The optimal management of patients on oral anticoagulation undergoing coronary artery stenting. The 10th Anniversary Overview

Feasibility of concomitant left atrial appendage closure and percutaneous coronary intervention in patients with acute coronary syndrome and atrial fibrillation: a randomized pilot study

The optimal approach for prevention of cardiovascular events and reduction of bleeding in patients with acute coronary syndrome (ACS) and atrial fibrillation (AF) is still controversial. The aim of our study is to asses our single-center experience with concomitant left atrial appendage occlusion (LAAO) and percutaneous coronary intervention (PCI). 50 patients with ACS without ST elevation and history of AF were randomized after successful PCI to LAAO or conventional medical therapy. The primary endpoints were safety and length of hospitalization. The follow-up period was 30 days. The mean procedural times were 113 ± 23 min PCI + LAAO implantation and 39 ± 19 min of PCI only (p < 0.001), while mean fluoroscopy times were 18 ± 8 min and 12 ± 8 min (p < 0.001), respectively. No procedure-related complications were observed. There was no difference observed for length of hospitalization between two groups. LAAO in patients with ACS and AF undergoing PCI appears safe.

Simultaneous determination of Rivaroxaban and TAK-438 in rat plasma by LC-MS/MS: application to pharmacokinetic interaction study

Aim: A sensitive and reliable LC-MS/MS method has been established and validated to the quantitation of rivaroxaban (RIV) and TAK-438 in rat plasma using carbamazepine as internal standard. Results: The procedure of method validation was conducted according to the guidelines of EMA and US FDA. At the same time, the method was applied to pharmacokinetic interactions study between RIV and TAK-438 for the first time. When RIV and TAK-438 co-administration to rats, main pharmacokinetic parameters of TAK-438 like AUC_(0-t), AUC_(0-∞) and C_max had statistically significant increase. The main pharmacokinetic parameters of RIV have no statistically significant difference (p > 0.05) when co-administered except for t_1/2 (p < 0.01). Conclusion: The results indicated that drug-drug interactions occurred between RIV and TAK-438 when co-administered to rats.

VE-1902-A direct thrombin inhibitor with reversible covalent mechanism of action shows efficacy with reduced bleeding in rodent models of thrombosis

INTRODUCTION

High incidence of bleeding events remains a key risk for patients taking anticoagulants, especially those in need of long-term combination therapy with antiplatelet agents. As a consequence, patients may not receive clinically indicated combination antithrombotic therapy. Here, we report on VE-1902, a member of a novel class of precision oral anticoagulants (PROACs) that combines effective anticoagulation with reduced bleeding in preclinical testing.

METHODS AND RESULTS

Acting through covalent, reversible active-site modification of thrombin similar to a previously described molecule [1], VE-1902 shows potency and selectivity for thrombin inhibition in human plasma comparable to clinically relevant direct thrombin inhibitors (DTI) such as argatroban and dabigatran (thrombin generation assay ETP EC₅₀ = 1.3 μM compared to 0.36 μM and 0.31 μM for argatroban and dabigatran; >100-fold selectivity against related serine proteases). Unlike the current anticoagulants, VE-1902 does not significantly inhibit thrombin-mediated platelet activation in in vivo models of thrombosis. In the thrombin generation assay, the compound inhibits thrombin formation without significantly delaying the initiation phase of the clotting cascade. These features are possibly responsible for the observed reduced bleeding in tail bleeding and saphenous vein bleeding models. Consistent with this novel pharmacological profile, VE-1902 shows efficacious anticoagulation in several fibrin-driven animal models of thrombosis (arteriovenous shunt, venous stasis thrombosis, and thrombin-induced thromboembolism models), whereas it does not significantly prevent arterial occlusion in the platelet dependent FeCl₃ model.

CONCLUSIONS

By leaving platelet activation following vascular injury mostly unaffected, VE-1902, and the PROACs more generally, represent a new generation of precision anticoagulants with reduced bleeding risk.

