Switching of oral anticoagulants in patients with non-valvular atrial fibrillation: A narrative review

Decision model to evaluate the cost of clinical events associated with switching from apixaban to rivaroxaban among patients with non-valvular atrial fibrillation in the United States and Germany

AIMS

Direct-acting oral anticoagulants (DOACs) have emerged as the preferred treatment for nonvalvular atrial fibrillation (NVAF). However, evidence concerning the economic outcomes of DOAC switching remains limited. This study aimed to assess the economic outcomes of DOAC switching in the US and Germany, two countries with a high AF prevalence and DOAC utilization.

METHODS

A decision model was developed to assess the incidence and cost of stroke/systemic embolism (SE) and major bleeding (MB) associated with switching from apixaban to rivaroxaban in patients with NVAF. The model compared two scenarios: continuers (patients continuing apixaban) and switchers (patients switching from apixaban to rivaroxaban). Model inputs on clinical event rates were sourced from a published real-world study, cost inputs were from a standard costing database and published literature. The analysis was conducted over a 1-year time horizon from US Medicare fee-for-service and German public healthcare payer perspectives.

RESULTS

Over one year, 47,036 patients among a hypothetical plan size of 1,000,000 US Medicare fee-for-service members and 1,019,079 patients among the German adult population size of 70,107,122 were estimated to be treated for NVAF with apixaban. Switching all patients from apixaban to rivaroxaban resulted in 1,498 and 32,447 additional clinical events (stroke/SE and MB) and deaths in the US and Germany, respectively, compared to continuing with apixaban. This led to a total incremental cost of $17.3 million and €153 million from Medicare fee-for-service and German public healthcare perspectives, respectively.

LIMITATIONS

The incidence and hazard ratios of clinical events informing this analysis were based on a US commercial and Medicare Advantage population and may not be generalizable to other populations.

CONCLUSIONS

Switching from apixaban to rivaroxaban was associated with increased clinical events, deaths, and higher medical care costs, potentially representing a less favorable strategy economically compared to continuing apixaban among patients with NVAF.

Transitioning between therapeutic anticoagulants: a clinicians guide to switching patients to or from DOAC therapy

INTRODUCTION

The transition to or from direct oral anticoagulants (DOACs) is common in clinical practice.

AREAS COVERED

A literature search was conducted on PubMed, Google Scholar, and UpToDate up to March 2024 for conditions and approaches for transitioning from one agent to the other. No randomized clinical trials were retrieved except for two studies regarding switching to DOAC in well-conducted vitamin K antagonist (VKA) therapy. A narrative review was conducted addressing the conditions for switching from one agent to the other, such as thromboembolic events and major bleeding during anticoagulation, development or worsening of kidney or liver failure, initiation of interfering drugs, adverse events such as allergic reactions, frailty, patients' preferences, and affordability. During transitions from one anticoagulant to the other, the risk of both thromboembolic and bleeding complications should be minimized. The current approaches for such transitions are derived from those employed in clinical trials evaluating DOAC and from product information.

EXPERT OPINION

Many uncertainties remain regarding those circumstances requiring a change in anticoagulant strategies, as they lack evidence-based guidance. It can be envisaged that the problem of switching to and from DOAC will need additional studies especially addressing the conditions and the best approach to such transitions.

Development and Application of an Attribute-Based Taxonomy on the Benefits of Oral Anticoagulant Switching in Atrial Fibrillation: A Delphi Study

INTRODUCTION

Patients with atrial fibrillation (AF) often switch between oral anticoagulants (OACs). It can be hard to know why a patient has switched outside of a clinical setting. Medication attribute comparisons can suggest benefits. Consensus on terms and definitions is required for inferring OAC switch benefits. The objectives of the study were to generate consensus on a taxonomy of the potential benefits of OAC switching in patients with AF and apply the taxonomy to real-world data.

METHODS

Nine expert clinicians (seven clinical pharmacists, two cardiologists) with at least 3 years of clinical and research experience in AF participated in a Delphi process. The experts rated and commented on a proposed taxonomy on the potential benefits of OAC switching. After each Delphi round, ratings were analyzed with the RAND Corporation/University of California, Los Angeles (RAND/UCLA) appropriateness method. Median ratings, disagreement index, and comments were used to modify the taxonomy. The resulting taxonomy from the Delphi process was applied to a cohort of patients with AF who switched OACs in a population-based administrative health dataset from 1996 to 2019 in British Columbia, Canada.

