Apixaban, an Oral, Direct, Selective Factor Xa Inhibitor, in Combination With Antiplatelet Therapy After Acute Coronary Syndrome

Role of anticoagulation in non-ST-elevation myocardial infarction: a contemporary narrative review

INTRODUCTION

Anticoagulants play a vital role as part of the antithrombotic therapy of myocardial infarction and are complementary to antiplatelet therapies. In the acute setting, the rationale for their use is to antagonize the ongoing clotting cascade including during percutaneous coronary intervention. Anticoagulation may be an important part of the longer-term antithrombotic strategy especially in patients who have other existing indications (e.g. atrial fibrillation) for their use.

AREAS COVERED

In this narrative review, the authors provide a contemporary summary of the anticoagulation strategies of patients presenting with NSTEMI, both in terms of anticoagulation during the acute phase as well as suggested antithrombotic regimens for patients who require long-term anticoagulation for other indications.

EXPERT OPINION

Patients presenting with non-ST-elevation myocardial infarction (NSTEMI) should be initiated on anticoagulation (e.g. heparin/low molecular weight heparin) for the initial hospitalization period for those medically managed or until percutaneous coronary intervention. Longer term management of NSTEMI for patients with an existing indication for long-term anticoagulation should comprise triple antithrombotic therapy of anticoagulant (preferably DOAC) with aspirin and clopidogrel for up to 1 month (typically 1 week or until hospital discharge), followed by DOAC plus clopidogrel for up to 1 year, and then DOAC monotherapy thereafter.

Non-vitamin-K-antagonist oral anticoagulants (NOACs) after acute myocardial infarction: a network meta-analysis

BACKGROUND

Balancing the risk of bleeding and thrombosis after acute myocardial infarction (AMI) is challenging, and the optimal antithrombotic therapy remains uncertain. The potential of non-vitamin K antagonist oral anticoagulants (NOACs) to prevent ischaemic cardiovascular events is promising, but the evidence remains limited.

OBJECTIVES

To evaluate the efficacy and safety of non-vitamin-K-antagonist oral anticoagulants (NOACs) in addition to background antiplatelet therapy, compared with placebo, antiplatelet therapy, or both, after acute myocardial infarction (AMI) in people without an indication for anticoagulation (i.e. atrial fibrillation or venous thromboembolism).

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, the Conference Proceedings Citation Index - Science, and two clinical trial registers in September 2022 with no language restrictions. We checked the reference lists of included studies for any additional trials.

SELECTION CRITERIA

We searched for randomised controlled trials (RCTs) that evaluated NOACs plus antiplatelet therapy versus placebo, antiplatelet therapy, or both, in people without an indication for anticoagulation after an AMI.

DATA COLLECTION AND ANALYSIS

Two review authors independently checked the results of searches to identify relevant studies, assessed each included study, and extracted study data. We conducted random-effects pairwise analyses using Review Manager Web, and network meta-analysis using the R package 'netmeta'. We ranked competing treatments by P scores, which are derived from the P values of all pairwise comparisons and allow ranking of treatments on a continuous 0-to-1 scale.

MAIN RESULTS

We identified seven eligible RCTs, including an ongoing trial that we could not include in the analysis. Of the six RCTs involving 33,039 participants, three RCTs compared rivaroxaban with placebo, two RCTs compared apixaban with placebo, and one RCT compared dabigatran with placebo. All participants in the six RCTs received concomitant antiplatelet therapy. The available evidence suggests that rivaroxaban compared with placebo reduces the rate of all-cause mortality (risk ratio (RR) 0.82, 95% confidence interval (CI) 0.69 to 0.98; number needed to treat for an additional beneficial outcome (NNTB) 250; 3 studies, 21,870 participants; high certainty) and probably reduces cardiovascular mortality (RR 0.83, 95% CI 0.69 to 1.01; NNTB 250; 3 studies, 21,870 participants; moderate certainty). There is probably little or no difference between apixaban and placebo in all-cause mortality (RR 1.09, 95% CI 0.88 to 1.35; number needed to treat for an additional harmful outcome (NNTH) 334; 2 studies, 8638 participants; moderate certainty) and cardiovascular mortality (RR 0.99, 95% CI 0.77 to 1.27; number needed to treat not applicable; 2 studies, 8638 participants; moderate certainty). Dabigatran may reduce the rate of all-cause mortality compared with placebo (RR 0.57, 95% CI 0.31 to 1.06; NNTB 63; 1 study, 1861 participants; low certainty). Dabigatran compared with placebo may have little or no effect on cardiovascular mortality, although the point estimate suggests benefit (RR 0.72, 95% CI 0.34 to 1.52; NNTB 143; 1 study, 1861 participants; low certainty). Two of the investigated NOACs were associated with an increased risk of major bleeding compared to placebo: apixaban (RR 2.41, 95% CI 1.44 to 4.06; NNTH 143; 2 studies, 8544 participants; high certainty) and rivaroxaban (RR 3.31, 95% CI 1.12 to 9.77; NNTH 125; 3 studies, 21,870 participants; high certainty). There may be little or no difference between dabigatran and placebo in the risk of major bleeding (RR 1.74, 95% CI 0.22 to 14.12; NNTH 500; 1 study, 1861 participants; low certainty). The results of the network meta-analysis were inconclusive between the different NOACs at all individual doses for all primary outcomes. However, low-certainty evidence suggests that apixaban (combined dose) may be less effective than rivaroxaban and dabigatran for preventing all-cause mortality after AMI in people without an indication for anticoagulation.

AUTHORS' CONCLUSIONS

Compared with placebo, rivaroxaban reduces all-cause mortality and probably reduces cardiovascular mortality after AMI in people without an indication for anticoagulation. Dabigatran may reduce the rate of all-cause mortality and may have little or no effect on cardiovascular mortality. There is probably no meaningful difference in the rate of all-cause mortality and cardiovascular mortality between apixaban and placebo. Moreover, we found no meaningful benefit in efficacy outcomes for specific therapy doses of any investigated NOACs following AMI in people without an indication for anticoagulation. Evidence from the included studies suggests that rivaroxaban and apixaban increase the risk of major bleeding compared with placebo. There may be little or no difference between dabigatran and placebo in the risk of major bleeding. Network meta-analysis did not show any superiority of one NOAC over another for our prespecified primary outcomes. Although the evidence suggests that NOACs reduce mortality, the effect size or impact is small; moreover, NOACs may increase major bleeding. Head-to-head trials, comparing NOACs against each other, are required to provide more solid evidence.

Safety and Efficacy of Direct Oral Anticoagulant in Addition to Antiplatelet Therapy After Acute Coronary Syndrome: A Systemic Review and Meta-analysis of 53,869 Patients

INTRODUCTION

Significant progress has been made in the management of patients with acute coronary syndrome (ACS) during the past few decades. However, the role of direct oral anticoagulants (DOACs) in post-ACS prophylactic therapy remains unknown. This study aims to assess the efficacy and safety of DOACs plus antiplatelet treatment (APT) after ACS.

METHODS

A systematic literature search was conducted to identify randomized clinical trials comparing DOACs plus APT with APT alone after ACS. The primary efficacy end points were cardiovascular mortality, myocardial infarction, all-cause mortality, and stroke and systemic embolization (SSE). The primary safety end point was major bleeding. The random-effects model was used to calculate relative risk (RR) and corresponding 95% CIs.

RESULTS

Nine trials with a total of 53,869 patients were identified, with 33,011 (61.2%) in the DOACs plus APT group and 20,858 (38.8%) in the APT alone group. The use of DOACs did not decrease the risk of cardiovascular death (RR = 0.87; 95% CI, 0.75-1.01; P = 0.08; I2 = 0%) or myocardial infarction (RR = 0.90; 95% CI, 0.80-1.02; P = 0.10; I2 = 6%). However, the risk of SSE was significantly lower in patients who received DOACs plus APT compared with APT alone (RR = 0.67; 95% CI, 0.50-0.90; P = 0.008). Moreover, all-cause mortality was significantly lower in the DOACs plus APT group (RR = 0.83; 95% CI, 0.71-98; P = 0.03; I2 = 0%). However, the risk of major bleeding was significantly higher in patients treated with DOACs plus APT compared with APT alone (RR = 2.53; 95% CI, 1.96-3.26; P < 0.01; I2 = 0%), as was the risk of nonmajor bleeding (RR = 2.27; 95% CI, 1.51-3.41; P < 0.01).

IMPLICATIONS

DOACs plus APT for the prevention of left ventricular thrombus in patients with ACS were associated with a lower risk of SSE and all-cause mortality but increased the risk of major and nonmajor bleeding. The benefits and risks of this approach should be weighed based on a patient's individual clinical characteristics.

Safety and efficacy of factor XIa inhibition with milvexian for secondary stroke prevention (AXIOMATIC-SSP): a phase 2, international, randomised, double-blind, placebo-controlled, dose-finding trial

BACKGROUND

People with factor XI deficiency have lower rates of ischaemic stroke than the general population and infrequent spontaneous bleeding, suggesting that factor XI has a more important role in thrombosis than in haemostasis. Milvexian, an oral small-molecule inhibitor of activated factor XI, added to standard antiplatelet therapy, might reduce the risk of non-cardioembolic ischaemic stroke without increasing the risk of bleeding. We aimed to estimate the dose-response of milvexian for recurrent ischaemic cerebral events and major bleeding in patients with recent ischaemic stroke or transient ischaemic attack (TIA).

