Advancement in antithrombotics for stroke prevention in atrial fibrillation

[Current situation of direct oral anticoagulants in primary care in Spain: Positioning of SEMERGEN in 2023]

Oral anticoagulation is the key to reduce the risk of stroke in atrial fibrillation. Although vitaminK antagonists (VKA) have classically been used for this purpose, they have been largely overcome by direct oral anticoagulants (DOAC), as demonstrated by evidence from clinical trials, real-life and population studies. In fact, all clinical practice guidelines recommend their use preferentially over VKA. However, in Spain the prescription of DOAC is subordinated to an inspection visa that includes the clinical conditions defined in the Therapeutic Positioning Report of the Spanish Medicines Agency, and that still imposes important restrictions on their use, limiting the benefits of using DOACs in patients with atrial fibrillation (AF), and also generating inequalities between the different autonomous communities. In fact, the use of DOAC in Spain is much lower than that observed in neighboring countries. This has made that while in other countries the incidence of ischemic stroke has decreased at the population level, along with a reduction in the cost per patient with AF, in Spain this decrease has been modest. For all these reasons, and for assuring the sustainability of the health care system, we ask for the elimination of the visa so that DOAC can be prescribed according to the recommendations made by the guidelines. In addition, we are also committed to reinforce medical education and decisions made by consensus with the patient, with the primary care physician acquiring a key role in the protection of the patient with AF.

Antithrombotic treatment pattern in newly diagnosed atrial fibrillation patients and 2-year follow-up results for dabigatran-treated patients in the Africa/Middle-East Region: Phase II results from the GLORIA-AF registry program

BACKGROUND

Data on the epidemiology and treatment of atrial fibrillation in the Africa/Middle East region are limited, and the use of novel oral anticoagulants and their effectiveness in real-world clinical practice has not been evaluated.

METHODS AND RESULTS

This study used prospectively collected data from the Global Registry on Long-Term Oral Antithrombotic Treatment in Patients With Atrial Fibrillation (GLORIA-AF) to describe anticoagulant use and outcomes in Africa and the Middle East. Baseline characteristics of patients newly diagnosed with nonvalvular atrial fibrillation from Lebanon (242 patients, 40.3%), Saudi Arabia (236 patients, 39.3%), United Arab Emirates (87 patients, 14.5%), and South Africa (35 patients, 5.8%) were described, and clinical outcomes were investigated for all patients in this region who received dabigatran.In newly diagnosed patients (having a diagnosis within the last three months) with nonvalvular atrial fibrillation in Africa and the Middle East, the observed uptake of non-vitamin K oral anticoagulants was high in the first years following their availability; dabigatran was the most commonly used antithrombotic agent (314/600 patients), and only 1.5% of patients did not receive any antithrombotic therapy. Use of dabigatran was associated with a high persistence rate (>88% at 24 months) and low incidence rates of stroke, myocardial infarction, major bleeding, and all-cause mortality after 2 years of follow-up.

CONCLUSIONS

Data from GLORIA-AF reveal a change in the landscape for stroke prevention in the AME region, and the results were consistent with those observed in the global GLORIA-AF registry, as well as those of randomized clinical trials.Clinical Trial Registration: NCT01937377 (https://clinicaltrials.gov/ct2/show/NCT01937377).

Identification of the key target profiles underlying the drugs of narrow therapeutic index for treating cancer and cardiovascular disease

