Are low doses of non-vitamin K antagonists effective in Chinese patients with atrial fibrillation? A report from the Optimal Thromboprophylaxis in Elderly Chinese Patients with Atrial Fibrillation (ChiOTEAF) registry

2024 Chinese Expert Consensus Guidelines on the Diagnosis and Treatment of Atrial Fibrillation in the Elderly, Endorsed by Geriatric Society of Chinese Medical Association (Cardiovascular Group) and Chinese Society of Geriatric Health Medicine (Cardiovascular branch): Executive Summary

The consensus guidelines of the Geriatric Society of Chinese Medical Association on the management of atrial fibrillation (AF) in the elderly was first published in 2011 and updated in 2016, with endorsement by Chinese Society of Geriatric Health Medicine. Since then, many important studies regarding the screening and treatment in the elderly population have been reported, necessitating this updated expert consensus guideline. The writing committee members comprehensively reviewed updated evidence pertaining to elderly patients with AF, and formulated this 2024 update. The highlighted issues focused on the following: screening for AF, geriatric comprehensive assessment, use of the Atrial fibrillation Better Care (ABC) pathway for the elderly patients, and special clinical settings related to elderly patients with AF. New recommendations addressing smart technology facilitated AF screening, ABC pathway based management, and optimal anticoagulation were developed, with a focus on the elderly.

Real world time trends in antithrombotic treatment for newly diagnosed atrial fibrillation in China: reports from the GLORIA-AF Phase III registry : Trends in antithrombotic therapy use in China

BACKGROUND

Stroke prevention with oral anticoagulant (OAC) therapy, including non-vitamin K antagonist oral anticoagulants (NOACs), is recommended in patients with atrial fibrillation (AF). This analysis describes the antithrombotic prescription patterns for Chinese patients enrolled post-dabigatran approval during Phase II and III of the Global Registry on Long-Term Oral Antithrombotic Treatment in Patients with Atrial Fibrillation (GLORIA-AF) program in China.

METHODS

Patients aged ≥ 18 years with newly diagnosed (< 3 months before baseline visit) nonvalvular AF at risk of stroke (CHA₂DS₂-VASc score ≥ 1) were consecutively enrolled in the GLORIA-AF registry. This cross-sectional analysis provides descriptive comparison of Chinese patients in Phase III (2015-2016) with those enrolled in Phase II (2013-2014).

RESULTS

Overall, 1,018 and 1,911 Chinese patients were eligible for analysis in Phase II and III, respectively. Most patients (69.6% and 69.1%, respectively) had high stroke risk (CHA₂DS₂-VASc score ≥ 2 for males and ≥ 3 for females). High bleeding risk (HAS-BLED score ≥ 3) rates were similar (17.3% for Phase II, 17.6% for Phase III). In Phase II, 5.8%, 15.2%, 36.7% and 42.2% of patients were prescribed NOACs, vitamin K antagonists (VKAs), antiplatelet therapies or no antithrombotic treatment, respectively. The corresponding figures were 17.2%, 23.5%, 37.4% and 21.8% for patients in Phase III, with an overall increase in OAC prescriptions (NOACs or VKAs). In patients with high stroke risk, the prescription patterns in Phase II were 5.6%, 14.4%, 41.0% and 38.9% for NOACs, VKAs, antiplatelets or no antithrombotic treatment, respectively. The respective proportions in Phase III were 15.1%, 23.5%, 40.9% and 20.5%.

CONCLUSIONS

Since the availability of dabigatran in China, the overall trend of OAC, including NOAC, prescriptions in Chinese patients with nonvalvular AF has increased over time, albeit with VKAs as the most common antithrombotic treatment. Most patients, including those at high stroke risk, remain undertreated according to best practice guidelines.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01468701.

Efficacy and Safety Considerations With Dose-Reduced Direct Oral Anticoagulants: A Review

Importance

Dose-reduced regimens of direct oral anticoagulants (DOACs) may be used for 2 main purposes: dose-adjusted treatment intended as full-intensity anticoagulation (eg, for stroke prevention in atrial fibrillation [AF] in patients requiring dose reduction) or low-intensity treatment (eg, extended-duration treatment of venous thromboembolism [VTE]). We reviewed randomized clinical trials (RCTs) to understand the scenarios in which dose-adjusted or low-intensity DOACs were tested and reviewed the labeled indications by regulatory authorities, using data from large registries to assess whether the use of dose-reduced DOACs in routine practice aligned with the findings of RCTs.

Observations

Among 4191 screened publications, 35 RCTs that used dose-adjusted DOACs were identified for dabigatran, apixaban, rivaroxaban, and edoxaban. Of these 35 RCTs, 29 were related to stroke prevention in AF. Efficacy and safety results for dose-adjusted DOACs in large RCTs of AF were similar to those found for full-dose DOACs. To our knowledge, dabigatran, apixaban, and rivaroxaban have not been studied as dose-adjusted therapy for acute VTE treatment. Low-intensity DOACs were identified in 37 RCTs. Low-intensity DOACs may be used for extended-duration treatment of VTE (apixaban and rivaroxaban), primary prevention in orthopedic surgeries (dabigatran, apixaban, and rivaroxaban), primary prevention in ambulatory high-risk cancer patients (apixaban and rivaroxaban) or (postdischarge) high-risk medical patients (rivaroxaban), in stable atherosclerotic vascular disease, or after a recent revascularization for peripheral artery disease in conjunction with aspirin (rivaroxaban). Minor variations exist between regulatory authorities in different regions regarding criteria for dose adjustment of DOACs. Data from large registries indicated that dose-reduced DOACs were used occasionally with doses or for clinical scenarios different from those studied in RCTs or recommended by regulatory authorities.

Conclusions and Relevance

Dose adjustment and low-intensity treatment are 2 different forms of dose-reduced DOACs. Dose adjustment is mostly relevant for AF and should be done based on the approved criteria. Dose adjustment of DOACs should not be used for acute VTE treatment in most cases. In contrast, low-intensity DOACs may be used for primary or secondary VTE prevention for studied and approved indications. Attention should be given to routine practice patterns to align the daily clinical practice with existing evidence of safety and efficacy.