METHODS

AXIOMATIC-SSP was a phase 2, randomised, double-blind, placebo-controlled, dose-finding trial done at 367 hospitals in 27 countries. Eligible participants aged 40 years or older, with acute (<48 h) ischaemic stroke or high-risk TIA, were randomly assigned by a web-based interactive response system in a 1:1:1:1:1:2 ratio to receive one of five doses of milvexian (25 mg once daily, 25 mg twice daily, 50 mg twice daily, 100 mg twice daily, or 200 mg twice daily) or matching placebo twice daily for 90 days. All participants received clopidogrel 75 mg daily for the first 21 days and aspirin 100 mg daily for the first 90 days. Investigators, site staff, and participants were masked to treatment assignment. The primary efficacy endpoint was the composite of ischaemic stroke or incident covert brain infarct on MRI at 90 days, assessed in all participants allocated to treatment who completed a follow-up MRI brain scan, and the primary analysis assessed the dose-response relationship with Multiple Comparison Procedure-Modelling (MCP-MOD). The main safety outcome was major bleeding at 90 days, assessed in all participants who received at least one dose of the study drug. This trial is registered with ClinicalTrials.gov (NCT03766581) and the EU Clinical Trials Register (2017-005029-19).

FINDINGS

Between Jan 27, 2019, and Dec 24, 2021, 2366 participants were randomly allocated to placebo (n=691); milvexian 25 mg once daily (n=328); or twice-daily doses of milvexian 25 mg (n=318), 50 mg (n=328), 100 mg (n=310), or 200 mg (n=351). The median age of participants was 71 (IQR 62-77) years and 859 (36%) were female. At 90 days, the estimates of the percentage of participants with either symptomatic ischaemic stroke or covert brain infarcts were 16·8 (90·2% CI 14·5-19·1) for placebo, 16·7 (14·8-18·6) for 25 mg milvexian once daily, 16·6 (14·8-18·3) for 25 mg twice daily, 15·6 (13·9-17·5) for 50 mg twice daily, 15·4 (13·4-17·6) for 100 mg twice daily, and 15·3 (12·8-19·7) for 200 mg twice daily. No significant dose-response was observed among the five milvexian doses for the primary composite efficacy outcome. Model-based estimates of the relative risk with milvexian compared with placebo were 0·99 (90·2% CI 0·91-1·05) for 25 mg once daily, 0·99 (0·87-1·11) for 25 mg twice daily, 0·93 (0·78-1·11) for 50 mg twice daily, 0·92 (0·75-1·13) for 100 mg twice daily, and 0·91 (0·72-1·26) for 200 mg twice daily. No apparent dose-response was observed for major bleeding (four [1%] of 682 participants with placebo, two [1%] of 325 with milvexian 25 mg once daily, two [1%] of 313 with 25 mg twice daily, five [2%] of 325 with 50 mg twice daily, five [2%] of 306 with 100 mg twice daily, and five [1%] of 344 with 200 mg twice daily). Five treatment-emergent deaths occurred, four of which were considered unrelated to the study drug by the investigator.

INTERPRETATION

Factor XIa inhibition with milvexian, added to dual antiplatelet therapy, did not substantially reduce the composite outcome of symptomatic ischaemic stroke or covert brain infarction and did not meaningfully increase the risk of major bleeding. Findings from our study have informed the design of a phase 3 trial of milvexian for the prevention of ischaemic stroke in patients with acute ischaemic stroke or TIA.

FUNDING

Bristol Myers Squibb and Janssen Research & Development.

Design, expression and biological evaluation of DX-88mut as a novel selective factor XIa inhibitor for antithrombosis

Thrombotic diseases, such as myocardial infarction, stroke, and deep vein thrombosis, severely threaten human health, and anticoagulation is an effective way to prevent such illnesses. However, most anticoagulant drugs in the clinic have different bleeding risks. Previous studies have shown that coagulation factor XI is an ideal target for safe anticoagulant drug development. Here, we designed the FXIa inhibitory peptide DX-88mut by replacing Loop1 (DGPCRAAHPR) and Loop2 (IYGGC) in DX-88, which is a clinical drug targeting PKa for the treatment of hereditary angioedema, using Loop1 (TGPCRAMISR) and Loop2 (FYGGC) in the FXIa inhibitory peptide PN2KPI, respectively. DX-88mut selectively inhibited FXIa against a panel of serine proteases with an IC50 value of 14.840 ± 0.453 nM, dose-dependently prolonged APTT in mouse, rat and human plasma, and potently inhibited FeCl3-induced carotid artery thrombosis in mice at a dose of 1 µmol/kg. Additionally, DX-88mut did not show a significant bleeding risk at a dose of 5 µmol/kg. Taken together, these results show that DX-88mut is a potential candidate for the development of a novel antithrombotic agent.

Antithrombotic and prohemorrhagic actions of different concentrations of apixaban in patients exposed to single and dual antiplatelet regimens

We evaluated modifications in the hemostatic balance of different concentrations of apixaban (APIX) in 25 healthy donors and 53 patients treated with aspirin (ASA, n = 21), ASA and clopidogrel (ASA + CLOPI, n = 11), or ASA and ticagrelor (ASA + TICA, n = 21). Blood samples from participants were spiked ex vivo with apixaban 0 (APIX0), 40 (APIX40), and 160 ng/mL (APIX160). We assessed the effects of APIX on (1) clot formation, by ROTEM thromboelastometry; (2) thrombin generation primed by platelets; and (3) platelet and fibrin interactions with a thrombogenic surface, in a microfluidic model with circulating blood. APIX caused dose-related prolongations of clotting time with minimal impact on other ROTEM parameters. Thrombin generation was significantly inhibited by APIX160, with ASA + TICA actions showing the strongest inhibition (p < 0.01 vs APIX0). Microfluidic studies showed that APIX160 was more potent at suppressing platelet and fibrin interactions (p < 0.001 vs. APIX0). APIX40 demonstrated a consistent antithrombotic action but with a favorable protective effect on the structural quality of fibrin. APIX potentiated the antithrombotic effects of current antiplatelet regimens. APIX at 40 ng/mL, enhanced the antithrombotic action of single or dual antiplatelet regimens but was more conservative for hemostasis than the 160 ng/mL concentration.

Phenotype-directed clinically driven low-dose direct oral anticoagulant for atrial fibrillation

Clinically-driven dose reduction of direct oral anticoagulants in individuals with atrial fibrillation is prevalent worldwide. However, a paucity of evidence to tailor dose selection remained as clinical unmet need. Current doses of anticoagulant were determined largely by landmark clinical trials, in which the enrolled subjects were carefully selected and without major comorbidities. Our study reviewed the relevant real-world studies in specific patient phenotypes, including renal and hepatic diseases, elderly, low body weight, Asians and presence of concomitant drug-drug interactions. Thorough investigations toward the efficacy and safety of direct oral anticoagulants in reduced doses will facilitate substituting current universal approach with individualized prescriptions.

Are Factor Xa Inhibitors Efficacious for Ischemic Stroke Prevention in Patients Without Atrial Fibrillation? Evidence From Randomized Clinical Trials

BACKGROUND

Clinical trials provide conflicting evidence regarding oral factor Xa inhibitors for prevention of ischemic stroke in patients without a history of atrial fibrillation (AF).

METHODS

We performed a critical appraisal of randomized clinical trials that tested oral factor Xa inhibitors in patients without AF that reported ischemic stroke.

RESULTS

Considering the 11 trials that reported > 10 ischemic strokes during follow-up (97,578 participants, 1195 ischemic strokes), 1 tested apixaban (57 strokes), 1 betrixaban (52 strokes), and 9 rivaroxaban (1086 strokes). In 7 trials with placebo comparisons, numerically fewer ischemic strokes occurred among those assigned factor Xa inhibitors in 7 of 8 randomized comparisons (range of hazard ratios [HRs], 0.89-0.51), including statistically significant reductions in 2 trials that compared rivaroxaban 2.5 mg twice daily vs placebo on a background of aspirin in patients with cardiovascular disease, COMPASS (HR, 0.51; 95% confidence interval [CI], 0.38-0.68) and COMMANDER-HF (HR, 0.64; 95% CI, 0.43-0.95). Compared with aspirin in 4 trials, oral factor Xa inhibitors were associated with fewer ischemic strokes in 2, with statistically significant reduction in 1 (rivaroxaban 5 mg twice daily in COMPASS; HR, 0.69; 95% CI, 0.53-0.90). Major bleeding was increased by oral factor Xa inhibitors in all 7 placebo-controlled trials (HR range, 1.42-4.08), with statistically significant increases reported in 5 trials, and in all 4 aspirin-controlled trials (all statistically significant increases; HR range, 1.52-2.72).