Considerations when restarting anticoagulants in patients with atrial fibrillation after bleeding

Introduction: Oral anticoagulants (OACs) are established treatments to reduce thromboembolic risk in patients with atrial fibrillation (AF). Due to their mechanisms of action, they are associated with increased bleeding risk. Evaluation with bleeding risk scores may be useful to identify patients at high risk. However, the approach in patients who have suffered a recent bleeding event while on OACs is a contentious issue. If a decision is made to re-initiate OACs, the optimal timing for this remains controversial. Areas covered: Bleeding risk scores were designed to evaluate risk in patients with AF and indications for OACs. Some practical schemes were created to manage bleeding in this population. The types of bleeding were classified as minor, major non-life-threatening and major life-threatening bleeding. In AF patients suffering from severe acute bleeding, it is recommended to withhold OACs until the underlying cause is identified and treated. Each case will require an individualized decision to restarting OAC therapy after consideration of the risks, benefits, alternatives and patient's choice in the matter. Expert opinion: Management of major bleeding and restarting OACs in patients with a recent major bleeding poses a special challenge due to high bleeding and thrombotic risk. This will be discussed in this review.

Antithrombotic Medication and the Risk of Vitreous Hemorrhage in Atrial Fibrillation: Korean National Health Insurance Service National Cohort

PURPOSE

Antithrombotic therapy could be related with nuisance bleeding. This study investigated whether vitreous hemorrhage (VH) is associated with specific types of antithrombotic medication in patients with atrial fibrillation (AF).

MATERIALS AND METHODS

In the Korean National Health Insurance Service National Sample Cohort, we identified 9352 antiplatelet/anticoagulant-treated AF patients. The occurrence of VH was compared between warfarin (n=1493) and a propensity score (PS)-matched antiplatelet group (n=1493) and between warfarin (n=1493) and a PS-matched warfarin+antiplatelet group (n=1493).

RESULTS

The outcomes of VH were lower in the warfarin than in the matched antiplatelet (1.45 vs. 3.72 events/1000 patient-years) and matched warfarin+antiplatelet groups (1.45 vs. 6.87 events/1000 patient-years). Compared with warfarin, the risk of VH increased with antiplatelet [adjusted hazard ratio (aHR) 3.90; 95% confidence interval (CI) 1.22-12.4, p=0.022] and warfarin+antiplatelet agents (aHR 4.39, 95% CI 1.74-11.2, p=0.002). Compared with warfarin only, warfarin+antiplatelet agents increased the risk of VH in patients ≥65 years, regardless of gender and hypertension. The risk of VH was significantly higher with dual antiplatelet therapy (aHR: 5.02, 95% CI: 1.56-16.2, p=0.007) or in dual (aHR: 5.02, 95% CI: 1.74-14.5, p=0.003) or triple therapy using warfarin and antiplatelet agents than with warfarin monotherapy (aHR: 6.12, 95% CI: 1.76-21.3, p=0.004).

CONCLUSION

Dual antiplatelet or triple therapy increased the risk of VH significantly, compared to warfarin monotherapy. Considering the low efficacy of preventing ischemic stroke and high risk of bleeding, dual or triple therapy using warfarin and antiplatelet agents should be avoided to prevent VH in AF patients.

The Prevalence and Risks of Inappropriate Combination of Aspirin and Warfarin in Clinical Practice: Results From WARFARIN-TR Study

Background

The use of warfarin and aspirin in combination is restricted to limited patients under relevant guidelines.

Aims

To evaluate the prevalence of the inappropriate combination of aspirin and warfarin therapy in daily practice and its risks.

Study Design

Cross-sectional study.

Methods

The awareness, efficacy, safety, and time in the therapeutic range of warfarin in the Turkish population study is a multi-center observational study that includes 4987 patients using warfarin for any reason between January 1, 2014, and December 31, 2014. To determine the prevalence of inappropriate combination use in daily practice, all patients who had a history of atherosclerotic disease (ischemic heart disease, peripheral artery disease) or cerebrovascular disease (n=1498) were excluded. The data of 3489 patients were analyzed. We defined inappropriate combination as all patients who received aspirin and warfarin regardless of the indication for warfarin use, under the direction of the European Society of Cardiology guideline recommendation.

