Increased risk of myocardial infarction with dabigatran

Clinical Characteristics And Health Care Resources In Patients Treated With Oral Anticoagulants: Evidences From Italian Administrative Databases

Objectives

1) To evaluate anticoagulation treatment patterns and health care resource use in adult patients with a discharge diagnosis of non-valvular atrial fibrillation (NVAF) in an Italian real-world setting and 2) to describe the characteristics of NVAF patients in relation to treatment.

Design

A retrospective cohort study in a "real-world" setting.

Setting

Data were analysed by integrating administrative databases that included approximately 2,000,000 individuals assisted by the National Health System from two Italian Local Health Units.

Participants

All adult patients with at least one hospital discharge or ≥2 outpatient visits with a diagnosis code for NVAF from 1/01/2011 to 31/12/2015 were included.

Main outcome measures

Anticoagulation treatment patterns, health care resource use and major bleeding events that occurred during the follow-up period were evaluated.

Results

32,863 NVAF patients were included, of whom 7,831 had at least one prescription of oral anticoagulants. Among them, 6,876 patients were vitamin K antagonists (VKA) users and 955 were non-vitamin K antagonist oral anticoagulant (NOAC) users at index date (ID). During the follow-up period, the use of antiplatelet drugs was higher among VKA-naïve users than the NOAC-naïve users. Among NOAC users, 76.1% showed an adherence level ≥80% during follow-up. The rate of bleeding events resulted higher for VKA patients compared to NOAC patients. The unadjusted incidence rate was 10.46 per 1000 person-year for VKA patients and 4.55 per 1,000 person-years for NOAC patients. The overall annual cost (in term of drugs, hospitalisations and outpatient specialist services) was € 5,156.13 for VKA and € 4,630.57 for NOAC.

Conclusion

This unselected cohort study, on NVAF patients being prescribed oral anticoagulants, highlights that VKA was largely prescribed and the great majority of patients on NOACs were adherent to treatment. Most of the OAC patients still received antiplatelet agents in combination, and in NOAC patients, we registered a lower number of bleeding events compared with VKA.

Patient values and preferences for antithrombotic therapy in atrial fibrillation

Guidelines recommend that patients’ values and preferences should be considered when selecting stroke prevention therapy for atrial fibrillation (SPAF). However, doing so is difficult, and tools to assist clinicians are sparse. We performed a narrative systematic review to provide clinicians with insights into the values and preferences of AF patients for SPAF antithrombotic therapy. Narrative systematic review of published literature from database inception. Research questions: 1) What are patients’ AF and SPAF therapy values and preferences? 2) How are SPAF therapy values and preferences affected by patient factors? 3) How does conveying risk information affect SPAF therapy preferences? and 4) What is known about patient values and preferences regarding novel oral anticoagulants (NOACs) for SPAF? Twenty-five studies were included. Overall study quality was moderate. Severe stroke was associated with the greatest disutility among AF outcomes and most patients value the stroke prevention efficacy of therapy more than other attributes. Utilities, values, and preferences about other outcomes and attributes of therapy are heterogeneous and unpredictable. Patients’ therapy preferences usually align with their values when individualised risk information is presented, although divergence from this is common. Patients value the attributes of NOACs but frequently do not prefer NOACs over warfarin when all therapy-related attributes are considered. In conclusion, patients’ values and preferences for SPAF antithrombotic therapy are heterogeneous and there is no substitute for directly clarifying patients’ individual values and preferences. Research using choice modelling and tools to help clinicians and patients clarify their SPAF therapy values and preferences are needed.

Supplementary Material to this article is available online at www.thrombosis-online.com.

Oral Anticoagulants Initiation in Patients with Atrial Fibrillation: Real-World Data from a Population-Based Cohort

Objective: Little is known about initial prescription of currently used oral anticoagulants (OAC), and correlated characteristics in real-world practice. We aimed to assess patterns of initiation of Vitamin K antagonists (VKA) and non-VKA oral anticoagulants (NOAC) in naive patients with non-valvular atrial fibrillation and the factors associated with starting treatment with NOAC. Methods: Population-based retrospective cohort study of all patients with NVAF who had a first prescription of OAC from November 2011 to February 2014 in the Valencia region, Spain (n = 21,881). Temporal trends of OAC initiation are described for the whole population and by type of OAC and therapeutic agent. Factors associated with starting treatment with NOAC (vs. VKA) were identified using logistic multivariate regression models. Results: Among the patients initiating OAC, 25% started with NOAC 2 years after market release. Regarding temporal trends, prescription of NOAC doubled during the study period. VKA prescription also increased (by around 13%), resulting in a 30% rise in total treatment initiation with OAC during 2011-2014. NOAC initiation (vs. VKA) was associated with a lower baseline risk of thromboembolism and higher income. Conclusions: In this Spanish population-based cohort, initiation of OAC therapy saw a rapid increase, mainly but not exclusively, due to a two-fold rise in the use of NOAC. Initiation with NOAC was associated with a lower baseline risk of thromboembolism and higher income, which opposes the indications of NOAC use and reflects disparities in care. Inadequate prescription patterns might threaten the effectiveness and safety of these therapies, thus monitoring OAC prescription is necessary and should be setting-specific.

Differential benefit risk assessment of DOACs in the treatment of venous thromboembolism: focus on dabigatran

Venous thromboembolism includes deep vein thrombosis and pulmonary embolism and is a serious medical condition that requires anticoagulation as part of treatment. Currently, standard therapy consists of parenteral anticoagulation followed by a vitamin K antagonist (VKA). The pharmacokinetic and pharmacodynamic profiles of the direct oral anticoagulants (DOACs) differ from VKAs, which overcome some of the limitations of VKAs and have practical implications on their use in clinical situations. Dabigatran is a prodrug that undergoes primarily renal elimination and does not affect cytochrome P450 enzymes. Assays to quantify the degree of anticoagulation and the therapeutic level of DOAC are either unavailable for routine clinical use or require specific calibration. Routine monitoring of DOACs is not recommended at this time. Dabigatran, rivaroxaban, and apixaban are DOACs that have been studied for treatment of venous thromboembolism. Clinical trials comparing DOACs with standard therapy have shown them to be non-inferior for acute and extended therapy. Each DOAC has a unique benefit and harm profile that should be considered prior to use. The distinguishing characteristics of dabigatran include a requirement of parenteral anticoagulation prior to acute treatment, clinical trial results comparing it with a VKA for extended treatment, association with upper gastrointestinal adverse events, and increased risk of gastrointestinal bleed. Rivaroxaban is the only DOAC that has once-daily dosing while apixaban is the only DOAC that has lower risk of overall, major, and gastrointestinal bleeding compared with VKA. A common drawback of DOACs is the lack of an available reversal agent. Clinical trials of reversal agents are ongoing and one application for approval has been submitted to the US Food and Drug Administration. Selection of a DOAC for acute and extended therapy requires a shared decision-making approach that includes a comprehensive assessment of the benefits and harms of each individual DOAC.