RESULTS

The taxonomy was finalized in two Delphi rounds, reaching consensus on five switch benefit categories: safety, effectiveness, convenience, economic considerations, and drug interactions. Safety benefit (a switch that could lower the risk of adverse drug events) had three subcategories: major bleeding, intracranial hemorrhage (ICH), and gastrointestinal (GI) bleeding. Effectiveness benefit had four subcategories: stroke and systemic embolism (SSE), ischemic stroke, myocardial infarction (MI), and all-cause mortality. Real-world OAC switches revealed that more OAC switches had convenience (72.6%) and drug interaction (63.0%) benefits compared to effectiveness (SSE 22.0%, ischemic stroke 11.1%, MI 3.1%, all-cause mortality 10.1%), safety (major bleeding 24.3%, GI bleeding 10.6%, ICH 48.5%), and economic benefits (12.1%).

CONCLUSIONS

The Delphi-based taxonomy identified five criteria for the beneficial effects of OAC switching, aiding in characterizing real-world OAC switching.

Clinical Impact of Switching or Continuation of Apixaban or Rivaroxaban among Patients with Non-Valvular Atrial Fibrillation

BACKGROUND

Real-world evidence on direct oral anticoagulant outcomes among Non-Valvular Atrial Fibrillation (NVAF) patients is limited. We aimed to evaluate stroke/systemic embolism (SE) and major bleeding (MB) risks among NVAF patients continuing or switching to different oral anticoagulants.

METHODS

Using Optum's de-identified Clinformatics® Data Mart Database, we identified NVAF patients initiating apixaban or rivaroxaban between 1 January 2013 and 31 December 2021. Patients switching therapies within 30 days before or 90 days after discontinuing their initial DOAC and those who continued initial therapy were included. The index date was the switch date for switchers, while continuers were assigned a hypothetic index date. Switchers and continuers were propensity score matched based on pre-index characteristics.

RESULTS

Among 167,868 apixaban and 65,888 rivaroxaban initiators, 2900 apixaban-to-rivaroxaban switchers were matched with 14,500 apixaban continuers, and 2873 rivaroxaban-to-apixaban switchers were matched with 14,365 rivaroxaban continuers. Apixaban-to-rivaroxaban switching was associated with higher stroke/SE risk (HR: 1.99, 95% CI: 1.38-2.88) and MB risk (HR:1.80, 95% CI: 1.46-2.23) than continuing apixaban. Rivaroxaban-to-apixaban switching had similar stroke/SE risk (HR: 0.74, 95% CI: 0.45-1.22) but lower MB risk (HR: 0.49, 95% CI: 0.38-0.65) than continuing rivaroxaban.

CONCLUSIONS

These findings may aid physicians and patients in making informed decisions when considering a switch between apixaban and rivaroxaban.

Patients on vitamin K treatment: is switching to direct-acting oral anticoagulation cost-effective? A target trial on a prospective cohort

AIMS

Direct-acting oral anticoagulants (DOACs) have, to a substantial degree, replaced vitamin K antagonists (VKA) as treatments for stroke prevention in atrial fibrillation (AF) patients. However, evidence on the real-world causal effects of switching patients from VKA to DOAC is lacking. We aimed to assess the empirical incremental cost-effectiveness of switching patients to DOAC compared with maintaining VKA treatment.

METHODS

The target trial approach was applied to the prospective observational Swiss-AF cohort, which enrolled 2415 AF patients from 2014 to 2017. Clinical data, healthcare resource utilisation and EQ-5D-based utilities representing quality of life were collected in yearly follow-ups. Health insurance claims were available for 1024 patients (42.4%). Overall survival, quality-of-life, costs from the Swiss statutory health insurance perspective and cost-effectiveness were estimated by emulating a target trial in which patients were randomly assigned to switch to DOAC or maintain VKA treatment.

RESULTS

228 patients switching from VKA to DOAC compared with 563 patients maintaining VKA treatment had no overall survival advantage over a 5-year observation period (HR 0.99, 95% CI 0.45, 1.55). The estimated gain in quality-adjusted life years (QALYs) was 0.003 over the 5-year period at an incremental costs of CHF 23 033 (€ 20 940). The estimated incremental cost-effectiveness ratio was CHF 425 852 (€ 387 138) per QALY gained.

CONCLUSIONS

Applying a causal inference method to real-world data, we could not demonstrate switching to DOACs to be cost-effective for AF patients with at least 1 year of VKA treatment. Our estimates align with results from a previous randomised trial.

Oral anticoagulant switching in patients with atrial fibrillation: a scoping review

INTRODUCTION

Oral anticoagulants (OACs) prevent stroke in patients with atrial fibrillation (AF). Several factors may cause OAC switching.

OBJECTIVES

To examine the phenomenon of OAC switching in patients with AF, including all available evidence; frequency and patterns of switch, clinical outcomes, adherence, patient-reported outcomes, reasons for switch, factors associated with switch and evidence gaps.

DESIGN

Scoping review.

DATA SOURCES

MEDLINE, Embase and Web of Science, up to January 2022.