Results

The mean age of patients was 59.2±13.8 years (41.8% male). The prevalence of the inappropriate use of warfarin and aspirin combination was 20.0%. The prevalence of combination therapy in patients with a primary indication for mechanical heart valve, non-valvular atrial fibrillation, and other reasons was 20.5%, 18.7%, and 21.0%, respectively. Multivariate logistic regression analysis revealed that age (odds ratio, 1.009; 95% confidence interval, 1.002-1.015; p=0.010), heart failure (odds ratio, 1.765; 95% confidence interval, 1.448-2.151; p<0.001), smoking (odds ratio, 1.762; 95% confidence interval, 1.441-1.153; p<0.010), chronic kidney disease (odds ratio, 2.057; 95% confidence interval, 1.494-2.833; p<0.001), and deep vein thrombosis (odds ratio, 0.463; 95% confidence interval, 0.229-0.718; p=0.001) were independent predictors of combination therapy (r2=0.66). The mean time in therapeutic range of patients receiving combination therapy was significantly lower than in those on warfarin monotherapy (51.6±27.05 vs. 54.7±23.93; p=0.006). Overall, 19.4% (n=677) of patients had a bleeding event (major bleeding 13.0%, n=88) within a year. Percentages of patients with combination therapy were significantly higher in patients with major bleeding than in patients without major bleeding (29.5% vs. 19.7%; p=0.023).

Conclusion

Our study demonstrated that 20.0% of patients taking warfarin use concomitant aspirin inappropriately in daily practice. Patients receiving aspirin with warfarin were demonstrated to have more comorbidities, lower time in therapeutic range levels, and higher bleeding rates.

Long-Term Outcome of Acute Coronary Syndromes in Patients on Chronic Oral Anticoagulants: Data from the EPICOR Study

OBJECTIVE

To analyze characteristics, management and outcomes of patients with acute coronary syndromes (ACS) receiving chronic oral anticoagulant (OAC) therapy enrolled in the EPICOR (long-tErm follow-uP of antithrombotic management patterns In acute CORonary syndrome patients) prospective, international, observational study of antithrombotic management patterns in ACS survivors (NCT01171404).

METHODS

This post-hoc analysis evaluated the association between OAC use at baseline (OACb) and time from hospital admission to percutaneous coronary intervention (PCI) (tHA-PCI), pre-PCI thrombolysis in myocardial infarction (TIMI) 3 flow, stent type, length of hospitalization, and clinical endpoints; death, non-fatal MI, and non-fatal stroke, a composite of these ± bleeding, over 2 years' followup.

RESULTS

Of 10,568 ACS patients, 345 (3.3%) were on OACb (non-ST-segment elevation ACS [NSTEACS], n=268; ST-segment elevation MI [STEMI], n=77). OACb patients were older with more comorbidities. In NSTE-ACS OACb patients, tHA-PCI was longer (median 57.4 vs. 27.8 h; p=.008), and TIMI 3 flow rarer (26.0 vs. 33.5%; p=0.035). OACb patients had longer mean hospital stay (NSTEACS: 8.9 vs. 7.6 days; p<0.001; STEMI: 9.5 vs. 7.8 days; p=0.015), and higher rates of the composite endpoint (NSTE-ACS: 16.8 vs. 8.8%; p<0.0001; STEMI: 23.4 vs. 5.9%; p<0.0001). Bleeding events were more common with OACb (NSTE-ACS: 6.0 vs. 3.3%; p=0.01; STEMI: 6.5 vs. 2.8%; p=0.04).

CONCLUSION

At 2-years, OACb use was associated with an increased risk of cardiovascular and bleeding events in STEMI and NSTE-ACS. NSTE-ACS patients on OACb experienced prolonged time to intervention, lower rates of TIMI 3 flow and longer hospitalization.