An appropriate therapeutic index is crucial for drug discovery and development since narrow therapeutic index (NTI) drugs with slight dosage variation may induce severe adverse drug reactions or potential treatment failure. To date, the shared characteristics underlying the targets of NTI drugs have been explored by several studies, which have been applied to identify potential drug targets. However, the association between the drug therapeutic index and the related disease has not been dissected, which is important for revealing the NTI drug mechanism and optimizing drug design. Therefore, in this study, two classes of disease (cancers and cardiovascular disorders) with the largest number of NTI drugs were selected, and the target property of the corresponding NTI drugs was analyzed. By calculating the biological system profiles and human protein–protein interaction (PPI) network properties of drug targets and adopting an AI-based algorithm, differentiated features between two diseases were discovered to reveal the distinct underlying mechanisms of NTI drugs in different diseases. Consequently, ten shared features and four unique features were identified for both diseases to distinguish NTI from NNTI drug targets. These computational discoveries, as well as the newly found features, suggest that in the clinical study of avoiding narrow therapeutic index in those diseases, the ability of target to be a hub and the efficiency of target signaling in the human PPI network should be considered, and it could thus provide novel guidance in the drug discovery and clinical research process and help to estimate the drug safety of cancer and cardiovascular disease.

Perioperative management of patients with atrial fibrillation receiving anticoagulant therapy

The number of patients with atrial fibrillation (AF) and the number of patients indicated for anticoagulant therapy have been increasing because AF would affect patient survival due to thromboembolism. Once AF develops, following the disappearance of pulsation, the circumstances within the atrium become prothrombotic and thrombus formation within the left atrium occurs in patients with AF. In recent years, not only warfarin but also new oral anticoagulants were introduced clinically and have become used as oral anticoagulants. In the perioperative period, the risk of major hemorrhage needs to be reduced. On the other hand, the suspension of anticoagulant therapy and neutralization of anticoagulant effects elevate the risk of thrombosis. The perioperative management of patients receiving anticoagulant therapy is different from that of scheduled surgery and emergency surgery. In addition, knowledge of the characteristics of each oral anticoagulant is required at drug cessation and resumption. Unlike warfarin, which has been used in the past five decades, direct oral anticoagulants (DOACs) do not have sensitive indicators such as prothrombin time-international normalized ratio. To avoid major hemorrhages and thromboembolism, quantitative assays can be implemented for DOAC monitoring and for reversal therapies in perioperative settings.

Dabigatran-induced esophagitis: The prevalence and endoscopic characteristics

BACKGROUND AND AIM

There have been some descriptions of dabigatran-induced esophagitis in the literature. The aim of this study was to examine the prevalence and endoscopic characteristics of the disease.

METHODS

We reviewed the endoscopic database and medical records of 91 patients with dabigatran internal use who underwent upper gastrointestinal endoscopy. The frequency of dabigatran-induced esophagitis and its endoscopic findings were retrospectively analyzed. In addition, the clinical characteristics were compared between patients with dabigatran-induced esophagitis and those without the disease.

RESULTS

Dabigatran-induced esophagitis was found in 19 of 91 (20.9%) patients. Of the 19 patients with the esophagitis, 18 (94.7%) showed longitudinally sloughing epithelial casts in the mid and/or lower esophagus, which may be characteristic endoscopic findings of this disease. Symptomatic patients were more frequent in patients with dabigatran-induced esophagitis (68.4%) than those without (37.5%, P = 0.02). Other factors including age, gender, coexistence of hiatal hernia, gastroesophageal reflux disease, or concomitant other medications did not differ between the two groups.

CONCLUSIONS

Dabigatran causes the esophageal mucosal injury in approximately 20% of patients. Longitudinally sloughing casts in the distal esophagus are characteristic of dabigatran-induced esophagitis.

Post-marketing surveillance on the long-term use of dabigatran in Japanese patients with nonvalvular atrial fibrillation: Preliminary report of the J-dabigatran surveillance

Background/aim

A post-marketing surveillance (PMS) study is being conducted to investigate the safety and effectiveness of the long-term use of dabigatran etexilate (dabigatran) in Japanese patients with nonvalvular atrial fibrillation (NVAF). Results of an interim analysis of this prospective cohort study including patient characteristics and adverse drug reactions (ADRs) collected up to September 17, 2014 are reported here.