CONCLUSIONS

Aggregate evidence on the basis of placebo comparisons from randomized trials supports the potential for oral factor Xa inhibitors to reduce ischemic stroke in patients without AF, but major bleeding is increased.

Direct Oral Anticoagulants use in Patients with Stable Coronary Artery Disease, Acute Coronary Syndrome or Undergoing Percutaneous Coronary Intervention

The investigation for the optimal anticoagulation strategy for patients with stable coronary artery disease, acute coronary syndromes, and undergoing percutaneous coronary intervention constitutes a great challenge for physicians and is a field of extensive research. Although aspirin is commonly recommended as a protective measure for all patients with coronary artery disease and dual antiplatelet therapy for those undergoing procedures, such as percutaneous coronary intervention or coronary artery bypass graft surgery, the risk of recurrent cardiovascular events remains significant. In this context, the shortcomings associated with the use of vitamin K antagonists have led to the assessment of direct oral anticoagulants as promising alternatives. This review will explore and provide a comprehensive analysis of the existing data regarding the use of direct oral anticoagulants in patients with stable coronary artery disease or acute coronary syndrome, as well as their effectiveness in those undergoing percutaneous coronary intervention or coronary artery bypass graft surgery.

Dual pathway inhibition in patients with atherosclerotic disease: pharmacodynamic considerations and clinical implications

INTRODUCTION

The persistence of elevated rates of ischemic recurrences despite the use of antiplatelet therapy among patients with atherosclerotic disease together with the understanding of the pivotal role of coagulation in the thrombo-inflammatory processes involved in the pathogenesis of atherosclerosis and its complications has fostered the development of treatments targeting both platelets and coagulation, a strategy known as dual-pathway inhibition (DPI).

AREAS COVERED

In this review we discuss the recent advancements in the understanding of the interplay between coagulation, platelets and inflammation involved in the pathophysiology of atherosclerosis and atherothrombosis, as the rationale for the implementation of a DPI strategy. We also discuss the available pharmacodynamic (PD) evidence and clinical implications with the use of DPI in patients with atherosclerotic disease.

EXPERT OPINION

The implementation of a DPI by adding the so-called 'vascular dose of rivaroxaban' (i.e. 2.5 mg bis in die), on top of antiplatelet therapy has consistently been associated with reduced levels of thrombin generation in PD studies and with reduced ischemic event rates at the cost of increased bleeding compared to antiplatelet therapy alone. Further research is warranted to best define patients in whom a DPI regimen has the best safety and efficacy profile.

DOACs and Atherosclerotic Cardiovascular Disease Management: Can We Find the Right Balance Between Efficacy and Harm

PURPOSE OF REVIEW

The balance between efficacy and harm remains a challenge in the adoption of non-vitamin K antagonist direct oral anticoagulants (DOACs) for secondary atherosclerotic disease prevention. We provide a comprehensive review of the evidence for and against the addition of DOACs to the current management of atherosclerotic cardiovascular disease, including stable coronary artery disease (CAD), acute coronary syndrome (ACS), peripheral artery disease (PAD), and percutaneous coronary interventions (PCI).

RECENT FINDINGS

The DOAC class exerts pleiotropic effects on atherosclerotic progression through coagulation and inflammatory pathways. In ACS, low-dose DOAC provides no added efficacy in the setting of dual antiplatelet therapy; however, full-dose DOAC increases bleeding. Efficacy-safety profile favor use of low-dose rivaroxaban in select stable CAD or PAD patients. Atrial fibrillation patients undergoing PCI resort to dual therapy with DOAC due to prohibitory bleeding with triple anti-thrombotic therapy. Evidence favors DOAC use in CAD and PAD; however, careful individual considerations must be undertaken.

State-of-the-art-mini review: Dual pathway inhibition to reduce arterial and venous thromboembolism

Venous thromboembolism (VTE) and arterial thromboembolism (ATE) are linked by the common mechanism of thrombin generation. Historically these entities have been treated as separate pathophysiologic processes requiring different treatments: VTE, as the formation of fibrin-/coagulation-factor-derived thrombus in low flow vasculature, requiring anticoagulants; versus ATE, as largely platelet-derived thrombus in high flow vasculature, requiring antiplatelet agents. Observational studies have elucidated shared risk factors and co-morbidities predisposing individuals with VTE to ATE, and vice versa, and have bolstered the strategy of dual pathway inhibition (DPI) – the combination of low dose anticoagulants with antiplatelet agents – to reduce thrombotic outcomes on both sides of the vasculature. Randomized clinical trials have evaluated the efficacy and safety of such regimens - mostly rivaroxaban and aspirin - in high-risk groups of patients, including those with recent acute or chronic coronary syndrome, as well as those with peripheral artery disease with or without revascularization. Studies of extended VTE prophylaxis in acutely ill medical patients have also contributed to the evidence evaluating DPI. The totality of available data supports the concept that DPI can reduce major and fatal thromboembolic outcomes, including stroke, myocardial infarction, VTE, and cardiovascular death in key patient cohorts, with acceptable risk of bleeding. Further data are needed to refine which patients derive the best net clinical benefit from such an approach. At the same time, other novel agents such as contact pathway inhibitors that reduce thrombin generation without affecting hemostasis - and thus maximize safety - should be assessed in appropriate populations.

Prophylactic anticoagulation in sinus rhythm for stroke prevention in cardiovascular disease: contemporary meta-analysis of large randomized trials

AIMS

Anticoagulation with non-vitamin K oral anticoagulants (NOACs) to prevent stroke is a mainstay of atrial fibrillation (AF) management. However, multiple cardiovascular diseases (CVDs) are associated with elevated ischaemic stroke risk even in sinus rhythm. In this meta-analysis, we assess efficacy and safety of prophylactic NOAC agents for stroke prevention in patients without AF.

METHODS AND RESULTS

A search was conducted for randomized controlled trials (RCTs) that evaluated an NOAC and control drug (placebo or antiplatelet) in non-AF patients with mixed CVD. The primary efficacy and safety outcomes were ischaemic stroke and major bleeding, respectively. Results were stratified based on primary- and mini-NOAC doses. Thirteen RCTs were identified with a total of 89 383 patients with CVD in sinus rhythm (53 778 on NOAC, 35 605 on control drug; mean age 65.5 ± 2.7 years). Over a mean follow-up of 18.3 months, 1429 (1.6%) ischaemic strokes occurred. Use of NOAC was associated with 26% reduction in stroke [odds ratio (OR) 0.74, 95% confidence interval (CI) 0.62-0.87; 1.1 vs. 1.8 events per 100 person-years], with numbers needed to treat of 153 patients to prevent one stroke. Major bleeding was increased with NOAC (OR 1.74, 95% CI 1.44-2.09; 2.1 vs. 1.0 events per 100 person-years). The weighted net clinical benefit (wNCB, composite of ischaemic stroke and bleeding) did not suggest a favourable effect with any NOAC dose (wNCB for primary-dose: -0.35; mini-dose: -0.06).

CONCLUSION

Current evidence does not support use of NOACs for stroke prevention in non-AF CVD population as risk of major bleeding still exceeds ischaemic stroke benefit.

Long-Term Pharmacological Management of Reduced Ejection Fraction Following Acute Myocardial Infarction: Current Status and Future Prospects

Heart failure (HF) with reduced ejection fraction is common following acute myocardial infarction (MI), and active medical management can have a profound impact on prognosis. Reviewing relevant clinical trials, we focus on the pharmacological management of left ventricular systolic dysfunction (LVSD) following an acute MI, although there is overlap with the pharmacological management of chronic HF due to reduced ejection fraction. Angiotensin converting enzyme (ACE) inhibitors, beta-blockers, and mineralocorticoid receptor antagonists are the mainstay of medical management in patients with LVSD post MI; there may also be a role for anticoagulation. Sacubitril-valsartan (angiotensin receptor neprilysin inhibitor) has not yet been shown to be superior to an ACE inhibitor in reducing cardiovascular mortality and HF events in patients with LVSD post MI. Large randomised trials evaluating sodium glucose transporter 2 (SGLT-2) inhibitors in LVSD post MI are ongoing.

Direct Oral Anticoagulants Combined with Antiplatelet Therapy in the Treatment of Coronary Heart Disease: An Updated Meta-analysis

BACKGROUND

Direct oral anticoagulants (DOACs) combined with antiplatelet therapy for acute coronary syndrome (ACS) may reduce ischemic events, but there is no consensus on bleeding risk. Moreover, the effect of DOACs on stable coronary artery disease (CAD) needs to be elucidated. We conducted a meta-analysis to summarize the efficacy and safety of DOACs combined with antiplatelet therapy in the treatment of stable CAD and ACS.

METHODS

We searched PubMed, Web of Science, and the Cochrane Central Register of Controlled Trials, then performed a systematic review of all 17 randomized controlled trials.