Real clinical experiences of dual versus triple antithrombotic therapy after percutaneous coronary intervention

OBJECTIVES

We aimed to assess the impact of omitting aspirin on clinical outcomes in a real-world collective of patients receiving oral anticoagulation (OAC) therapy who were treated with a current-generation drug-eluting stent (DES) or an everolimus-eluting bioresorbable vascular scaffold (BVS).

BACKGROUND

Limited data are available regarding the clinical benefit of triple antithrombotic therapy (TAT) with aspirin compared with dual antithrombotic therapy (DAT) without aspirin in patients undergoing percutaneous coronary intervention (PCI) and requiring OAC.

METHODS

In total, 237 patients were analyzed. The primary outcome was a composite of major adverse cardiac and cerebrovascular events (MACCE) within 1 year after PCI. Secondary outcomes were the individual components of the primary endpoint, cardiovascular death, and any bleeding according to Bleeding Academic Research Consortium (BARC) or Thrombolysis in Myocardial Infarction (TIMI) criteria.

RESULTS

Eighty-nine patients (37.6%) received DAT, and 148 (62.4%) received TAT. The rate of MACCE was significantly higher in DAT patients than in TAT patients (16 (18%) vs. 11 (7.4%); hazard ratio [HR] 2.73, 95% confidence interval [CI] 1.24-6.03; P = 0.01). The results of the multivariable Cox proportional hazards model including corrections for imbalances in baseline characteristics confirmed a significant independent association between DAT and MACCE (HR_adj 3.14, 95% CI 1.31-7.54; P = 0.01). Major bleeding did not differ significantly between treatment groups.

CONCLUSION

DAT was associated with a significantly higher rate of MACCE than TAT after DES or BVS implantation. Further studies are required to evaluate the safety and efficacy of dual versus TAT after PCI in clinical practice.

2018 Korean Guideline of Atrial Fibrillation Management

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia in the general population. The Korean Heart Rhythm Society organized a Korean AF Management Guideline Committee and analyzed all available studies regarding the management of AF, including studies on Korean patients. This guideline is based on recent data of the Korean population and the recent guidelines of the European Society of Cardiology, European Association for Cardio-Thoracic Surgery, American Heart Association, and Asia Pacific Heart Rhythm Society. Expert consensus or guidelines for the optimal management of Korean patients with AF were achieved after a systematic review with intensive discussion. This article provides general principles for appropriate risk stratification and selection of anticoagulation therapy in Korean patients with AF. This guideline deals with optimal stroke prevention, screening, rate and rhythm control, risk factor management, and integrated management of AF.

In-hospital outcomes of STEMI patients on warfarin undergoing primary PCI

OBJECTIVES

We sought to describe the safety and efficacy outcomes of patients on warfarin presenting with ST-elevation myocardial infarction (STEMI).

BACKGROUND

Limited data exist on the outcomes and optimal management of STEMI patients on warfarin undergoing primary percutaneous coronary intervention (PCI).

METHODS

Baseline characteristics and outcomes were prospectively collected for 2,390 consecutive STEMI patients referred for primary PCI. Patients were stratified based on warfarin use at baseline. The primary safety endpoint was the rate of in-hospital bleeding (a composite of major bleeding or minor bleeding) according to the thrombolysis in myocardial infarction (TIMI) classification. Efficacy endpoints included major adverse cardiovascular events (MACE), defined as death, myocardial infarction, or stroke, as well as intracranial bleeding, cardiogenic shock, and length of stay. Multiple logistic regression was used to determine if warfarin was independently associated with bleeding and MACE.

RESULTS

Warfarin patients (n = 59 vs. n = 2,331) were significantly older (73.2 years vs. 61.7 years; P < 0.01), and more likely to present as Killip Class IV (13.6% vs. 2.7%; P < 0.01). TIMI major/minor bleeding occurred in 30.4% of the warfarin patients and 14.2% of the control patients (P < 0.01). After adjustment warfarin was independently associated with an increased risk of bleeding (OR 2.08; P = 0.04). Warfarin patients also had an increased frequency of MACE (20.3% vs. 5.9%; P < 0.01), though this was not significant after adjustment (OR 2.00; P = 0.10).

