Oral anticoagulant therapy in patients with coronary artery disease: a meta-analysis

Association of antiplatelet therapy with clinical outcomes in patients with peripheral artery disease

BACKGROUND

The beneficial role of dual anti-platelet therapy (DAPT) in coronary artery disease is well established. However, there is limited data describing the effects of DAPT in patients with atherosclerotic peripheral artery disease (PAD). The aim of this meta-analysis is to compare clinical outcomes associated with DAPT versus single anti-platelet therapy (SAPT) in patients with symptomatic PAD.

METHODS

We performed a literature search for studies assessing the risk of adverse cardiovascular and limb events in cohorts receiving either DAPT or SAPT. The primary endpoint was all cause mortality. The secondary endpoints included graft failure, amputation, total bleeding, severe bleeding and fatal bleeding. The search included the following databases: Ovid MEDLINE, EMBASE, Web of Science, and Google Scholar. The search was not restricted to time or publication status.

RESULTS

A total of 11 studies with 54,331 participants (24,449 on SAPT and 29,882 on DAPT) were included. Patients with PAD treated with SAPT had higher all-cause mortality compared to patients treated with DAPT (OR 1.37, 95 % CI 1.09-1.74; p < 0.01). There was no difference in risk of graft failure or amputation between patients treated with SAPT or DAPT (OR 0.9, 95 % CI 0.77-1.06; p = 0.19; OR 1.11, 95 % CI 0.88-1.41; p = 0.37). Patients treated with SAPT had lower total bleeds compared to patients treated with DAPT (OR 0.53, 95 % CI 0.36-0.77; p < 0.01). However, For SAPT plus AC vs SAPT, a total of 8 studies with 17,100 participants (3447 with SAPT plus AC and 8619 with only SAPT) were included. Patients on SAPT plus AC did not have a statistically significant difference in risk for all-cause mortality, (OR 0.91, 95 % CI 0.67-1.24; p = 0.56). SAPT plus AC had significantly lower risk of MI (OR 0.82, 95 % CI 0.69-0.97; p = 0.02), amputation (OR 0.72, 95 % CI 0.53-0.97; p = 0.03), and graft failure (OR 0.66, 95 % CI 0.48-0.93; p = 0.02). There was no significant different in risk of fatal bleeding be-tween the two groups (OR 1.60, 95 % CI 0.76-3.35; p = 0.22).

CONCLUSIONS

In patients with symptomatic PAD, a strategy of DAPT may confer a mortality benefit when compared to SAPT without significantly increasing the risk of serious bleeding events.

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

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

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.

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.

Low-dose rivaroxaban and aspirin among patients with peripheral artery disease: a meta-analysis of the COMPASS and VOYAGER trials

AIMS

Peripheral artery disease (PAD) patients suffer a high risk of major cardiovascular (CV) events, with athero-thrombo-embolism as the underlying pathophysiologic mechanism. Recently, two large randomized clinical trials evaluated the efficacy and safety of low-dose rivaroxaban twice daily plus aspirin in stable PAD outpatients and those immediately after peripheral revascularization. We sought to determine if the effects of low-dose rivaroxaban and aspirin compared to aspirin alone are consistent across this broad spectrum of PAD patients.

METHODS AND RESULTS

We conducted a random-effects meta-analysis of the COMPASS and VOYAGER randomized trials among 11 560 PAD patients (4996 from COMPASS and 6564 from VOYAGER) in the primary analysis and 9332 (2768 from COMPASS and 6564 from VOYAGER) with lower extremity (LE)-PAD in the secondary analysis. The hazard ratio (HR) for the composite of CV death, myocardial infarction, ischaemic stroke, acute limb ischaemia, or major vascular amputation was 0.79 (95% confidence interval, CI: 0.65-0.95) comparing low-dose rivaroxaban plus aspirin to aspirin alone. While the risk of major bleeding was increased with low-dose rivaroxaban plus aspirin compared to aspirin alone [HR: 1.51 (95% CI: 1.22-1.87)], there was no significant increase in severe bleeding [HR: 1.18 (95% CI: 0.79-1.76)]. Similar effects were observed in the subset with symptomatic LE-PAD.

CONCLUSIONS

Among PAD patients, low-dose rivaroxaban plus aspirin is superior to aspirin alone in reducing CV and limb outcomes including acute limb ischaemia and major vascular amputation. This reduction is offset by a relative increase in major bleeding, but not by an excess of fatal or critical organ bleeding. The consistency of findings of these trials supports the use of combination low-dose rivaroxaban plus aspirin in PAD patients across a broad spectrum of disease.

Natural Coumarins: Exploring the Pharmacological Complexity and Underlying Molecular Mechanisms

Coumarins belong to the benzopyrone family commonly found in many medicinal plants. Natural coumarins demonstrated a wide spectrum of pharmacological activities, including anti-inflammatory, anticoagulant, anticancer, antibacterial, antimalarial, casein kinase-2 (CK2) inhibitory, antifungal, antiviral, Alzheimer's disease inhibition, neuroprotective, anticonvulsant, phytoalexins, ulcerogenic, and antihypertensive. There are very few studies on the bioavailability of coumarins; therefore, further investigations are necessitated to study the bioavailability of different coumarins which already showed good biological activities in previous studies. On the evidence of varied pharmacological properties, the present work presents an overall review of the derivation, availability, and biological capacities of coumarins with further consideration of the essential mode of their therapeutic actions. In conclusion, a wide variety of coumarins are available, and their pharmacological activities are of current interest thanks to their synthetic accessibility and riches in medicinal plants. Coumarins perform the valuable function as therapeutic agents in a range of medical fields.

Efficacy and safety of low dose rivaroxaban in patients with coronary heart disease: a systematic review and meta-analysis

The mortality effects and risk-benefit profile of low dose rivaroxaban (2.5 mg twice daily) in patients with coronary heart disease are not completely understood. Five randomized controlled trials (26,110 patients) were selected using PubMed and Cochrane library till April 2019. The background antiplatelet therapy was aspirin in 3 trials, P2Y12 inhibitor in 1 trial, and in 1 trial 65% patients received aspirin and 35% were on dual antiplatelet therapy (DAPT). The outcomes of interest were cardiovascular mortality, all-cause mortality, myocardial infarction (MI), stroke and major bleeding events. Random effects hazard ratios (HR) with 95% confidence intervals (CI) were calculated. Low dose rivaroxaban did not reduce the risk of cardiovascular mortality (HR 0.90, 95% CI 0.73-1.11, P = 0.34) or all-cause mortality (HR 0.91, 95% CI 0.74-1.12, P = 0.38) compared with control. However, low dose rivaroxaban was associated with reduction in MI (HR 0.85, 95% CI 0.73-0.99, P = 0.04), and stroke (HR 0.59, 95%CI 0.48-0.73, P < 0.001) at the expense of major bleeding (HR 1.64, 95% CI 1.39-1.94, P < 0.001) compared with control. These effects did not vary according to acute coronary syndrome or stable coronary heart disease (P-interaction > 0.05). The use of low dose rivaroxaban in patients with coronary heart disease predominantly receiving antiplatelet monotherapy did not reduce cardiovascular or all-cause mortality. The benefits of preventing MI and stroke were balanced by increased risk of major bleeding.