RESULTS

For patients with stable CAD, DOACs combined with antiplatelet therapy significantly reduced the rate of major adverse cardiovascular events (MACE) (risk ratio; 95% confidence interval: 0.88; 0.81-0.95) and ischemic stroke (0.62; 0.50-0.77), with a relatively low risk of major bleeding (1.72; 1.42-2.07). For patients with ACS, the combination of DOACs reduced the risk of MACE (0.91; 0.85-0.97), myocardial infarction (MI) (0.90; 0.83-0.98), and ischemic stroke (0.75; 0.58-0.97), accompanied by increased non-fatal bleeding events and intracranial hemorrhage (3.42; 1.76-6.65). Results were similar when restricting the analysis to phase III studies except for the rate of stroke in patients with ACS.

CONCLUSIONS

Combination therapy reduced the incidence of MI in ACS patients, but the risk of bleeding from intracranial hemorrhaging outweighs the benefit of MACE driven by MI. That is due to combination therapy having no positive impact on mortality; thus, the benefit-risk balance may be more favorable  in patients with stable CAD.

Association of Parenteral Anticoagulation Therapy With Outcomes in Non-ST-Segment Elevation Acute Coronary Syndrome Patients Without Invasive Therapy: Findings from the Improving Care for Cardiovascular Disease in China (CCC) project

Our previous study showed that parenteral anticoagulation therapy (PACT) in the context of aggressive antiplatelet therapy failed to improve clinical outcomes in patients undergoing percutaneous coronary intervention for non-ST-segment elevation acute coronary syndrome (NSTE-ACS). However, the role of PACT in patients managed medically remains unknown. This observational cohort study enrolled patients with NSTE-ACS receiving medical therapy from November 2014 to June 2017 in the Improving Care for Cardiovascular Disease in China-Acute Coronary Syndrome project. Eligible patients were included in the PACT group and non-PACT group. The primary outcomes were in-hospital all-cause mortality and major bleeding. The secondary outcome included minor bleeding. Among 23,726 patients, 8,845 eligible patients who received medical therapy were enrolled. After adjusting the potential confounders, PACT was not associated with a lower risk of in-hospital all-cause mortality (adjusted odds ratio (OR), 1.25; 95% confidence interval (CI), 0.92-1.71; P = 0.151). Additionally, PACT did not increase the incidence of major bleeding or minor bleeding (major bleeding: adjusted OR, 1.04; 95% CI, 0.80-1.35; P = 0.763; minor bleeding: adjusted OR, 1.27; 95% CI, 0.91-1.75; P = 0.156). The propensity score analysis confirmed the primary analyses. In patients with NSTE-ACS receiving antiplatelet therapy, PACT was not associated with a lower risk of in-hospital all-cause mortality or a higher bleeding risk in patients with NSTE-ACS receiving non-invasive therapies and concurrent antiplatelet strategies. Randomized clinical trials are warranted to reevaluate the safety and efficacy of PACT in all patients with NSTE-ACS who receive noninvasive therapies and current antithrombotic strategies.

Drug interactions with apixaban: A systematic review of the literature and an analysis of VigiBase, the World Health Organization database of spontaneous safety reports

Apixaban, a direct oral anticoagulant, has emerged over the past few years because it is considered to have a low risk of drug‐drug interactions compared to vitamin K antagonists. To better characterize these interactions, we systematically reviewed studies evaluating the drug‐drug interactions involving apixaban and analyzed the drug‐drug interactions resulting in an adverse drug reaction reported in case reports and VigiBase. We systematically searched Medline, Embase, and Google Scholar up to 20 August 2018 for articles that investigated the occurrence of an adverse drug reaction due to a potential drug interacting with apixaban. Data from VigiBase came from case reports retrieved up to the 2 January 2018, where identification of potential interactions is performed in terms of two drugs, one adverse drug reaction triplet and potential signal detection using Omega, a three‐way measure of disproportionality. We identified 15 studies and 10 case reports. Studies showed significant variations in the area under the curve for apixaban and case reports highlighted an increased risk of hemorrhage or thromboembolic events due to a drug‐drug interaction. From VigiBase, a total of 1617 two drugs and one adverse drug reaction triplet were analyzed. The most reported triplet were apixaban—aspirin—gastrointestinal hemorrhage. Sixty‐seven percent of the drug‐drug interactions reported in VigiBase were not described or understood. In the remaining 34%, the majority were pharmacodynamic drug‐drug interactions. These data suggest that apixaban has significant potential for drug‐drug interactions, either with CYP3A/P‐gp modulators or with drugs that may impair hemostasis. The most described adverse drug reactions were adverse drug reactions related to hemorrhage or thrombosis, mostly through pharmacodynamic interactions. Pharmacokinetic drug‐drug interactions seem to be poorly detected.

Increased bleeding events with the addition of apixaban to the dual anti-platelet regimen for the treatment of patients with acute coronary syndrome: A meta-analysis

BACKGROUND

Dual anti-platelet therapy (DAPT) with aspirin and clopidogrel has been the mainstay of treatment for patients with acute coronary syndrome (ACS). However, the recurrence of thrombotic events, potential aspirin and clopidogrel hypo-responsiveness, and other limitations of DAPT have led to the development of newer oral anti-thrombotic drugs. Apixaban, a new non-vitamin K antagonist, has been approved for use. In this meta-analysis, we aimed to compare the bleeding outcomes observed with the addition of apixaban to DAPT for the treatment of patients with ACS.

METHODS

Online databases including EMBASE, Cochrane Central, http://www.ClinicalTrials.gov, MEDLINE and Web of Science were searched for English based publications comparing the use of apixaban added to DAPT for the treatment of patients with ACS. Different categories of bleeding events and cardiovascular outcomes were assessed. The analysis was carried out by the RevMan software version 5.4. Odds ratios (OR) with 95% confidence intervals (CI) were used to represent the data following analysis.

RESULTS

This research analysis consisted of 4 trials with a total number of 9010 participants. Thrombolysis in myocardial infarction (TIMI) defined major bleeding (OR: 2.45, 95% CI: 1.45-4.12; P = .0008), TIMI defined minor bleeding (OR: 3.12, 95% CI: 1.71-5.70; P = .0002), International society of thrombosis and hemostasis (ISTH) major bleeding (OR: 2.49, 95% CI: 1.80-3.45; P = .00001) and Global Use of Strategies to Open Occluded Arteries (GUSTO) defined severe bleeding (OR: 3.00, 95% CI: 1.56-5.78; P = .01) were significantly increased with the addition of apixaban to DAPT versus DAPT alone in these patients with ACS. However fatal bleeding (OR: 10.96, 95% CI: 0.61-198.3; P = .11) was not significantly different.

CONCLUSIONS

Addition of the novel oral anticoagulant apixaban to the DAPT regimen significantly increased bleeding and therefore did not show any beneficial effect in these patients with ACS. However, due to the extremely limited data, we apparently have to rely on future larger studies to confirm this hypothesis.

Antithrombotic Therapy in Acute Coronary Syndromes: Current Evidence and Ongoing Issues Regarding Early and Late Management

A few decades ago, the understanding of the pathophysiological processes involved in the coronary artery thrombus formation has placed anticoagulant and antiplatelet agents at the core of the management of acute coronary syndrome (ACS). Increasingly potent antithrombotic agents have since been evaluated, in various association, timing, or dosage, in numerous randomized controlled trials to interrupt the initial thrombus formation, prevent ischemic complications, and ultimately improve survival. Primary percutaneous coronary intervention, initial parenteral anticoagulation, and dual antiplatelet therapy with potent P2Y₁₂ inhibitors have become the hallmark of ACS management revolutionizing its prognosis. Despite these many improvements, much more remains to be done to optimize the onset of action of the various antithrombotic therapies, for further treating and preventing thrombotic events without exposing the patients to an unbearable hemorrhagic risk. The availability of various potent P2Y₁₂ inhibitors has opened the door for individualized therapeutic strategies based on the clinical setting as well as the ischemic and bleeding risk of the patients, while the added value of aspirin has been recently challenged. The strategy of dual-pathway inhibition with P2Y₁₂ inhibitors and low-dose non-vitamin K antagonist oral anticoagulant has brought promising results for the early and late management of patients presenting with ACS with and without indication for oral anticoagulation. In this updated review, we aimed at describing the evidence supporting the current gold standard of antithrombotic management of ACS. More importantly, we provide an overview of some of the ongoing issues and promising therapeutic strategies of this ever-evolving topic.

Use of Non-vitamin K Antagonist Oral Anticoagulants for Stroke Prevention across the Stroke Spectrum: Progress and Prospects

Multiple randomized controlled trials and many real-world evidence studies have consistently shown that non-vitamin K antagonist oral anticoagulants (NOACs) are preferable to vitamin K antagonists for thromboembolic stroke prevention in the majority of patients with atrial fibrillation (AF). However, their role in the management of patients with AF and comorbidities, as well as in other patient populations with a high risk of stroke, such as patients with prior embolic stroke of undetermined source (ESUS) and those with atherosclerosis, is less clear. There is now increasing evidence suggesting that NOACs have a beneficial effect in the prevention of stroke in patients with AF and comorbidities, such as renal impairment and diabetes. In addition, while studies investigating the efficacy and safety of NOACs for the prevention of secondary stroke in patients with a history of ESUS demonstrated neutral results, subanalyses suggested potential benefits in certain subgroups of patients with ESUS. One NOAC, rivaroxaban, has also recently been found to be effective in reducing the risk of stroke in patients with chronic cardiovascular disease including coronary artery disease and peripheral artery disease, further broadening the patient groups that may benefit from NOACs. In this article, we will review recent evidence for the use of NOACs across the stroke spectrum in detail, and discuss the progress and future prospects in the different stroke areas.