Methods

Patients with NVAF who began to receive dabigatran for the first time from December 2011 to November 2013 were enrolled at 1042 study sites in Japan. Clinical parameters included patient characteristics, dabigatran dose strength, concomitant medications and outcome events. All outcome events were collected as serious and non-serious adverse events (AEs). ADRs were evaluated in this report. Pre-defined safety events of special interest for intensive survey were serious and non-serious outcome events such as myocardial infarction, as well as the total number of hemorrhage and gastrointestinal disorders.

Results

A total of 6772 patients were registered. The safety analysis set included 6148 patients; mean age was 70.8±9.9 (SD) years: 2323 patients (37.8%) were aged 75 years or older. Males accounted for 66.8% of the patients. Mean CHADS₂ score was 1.8±1.3; the CHADS₂ score was 0 in 13.6%, 1 in 31.3%, 2 in 25.9%, 3 in 14.9%, and 4 to 6 in 11.1% of the patients. Of the 6148 patients, 1701 patients (27.7%) were switchers from warfarin and 4407 patients (71.7%) were non-switchers (OAC naïve patients). Treatment adherence was assessed for the first 3 months from the start of treatment for this analysis. Total 5656 patients (92.0%) reported taking dabigatran twice daily (bid) every day according to the label recommendation. During the follow up period [mean duration of follow up: 498±259 days (corresponding to 8386 patient-years)], pre-defined safety events of special interest for intensive survey (reported as serious ADRs) were: myocardial infarction, reported in 5 patients (0.06 per 100 patient-years); serious hemorrhage, reported in 46 patients (0.55 per 100 patient-years); and gastrointestinal disorders (non-hemorrhagic), reported in 11 patients (0.13 per 100 patient-years). Fifteen patients had ADRs with fatal outcome.

Conclusions

The interim findings from this 6148 patient PMS study further corroborate the favorable safety profile of dabigatran as demonstrated previously in controlled clinical trials.

(ClinicalTrials.gov number, NCT01491178.)

Stroke Prevention in Atrial Fibrillation - Outcomes and Future Directions

Stroke prevention is central to the management of patients with atrial fibrillation (AF). Vitamin K antagonists (VKAs) are the established and long-standing option for stroke prevention therapy in patients with AF. However, non-VKA oral anticoagulants (NOACs) have recently been developed and demonstrated non-inferior efficacy vs VKA treatment, with fewer limitations in clinical practice and with reduced risks of major bleeding. In order to discuss the usage, efficacy and safety of NOACs, a satellite symposium was held at the Cardiostim/ EHRA Europace Congress in Nice in June 2014. At present, three NOACs, a direct thrombin inhibitor (dabigatran) and two direct factor Xa inhibitors (rivaroxaban and apixaban) have been approved in Europe for stroke prevention in patients with AF. In addition, the once-daily factor Xa inhibitor edoxaban has recently been evaluated in this setting in the phase III Effective Anticoagulation with Factor Xa Next Generation in Atrial Fibrillation - Thrombolysis In Myocardial Infarction Study 48 (ENGAGE AF-TIMI 48) that compared edoxaban 30 mg once daily (low-dose regimen) with dose-adjusted warfarin (international normalised ratio 2.0-3.0). ENGAGE AF-TIMI 48 was the largest trial with a NOAC to date, and demonstrated that both dosing regimens of once-daily edoxaban were non-inferior to well-managed warfarin treatment for the prevention of stroke or systemic embolism and also provided significant reductions in the risk of haemorrhagic stroke, cardiovascular mortality, major bleeding and intracranial bleeding. In summary, the recent availability of NOACs has enabled physicians to avoid the limitations of VKA therapy in clinical practice and tailor anticoagulant treatment to the individual patient. However, worldwide usage of oral anticoagulant therapy remains suboptimal compared with guideline recommendations, and further dissemination of its benefits may prove helpful.