CHA2DS2-VASC score predicts coronary artery disease progression and mortality after ventricular arrhythmia in patients with implantable cardioverter-defibrillator

Aim

The CHA₂DS₂-VASC score has expanded its use beyond the initial purpose of predicting the risk of stroke in patients with atrial fibrillation. We aimed to investigate the value of the CHA₂DS₂-VASC score as a risk assessment tool to predict relevant coronary artery disease (CAD) leading to percutaneous coronary intervention (PCI), and all-cause mortality after detected ventricular arrhythmia (VA) in patients with an Implantable Cardioverter-Defibrillator (ICD).

Methods

A total of 183 ICD-patients who underwent coronary angiography after VA were included and classified according to their CHA₂DS₂-VASC score in a low(1-3), intermediate(4-5) and high(6-8) score group. We evaluated the predictive value of CHA₂DS₂-VASC score for the presence of relevant CAD leading to percutaneous coronary intervention (PCI), as well as late all-cause mortality.

Results

A total of 60 patients (32.8%) had significant CAD and underwent successful PCI. After adjustment for relevant parameters such as ischemic cardiomyopathy, angina pectoris, left ventricular ejection fraction, CHA₂DS₂-VASC score remained the only independent predictor of CAD leading to PCI [HR 1.73 (1.07–2.80)]. The Area under curve was 0.64 (0.56–72, p = 0.002). Kaplan-Meier analysis and log-rank showed an increased three-year mortality of ICD-patients with an intermediate or high score after VA (p = 0.003). Multivariate cox-regression analysis revealed that CHA₂DS₂-VASC score was also independently associated with all-cause mortality following adjustment for clinically relevant variables (HR 2.20, 1.17–4.14).

Conclusions

CHA₂DS₂-VASC score can be a predictor of CAD leading to PCI in ICD-patients after VA. ICD-Patients with a high score have an increased risk for reduced three-year all-cause mortality after VA.

Features of Risk Stratification, Diagnosis and Secondary Prevention in Patients with Multifocal Arterial Disease. Part 2: Treatment Options

The similarity of the pathogenesis of atherosclerosis and atherothrombotic complications, regardless of their location, makes the approaches to secondary prevention similar, which include lifestyle modification, pharmacotherapy of hemodynamic disorders, metabolic changes and hemostasis. Secondary prophylaxis in patients with multifocal arterial lesions using antihypertensive, antithrombotic and lipid-lowering therapy provides a more pronounced decrease in the incidence of cardiovascular complications than in lesions of single vascular lesions due to a higher initial risk. However, these treatments do not reduce the risk to the level that is achieved by treating patients with less atherosclerotic lesion. In this regard, it is of interest to use the currently available new methods and regimens of drug therapy in patients with multifocal arterial lesions, which make it possible to more intensively influence the mechanisms of atherosclerosis progression and more effectively prevent the development of its complications.

Features of Antithrombotic Therapy in Patients with Multifocal Arterial Disease

Multifocal arterial injury is common in patients with atherosclerotic cardiovascular diseases and is associated with increased risk of cardiovascular complications and death. Administration of more intensive antithrombotic therapy, particularly combinations of acetylsalicylic acid and a "vascular" dose of rivaroxaban, in patients with multifocal arterial injury is characterized by a beneficial ratio of efficiency and safety due to a pronounced decrease in the risk of cardiovascular complications. Detection of peripheral artery diseases in patients with ischemic heart disease and atherosclerotic cerebrovascular pathology makes it possible to improve the risk stratification, optimize the diagnostic tactics and clarify indications for more intensive antithrombotic therapy.

Phytochemical constituents, biological activities, and health-promoting effects of the genus Origanum

Origanum species are mostly distributed around the Mediterranean, Euro-Siberian, and Iran-Siberian regions. Since time immemorial, the genus has popularly been used in Southern Europe, as well as on the American continent as a spice now known all over the world under the name "oregano" or "pizza-spice." Origanum plants are also employed to prepare bitter tinctures, wines, vermouths, beer, and kvass. The major components of Origanum essential oil are various terpenes, phenols, phenolic acids, and flavonoids with predominant occurrence of carvacrol and thymol (with reasonable amounts of p-cymen and -terpinene) or of terpinene-4-ol, linalool, and sabinene hydrate. Many species of Origanum genus are used to treat kidney, digestive, nervous, and respiratory disorders, spasms, sore throat, diabetes, lean menstruation, hypertension, cold, insomnia, toothache, headache, epilepsy, urinary tract infections, etc. Origanum essential oil showed potent bioactivities owing to its major constituents' carvacrol, thymol, and monoterpenes. Several preclinical studies evidenced its pharmacological potential as antiproliferative or anticancer, antidiabetic, antihyperlipidemic, anti-obesity, renoprotective, antiinflammatory, vasoprotective, cardioprotective, antinociceptive, insecticidal, and hepatoprotective properties. Its nanotechnological applications as a promising pharmaceutical in order to enhance the solubility, physicochemical stability, and the accumulation rate of its essential oils have been investigated. However, Origanum has been reported causing angioedema, perioral dermatitis, allergic reaction, inhibition of platelet aggregation, hypoglycemia, and abortion. Conclusive evidences are still required for its clinical applications against human medical conditions. Toxicity analyses and risk assessment will aid to its safe and efficacious application. In addition, elaborate structure-activity studies are needed to explore the potential use of Origanum-derived phytochemicals as promising drug candidates.

Association of Factor V Leiden With Subsequent Atherothrombotic Events: A GENIUS-CHD Study of Individual Participant Data

BACKGROUND

Studies examining the role of factor V Leiden among patients at higher risk of atherothrombotic events, such as those with established coronary heart disease (CHD), are lacking. Given that coagulation is involved in the thrombus formation stage on atherosclerotic plaque rupture, we hypothesized that factor V Leiden may be a stronger risk factor for atherothrombotic events in patients with established CHD.

METHODS

We performed an individual-level meta-analysis including 25 prospective studies (18 cohorts, 3 case-cohorts, 4 randomized trials) from the GENIUS-CHD (Genetics of Subsequent Coronary Heart Disease) consortium involving patients with established CHD at baseline. Participating studies genotyped factor V Leiden status and shared risk estimates for the outcomes of interest using a centrally developed statistical code with harmonized definitions across studies. Cox proportional hazards regression models were used to obtain age- and sex-adjusted estimates. The obtained estimates were pooled using fixed-effect meta-analysis. The primary outcome was composite of myocardial infarction and CHD death. Secondary outcomes included any stroke, ischemic stroke, coronary revascularization, cardiovascular mortality, and all-cause mortality.

RESULTS

The studies included 69 681 individuals of whom 3190 (4.6%) were either heterozygous or homozygous (n=47) carriers of factor V Leiden. Median follow-up per study ranged from 1.0 to 10.6 years. A total of 20 studies with 61 147 participants and 6849 events contributed to analyses of the primary outcome. Factor V Leiden was not associated with the combined outcome of myocardial infarction and CHD death (hazard ratio, 1.03 [95% CI, 0.92-1.16]; I2=28%; P-heterogeneity=0.12). Subgroup analysis according to baseline characteristics or strata of traditional cardiovascular risk factors did not show relevant differences. Similarly, risk estimates for the secondary outcomes including stroke, coronary revascularization, cardiovascular mortality, and all-cause mortality were also close to identity.