Lower dose direct oral anticoagulants and improved survival: A combined analysis in patients with established atherosclerosis

BACKGROUND

Antithrombotic/anticoagulation effects of direct oral anticoagulants (DOACs) are dose-dependent. However, recent observations suggest that administering lower dose DOACs may better protect against all-cause mortality. We investigated whether, in patients with established atherosclerosis, DOAC dose selection would affect the risk of all-cause mortality.

METHODS

We performed a structured literature research for controlled trials allowing random assignment to a lower dose DOAC, a higher dose DOAC, or control therapy in patients with established atherosclerosis. Pooled risk ratios (RRs) of all-cause mortality in lower and higher dose DOACs versus control therapy were estimated using a random-effect model.

RESULTS

Atherosclerosis manifested as acute coronary syndrome (n=17,220), stable coronary (CAD) and/or peripheral artery disease (PAD) (n=27,395) or CAD associated with atrial fibrillation (n=4,510). Antithrombotic doses of rivaroxaban (2.5 mg or 5.0 mg BID) or dabigatran (50 mg, 75 mg, 110 mg, or 150 mg, BID) were tested in three trials versus single or dual antiplatelet control therapy, whereas anticoagulation doses of edoxaban (30 mg or 60 OD) were tested versus warfarin in one trial. Compared to control, patients receiving lower dose (RR 0.80, 95% CI 0.73-0.89, p<0.0001, I²=0%), but not those receiving higher dose DOACs (RR 0.95, 95% CI 0.87-1.05, p=0.3074, I²=0%), had a significant reduction of all-cause mortality. Benefit from lower dose DOACs remained after sensitivity analysis or direct comparison with higher dose DOACs (RR 0.84, 95% CI 0.76-0.93, p=0.0009, I²=0%).

CONCLUSIONS

Within antithrombotic/anticoagulation regimens of DOAC administration, selection of lower dose appears to protect from all-cause mortality in patients with established atherosclerosis.

Different DOACs Control Inflammation in Cardiac Ischemia-Reperfusion Differently

RATIONALE

While thrombin is the key protease in thrombus formation, other coagulation proteases, such as fXa (factor Xa) or aPC (activated protein C), independently modulate intracellular signaling via partially distinct receptors.

OBJECTIVES

To study the differential effects of fXa or fIIa (factor IIa) inhibition on gene expression and inflammation in myocardial ischemia-reperfusion injury.

METHODS AND RESULTS

Mice were treated with a direct fIIa inhibitor (fIIai) or direct fXa inhibitor (fXai) at doses that induced comparable anticoagulant effects ex vivo and in vivo (tail-bleeding assay and FeCl₃-induced thrombosis). Myocardial ischemia-reperfusion injury was induced via left anterior descending ligation. We determined infarct size and in vivo aPC generation, analyzed gene expression by RNA sequencing, and performed immunoblotting and ELISA. The signaling-only 3K3A-aPC variant and inhibitory antibodies that blocked all or only the anticoagulant function of aPC were used to determine the role of aPC. Doses of fIIai and fXai that induced comparable anticoagulant effects resulted in a comparable reduction in infarct size. However, unbiased gene expression analyses revealed marked differences, including pathways related to sterile inflammation and inflammasome regulation. fXai but not fIIai inhibited sterile inflammation by reducing the expression of proinflammatory cytokines (IL [interleukin]-1β, IL-6, and TNFα [tumor necrosis factor alpha]), as well as NF-κB (nuclear factor kappa B) and inflammasome activation. This anti-inflammatory effect was associated with reduced myocardial fibrosis 28 days post-myocardial ischemia-reperfusion injury. Mechanistically, in vivo aPC generation was higher with fXai than with fIIai. Inhibition of the anticoagulant and signaling properties of aPC abolished the anti-inflammatory effect associated with fXai, while inhibiting only the anticoagulant function of aPC had no effect. Combining 3K3A-aPC with fIIai reduced the inflammatory response, mimicking the fXai-associated effect.

CONCLUSIONS

We showed that specific inhibition of coagulation via direct oral anticoagulants had differential effects on gene expression and inflammation, despite comparable anticoagulant effects and infarct sizes. Targeting individual coagulation proteases induces specific cellular responses unrelated to their anticoagulant effect.

Benefit and risk of adding rivaroxaban in patients with coronary artery disease: A systematic review and meta-analysis

Background

Although the European Medicines Agency and the US Food and Drug Administration have, respectively, approved rivaroxaban for the prevention of recurrent major adverse cardiovascular events in patients with myocardial infarction and stable coronary artery disease, its efficacy and safety is unclear. This meta‐analysis aimed to evaluate the benefit and risk of adding rivaroxaban in coronary artery disease (CAD) patients, focusing on treatment effects stratified by different baseline clinical presentations.

Hypothesis

There are differences in treatment effects of adding rivaroxaban among CAD patients with different baseline clinical presentations.

Methods

Medline, EMBASE, and Cochrane Databases were systematically searched from inception to 21 July 2020 for randomized controlled trials (RCTs) comparing rivaroxaban in CAD patients. The primary efficacy endpoint and safety endpoint were assessed by using Mantel–Haenszel pooled risk ratios (RRs) and 95% confidence intervals (CIs).

Results

Five RCTs that included 43 650 patients were identified. Patients receiving rivaroxaban had a significantly lower risk of the primary efficacy endpoint (RR, 0.86; 95% CI, 0.76–0.97, p = .01) accompanied by increased risk of the primary safety endpoint (RR, 1.83; 95% CI, 1.10–3.05, p = .02). Subgroup analyses showed that in males the risk–benefit appears to be more favorable while in patients ≥65 years, in females, in patients with diabetes, those with mild to moderate impaired renal function, and region of Asia/other seems unfavorable.

Conclusion

Rivaroxaban may provide an additional choice for secondary prevention in CAD patients. However, careful estimation of the risk of ischemic and bleeding events using patient characteristics are critical to achieving net benefit.

Twice- or Once-Daily Dosing of Direct Oral Anticoagulants, a systematic review and meta-analysis

AIM

The direct oral anticoagulants (DOAC) have similar half-lives, but the dosing regimen varies between once daily (QD) or twice daily (BID). For some prescribers, the QD regimen improves compliance. Others prefer BID regimens to promote better stability of plasma concentrations, particularly in the event of missed doses. Limited level of evidence provides guidance about the best treatment strategy. The purpose of this study was to compare the treatment effect of QD vs. BID administration of DOACs in major orthopedic surgery (MOS), non-valvular atrial fibrillation (NVAF), venous thromboembolism (VTE), and acute coronary syndrome (ACS).

METHODS

We conducted a systematic review up to April 2020. We included phase II clinical trials comparing DOAC QD vs BID with same daily dose. We extracted data for the occurrence of major thrombosis (proximal deep vein thrombosis, pulmonary embolism, myocardial infarction, ischemic stroke) and major hemorrhage (ISTH criteria and recommendations of the European Medicines Agency for surgical patients). Relative risks (RR) were combined using a fixed and random effects weighted meta-analysis.

RESULTS

Twelve randomized, controlled, phase II trials were included (10,716 patients), representing 24 dosing regimen comparisons of apixaban, darexaban, edoxaban, rivaroxaban, letaxaban, and dabigatran. There was no difference for major thrombotic event (RR_BID/QD = 1.06, 95%IC 0.86-1.30) nor for major bleeding (RR_BID/QD = 1.02, 95%IC 0.84-1.23) between the BID vs QD regimens, without heterogeneity (I² = 0%).

CONCLUSION

Our study does not support a global difference in term of efficacy and safety of the BID and QD regimens of DOAC in MOS, NVAF, VTE and ACS.

Rivaroxaban for the prevention of major adverse cardiovascular events in patients with coronary or peripheral artery disease

In the COMPASS trial, the combination of rivaroxaban 2.5 mg twice daily and low-dose aspirin 75-100 mg daily produced a net clinical benefit of 20% in patients with chronic atherosclerotic vascular disease because it reduced major adverse events by 24% and overall mortality by 18% despite an initial increase in major bleeding. In this paper, we examine the rationale for targeting coagulation factor Xa in patients with atherosclerosis, summarize the pharmacology of the 2.5-mg dose, review the trials that led to the approval of the combination of rivaroxaban and aspirin for the long-term management of patients with chronic coronary artery disease or peripheral artery disease and discuss who would benefit the most. We also address the unresolved issues and challenges in the implementation of this therapy.