An evidence-based review of apixaban and its potential in the prevention of stroke in patients with atrial fibrillation

Atrial fibrillation (AF) is a common cardiac arrhythmia, especially in the elderly population. It is associated with cardioembolic complications, particularly strokes, resulting in severe functional deficit or death. AF patients are first stratified into low, intermediate, and high risk for thromboembolic events using the CHADS(2) and CHA(2)DS(2)-VASc score systems. Depending on their risks, patients are treated with either therapeutic anticoagulation with warfarin or acetylsalicylic acid for stroke prevention. Although warfarin is the recommended therapy, it is underutilized clinically due to concern for narrow therapeutic window, drug-to-drug and drug-to-food interactions, and hemorrhagic complications. Newer anticoagulant agents such as dabigatran (a direct thrombin inhibitor) and rivaroxaban (a direct factor Xa inhibitor) have already been approved by US Food and Drug Administration for stroke prevention in patients with nonvalvular atrial fibrillation. Apixaban is the newest oral direct factor Xa inhibitor and it has been extensively studied in the AVERROES and ARISTOTLE trials. Apixaban demonstrated reduced incidence of primary outcome of stroke and bleeding events when compared with warfarin. Apixaban is currently being reviewed by the Food and Drug Administration as a stroke prophylactic agent. In addition, there are several other indirect factor Xa inhibitors and vitamin K antagonists under study presently. Results from these studies will provide us with information about possible alternatives to warfarin.

New and emerging anticoagulant therapy for atrial fibrillation and acute coronary syndrome

Abstract Thrombosis is an underlying cause of many cardiovascular disorders, and generation of thrombi in the arterial circulation can lead to unstable angina, myocardial infarction, or ischemic stroke. Antithrombotic therapy is widely used, with proven benefit to prevent ischemic stroke and thromboembolic events in patients with atrial fibrillation (AF) or to prevent further ischemic complications in patients with acute coronary syndrome (ACS). Traditional anticoagulants (including unfractionated heparin, low-molecular-weight heparin, and warfarin) and antiplatelet agents (including aspirin, clopidogrel, and prasugrel) are typically used for these indications. Limitations to their use include variable pharmacokinetic and pharmacodynamic profiles, inability to inhibit fibrin-bound thrombin, risk of heparin-induced thrombocytopenia, delayed onset of action, numerous drug interactions, need for substantial laboratory monitoring and dosage titrations, hyporesponsiveness or resistance, hypersensitivity, adverse events, and bleeding. To overcome some of the limitations of traditional agents, new antithrombotic agents under development are highly selective for specific coagulation factors blocking the synthesis of thrombin. Clinicians must have an understanding of the new anticoagulants to aid in the selection of appropriate therapies for patients. We describe the most relevant phases II and III clinical trials that evaluated several recent emerging anticoagulant drugs for use in patients with AF or ACS. The advantages of many new agents include predictable pharmaco-dynamic response and pharmacokinetic parameters, allowing for fixed oral dosing with no need for laboratory monitoring. For patients with AF, dabigatran is already approved for the prevention of stroke and systemic embolism, rivaroxaban appears to be an effective alternative to warfarin in high-risk patients, and apixaban may also be an effective alternative to aspirin in patients unable to take warfarin. Otamixaban shows promise as an intravenous alternative for patients with ACS in the acute care setting. Likewise, rivaroxaban, dabigatran, and darexaban with or without dual antiplatelet therapy may be beneficial for secondary prevention of ischemic events in patients with ACS.

Current therapies in ischemic stroke. Part A. Recent developments in acute stroke treatment and in stroke prevention

Stroke is the third leading cause of death with an increasing prevalence. In previous years many important achievements and new therapeutic strategies have been established. This article provides an overview on recent developments and is an update to the article of Green et al. that was published in 2004. As this article is a comprehensive review we divided it in two parts. In this Part A of our review, recent developments in acute stroke treatment and in stroke prevention are described. In Part B we will reflect on neuroprotection.