CONCLUSIONS

STEMI patients on warfarin referred for primary PCI are more likely to experience bleeding. New strategies are needed to optimize the management and minimize bleeding in this high-risk population.

Choosing a particular oral anticoagulant and dose for stroke prevention in individual patients with non-valvular atrial fibrillation: part 1

Patients with atrial fibrillation (AF) have a high risk of stroke and mortality, which can be considerably reduced by oral anticoagulants (OAC). Recently, four non-vitamin-K oral anticoagulants (NOACs) were compared with warfarin in large randomized trials for the prevention of stroke and systemic embolism. Today's clinician is faced with the difficult task of selecting a suitable OAC for a patient with a particular clinical profile or a particular pattern of risk factors and concomitant diseases. We reviewed analyses of subgroups of patients from trials of vitamin K antagonists vs. NOACs for stroke prevention in AF with the aim to identify patient groups who might benefit from a particular OAC more than from another. In the first of a two-part review, we discuss the choice of NOAC for stroke prevention in the following subgroups of patients with AF: (i) stable coronary artery disease or peripheral artery disease, including percutaneous coronary intervention with stenting and triple therapy; (ii) cardioversion, ablation and anti-arrhythmic drug therapy; (iii) mechanical valves and rheumatic valve disease, (iv) patients with time in therapeutic range of >70% on warfarin; (v) patients with a single stroke risk factor (CHA2DS2VASc score of 1 in males, 2 in females); and (vi) patients with a single first episode of paroxysmal AF. Although there are no major differences in terms of efficacy and safety between the NOACs for some clinical scenarios, in others we are able to suggest that particular drugs and/or doses be prioritized for anticoagulation.

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.

Time in therapeutic range and major adverse outcomes in atrial fibrillation patients undergoing percutaneous coronary intervention: The Atrial Fibrillation Undergoing Coronary Artery Stenting (AFCAS) registry

BACKGROUND

Combination of oral anticoagulation (OAC) and antiplatelets is used in atrial fibrillation (AF) patients undergoing percutaneous coronary intervention and stent (PCI-S) procedure but is associated with increased bleeding when triple antithrombotic therapy (TAT) is used. Our aim was to analyze the impact of time in therapeutic range (TTR) on outcomes, in patients prescribed with TAT.

METHODS

Ancillary analysis from the AFCAS registry in patients assigned to TAT. TTR was calculated with Rosendaal method. Outcomes were analyzed according to TTR tertiles (T1 [≤56.8%] vs. T2 [56.9-93.8%] vs. T3 [≥93.9%]). Major bleeding was the primary outcome.

RESULTS

Of 963 patients enrolled, 470(48.8%) were prescribed with TAT at discharge and qualified for this analysis. Median [IQR] TTR was 80.0% [45.3-100%]. After 359 [341-370] days, major bleeding rates were progressively lower with increasing TTR tertiles (T1 vs. T2 vs. T3: 10.3% vs. 4.7% vs. 2.3%, P=.006). Kaplan-Meier analysis demonstrated a progressively lower risk for major bleeding across tertiles (P=.006). Patients in the highest TTR tertile had a non-significant lower risk for major adverse coronary and cerebrovascular events (MACCE) (log-rank: 4.905, P=.086). Cox regression analysis showed that T2 and T3 were inversely associated with major bleeding (hazard ratio [HR]:0.39, P=.050 and HR: 0.21, P=.005). Continuous TTR was inversely associated with major bleeding (HR: 0.98, P<.001). For MACCE, adjusted Cox analysis found a non-significant lower risk for T3 (HR: 0.64, P=.128).

CONCLUSIONS

In AF patients undergoing PCI-S prescribed TAT, good quality anticoagulation control (as reflected by TTR) was closely related to bleeding outcomes during follow-up. Despite some suggestive trends for an inverse relationship between TTR and MACCE, no definitive conclusions can be drawn, and further large studies are needed.