CONCLUSIONS

Factor V Leiden was not associated with increased risk of subsequent atherothrombotic events and mortality in high-risk participants with established and treated CHD. Routine assessment of factor V Leiden status is unlikely to improve atherothrombotic events risk stratification in this population.

Synthesis and antithrombotic activity of 1-benzyl-N'-benzylidenepiperidine-3-carbohydrazide derivatives

: Platelet aggregation inhibition and interfering with clot formation are essential tools for antithrombotic therapy and there is a need for discovering new antithrombotic agents. In this study, we synthesized a series of benzylidenepiperidine-3-carbohydrazide derivatives (1f-11f), bearing various selected substituents on both the piperidine ring nitrogen and the hydrazide nitrogen. The synthesized compounds were characterized by FTIR, HNMR spectroscopic techniques, CHN/O elemental analysis and electrospray ionization mass spectra. All new 1-benzyl-N'-benzylidenepiperidine-3-carbohydrazides were evaluated for their antiplatelet aggregation activities (against platelet aggregation induced by AA, ADP and collagen separately) and anticoagulant activities [protrombin time (PT) and partial thromboplastin time (PTT)]. Antiplatelet aggregation activity of the new derivatives was measured using human plasma on an APACT 4004 aggregometer. All the compounds were mainly effective on ADP pathway of platelet aggregation compared with collagen and AA pathways. The most potent compound on platelet aggregation induced by ADP is compound 2f with 87% aggregation inhibition activity at 0.5 mmol/l concentration. The synthesized compounds were further investigated for their anticoagulant action via the two PT and PTT models. They all showed higher PT and PTT values compared with the blank control sample. The most potent compounds are 5f, 6f, 7f and 1f. All compounds were obtained in good yield and further evaluated for their antiplatelet and anticoagulant activity.

Direct-acting Anticoagulants in Chronic Coronary Syndromes

Direct-acting oral anticoagulants (DOACs) are easier to use, safer than and as effective as vitamin K antagonists (VKA) in the treatment of non-valvular AF (NVAF). Because of their favourable safety profile and easier use than VKAs, DOACs as anti-thrombotic therapy may have a role in the management of chronic coronary syndromes (CCS). To date, few studies have evaluated DOACs in this setting. Initial studies have focused on patients receiving DOACs for NVAF undergoing acute or elective percutaneous coronary intervention who additionally require dual antiplatelet therapy (DAPT). Rivaroxaban 15 mg once daily plus a P2Y₁₂ inhibitor compared with a VKA regimen was associated with a reduction of bleedings (HR 0.59; 95% CI [0.47–0.76]; p<0.001). Rivaroxaban 2.5 mg twice daily plus DAPT up to 12 months followed by rivaroxaban 15 mg once daily plus P2Y₁₂ inhibitor showed similar results. Dabigatran 110 mg twice daily plus a P2Y₁₂ inhibitor versus a VKA regimen was associated with a reduction of bleedings (HR 0.52; 95% CI [0.42–0.63]; p<0.001), after a mean follow-up of 14 months. A dabigatran 150 mg regimen showed similar results. Apixaban 5 mg twice daily plus a P2Y₁₂ inhibitor versus a VKA regimen confirmed at 6 months the safety of DOACs with a reduction of bleedings (HR 0.69; 95% CI [0.58–0.81]; p<0.001 for non-inferiority and superiority). Edoxaban 60 mg once daily plus a P2Y₁₂ inhibitor was non-inferior to a VKA regimen on bleeding outcomes (major bleeding or non-major clinically relevant non-major bleeding) after a 12-month follow-up (HR 0.83; 95% CI [0.65–1.05]; p=0.001 for non-inferiority; p=0.1154 for superiority). Meta-analysis of these four trials confirmed the safety of DOACs regarding bleeding outcomes, but showed a trend toward stent thrombosis for dual antithrombotic therapy using DOACs versus triple antithrombotic therapy using VKAs. DOACs may show promise in the management of high-risk patients with chronic coronary syndromes. In these patients, rivaroxaban 2.5 mg twice daily in addition to aspirin was shown to reduce the composite outcome of cardiovascular death, stroke or MI compared to aspirin alone (HR 0.76; 95% CI [0.66–0.86]; p<0.001). All-cause death, cardiovascular death and stroke were also significantly lower. This benefit was at the cost of an increase in non-fatal bleeding.

Biomimetic nanoparticle technology for cardiovascular disease detection and treatment

Cardiovascular disease (CVD), which encompasses a number of conditions that can affect the heart and blood vessels, presents a major challenge for modern-day healthcare. Nearly one in three people has some form of CVD, with many suffering from multiple or intertwined conditions that can ultimately lead to traumatic events such as a heart attack or stroke. While the knowledge obtained in the past century regarding the cardiovascular system has paved the way for the development of life-prolonging drugs and treatment modalities, CVD remains one of the leading causes of death in developed countries. More recently, researchers have explored the application of nanotechnology to improve upon current clinical paradigms for the management of CVD. Nanoscale delivery systems have many advantages, including the ability to target diseased sites, improve drug bioavailability, and carry various functional payloads. In this review, we cover the different ways in which nanoparticle technology can be applied towards CVD diagnostics and treatments. The development of novel biomimetic platforms with enhanced functionalities is discussed in detail.

Antithrombotic Agents

Recent advances in our understanding of the contribution of thrombin generation to arterial thrombosis and the role of platelets in venous thrombosis have prompted new treatment paradigms. Nonetheless, bleeding remains the major side effect of such treatments spurring the quest for new antithrombotic regimens with better benefit-risk profiles and for safer anticoagulants for existing and new indications. The aims of this article are to review the results of recent trials aimed at enhancing the benefit-risk profile of antithrombotic therapy and explain how these findings are changing our approach to the management of arterial and venous thrombosis. Focusing on these 2 aspects of thrombosis management, this article discusses 4 advances: (1) the observation that in some indications, lowering the dose of some direct oral anticoagulants reduces the risk of bleeding without compromising efficacy, (2) the recognition that aspirin is not only effective for secondary prevention of atherothrombosis but also for prevention of venous thromboembolism, (3) the finding that dual pathway inhibition with the combination of low-dose rivaroxaban to attenuate thrombin generation plus aspirin to reduce thromboxane A2-mediated platelet activation is superior to aspirin or rivaroxaban alone for prevention of atherothrombosis in patients with coronary or peripheral artery disease, and (4) the development of inhibitors of factor XI or XII as potentially safer anticoagulants.