Apixaban versus No Anticoagulation in Patients Undergoing Long-Term Dialysis with Incident Atrial Fibrillation

BACKGROUND AND OBJECTIVES

The relative efficacy and safety of apixaban compared with no anticoagulation have not been studied in patients on maintenance dialysis with atrial fibrillation. We aimed to determine whether apixaban is associated with better clinical outcomes compared with no anticoagulation in this population.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This retrospective cohort study used 2012-2015 US Renal Data System data. Patients on maintenance dialysis with incident, nonvalvular atrial fibrillation treated with apixaban (521 patients) were matched for relevant baseline characteristics with patients not treated with any anticoagulant agent (1561 patients) using a propensity score. The primary outcome was hospital admission for a new stroke (ischemic or hemorrhagic), transient ischemic attack, or systemic thromboembolism. The secondary outcome was fatal or intracranial bleeding. Competing risk survival models were used.

RESULTS

Compared with no anticoagulation, apixaban was not associated with lower incidence of the primary outcome: hazard ratio, 1.24; 95% confidence interval, 0.69 to 2.23; P=0.47. A significantly higher incidence of fatal or intracranial bleeding was observed with apixaban compared with no treatment: hazard ratio, 2.74; 95% confidence interval, 1.37 to 5.47; P=0.004. A trend toward fewer ischemic but more hemorrhagic strokes was seen with apixaban compared with no treatment. No significant difference in the composite outcome of myocardial infarction or ischemic stroke was seen with apixaban compared with no treatment. Compared with no anticoagulation, a significantly higher rate of the primary outcome and a significantly higher incidence of fatal or intracranial bleeding and of hemorrhagic stroke were seen in the subgroup of patients treated with the standard apixaban dose (5 mg twice daily) but not in patients who received the reduced apixaban dose (2.5 mg twice daily).

CONCLUSIONS

In patients with kidney failure and nonvalvular atrial fibrillation, treatment with apixaban was not associated with a lower incidence of new stroke, transient ischemic attack, or systemic thromboembolism but was associated with a higher incidence of fatal or intracranial bleeding.

PODCAST

This article contains a podcast at https://www.asn-online.org/media/podcast/CJASN/2020_05_29_CJN11650919.mp3.

The Combination of Oral Anticoagulant and Antiplatelet Therapies: Stay One Step Ahead

Antithrombotic drugs, which include antiplatelets and anticoagulants, are effective in prevention and treatment of many cardiovascular disorders such as acute coronary syndromes, stroke, and venous thromboembolism and are among the drugs most commonly prescribed worldwide. The advent of direct oral anticoagulants, which are safer alternatives to vitamin K antagonists and do not require laboratory monitoring, has revolutionized the treatment of nonvalvular atrial fibrillation and venous thromboembolism. The combination of oral anticoagulant and antiplatelet therapy is required in many conditions of great clinical impact such as the coexistence of atrial fibrillation and coronary artery disease, with indication to percutaneous coronary intervention. However, strategies that combine anticoagulant and antiplatelet therapies lead to a significant increase in bleeding rates and it is crucial to find the right combination in the single patient in order to optimize the ischemic and bleeding risk. The aim of this review is to explore the evidence and controversies regarding the optimal combination of anticoagulant and antiplatelet therapy through the consideration of past dogmas and new perspectives from recent clinical trials and to propose a tailored therapeutic approach, according to specific clinical scenarios and individual patient characteristics. In particular, we separately explored the clinical settings of stable and acute coronary syndromes and percutaneous revascularization in patients with atrial fibrillation.

Risk of Major Gastrointestinal Bleeding With New vs Conventional Oral Anticoagulants: A Systematic Review and Meta-analysis

BACKGROUND & AIMS

There is controversy over whether use of non-vitamin K antagonist oral anticoagulants (NOACs) associates with increased risk of major gastrointestinal bleeding (GIB) compared with conventional therapies (such as vitamin K antagonists or anti-platelet agents). We performed a systematic review and meta-analysis of data from randomized controlled trials and high-quality real-world studies.

METHODS

We performed a systematic search of the MEDLINE, EMBASE, Cochrane Library, and ClinicalTrials.gov Website databases (through Oct 12, 2018) for randomized controlled trials and high-quality real-world studies that reported major GIB events in patients given NOACs or conventional therapy. Relative risks (RRs) for randomized controlled trials and adjusted hazard ratios (aHRs) for real-world studies were calculated separately using random-effects models.

RESULTS

We analyzed data from 43 randomized controlled trials (183,752 patients) and 41 real-world studies (1,879,428 patients). The pooled major rates of GIB for patients on NOACs (1.19%) vs conventional treatment (0.92%) did not differ significantly (RR from randomized controlled trials, 1.09; 95% CI, 0.91-1.31 and aHR from real-world studies, 1.02; 95% CI, 0.94-1.10; P_interaction=.52). Rivaroxaban, but not other NOACs, was associated with an increased risk for major GIB (RR from randomized controlled trials, 1.39; 95% CI, 1.17-1.65 and aHR from real-world studies, 1.14; 95% CI, 1.04-1.23; P_interaction = .06). Analyses of subgroups, such as patients with different indications, dosage, or follow-up time, did not significantly affect results. Meta-regression analysis failed to detect any potential confounding to impact the primacy outcome.

CONCLUSIONS

In a systematic review and meta-analysis of data from randomized controlled trials and real-world studies, we confirmed that there is no significant difference in risk of major GIB between patients receiving NOACs vs conventional treatment. Rivaroxaban users had a 39% increase in risk for major GIB.

Drug-Drug Interactions with Direct Oral Anticoagulants

A large body of evidence suggests that not only direct anticoagulant effects but also major bleeding events and stroke prevention depend on plasma concentrations of direct oral anticoagulants (DOACs). Concomitant drugs that cause drug–drug interactions (DDIs) alter DOAC exposure by increasing or decreasing DOAC bioavailability and/or clearance; hence, they might affect the efficacy and safety of DOAC therapy. Patients with renal impairment already receive smaller DOAC maintenance doses because avoidance of elevated DOAC exposure might prevent serious bleeding events. For other causes of increased exposure such as DDIs, management is often less well-defined. Considering that DOAC patients are often older and have multiple co-morbidities, polypharmacy is highly prevalent. However, the effect of multiple drugs on DOAC exposure, and especially the impact of DDIs when concurring with drug–disease interactions as observed in renal impairment, has not been thoroughly elucidated. In order to provide effective and safe anticoagulation with DOACs, understanding the mechanisms and magnitude of DDIs appears relevant. Instead of avoiding drug combinations with DOACs, more DDI trials should be conducted and new strategies such as dose adjustments based on therapeutic drug monitoring should be investigated. However, dose adjustments based on concentration measurements cannot currently be recommended because evidence-based data are missing.

CYP2C19*17 May Increase the Risk of Death Among Patients with an Acute Coronary Syndrome and Non-Valvular Atrial Fibrillation Who Receive Clopidogrel and Rivaroxaban

INTRODUCTION

The aim of this study is to assess the influence of gene CYP2C19, CYP3A4, CYP3A5 and ABCB1 polymorphisms on clopidogrel antiplatelet activity, rivaroxaban concentration equilibrium, and clinical outcomes among patients with acute coronary syndrome and non-valvular atrial fibrillation.

METHODS

In the multicenter prospective registry study of the efficacy and safety of a combined antithrombotic therapy 103 patients with non-valvular atrial fibrillation both undergoing or not a percutaneous coronary intervention were enrolled. The trial assessed the primary outcomes (major bleeding, in-hospital death, cardiovascular death, stroke\transient ischaemic attack, death/renal insufficiency) and secondary outcomes (platelet reactivity units (PRU), rivaroxaban concentration).

RESULTS

For none of the clinical outcomes when combined with other covariates, the carriership of polymorphisms CYP3A5*3 rs776746, CYP2C19*2 rs4244285;*17 rs12248560, ABCB1 3435 C>T, ABCB1 rs4148738 was significant. None of the markers under study (CYP3A5*3 rs776746, CYP2C19*2 rs4244285, *17 rs12248560, ABCB1 3435 C>T, ABCB1 rs4148738) has proven to affect rivaroxaban equilibrium concentration in blood plasma among patients with atrial fibrillation and acute coronary syndrome.

CONCLUSION

In situations of double or triple antithrombotic rivaroxaban and clopidogrel therapy among patients with atrial fibrillation and acute coronary syndrome, the genetic factors associated with bleeding complications risk (CYP2C19*17) may prove to be clinically relevant.

Dual-pathway inhibition for secondary and tertiary antithrombotic prevention in cardiovascular disease

Advances in antiplatelet therapies for patients with cardiovascular disease have improved patient outcomes over time, but the challenge of balancing the risks of ischaemia and bleeding remains substantial. Moreover, many patients with cardiovascular disease have a residual risk of ischaemic events despite receiving antiplatelet therapy. Therefore, novel strategies are needed to prevent clinical events through mechanisms beyond platelet inhibition and with an acceptable associated risk of bleeding. The advent of non-vitamin K antagonist oral anticoagulants, which attenuate fibrin formation by selective inhibition of factor Xa or thrombin, has renewed the interest in dual-pathway inhibition strategies that combine an antiplatelet agent with an anticoagulant drug. In this Review, we highlight the emerging pharmacological rationale and clinical development of dual-pathway inhibition strategies for the prevention of atherothrombotic events in patients with different manifestations of cardiovascular disease, such as coronary artery disease, cerebrovascular disease and peripheral artery disease.

