Discontinuation and primary care visits in nonvalvular atrial fibrillation patients treated with apixaban or warfarin

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.

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

Approval of direct-acting oral anticoagulants (DOACs) for stroke prevention in atrial fibrillation (AF) was an important milestone, providing a wider range of treatment options and creating the possibility for drug switching after initiation. In addition to improved utilisation of oral anticoagulants (OACs) for stroke prevention, reports of switching among OACs are growing in the literature; switching may influence clinical outcomes, healthcare costs and patient satisfaction. This review aimed to summarise the current literature on the pattern of OAC switching in patients with AF, including reasons for switching and clinical consequences following switching. A literature search was conducted in PubMed, Scopus, and Embase on Jun 27, 2020. We included 39 articles published after 2013, following the introduction of apixaban. The review found that switching among OACs was common in clinical practice, significantly varying with the type of OAC. Studies reporting the reason for switching and clinical outcomes were comparatively limited. The decision to switch was often related to safety issues (usually bleeding), poor anticoagulation control and ease-of-use. Patient characteristics, clinical conditions and drug interactions were found to be associated with switching from OACs. Findings regarding bleeding outcomes following switching were inconsistent, possibly confounded by the rationale for switching and the switching protocol. Noting the limited number of studies included and their relatively short follow-up periods, switching did not have a significant impact on the risk of stroke and other thrombotic outcomes. Further prospective studies are needed to understand better potential rationales for switching and the clinical outcomes.

Real-world persistence to direct oral anticoagulants in patients with atrial fibrillation: a systematic review and network meta-analysis

OBJECTIVE

To conduct a systematic review and network meta-analysis of real-world evidence comparing adherence, persistence, cost, and utilization between oral anticoagulant (OAC) in non-valvular atrial fibrillation (NVAF) patients.

METHODS

A systematic search of MEDLINE and Embase (inception-July 2019) was conducted for published observational cohort studies comparing outcomes between ≥2 OACs. A network meta-analysis was performed to estimate odds ratios for non-persistence using a random-effects model.

RESULTS

There were 80 studies evaluating the outcomes of interest. However, due to a paucity in adherence studies and heterogeneity in adherence, cost, and utilization definitions, persistence was the focus of this network meta-analysis. There were 36 studies evaluating non-persistence in 395,593 participants, 24 of which used 3 gap definitions (30-, 60-, and 90-days); 18 unique studies evaluating non-persistence at 12 months were included in the network meta-analysis. Using 30- and 90-day gaps, all NOACs, when compared with VKAs, had lower odds of non-persistence (30-day OR (95%CI): apixaban: 0.63 (0.58, 0.69); rivaroxaban: 0.69 (0.62, 0.76); dabigatran: 0.89 (0.82, 0.97); 90-day OR (95%CI): apixaban: 0.33 (0.22, 0.47); rivaroxaban: 0.47 (0.36, 0.61); dabigatran 0.61 (0.44, 0.85)). When using a 60-day gap, dabigatran had higher odds of non-persistence vs VKAs (OR: 1.35; 95%CI: 1.12, 1.61), but there were no significant differences for apixaban and rivaroxaban. Apixaban had the lowest probability of non-persistence across the 3-gap definitions (95.7% with 30-day gap, 76.9% with 60-day gap, 98.4% with 90-day gap).

CONCLUSIONS

The current findings, despite multiple limitations, can raise awareness and understanding of real-world persistence associated with OAC therapy in NVAF patients.

Costs of gastrointestinal bleeding events in atrial fibrillation: a UK Clinical Practice Research Datalink study

Aim: To estimate the healthcare costs attributable to gastrointestinal (GI) bleeds in nonvalvular atrial fibrillation (NVAF) patients. Material & methods: A difference-in-differences approach was used in which NVAF patients suffering a (GI) bleed were propensity score matched to those not suffering a GI bleed, and the difference in healthcare costs in the year prior to the GI bleed and the subsequent 3 years was compared between the two groups. Results: The mean cost attributable to GI bleeds was £3989 (p < 0.0001) in the year of the bleed and £1816 (p = 0.001) in the subsequent year. Attributable costs arose primarily from inpatient visits. Conclusion: GI bleeds among NVAF patients are associated with significant healthcare costs up to 2 years following the bleed.

Commonly used definitions in real-world studies may underestimate the prevalence of renal disease among nonvalvular atrial fibrillation patients

Aim: To describe comorbidities among treated nonvalvular atrial fibrillation (NVAF) patients and assess the impact of using different time ('look back' windows) on the prevalence estimates. Patients & methods: We included all adult nonvalvular atrial fibrillation patients newly initiating treatment in the Clinical Practice Research Datalink. Comorbidities included in the Charlson Comorbidity Index were defined using an all available, 3- and 1-year look back window before the start of treatment. Results: The prevalence of comorbidities was high and increased when using longer look back windows; the largest difference was observed for renal disease (+15.6%). Conclusion: Our findings emphasize the importance of using all available data when characterizing chronic conditions and highlights the high comorbidity burden in this population.