Synergy of Dual Pathway Inhibition in Chronic Cardiovascular Disease

Although acetylsalicylic acid is of proven benefit for secondary prevention in patients with cardiovascular disease, the risk of recurrent ischemic events remains high. Intensification of antithrombotic therapy with more potent antiplatelet drugs, dual antiplatelet therapy, or vitamin K antagonists further reduces the risk of major adverse cardiovascular events compared with acetylsalicylic acid alone but increases the risk of bleeding without reducing mortality. In patients with prior coronary artery disease or peripheral arterial disease the COMPASS (Cardiovascular Outcomes for People Using Anticoagulation Strategies) trial revealed that compared with acetylsalicylic acid alone, dual pathway inhibition with low-dose rivaroxaban (2.5 mg twice-daily), an oral factor Xa inhibitor, plus acetylsalicylic acid reduced major adverse cardiovascular event by 24%, major adverse limb events by 47%, and mortality by 18%. Major bleeding was increased by 70%, but there was no increase in fatal or intracranial bleeding. This article (1) reviews the results of the COMPASS trial, (2) explains why dual pathway inhibition is superior to antiplatelet or anticoagulant therapy alone, (3) compares the results with rivaroxaban plus aspirin with those with other antithrombotic regimens, and (4) provides insight into how best to apply the COMPASS results into practice.

Edoxaban Plus Aspirin vs Dual Antiplatelet Therapy in Endovascular Treatment of Patients With Peripheral Artery Disease: Results of the ePAD Trial

Purpose: To report a randomized study that investigated the safety (risk of major bleeds) and potential efficacy of edoxaban, an oral anticoagulant that targets the major components of arterial thrombi, to prevent loss of patency following endovascular treatment (EVT). Methods: Between February 2012 and June 2014, 203 patients who underwent femoropopliteal EVT were randomized to receive aspirin plus edoxaban or aspirin plus clopidogrel for 3 months in the Edoxaban in Peripheral Arterial Disease (ePAD) study (ClinicalTrials.gov identifier NCT01802775). Randomization assigned 101 patients (mean age 68.0±10.4 years; 67 men) to the edoxaban group and 102 patients (mean age 66.7±8.6 years; 78 men) to the clopidogrel group. The primary safety endpoint was bleeding as classified by the TIMI (Thrombolysis in Myocardial Infarction) criteria and ISTH (International Society of Thrombosis and Hemostasis) criteria; the efficacy endpoint was the rate of restenosis/reocclusion. Results: There were no major or life-threatening bleeding events in the edoxaban group, while there were 2 major and 2 life-threatening bleeding events in the clopidogrel group by the TIMI criteria. By the ISTH classification, there was 1 major and 1 life-threatening bleeding event vs 5 major and 2 life-threatening bleeding events, respectively [relative risk (RR) 0.20, 95% confidence interval (CI) 0.02 to 1.70]. The bleeding risk was not statistically different with either treatment when assessed by TIMI or ISTH. Following 6 months of observation, there was a lower incidence of restenosis/reocclusion with edoxaban compared with clopidogrel (30.9% vs 34.7%; RR 0.89, 95% CI 0.59 to 1.34, p=0.643). Conclusion: These results suggest that patients who have undergone EVT have similar risks for major and life-threatening bleeding events with edoxaban and aspirin compared with clopidogrel and aspirin. The incidence of restenosis/reocclusion events, while not statistically different, was lower with edoxaban and aspirin, but an adequately sized trial will be needed to confirm these findings.

Role of oral anticoagulant therapy for secondary prevention in patients with stable atherothrombotic disease manifestations

Coronary artery disease and peripheral arterial disease are strong predictors of risk for a future ischemic event. Despite the utilization of effective secondary prevention strategies, the prevalence of ischemic recurrences remains high, underscoring the need for effective secondary prevention antithrombotic treatment regimens. To date, most of the tested approaches have been with the use of antiplatelet therapies, used either individually or in combination. However, most recent findings support the potential role of oral anticoagulant therapy in addition to antiplatelet therapy to reduce the risk of ischemic recurrences. This approach has been tested in both acute and stable settings of patients with cardiovascular disease manifestations. The present manuscript provides an overview on the rationale and clinical trial updates on the role of oral anticoagulant therapy, in particular rivaroxaban used at the so-called vascular protection dose, in adjunct to antiplatelet therapy (i.e. aspirin), a strategy known as dual pathway inhibition, for secondary prevention of ischemic recurrences in patients with stable atherosclerotic disease manifestations.

Use of oral anticoagulant drugs is associated with carotid intraplaque hemorrhage in atherosclerosis patients: a meta-analysis

Patients with carotid atherosclerosis, especially the elderly population, take antithrombotic medicine regularly. However, no previous meta-analysis has focused on one of the possible side effects of such drugs, namely intraplaque hemorrhage (IPH). To determine whether antiplatelet drugs or anticoagulants are associated with an increased risk of carotid IPH. We searched Pubmed, Embase, Ovid MEDLINE, Cochrane Library for relevant studies that were published in English, from January 1st, 1989 to January 1st, 2019. We pooled the odds ratio (OR) with 95% confidence interval (CI) from individual studies and conducted quality assessment, heterogeneity, publication bias analysis and sensitivity analysis. A total of four cross-sectional studies, involving 2714 participants with carotid atherosclerotic plaques was included into this meta-analysis. We found a significant association between the use of anticoagulants and higher risk of carotid IPH (OR 1.95; 95% CI 1.16-3.30, P = 0.92; I² = 0). No significant association was found between the use of antiplatelet drugs and increased risk of carotid IPH (OR 1.34; 95% CI 0.68-2.61, P = 0.03; I² = 65%). Our meta-analysis reveals that it is the use of oral anticoagulants rather than antiplatelet drugs that may be associated with an increased risk of carotid IPH in atherosclerosis patients.

Antithrombotic therapy in patients undergoing transcatheter aortic valve implantation

This review provides a comprehensive overview of the available data on antithrombotic therapy after transcatheter aortic valve implantation (TAVI). In the absence of large randomised clinical trials, clinical practice is leaning towards evidence reported in other populations. Due to the greater risk of major bleeding associated with oral anticoagulation using a vitamin-K antagonist (VKA), antiplatelet therapy (APT) may be considered as the first-line treatment of patients undergoing TAVI. Overall, single rather than dual APT is preferred. However, dual APT should be considered in patients with a recent acute coronary syndrome (ie, within 6 months), complex coronary stenting, large aortic arch atheromas or previous non-cardioembolic stroke. Monotherapy with VKA should be considered if concomitant atrial fibrillation or any other indication for long-term oral anticoagulation is present. APT on top of VKA seems only reasonable in patients with recent acute coronary syndrome, extensive or recent coronary stenting or large aortic arch atheromas. A direct-acting oral anticoagulant may be considered if oral anticoagulation is indicated in the absence of contraindications. Initiation of VKA is indicated in clinical valve thrombosis, for example, with high transvalvular gradient, whereas the role of VKA in the case of subclinical leaflet thrombosis is currently uncertain.

Antithrombotic treatment is associated with intraplaque haemorrhage in the atherosclerotic carotid artery: a cross-sectional analysis of The Rotterdam Study

Aims

Antithrombotic treatment plays a key role in stroke prevention, but their direct effects on the composition of carotid artery atherosclerotic plaques are unknown. To investigate the association of antithrombotic treatment with carotid artery plaque composition, with a specific focus on an intraplaque haemorrhage (IPH).