RESULTS

Of the 116 included studies, 2/3 examined vitamin K antagonist (VKA) to direct-acting OAC (DOAC) switching. Overall, OAC switching was common and the definition of an OAC switch varied across. Switching from VKA to dabigatran was the most prevalent switch type, but VKA to apixaban has increased in recent years. Patients on DOAC switched more to warfarin than to other DOACs. OAC doses involved in the switches were hardly reported and patients were often censored after the first switch. Switching back to a previously taken OAC (frequently warfarin) occurred in 5%-21% of switchers.The risk of ischaemic stroke and gastrointestinal bleeding in VKA to DOAC switchers compared with non-switchers was conflicting, while there was no difference in the risk of other types of bleeding. The risk of ischaemic stroke in switchers from DOAC versus non-switchers was conflicting. Studies evaluating adherence found no significant changes in adherence after switching from VKA to DOAC, however, an increase in satisfaction with therapy were reported. Reasons for OAC switch, and factors associated with OAC switch were mostly risk factors for stroke and bleeding. Clinical outcomes, adherence and patient-reported outcomes were sparse for switches from DOACs.

CONCLUSIONS

OAC switching is common in patients with AF and patients often switch back to an OAC they have previously been on. There are aspects of OAC switching that have received little study, especially in switches from DOACs.

Incidence and Predictors of Switching and Dose Change of Direct Oral Anticoagulants among Elderly Patients with Nonvalvular Atrial Fibrillation: A 5-Year Analysis of a Large Administrative Database

In the last decade, novel oral anticoagulants (NOACs) have emerged as prominent therapeutic options in non-valvular atrial fibrillation (NVAF). We analysed the clinical burden and the switching rate between all available NOACs, and their dosage change over a period of 5 years in a representative population of patients with NVAF aged between 70 and 75 years. Methods and Results: This is a retrospective observational study on administrative databases, covering approximately 6.2 million health-assisted individuals by the Italian National Health System (around 11% of the entire Italian residents). Out of 4640 NVAF patients treated with NOACs and aged 70-75 years in 2017, 3772 (81.3%) patients were still in treatment with NOAC up to 2021 and among them, 3389 (73.0%) patients remained in treatment with the same NOAC during 2017-2021. In fact, 10.2% of patients switched NOAC type and 10.3% changed the dose of the same NOAC. Overall, after switching, the dabigatran and rivaroxaban groups lost, respectively, 13.5% and 2.8% of patients, while apixaban and edoxaban resulted in a relative percentage increase of 6.8% and 44.6% of patients, respectively. By a logistic regression analysis, the treatment with rivaroxaban, apixaban, and edoxaban (respect to dabigatran) was associated with a significant risk reduction of switch of 57%, 68%, and 44%, respectively. On the other hand, several features of high risk were associated with dose reduction. Conclusions. In our 5-year analysis of a large administrative database, a switching among NOACs or a change in NOAC dosages occurred in around 20% of elderly patients with NVAF. The type of NOAC was associated with a high switching rate, while several characteristics of high risk resulted as predictors of dose reduction of NOACs. Moreover, a worsening trend of clinical conditions occurred in patients maintaining the same NOAC treatment across 2017-2021.

Prescribing Trends of Oral Anticoagulants from 2010 to 2020 in Shanghai, China: A Retrospective Study

Aim

Non-vitamin K antagonist oral anticoagulants (NOACs) were developed as an alternative to warfarin to prevent thromboembolism in patients with atrial fibrillation (AF), prosthetic heart valves, venous thromboembolism (VTE), or other thrombotic disorders. The aim of this study is to explore the trends in prescribing OACs, including warfarin and NOACs, in Shanghai, China.

Methods

Prescription data of OACs were retrospectively collected from Rx Analysis System from 2010 to 2020 in Shanghai, China. Comparisons were made on the trends of each OACs according to different indications, age groups, and hospital grades. The costs and the contribution of individual OACs were also explored.

Results

Growing trends in overall prescriptions for OACs were observed. The prescriptions of NOACs were significantly increased since 2016, while the prescriptions of warfarin kept decreasing since 2017. A highly statistically significant increase in prescriptions of Rivaroxaban was observed from 2016 to 2020 (P < .001). Despite the price reduction of rivaroxaban in 2018, the total cost of rivaroxaban continued to rise (P < .001). Rivaroxaban emerged as a preferred NOAC in both indications of AF and VTE, and accounted for more than three-quarters of the total costs for OACs since 2019. Compared with rivaroxaban, the prescription numbers of dabigatran and apixaban were much smaller, and the growth of prescriptions were much slower. Differences in prescribing patterns in different indications, age groups, and grades of hospitals were also founded.

Conclusion

There has been a rapid increase in the use of OAC over the last 11 years in Shanghai, China. NOACs have been adopted rapidly, and have been gradually replacing warfarin. Warfarin remains the top choice for certain patients with valvular heart disease. Future studies are warranted considering changes in the OAC use in a larger scale, as well as the rationality and its influence factors on OAC use.