A review of oral anticoagulants in patients with atrial fibrillation

Impact of comparative effectiveness research on Medicare coverage of direct oral anticoagulants

Aim: To evaluate the association of comparative effectiveness research with Medicare coverage of direct oral anticoagulants. Materials & methods: A literature review for direct oral anticoagulants was conducted from 2011 to 2017. Monthly prescription drug plan and formulary files (n = 28) were used to conduct change-point analysis and assess each outcome variable. Results: Up to 2013, studies showed that dabigatran was more effective than rivaroxaban. In 2015, apixaban was shown to be the safest and most effective drug in comparison with all direct oral anticoagulants. In 2016-2017, dabigatran and apixaban were shown to have similar efficacy. Approximately 75% of plans covered dabigatran under tier 3 until 2015. From 2011 to 2017, less than 30% of plans required prior authorizations, 50% imposed quantity limits and mean copayment was lowest for rivaroxaban. Conclusion: Consistent with comparative effectiveness research, Medicare plans covered apixaban more favorably and edoxaban less favorably. However, discrepancies in comparative effectiveness research translation were found for rivaroxaban and dabigatran.

Non-Vitamin K Antagonist Oral Anticoagulants Provide Less Adverse Renal Outcomes Than Warfarin In Non-Valvular Atrial Fibrillation: A Systematic Review and MetaAnalysis

Background

Non‐vitamin K antagonist oral anticoagulants (NOACs) have better pharmacologic properties than warfarin and are recommended in preference to warfarin in most patients with non‐valvular atrial fibrillation. Besides lower bleeding complications, other advantages of NOACs over warfarin particularly renal outcomes remain inconclusive.

Methods and Results

Electronic searches were conducted through Medline, Scopus, Cochrane Library databases, and ClinicalTrial.gov. Randomized controlled trials and observational cohort studies reporting incidence rates and hazard ratio (HR) of renal outcomes (including acute kidney injury, worsening renal function, doubling serum creatinine, and end‐stage renal disease) were selected. The random‐effects model was used to calculate pooled incidence and HR with 95% CI. Eighteen studies were included. A total of 285 201 patients were enrolled, 118 863 patients with warfarin and 166 338 patients with NOACs. The NOACs group yielded lower incidence rates of all renal outcomes when compared with the warfarin group. Patients treated with NOACs showed significantly lower HR of risk of acute kidney injury (HR, 0.70, 95% CI, 0.64–0.76; P<0.001), worsening renal function (HR, 0.83; 95% CI, 0.73–0.95; P=0.006), doubling serum creatinine (HR, 0.58; 95% CI, 0.41–0.82; P=0.002), and end‐stage renal disease (HR, 0.82; 95% CI, 0.78–0.86; P<0.001).

Conclusions

In non‐valvular atrial fibrillation, patients treated with NOACs have a lower risk of both acute kidney injury and end‐stage renal disease when compared with warfarin.

Reversing the anticoagulation effects of dabigatran

The standard of care for oral anticoagulation therapy has primarily been warfarin, which is limited by its indirect mechanism-of-action, variable kinetics, tolerability, and routine monitoring concerns. The direct-acting oral anticoagulants (DOACs) have predictable pharmacokinetics and pharmacodynamics, and improved safety and efficacy compared to warfarin for the prevention of stroke in patients with nonvalvular atrial fibrillation and prevention or management of venous thromboembolism. Consequential bleeding is a concern with all anticoagulants. Vitamin K is not a rapid reversal agent for warfarin; rather it facilitates synthesis of new vitamin K-dependent clotting factors, which can take longer than 24 h. Other nonspecific agents, including recombinant activated factor VII, three- and four-factor prothrombin complex concentrates (PCC), and activated PCC or Factor Eight Inhibitor Bypassing Activity (FEIBA®), are options based on clinical need. Specific agents to quickly reverse the effects of DOACs have been under development, and idarucizumab, a monoclonal antibody fragment that rapidly binds dabigatran, has been approved for clinical use in cases of dabigatran-related life-threatening bleeding, or if a dabigatran-treated patient needs emergency surgery or an invasive procedure. Idarucizumab specifically and rapidly reverses dabigatran-induced anticoagulation as measured by established coagulation assays. However, this does not guarantee complete hemostasis, especially if a patient has underlying comorbidities such as renal or liver disease, or has experienced recent trauma that requires urgent surgery. In these cases, concomitant supportive therapy and/or administration of concentrated clotting factors may be considered. Emerging data from ongoing trials and clinical experience will further inform providers regarding optimal approaches for anticoagulation reversal.

Left atrial appendage morphology, echocardiographic characterization, procedural data and in-hospital outcome of patients receiving left atrial appendage occlusion device implantation: a prospective observational study

Background

Implantation of left atrial appendage (LAA) occlusion devices was shown to be a feasible and effective alternative to oral anticoagulation in patients with non-valvular atrial fibrillation. However, only few data about in-hospital and peri-procedural data are currently available. This study aims to report about echocardiographic, procedural and in-hospital data of patients receiving LAA occlusion devices.

Methods

This single-center, prospective and observational study includes consecutively patients being eligible for percutaneous implantation of LAA occlusion devices (either Watchman™ or Amplatzer™ Cardiac Plug 2). Data on pre- and peri-procedural transesophageal echocardiography (TEE), implantation and procedure related in-hospital complications were collected. The primary efficacy outcome measure was a successful device implantation without relevant peri-device leaks (i.e., < 5 mm).

Results

In total, 37 patients were included, 22 receiving the Watchman™ and 15 ACP 2 device. Baseline characteristics did not differ significantly in both patient groups. The primary efficacy outcome measure was reached in 91.9 % of patients (90.9 % for the Watchman™, 93.3 % for the ACP 2 group). One device embolization (Watchman™ group) with successful retrieval occurred (2.7 % of patients). No thromboembolism or device thrombosis were present. The majority of bleedings was caused by access site bleedings (88.3 % of all bleedings), consisting mostly of mild hematomas corresponding to a BARC type 1 bleeding (80.0 % of all access-site complications). One patient died due to septic shock (non-procedure related).

Conclusions

In daily real-life practice, percutaneous treatment with LAA occlusion devices appears to be an effective and safe.

Age as a Risk Factor for Stroke in Atrial Fibrillation Patients: Implications in Thromboprophylaxis in the Era of Novel Oral Anticoagulants

Atrial fibrillation is associated with significant morbidity and mortality. There is a strong relationship between atrial fibrillation and aging, thromboembolism, stroke, congestive heart failure and hypertension. In addition, advanced age is a powerful risk factor for stroke and thromboembolism in patients with atrial fibrillation. For many years, vitamin K antagonists were the only approved anticoagulants for the management of atrial fibrillation. Lately new anticoagulants made their appearance and large trials have already shown their superiority against vitamin K antagonists. Since the arrhythmia is encountered frequently in the elderly, it is crucial to identify the beneficial effects of the novel oral anticoagulants in this particular patient population.