Methods and results

From the population-based Rotterdam Study, 1740 participants with carotid atherosclerosis on ultrasound (mean age 72.9 years, 46.0 women) underwent magnetic resonance imaging of the carotid arteries to assess plaque composition. Information on the use of oral anticoagulants [vitamin K antagonists (VKA)] and antiplatelet agents (salicylates), including duration of use and dosage, was obtained from pharmacy records for all participants. We used logistic regression models to assess the association between the use of anticoagulants and antiplatelet agents, and the different plaque components adjusting for confounders. Current and past use of VKA [adjusted odds ratio (OR): 1.88, 95% confidence interval (CI): 0.74-4.75 and OR 1.89, 95% CI: 0.91-3.93] and antiplatelet agents (OR: 1.22, 95% CI: 0.91-1.62), and (OR: 1.23, 95% CI: 0.86-1.75) showed positive trend with a higher presence of IPH. Also, a longer duration of use was associated with a higher frequency of IPH (OR: 3.15, 95% CI: 1.23-8.05) for the use of VKA, and longer duration of the use for antiplatelet agents showed a positive trend (OR: 1.21, 95% CI: 0.88-1.67). We also found that higher levels of international normalized ratio above 2.97 for VKA (OR: 1.48, 95% CI: 1.03-2.15) and higher daily defined dosage than 1.0 for antiplatelet agents (OR: 1.50, 95% CI: 1.21-1.87) were related to a higher frequency of IPH. We found no association with lipid core or calcification.

Conclusions

The use of antithrombotic treatment relates to a higher frequency of IPH in carotid atherosclerotic plaques.

The Role of Direct Oral Anticoagulants in Patients With Coronary Artery Disease

Despite contemporary management, patients with coronary artery disease (CAD) remain at high risk for thrombotic events. Several randomized controlled trials have evaluated the use of direct oral anticoagulants (DOACs) in patients with CAD, including in the setting of acute coronary syndrome (ACS) and stable CAD, and in patients with concomitant atrial fibrillation. Trials of apixaban and dabigatran in patients with ACS demonstrate no benefit with an increased risk of bleeding. Conversely, rivaroxaban at a reduced dose of 2.5 mg twice daily reduced thrombotic events and all-cause mortality when added to dual antiplatelet therapy in patients with ACS. Similarly, the addition of low-dose rivaroxaban to acetylsalicylic acid reduced the risk of thrombotic events in patients with stable CAD. However, the addition of a DOAC to antiplatelet therapy increased the risk of major bleeding. In patients with atrial fibrillation undergoing percutaneous coronary intervention, dual-pathway or low-dose triple therapy regimens including dabigatran or rivaroxaban reduced bleeding risk compared to traditional warfarin-based triple therapy, although it remains unclear whether these regimens preserve antithrombotic efficacy. DOAC-based antithrombotic regimens prove useful in patients with CAD in various settings; however, careful selection of patients and regimens per trial protocols are critical to achieving net benefit.

Risk of myocardial infarction and death in patients with atrial fibrillation treated with dabigatran or vitamin K antagonists

The safety of dabigatran versus adjusted-dose vitamin K antagonist (VKA) treatment is the subject of debate. We evaluated the risk of myocardial infarction (MI) or mortality in patients with atrial fibrillation (AF) treated in clinical practice with dabigatran or a VKA. We performed a meta-analysis of observational studies that included an adjusted or matched analysis and reported MI, or death in AF patients treated with dabigatran or a VKA. Ten published analyses met the inclusion criteria. Of the 539,559 patients, 17,365 (3%) patients were on dabigatran 110 mg twice daily (bid), 150,948 (28%) were on dabigatran 150 mg bid, and 371,246 (69%) were on VKA. Adjusted risk for MI versus VKA was 0.71 (0.47–1.07; p=0.10) in patients starting oral anticoagulant (OAC) treatment with dabigatran 110 mg, 0.82 (0.71–0.96; p=0.01) in patients starting dabigatran 150 mg, 1.40 (1.04–1.88; p=0.03) in patients switching OAC treatment to dabigatran 110 mg, and 1.28 (0.88–1.87; p=0.19) in patients switching OAC treatment to dabigatran 150 mg, with statistical homogeneity in each subgroup. Risk of death was consistently lower in patients treated with dabigatran 110 mg (HR 0.79; 0.65–0.96; p=0.02) or 150 mg (HR 0.65; 0.57–0.73; p<0.00001) versus VKA. In conclusion, dabigatran use, as currently prescribed in routine practice for AF patients, was associated with a lower risk of MI in OAC-naïve patients treated with dabigatran 150 mg compared with VKA, and a higher risk of MI in patients switching from VKA to dabigatran 110 mg. Risk of death was lower in AF patients treated with either dose of dabigatran versus VKA.

[National disease management guidelines (NVL) for chronic CAD : What is new, what is particularly important?]

Coronary heart disease (CAD) is widespread and affects 1 in 10 of the population in the age group 40-79 years in Germany. The German national management guidelines on chronic CAD comprise evidence and expert-based recommendations for the diagnostics of chronic stable CAD as well as for interdisciplinary/multidisciplinary therapy and care of patients with stable CAD. The focus is on the diagnostics, prevention, medication therapy, revascularization, rehabilitation, general practitioner care and coordination of care. Recommendations for optimizing cooperation between all medical specialties involved as well as the definition of mandatory and appropriate measures are essential aims of the guidelines both to improve the quality of care and to strengthen the position of the patient.

Treatment and secondary prevention of ischemic coronary events in Croatia (TASPIC-CRO study)

AIMS

The objective of this study is to determine the status of major risk factors for coronary heart disease in patients with established coronary heart disease in Croatia and whether the Joint European Societies' recommendations on coronary heart disease prevention are being followed in Croatia and whether secondary prevention practices have improved between 1998 and 2003.

METHODS

Five surveys were undertaken in 35 centres covering the geographical area of the whole of Croatia between 1 June, 1998 and 31 March, 2003. Consecutive patients of both sexes were identified after coronary-bypass grafting or a percutaneous transluminal coronary angioplasty or a hospital admission with acute myocardial infarction or ischaemia. Data collection was based on a review of medical records and the methodology used was similar to the one used in the EUROASPIRE study.

RESULTS

Fifteen thousand, five hundred and twenty patients were enrolled (64.6% men); 35% of patients smoked cigarettes, 66% had raised blood pressure, 69% elevated serum total cholesterol, 69% elevated serum low-density lipoprotein (LDL) cholesterol, 42% low high-density lipoprotein (HDL) cholesterol, 37% elevated triglycerides, 30% diabetes and 34% family history of coronary heart disease. More men were smokers and had low HDL cholesterol, but more women had elevated total and LDL cholesterol, hypertension and diabetes. More men had Q wave acute myocardial infarction, but more women had angina. Over 5 years, the prevalence of hypercholesterolemia decreased substantially from 82.7 to 65%. Eighty-three percent of patients received aspirin and this percentage did not change during the study. The use of diuretics, calcium antagonists and nitrates did not change either. The reported use of statins, angiotensin-converting enzyme inhibitors and beta-blockers increased significantly.

CONCLUSION

This survey shows a high prevalence of modifiable risk factors in Croatian patients with coronary heart disease. Although the higher use of statins, angiotensin-converting enzyme inhibitors and beta-blockers is encouraging, the fact that most coronary heart disease patients are still not achieving the recommended goals remains a concern. There is real potential to reduce the very high coronary heart disease morbidity and mortality in Croatia.