Non-vitamin K antagonist oral anticoagulants (NOACs) post-percutaneous coronary intervention: a network meta-analysis

BACKGROUND

Clinicians must balance the risks of bleeding and thrombosis after percutaneous coronary intervention (PCI) in people with an indication for anticoagulation. The potential of non-vitamin K antagonists (NOACs) to prevent bleeding complications is promising, but evidence remains limited.

OBJECTIVES

To review the evidence from randomised controlled trials assessing the efficacy and safety of non-vitamin K antagonist oral anticoagulants (NOACs) compared to vitamin K antagonists post-percutaneous coronary intervention (PCI) in people with an indication for anticoagulation.

SEARCH METHODS

We identified studies by searching CENTRAL, MEDLINE, Embase, the Conference Proceedings Citation Index - Science and two clinical trials registers in February 2019. We checked bibliographies of identified studies and applied no language restrictions.

SELECTION CRITERIA

We searched for randomised controlled trials (RCT) that compared NOACs and vitamin K antagonists for people with an indication for anticoagulation who underwent PCI.

DATA COLLECTION AND ANALYSIS

Two review authors independently checked the results of searches to identify relevant studies, assessed each included study, and extracted study data. We conducted random-effects, pairwise analyses using Review Manager 5 and network meta-analyses (NMA) using the R package 'netmeta'. We ranked competing treatments by P scores, which are derived from the P values of all pairwise comparisons, and allow ranking of treatments on a continuous 0 to 1 scale.

MAIN RESULTS

We identified nine RCTs that met the inclusion criteria, but four were ongoing trials, and were not included in this analysis. We included five RCTs, with 8373 participants, in the NMA (two RCTs compared apixaban to a vitamin K antagonist, two RCTs compared rivaroxaban to a vitamin K antagonist, and one RCT compared dabigatran to a vitamin K antagonist). Very low- to moderate-certainty evidence suggests little or no difference between NOACs and vitamin K antagonists in death from cardiovascular causes (not reported in the dabigatran trial), myocardial infarction, stroke, death from any cause, and stent thrombosis. Apixaban (RR 0.85, 95% CI 0.77 to 0.95), high dose rivaroxaban (RR 0.86, 95% CI 0.74 to 1.00), and low dose rivaroxaban (RR 0.80, 95% CI 0.68 to 0.92) probably reduce the risk of recurrent hospitalisation compared with vitamin K antagonists. No studies looked at health-related quality of life. Very low- to moderate-certainty evidence suggests that NOACs may be safer than vitamin K antagonists in terms of bleeding. Both high dose dabigatran (RR 0.53, 95% CI 0.29 to 0.97), and low dose dabigatran (RR 0.38, 95% CI 0.21 to 0.70) may reduce major bleeding more than vitamin K antagonists. High dose dabigatran (RR 0.83, 95% CI 0.72 to 0.96), low dose dabigatran (RR 0.66, 95% CI 0.58 to 0.75), apixaban (RR 0,67 , 95% Cl 0.51 to 0.88), high dose rivaroxaban (RR 0.66, 95% CI 0.52 to 0.83), and low dose rivaroxaban (RR 0.71, 95% CI 0.57 to 0.88) probably reduce non-major bleeding more than vitamin K antagonists. The results from the NMA were inconclusive between the different NOACs for all primary and secondary outcomes.

AUTHORS' CONCLUSIONS

Very low- to moderate-certainty evidence suggests no meaningful difference in efficacy outcomes between non-vitamin K antagonist oral anticoagulants (NOAC) and vitamin K antagonists following percutaneous coronary interventions (PCI) in people with non-valvular atrial fibrillation. NOACs probably reduce the risk of recurrent hospitalisation for adverse events compared with vitamin K antagonists. Low- to moderate-certainty evidence suggests that dabigatran may reduce the rates of major and non-major bleeding, and apixaban and rivaroxaban probably reduce the rates of non-major bleeding compared with vitamin K antagonists. Our network meta-analysis did not show superiority of one NOAC over another for any of the outcomes. Head to head trials, directly comparing NOACs against each other, are required to provide more certain evidence.

The 2018 European Heart Rhythm Association Practical Guide on the use of non-vitamin K antagonist oral anticoagulants in patients with atrial fibrillation

The current manuscript is the second update of the original Practical Guide, published in 2013 [Heidbuchel et al. European Heart Rhythm Association Practical Guide on the use of new oral anticoagulants in patients with non-valvular atrial fibrillation. Europace 2013;15:625-651; Heidbuchel et al. Updated European Heart Rhythm Association Practical Guide on the use of non-vitamin K antagonist anticoagulants in patients with non-valvular atrial fibrillation. Europace 2015;17:1467-1507]. Non-vitamin K antagonist oral anticoagulants (NOACs) are an alternative for vitamin K antagonists (VKAs) to prevent stroke in patients with atrial fibrillation (AF) and have emerged as the preferred choice, particularly in patients newly started on anticoagulation. Both physicians and patients are becoming more accustomed to the use of these drugs in clinical practice. However, many unresolved questions on how to optimally use these agents in specific clinical situations remain. The European Heart Rhythm Association (EHRA) set out to coordinate a unified way of informing physicians on the use of the different NOACs. A writing group identified 20 topics of concrete clinical scenarios for which practical answers were formulated, based on available evidence. The 20 topics are as follows i.e., (1) Eligibility for NOACs; (2) Practical start-up and follow-up scheme for patients on NOACs; (3) Ensuring adherence to prescribed oral anticoagulant intake; (4) Switching between anticoagulant regimens; (5) Pharmacokinetics and drug-drug interactions of NOACs; (6) NOACs in patients with chronic kidney or advanced liver disease; (7) How to measure the anticoagulant effect of NOACs; (8) NOAC plasma level measurement: rare indications, precautions, and potential pitfalls; (9) How to deal with dosing errors; (10) What to do if there is a (suspected) overdose without bleeding, or a clotting test is indicating a potential risk of bleeding; (11) Management of bleeding under NOAC therapy; (12) Patients undergoing a planned invasive procedure, surgery or ablation; (13) Patients requiring an urgent surgical intervention; (14) Patients with AF and coronary artery disease; (15) Avoiding confusion with NOAC dosing across indications; (16) Cardioversion in a NOAC-treated patient; (17) AF patients presenting with acute stroke while on NOACs; (18) NOACs in special situations; (19) Anticoagulation in AF patients with a malignancy; and (20) Optimizing dose adjustments of VKA. Additional information and downloads of the text and anticoagulation cards in different languages can be found on an EHRA website (www.NOACforAF.eu).

Non-Vitamin K Antagonist Oral Anticoagulants in Medical Conditions at High Risk of Thromboembolism beyond Atrial Fibrillation

Non-Vitamin K antagonist oral anticoagulants (NOACs) have been extensively investigated in medical conditions at high risk of venous or arterial thrombosis other than atrial fibrillation (AF), including hip or knee arthroplasty, acute venous thromboembolism (VTE), cancer-associated VTE, acute coronary syndrome (ACS), stable atherosclerotic vascular disease, chronic heart failure, and embolic stroke of undetermined source (ESUS). Two large ESUS trials failed to show the benefit of rivaroxaban or dabigatran, and large randomized controlled trial (RCT) data of NOACs are lacking for another potential candidates of patent foramen ovale-related stroke, acute ischemic stroke, and cerebral venous thrombosis. On the other hand, high quality evidences of NOACs have been compiled for VTE prophylaxis after hip or knee arthroplasty, acute VTE, cancer-associated VTE, and concomitant ACS and AF, which have been reflected in clinical practice guidelines. In addition, RCTs showed the benefit of very low dose rivaroxaban in combination with antiplatelet therapy in patients with ACS and in those with stable cardiovascular disease. This article summarizes the accumulated evidences of NOACs in cardiovascular diseases beyond AF, and aims to inform healthcare providers of optimal regimens tailored to individual medical conditions and help investigators design future clinical trials.

Antithrombotic therapy in patients with atrial fibrillation and coronary artery disease

Atrial fibrillation and coronary artery disease are commonly coexisting conditions that necessitate the use of an oral anticoagulant as well as dual antiplatelet therapy. Commonly referred to as triple oral antithrombotic therapy (TT), this helps prevent ischemic stroke and myocardial infarction but comes at the expense of an increased risk of bleeding. There is a growing body of evidence that the omission of aspirin from TT has the same preventive efficacy in terms of major adverse cardiacvascular and cerebrovascular events (MACCE) with significantly lower bleeding events. The combination of antiplatelet agents and direct oral anticoagulants (DOAC) is a matter of ongoing research. However, initial studies showed favorable safety profile of DOAC over vitamin K antagonist in combination with antiplatelet agents.

