource utilization. Patients will be followed for up to 3 years. Here we report the rationale, design, patient distribution, and selected baseline characteristics of the TIGRIS study. TIGRIS will describe real-world management, quality of life (self-reported health), and healthcare resource utilization for patients with stable coronary artery disease ≥1 year post-MI.

[Platelet inhibition in elderly patients]

Single antiplatelet therapy (SAPT) using predominantly acetylsalicylic acid (ASA) is the baseline anti-thrombotic therapy in primary as well as secondary prevention of atherosclerotic disease. Dual antiplatelet therapy (DAPT) is the cornerstone of maintenance medication following elective percutaneous coronary interventions or acute coronary syndromes (ST elevation myocardial infarction, non-ST elevation myocardial infarction and unstable angina pectoris). In the past the duration of DAPT in particular has been frequently discussed. Current recommendations, such as the "Focused Update DAPT 2017" of the European Society of Cardiology (ESC) emphasize the importance of strategies aiming to reduce an increased risk of bleeding based on clinical predictors. In this case older age is an important factor relevant for bleeding. In this article, the evidence for SAPT or DAPT is summarized with a special focus on patients aged ≥75 years.