Impact of Antithrombotic Therapy in Atrial Fibrillation on the Presentation of Coronary Artery Disease

Background

Little is known about whether atrial fibrillation is a presentation of coronary disease. There is a paucity of knowledge about their causal relationship and also the impact of different antithrombotic strategies on the subsequent presentation of symptomatic coronary disease.

Methods and Results

We studied 7,526 Chinese patients diagnosed with non-valvular atrial fibrillation and no documented history of coronary artery disease. The primary endpoint was the new occurrence of coronary artery disease—either stable coronary artery disease or acute coronary syndrome. After a mean follow-up of 3.2±3.5 years (24,071 patient-years), a primary endpoint occurred in 987 patients (13.1%). The overall annual incidence of coronary artery disease was 4.10%/year. No significant differences in age, sex, and mean CHA₂DS₂-VASc score were observed between patients with and without the primary endpoint. When stratified according to the antithrombotic strategies applied for stroke prevention, the annual incidence of coronary artery disease was 5.49%/year, 4.45%/year and 2.16%/year respectively in those prescribed no antithrombotic therapy, aspirin, and warfarin. Similar trends were observed in patients with acute coronary syndromes. Diabetes mellitus, smoking history and renal failure requiring dialysis were predictors for primary endpoint in all antithrombotic therapies.

Conclusion

In patients with non-valvular atrial fibrillation, there is a modest association with coronary artery disease. Patients prescribed warfarin had the lowest risk of new onset coronary artery disease.

Atrial Fibrillation and Risk of ST-Segment-Elevation Versus Non-ST-Segment-Elevation Myocardial Infarction: The Atherosclerosis Risk in Communities (ARIC) Study

BACKGROUND

It has recently been reported that atrial fibrillation (AF) is associated with an increased risk of myocardial infarction (MI). However, the mechanism underlying this association is currently unknown. Further study of the relationship of AF with the type of MI (ST-segment-elevation MI [STEMI] versus non-ST-segment-elevation MI [NSTEMI]) might shed light on the potential mechanisms.

METHODS AND RESULTS

We examined the association between AF and incident MI in 14 462 participants (mean age, 54 years; 56% women; 26% blacks) from the Atherosclerosis Risk in Communities (ARIC) study who were free of coronary heart disease at baseline (1987-1989) with follow-up through December 31, 2010. AF cases were identified from study visit ECGs and by review of hospital discharge records. Incident MI and its types were ascertained by an independent adjudication committee. Over a median follow-up of 21.6 years, 1374 MI events occurred (829 NSTEMIs, 249 STEMIs, 296 unclassifiable MIs). In a multivariable-adjusted model, AF (n=1545) as a time-varying variable was associated with a 63% increased risk of MI (hazard ratio,1.63; 95% confidence interval, 1.32-2.02). However, AF was associated with NSTEMI (hazard ratio, 1.80; 95% confidence interval, 1.39-2.31) but not STEMI (hazard ratio, 0.49; 95% confidence interval, 0.18-1.34; P for hazard ratio comparison=0.004). Combining the unclassifiable MI group with either STEMI or NSTEMI did not change this conclusion. The association between AF and MI, total and NSTEMI, was stronger in women than in men (P for interaction <0.01 for both).

CONCLUSIONS

AF is associated with an increased risk of incident MI, especially in women. However, this association is limited to NSTEMI.

Global assays and the management of oral anticoagulation

Coagulation tests range from global or overall tests to assays specific to individual clotting factors and their inhibitors. Whether a particular test is influenced by an oral anticoagulant depends on the principle of the test and the type of oral anticoagulant. Knowledge on coagulation tests applicable in monitoring status and reversal of oral anticoagulation is a prerequisite when studying potential reversal agents or when managing anticoagulation in a clinical setting. Specialty tests based on the measurement of residual activated factor X (Xa) or thrombin activity, e.g., are highly effective for determining the concentration of the new generation direct factor Xa- and thrombin inhibitors, but these tests are unsuitable for the assessment of anticoagulation reversal by non-specific prohemostatic agents like prothrombin complex concentrate (PCC) and recombinant factor VIIa (FVIIa). Global coagulation assays, in this respect, seem more appropriate. This review evaluates the current status on the applicability of the global coagulation assays PT, APTT, thrombin generation and thromboelastography in the management of oral anticoagulation by vitamin K antagonists and the direct factor Xa and thrombin inhibitors. Although all global tests are influenced by both types of anticoagulants, not all tests are useful for monitoring anticoagulation and reversal thereof. Many (pre)analytical conditions are of influence on the assay readout, including the oral anticoagulant itself, the concentration of assay reagents and the presence of other elements like platelets and blood cells. Assay standardization, therefore, remains an issue of importance.

Society for Vascular Surgery practice guidelines for atherosclerotic occlusive disease of the lower extremities: management of asymptomatic disease and claudication

Peripheral arterial disease (PAD) continues to grow in global prevalence and consumes an increasing amount of resources in the United States health care system. Overall rates of intervention for PAD have been rising steadily in recent years. Changing demographics, evolution of technologies, and an expanding database of outcomes studies are primary forces influencing clinical decision making in PAD. The management of PAD is multidisciplinary, involving primary care physicians and vascular specialists with varying expertise in diagnostic and treatment modalities. PAD represents a broad spectrum of disease from asymptomatic through severe limb ischemia. The Society for Vascular Surgery Lower Extremity Practice Guidelines committee reviewed the evidence supporting clinical care in the treatment of asymptomatic PAD and intermittent claudication (IC). The committee made specific practice recommendations using the GRADE (Grades of Recommendation Assessment, Development and Evaluation) system. There are limited Level I data available for many of the critical questions in the field, demonstrating the urgent need for comparative effectiveness research in PAD. Emphasis is placed on risk factor modification, medical therapies, and broader use of exercise programs to improve cardiovascular health and functional performance. Screening for PAD appears of unproven benefit at present. Revascularization for IC is an appropriate therapy for selected patients with disabling symptoms, after a careful risk-benefit analysis. Treatment should be individualized based on comorbid conditions, degree of functional impairment, and anatomic factors. Invasive treatments for IC should provide predictable functional improvements with reasonable durability. A minimum threshold of a >50% likelihood of sustained efficacy for at least 2 years is suggested as a benchmark. Anatomic patency (freedom from restenosis) is considered a prerequisite for sustained efficacy of revascularization in IC. Endovascular approaches are favored for most candidates with aortoiliac disease and for selected patients with femoropopliteal disease in whom anatomic durability is expected to meet this minimum threshold. Conversely, caution is warranted in the use of interventions for IC in anatomic settings where durability is limited (extensive calcification, small-caliber arteries, diffuse infrainguinal disease, poor runoff). Surgical bypass may be a preferred strategy in good-risk patients with these disease patterns or in those with prior endovascular failures. Common femoral artery disease should be treated surgically, and saphenous vein is the preferred conduit for infrainguinal bypass grafting. Patients who undergo invasive treatments for IC should be monitored regularly in a surveillance program to record subjective improvements, assess risk factors, optimize compliance with cardioprotective medications, and monitor hemodynamic and patency status.