Rivaroxaban With or Without Aspirin for the Secondary Prevention of Cardiovascular Disease: Clinical Implications of the COMPASS Trial

The COMPASS trial compared the impact of the selective direct factor Xa inhibitor, rivaroxaban, as monotherapy or in combination with aspirin on major adverse cardiovascular events (MACE) in patients with stable atherosclerotic disease. Patients treated with rivaroxaban 2.5 mg twice daily in combination with aspirin experienced fewer cardiovascular events but more bleeding complications than those who received aspirin monotherapy. In contrast, a higher dose of rivaroxaban (5 mg twice daily) and aspirin produced no clinical benefit and continued to be associated with greater bleeding rates than aspirin. Examining this study in the context of other trials of anticoagulant therapy in atherosclerotic vascular disease, this review attempts to place the role of very low-dose rivaroxaban in clinical context and highlights areas for future research.

Efficacy and Safety of Antiplatelet Therapy Plus Xa Factor Inhibitors in Patients with Coronary Heart Disease: A Meta-Analysis

Background

The aim of this study was to systematically evaluate the effect of oral Xa inhibitors plus antiplatelet therapy in the treatment of coronary artery disease.

Material/Methods

All randomized controlled trials (RCTs) about antiplatelet therapy plus Xa factor inhibitors for coronary artery disease from database inception to January 2019 were searched for and collected from PubMed, Embase, and the Cochrane Library. Two reviewers extracted and analyzed the data independently. Additionally, RevMan 5.0 software was applied for meta-analysis.

Results

Seven RCTs with 50 044 patients were included. The meta-analysis results showed that treatment with antiplatelet therapy plus Xa factor inhibitors in patients with coronary artery disease could significantly reduce the risk of ischemic events (P<0.00001). Besides, risk of all-cause mortality (P=0.003), myocardial infarction (P=0.02) and ischemic stroke (P<0.0001) were also significantly reduced. However, risk of massive hemorrhage after TIMI (P<0.00001), minor hemorrhage after TIMI (P<0.00001), and intracranial hemorrhage (P=0.006) were significantly increased, respectively. Xa inhibition drugs also intended to increase risk of fatal bleeding, but there was no significant difference (P=0.08).

Conclusions

Antiplatelet therapy plus Xa factor inhibitors in patients with coronary artery disease was effective, which could reduce the risk of ischemic composite endpoints, all-cause mortality, myocardial infarction, and ischemic stroke. However, it could significantly increase risk of bleeding in terms of safety.

[Antithrombotic Therapy in Atrial Fibrillation and Chronic Ischemic Heart Disease]

The review is devoted to the use of antithrombotic therapy in patients with atrial fibrillation (AF) and chronic ischemic heart disease (IHD). We discuss data of international registries, meta-analyses assessing possibilities of the use of oral anticoagulants for secondary prevention of IHD. We present here results of randomized and observational clinical studies demonstrating advantages of prescription of monotherapy with oral anticoagulants (OAC) in combination of AF and chronic IHD. Modern evidence base of advantages of dual antithrombotic therapy with the use of direct OAC following percutaneous coronary intervention is also presented.

Anticoagulation in Acute Coronary Syndrome: Review of Major Therapeutic Advances

BACKGROUND

In patients with acute coronary syndrome (ACS), a persistent hypercoagulable state has been demonstrated and antithrombin therapy in addition to platelet inhibition has been proposed.

AREAS OF UNCERTAINTY

Vitamin K antagonists (VKAs) were used as oral anticoagulant (OAC) therapy and produced mixed results whereas trials are still ongoing with non-vitamin K OACs (NOACs).

DATA SOURCES

A literature search regarding benefits and risks of different OAC therapies in ACS was conducted through MEDLINE and EMBASE (last 20 years until September 2018).

THERAPEUTIC ADVANCES

Patients receiving dual antiplatelet therapy (DAPT) in combination with NOAC are to be considered at high bleeding risk. Rivaroxaban 2.5 mg BID in triple therapy with DAPT, rivaroxaban 15 mg, or dabigatran 110/150 mg BID in dual therapy with P2Y12 inhibitor (mainly clopidogrel) is safer in terms of bleeding risk than triple therapy with VKA plus DAPT. The reduction in ischemic events by NOACs was most promising when added to single antiplatelet therapy. Ongoing trials with apixaban and edoxaban could clarify whether dual therapy NOACs with P2Y12 inhibitor sufficiently protect against stent thrombosis or myocardial infarction and are safer in terms of bleeding risk than a dual therapy with a VKA and clopidogrel. In the absence of randomized trials, it is unknown whether dual therapy with NOAC and aspirin could be an alternative to NOAC and a P2Y12 inhibitor. Thus, the overall benefit of adding NOAC to antiplatelet treatment after ACS in patients without clear indication for long-term OAC is still unknown.

CONCLUSIONS

Different OACs have been tested as antithrombotic therapy after ACS in combination with single or DAPT and led to a modest reduction in ischemic events. Further studies evaluating NOACs in combination with single antiplatelet therapy or shorter duration of triple antithrombotic therapy are warranted.

Efficacy and Safety of the Use of Non-vitamin K Antagonist Oral Anticoagulants in Patients with Ischemic Heart Disease: A Meta-Analysis of Phase III Randomized Trials

BACKGROUND

There are conflicting published data on non-vitamin K antagonist oral anticoagulants (NOACs), with varying evidence of benefit or harm in acute coronary syndrome (ACS) and non-ACS cohorts. To explore the efficacy and safety of NOAC use in patients with ischemic heart disease (IHD), we conducted a meta-analysis of phase III randomized controlled trials (RCTs).

METHODS

We systematically searched the Cochrane Library, PubMed, and Embase databases. A random-effect model was selected to pool the effect measurement estimates (hazard ratios [HRs] and 95% confidence intervals [CIs]).

RESULTS

Three RCTs with 39,492 enrolled IHD patients were included. Compared with placebo, NOACs were associated with reduced risks of major adverse cardiac events (MACE) (HR 0.83, 95% CI 0.76-0.90), cardiovascular death (HR 0.82, 95% CI 0.72-0.93), and myocardial infarction (HR 0.87, 95% CI 0.78-0.97) accompanied by increased risks of major bleeding (HR 2.46, 95% CI 1.42-4.26), but not fatal bleeding (HR 1.35, 95% CI 0.76-2.39) or intracranial hemorrhage (HR 2.19, 95% CI 0.91-5.27). Subgroup analysis revealed that NOACs were associated with an increased risk of major bleeding in patients who received dual antiplatelet therapy compared with patients who received single antiplatelet therapy (3.01, 1.82-4.98 vs. 1.66, 1.37-2.03; P for interaction 0.03) and patients with ACS compared with patients with non-ACS (3.27, 2.16-4.95 vs. 1.66, 1.36-2.02; P for interaction 0.004).

CONCLUSIONS

In patients with IHD, NOACs confer protection against thrombosis-related complications, but at the cost of an increased hazard of major bleeding. NOACs plus a single antiplatelet drug seem to be a good choice for patients with IHD.

Direct Oral Anticoagulants in Addition to Antiplatelet Therapy for Secondary Prevention after Acute Coronary Syndromes: a Review

PURPOSE OF REVIEW

As the management of acute coronary syndrome (ACS) continues to evolve, many old practices proved to be of a little benefit and other approaches established the new pillars of modern medicine. Treating ACS patients with dual antiplatelet therapy (DAPT) for a year by combining aspirin and a P2Y12 inhibitor (clopidogrel, ticagrelor, or prasugrel) has resulted in better outcomes and is currently the standard of therapy. However, owing to the persistent activation of the coagulation cascade, patients may continue to experience recurrent ischemia and high mortality rates despite compliance with the dual antiplatelet therapy. Research is underway to establish new treatment modalities for secondary prevention post-ACS, including the use of the novel direct oral anticoagulants (DOACs).

RECENT FINDINGS

Multiple trials have been conducted to evaluate the use of DOACs for the secondary prevention after ACS. Recent emerging data showed that the addition of rivaroxaban in a very low dose of 2.5 mg twice daily to the regular DAPT regimen after ACS is beneficial in the reduction of major cardiovascular events, including recurrent myocardial infarction (MI) and strokes. On the other hand, other DOACs, including apixaban, did not show similar efficacy and did not improve the cardiovascular outcomes. Patients who experience an ACS continue to suffer long-term consequences and thromboembolic complications. Many studies have shown that after the initial ACS event, patients remain in a hypercoagulable state and are more prone to recurrent ischemic attacks including stroke, recurrent MI, or unstable angina (UA). With the objective of seeking better outcomes, it is imperative to explore more aggressive anticoagulation strategies in ACS patients. In this article, we discuss the progress that was made and the limitations we face regarding the role of different anticoagulants in this setting.

Direct Oral Anticoagulants in Cirrhotic Patients: Current Evidence and Clinical Observations

The introduction of Direct Oral Anticoagulants (DOACs) to the pharmaceutical market provided patients and clinicians with novel convenient and safe options of anticoagulation. The use of this class of medications is currently limited to venous thromboembolic therapy and prophylaxis, in addition to stroke prophylaxis in patients with nonvalvular atrial fibrillation. Despite their altered hemostasis, patients with cirrhosis are thought to be in a procoagulant state and thus prone to thrombus formation. Patients with cirrhosis might benefit from the convenience of DOACs; however, the medical literature includes limited data on the efficacy and safety of DOACs in this special patient population. The aim of this review is to summarize the current evidence for anticoagulation options in patients with cirrhosis and their safety profile.