Consensus Document of the Italian Association of Hospital Cardiologists (ANMCO), Italian Society of Cardiology (SIC), Italian Association of Interventional Cardiology (SICI-GISE) and Italian Society of Cardiac Surgery (SICCH): clinical approach to pharmacologic pre-treatment for patients undergoing myocardial revascularization procedures

The wide availability of effective drugs in reducing cardiovascular events together with the use of myocardial revascularization has greatly improved the prognosis of patients with coronary artery disease. The combination of antithrombotic drugs to be administered before the knowledge of the coronary anatomy and before the consequent therapeutic strategies, can allow to anticipate optimal treatment, but can also expose the patients at risk of bleeding that, especially in acute coronary syndromes, can significantly weigh on their prognosis, even more than the expected theoretical benefit. In non ST-elevation acute coronary syndromes patients in particular, we propose a 'selective pre-treatment' with P2Y12 inhibitors, based on the ischaemic risk, on the bleeding risk and on the time scheduled for the execution of coronary angiography. Much of the problems concerning this issue would be resolved by an early access to coronary angiography, particularly for patients at higher ischaemic and bleeding risk.

Clinical Stroke prevention in atrial fibrillation

Oral anticoagulation therapy has reduced the risk of ischaemic stroke and improved the outcomes for patients with atrial fibrillation considerably. The emergence of the non-vitamin K oral anticoagulants as alternatives to vitamin K antagonists has significantly changed the practice of stroke prevention in atrial fibrillation. As the main complication with antithrombotic therapy is bleeding, physicians should always balance the risk of ischaemic stroke against intracranial haemorrhage and intervene where appropriate to reduce both risks. Individual approach is often mandatory due to heterogeneity of the risks and patient preferences. The purpose of this review is to summarise the current knowledge of the oral anticoagulation therapy in atrial fibrillation patients and guide physicians with the management of anticoagulants based on data from clinical trials and systematic reviews.

Antiplatelet therapy - a summary for the general physicians

Platelets play a very important role in physiological haemostasis and thrombus formation. Platelet aggregation is the key pathophysiological factor in the development of arterial ischaemic events, including coronary artery disease, cerebrovascular accidents and peripheral arterial disease. As such, antiplatelet therapy plays a very important role in preventing recurrent events in the individuals who are affected by one of these conditions. Until recently, the repertoire of antiplatelet therapy was limited to aspirin and clopidogrel. However, this landscape has changed dramatically with the advent of newer and more potent agents, prasugrel and ticagrelor and also the glycoprotein IIb/IIIa antagonists. This armamentarium is likely to expand further with the advent of protease-activated receptor-1 antagonists and the intravenous cangrelor. This review summarises the different agents available and some practical considerations for their use from a general physician's perspective.

Self-Powered Microfluidic Device for Rapid Assay of Antiplatelet Drugs

We report the development of a microfluidic device for the rapid assay in whole blood of interfacial platelet-protein interactions indicative of the efficacy of antiplatelet drugs, for example, aspirin and Plavix, two of the world's most widely used drugs, in patients with cardiovascular disease (CVD). Because platelet adhesion to surface-confined protein matrices is an interfacial phenomenon modulated by fluid shear rates at the blood/protein interface, and because such binding is a better indicator of platelet function than platelet self-aggregation, we designed, fabricated, and characterized the performance of a family of disposable, self-powered microfluidic chips with well-defined flow and interfacial shear rates suitable for small blood volumes (≤200 μL). This work demonstrates that accurate quantification of cell adhesion to protein matrices, an important interfacial biological phenomenon, can be used as a powerful diagnostic tool in those with CVD, the world's leading cause of death. To enable such measurements, we developed a simple technique to fabricate single-use self-powered chips incorporating shear control (SpearChips). These parallel-plate flow devices integrate on-chip vacuum-driven blood flow, using a predegassed elastomer component to obviate active pumping, with microcontact-printed arrays of 6-μm-diameter fluorescently labeled fibrinogen dots on a cyclic olefin polymer base plate as a means to quantitatively count platelet-protein binding events. The use of SpearChips to assess in whole blood samples the effects of GPIIb/IIIa and P2Y12 inhibitors, two important classes of "antiplatelet" drugs, is reported.