Balancing ischaemia and bleeding risks with novel oral anticoagulants

Vitamin K antagonists (VKAs) have long been the standard of care for treatment of venous thromboembolism (VTE), and thromboprophylaxis in atrial fibrillation (AF). Despite their efficacy, their use requires frequent monitoring and is complicated by drug-drug interactions and the need to maintain a narrow therapeutic window. Since 2009, novel oral anticoagulants (NOACs), including the direct thrombin inhibitor dabigatran and the direct factor Xa inhibitors apixaban, edoxaban, and rivaroxaban, have become alternative options to VKAs owing to their predictable and safe pharmacological profiles. The overall clinical effect of these drugs, which is a balance between ischaemic benefit and bleeding harm, varies according to the clinical scenario. As adjunctive therapy to dual antiplatelet therapy in patients with acute coronary syndrome, NOACs are associated with incremental bleeding risks and modest benefits. For treatment of VTE, NOACs have a safer profile than VKAs and a similar efficacy. In thromboprophylaxis in AF, NOACs are associated with the greatest benefits by reducing both ischaemic events and haemorrhagic complications and might reduce mortality compared with VKAs. The role of NOACs continues to evolve as these drugs are evaluated in different patient populations, including those with renal impairment or with AF and undergoing percutaneous coronary intervention.

Oral anticoagulant use in addition to antiplatelet therapy for secondary prevention in acute coronary syndrome: current perspectives

Patients with acute coronary syndrome (ACS) are typically managed with long-term dual antiplatelet therapy of acetylsalicylic acid plus a P2Y12 platelet receptor antagonist; however, although effective, the risk of another vascular event within 12 months remains at approximately 10%. Considerable efforts have been made to find improved therapeutic approaches to secondary prevention in ACS. The ATLAS ACS 2-TIMI 51 trial demonstrated that rivaroxaban (2.5 mg twice daily) significantly reduced recurrent vascular events, increased the risk of major bleeding but not the risk of fatal bleeding, and resulted in reduced rates of death from cardiovascular causes. These results formed the basis for approval in Europe of rivaroxaban (2.5 mg twice daily) in conjunction with standard antiplatelet therapy for the secondary prevention of ACS.

Embolic strokes of undetermined source: the case for a new clinical construct

Cryptogenic (of unknown cause) ischaemic strokes are now thought to comprise about 25% of all ischaemic strokes. Advances in imaging techniques and improved understanding of stroke pathophysiology have prompted a reassessment of cryptogenic stroke. There is persuasive evidence that most cryptogenic strokes are thromboembolic. The thrombus is thought to originate from any of several well established potential embolic sources, including minor-risk or covert cardiac sources, veins via paradoxical embolism, and non-occlusive atherosclerotic plaques in the aortic arch, cervical, or cerebral arteries. Accordingly, we propose that embolic strokes of undetermined source are a therapeutically relevant entity, which are defined as a non-lacunar brain infarct without proximal arterial stenosis or cardioembolic sources, with a clear indication for anticoagulation. Because emboli consist mainly of thrombus, anticoagulants are likely to reduce recurrent brain ischaemia more effectively than are antiplatelet drugs. Randomised trials testing direct-acting oral anticoagulants for secondary prevention of embolic strokes of undetermined source are warranted.

Integrin modulators: a patent review

INTRODUCTION

Integrins are heterodimeric cell surface receptors, which enable adhesion, proliferation, and migration of cells by recognizing binding motifs in extracellular matrix (ECM) proteins. As transmembrane linkers between the cytoskeleton and the ECM, they are able to recruit a huge variety of proteins and to influence signaling pathways bidirectionally, thereby regulating gene expression and cell survival. Hence, integrins play a key role in various physiological as well as pathological processes, which has turned them into an attractive target for pharmaceutical research.

AREAS COVERED

In this review, the latest therapeutic developments of drug candidates and recently patented integrin ligands are summarized.

EXPERT OPINION

Integrins have been proven to be valuable therapeutic targets in the treatment of several inflammatory and autoimmune diseases, where leukocyte adhesion processes are regulated by them. Furthermore, they play an important role in pathological angiogenesis and tumor metastasis, being a promising target for cancer therapy.

Antithrombotics in Heart Failure With Reduced Ejection Fraction and Normal Sinus Rhythm

Objective: To review the thromboembolic risk, pathophysiology associated with the risk, and literature investigating the use of antithrombotics in patients with heart failure with reduced ejection fraction and normal sinus rhythm (HFrEF-NSR). Data Sources: An English language literature search was performed with MEDLINE/PubMed and Embase from January 1950 to October 2013 using the search terms heart failure, HFrEF, systolic heart failure, cardiomyopathy, left ventricular dysfunction, sinus rhythm, thromboembolism, deep vein thrombosis, pulmonary embolism, myocardial infarction, acute coronary syndrome, acute coronary events, coronary artery disease, stroke, and cerebrovascular events to identify relevant articles. References in the retrieved articles were also assessed to identify other important articles. Study Selection and Data Abstraction: All pertinent original studies, reviews, consensus documents, and guidelines were evaluated for inclusion. Data Synthesis: Patients with HFrEF-NSR may be predisposed to developing thromboembolic events. Studies that have examined the role of antithrombotics (warfarin and/or antiplatelet therapy) for reducing thromboembolic risk have been inconclusive. The WASH and HELAS pilot trials—the only studies with a no-antithrombotics or placebo comparator group—did not find a benefit with antithrombotic therapy but found an increased risk of bleeding with warfarin and of hospitalizations with aspirin. Although the clinical outcome studies (WATCH and WARCEF) suggested that warfarin may reduce stroke risk compared with antiplatelet therapy, the lack of a placebo group and lower-than-projected enrollment prevents definitive conclusions from being made. Conclusions: Current evidence does not support the routine use of antithrombotics for preventing thromboembolic events in patients with HFrEF-NSR without compelling indications.

Atrial fibrillation in the elderly

Atrial fibrillation (AF) is the most common arrhythmia in older adults with a prevalence of 9 % in adults aged 80 years or older. AF patients have a five times greater risk of developing stroke than the general population. Using anticoagulants for stroke prevention in the elderly becomes a challenge because both stroke and bleeding complications increase with age. CHA₂DS₂-VASc and HAS-BLED scores are currently used as stroke and bleeding risk evaluations. When the HAS-BLED score is 3 or higher, caution and efforts to correct reversible risk factors are advised. Regardless of the HAS-BLED score, warfarin or novel oral anticoagulants are a IIa recommendation for CHA₂DS₂-VASc of 1, except for a score of 1 for females, and a IA recommendation for the score of 2 or higher. Aspirin is no longer recommended for AF thromboprophylaxis. In an elderly patient, lenient rate control is preferred over rhythm control owing to fewer adverse drugs effects and hospitalizations. When rhythm control is needed, dronedarone is a new antiarrhythmic drug that can be considered in patients who have paroxysmal AF and no history of heart failure. Although less efficacious than amiodarone, dronedarone has a fewer thyroid, neurologic, dermatologic, and ocular side effects than amiodarone.

Medical management of critical limb ischaemia: where do we stand today?

Critical limb ischaemia (CLI) is a severe form of peripheral arterial disease (PAD). CLI often causes disabling symptoms of pain and can lead to loss of the affected limb. It is also associated with increased risk of myocardial infarction, stroke and death from cardiovascular disease. The aims of management in patients with CLI are to relieve ischaemic pain, heal ulcers, prevent limb loss, improve function and quality of life and prolong survival. Here, current evidence regarding the medical management of CLI is reviewed. Cardiovascular risk factors should be assessed in all patients with CLI; smoking cessation and treatment of hypertension, hyperlipidaemia and diabetes all reduce the mortality rate in those with PAD. Antiplatelet agents (either aspirin or clopidogrel) are recommended to reduce both the incidence of cardiovascular events and risk of arterial occlusion. By contrast, routine use of anticoagulation (either warfarin or heparin) is not recommended. Treatment of the limbs themselves is often more challenging. Prostanoids may have some efficacy for treating rest pain and for ulcer healing, and iloprost shows favourable results in reducing the risk of major amputations, but long-term follow-up data regarding disease progression are lacking. There is insufficient evidence to support the use of naftidrofuryl or cilostazol, and pentoxifylline is not beneficial. Furthermore, there is no evidence of proven benefit of hyperbaric oxygen. A number of angiogenic growth factors have been studied in Phase I studies and randomized controlled trials (RCTs). They appear to be safe, but efficacy results have been mixed. Treatment with stem cells also shows some potential from early trials, but further larger RCTs are needed to demonstrate clear benefit. Thrombolysis may be an alternative for patients who develop acute limb ischaemia and are unsuitable for surgical intervention. However, newer endovascular techniques are likely to have a greater role in the future.

A systematic review on the use of new anticoagulants in pregnancy

New anticoagulants such as direct factor Xa inhibitors and direct thrombin inhibitors have been recently developed, but their experience in pregnancy is limited. This review therefore aims to systematically search for studies on the use of these newer anticoagulants in pregnancy and the puerperal period. Searches were performed on electronic databases MEDLINE (from 1966), EMBASE (from 1974) and the Cochrane Library, until October 2011 using terms of 'pregnancy', 'puerperium', 'breastfeeding' and names of specific anticoagulants. The search yielded 561 citations and 11 studies (10 on fondaparinux, 1 on ximelagatran) were included. Newer anticoagulants (fondaparinux, hirudin and argatroban) on the limited evidence appear not to have adverse pregnancy outcomes, but there is currently no experience of new oral anticoagulants (rivaroxaban, apixaban, betrixaban or dabigatran) use in pregnancy. There is a need for reporting on new oral anticoagulation use in pregnancy to provide more information about the safety and risks to the fetus in utero.

Low-dose of oral factor Xa inhibitors in patients with a recent acute coronary syndrome: a systematic review and meta-analysis of randomized trials

BACKGROUND

Recently, randomized controlled trials (RCTs) have shown that therapy with new oral activated factor X (Xa) inhibitors in acute coronary syndrome (ACS) yielded a reduction of ischemic events. However, this therapy was associated with a dose-related increase in major bleeding complications. We aimed to perform a systematic review and meta-analysis to appraise the clinical efficacy and safety of the lowest doses of oral factor Xa inhibitors compared with placebo in patients after a recent ACS.

METHODS

The primary endpoint was cardiovascular mortality. The rate of new myocardial infarction (MI) was the secondary efficacy endpoint, whereas major bleeding complications were recorded as a safety endpoint. Five RCTs were included in the meta-analysis enrolling a total of 25,643 patients.

RESULTS

There was no significant difference in mortality between patients treated with new antithrombotics compared with those receiving the standard therapy: odds ratio (OR), [95% confidence interval (CI)] = 0.97 [0.72-1.31], p = 0.86. Recurrent MI rates were decreased in the anti-Xa group: OR [95%CI] = 0.86 [0.76-0.98], p = 0.02, number needed to treat (NNT) = 189. The administration of new oral anticoagulants was associated with a strongly increased risk of major bleedings compared with the standard treatment: OR [95%CI] = 3.24 [2.29-4.59], p < 0.001, number needed to harm (NNH) = 104; similarly, intracranial bleeding rates were significantly higher in the anti-Xa arm.

CONCLUSIONS

The addition of the new oral anticoagulants on top of standard therapy in the setting of ACS results in an excessive risk of major bleedings without any clear evidence of outweighing clinical benefits.

The aspirin cardiovascular/gastrointestinal risk calculator--a tool to aid clinicians in practice

BACKGROUND

Assessment of both GI and CV risks vs. the benefits of low-dose aspirin for individual patients can be difficult in clinical practice.

AIM

To develop a tool to estimate CV and GI risks to facilitate the clinical decision-making process.

METHODS

We constructed risk-ratio estimations and determined the incidence of CV events and upper GI complications according to the presence of different risk factors. For upper GI complications we assumed a baseline incidence of 1 case/1000-persons-year, a twofold increased risk with low-dose aspirin, and estimated a 60% GI risk reduction with proton pump inhibitors (PPI) co-therapy and a 60% risk reduction with H. pylori eradication in patients with a history of peptic ulcer.

RESULTS

The calculator can be found at http://www.asariskcalculator.com. In patients with low CV risk the number of GI complications induced by low-dose aspirin may be greater than the number of CV events prevented. In patients with high CV risk, low-dose aspirin is recommended, but the number of GI complications induced may still overcome the CV events saved. The use of PPI reduces the number of complication events induced by low-dose aspirin, but the number of CV events saved may still be offset by the number of GI complications induced in patients at very high GI risk.

CONCLUSIONS

There are many clinical situations where the number of potential upper GI complications induced by low-dose aspirin may exceed the number of potentially prevented CV events. A risk calculator should guide physicians in choosing appropriate therapy and maximise the aspirin benefit.

Acute pulmonary emboli in a patient on long-term dabigatran therapy

OBJECTIVE

To describe the case of a patient who developed acute pulmonary emboli (PE) despite long-term anticoagulation with dabigatran.

CASE SUMMARY

A 69-year-old obese woman was hospitalized for worsening shortness of breath, dyspnea on exertion, and left pleuritic chest pain. On admission, a computed tomography angiogram revealed acute bilateral PE, despite use of dabigatran for atrial fibrillation for approximately 5 years prior to admission. Dabigatran was stopped and therapeutic enoxaparin was initiated concomitantly with warfarin. An investigation into possible causes for the development of the PE, including hypercoagulability, was unrevealing. Since dabigatran should have protected against PE, the patient was questioned regarding adherence to her regimen. She stated that she was adherent but reported using a pillbox. The patient was discharged home on warfarin with an enoxaparin bridge until her international normalized ratio was at least 2.0.

DISCUSSION

The underlying cause for the patient's acute PE is unknown but could possibly be attributed to obesity and reduced mobility. Although dabigatran should have prevented PE, the presence of interacting drugs, patient-specific pharmacokinetics, suboptimal medication storage, and laboratory abnormalities may have resulted in reduced dabigatran exposure and protection. This is a reasonable hypothesis; however, the patient did not develop a stroke while receiving dabigatran.

CONCLUSIONS

Our patient developed acute bilateral PE despite receiving long-term anticoagulation with dabigatran. While it is possible that patient-specific factors resulted in reduced dabigatran exposure and efficacy, conclusions cannot be made.