Oral anticoagulants in coronary heart disease (Section IV). Position paper of the ESC Working Group on Thrombosis - Task Force on Anticoagulants in Heart Disease

Until recently, vitamin K antagonists (VKAs) were the only available oral anticoagulants evaluated for long-term treatment of patients with coronary heart disease (CHD), particularly after an acute coronary syndrome (ACS). Despite efficacy in this setting, VKAs are rarely used because they are cumbersome to administer. Instead, the more readily manageable antiplatelet agents are the mainstay of prevention in ACS patients. This situation has the potential to change with the introduction of non-VKA oral anticoagulants (NOACs), which are easier to administer than VKAs because they can be given in fixed doses without routine coagulation monitoring. The NOACs include dabigatran, which inhibits thrombin, and apixaban, rivaroxaban and edoxaban, which inhibit factor Xa. Apixaban and rivaroxaban were evaluated in phase III trials for prevention of recurrent ischaemia in ACS patients, most of whom were also receiving dual antiplatelet therapy with aspirin and clopidogrel. Although at the doses tested rivaroxaban was effective and apixaban was not, both agents increased major bleeding. The role for the NOACs in ACS management, although promising, is therefore complicated, because it is uncertain how they compare with newer antiplatelet agents, such as prasugrel, ticagrelor or vorapaxar, and because their safety in combination with these other drugs is unknown. Ongoing studies are also now evaluating the use of NOACs in non-valvular atrial fibrillation patients, where their role is established, with coexistent ACS or coronary stenting. Focusing on CHD, we review the results of clinical trials with the NOACs and provide a perspective on their future incorporation into clinical practice.

Emerging Tools for Stroke Prevention in Atrial Fibrillation

Ischaemic strokes resulting from atrial fibrillation (AF) constitute a devastating condition for patients and their carers with huge burden on health care systems. Prophylactic treatment against systemic embolization and ischaemic strokes is the cornerstone for the management of AF. Effective stroke prevention requires the use of the vitamin K antagonists or non-vitamin K oral anticoagulants (NOACs). This article summarises the latest developments in the field of stroke prevention in AF and aims to assist physicians with the choice of oral anticoagulant for patients with non-valvular AF with different risk factor profile.

New-onset atrial fibrillation after recent coronary stenting: Warfarin or non-vitamin K-antagonist oral anticoagulants to be added to aspirin and clopidogrel? A viewpoint

The antithrombotic management of patients on oral anticoagulation (OAC), with either warfarin or non-vitamin K-antagonist oral anticoagulants (NOACs), undergoing percutaneous coronary intervention with stent (PCI-S) has been recently addressed in a joint European consensus document. In accordance, triple therapy (TT) of OAC, aspirin and clopidogrel should generally be given as the initial therapy. More uncertainty exists over whether warfarin or a NOAC should be added in patients already on dual antiplatelet therapy of aspirin and clopidogrel (DAPT) after recent PCI-S. Upon review of available data, it appears that the risk of major bleeding of TT as compared to DAPT is similar with either warfarin or a NOAC. In particular, TT consistently appears associated to an approximately 2.5 fold increase in the risk of major bleeding. Because of the higher convenience, NOACs might be considered the preferred OAC to be added to DAPT. Given the reported different safety profiles of the various NOACs on the incidence of major, and gastrointestinal, bleeding, the NOACs, and the dose, showing the greatest safety in this regard should be selected. In accordance, dabigatran 110 mg and apixaban 2.5mg twice daily appear as the most valuable options in patients who are not and who are respectively, at increased risk of bleeding. As an alternative, apixaban 5mg twice daily might be considered in patients at risk of bleeding not increased, whereas rivaroxaban 15 mg once daily may be considered in the presence of increased risk of bleeding (essentially when related to moderate renal impairment).