Safety and Effectiveness of Apixaban in Very Elderly Patients With Non-valvular Atrial Fibrillation (NVAF) Compared to Warfarin Using Administrative Claims Data

Completed

• Conditions: Non-valvular Atrial Fibrillation
• Interventions: Drug: Warfarin; Drug: Apixaban

• Registration Number: NCT05438888
• Lead Sponsor: Pfizer

Brief Summary

The objective of this study is to investigate safety and effectiveness of apixaban compared to warfarin in very elderly patients with Non-valvular atrial fibrillation (NVAF). In addition to the absolute age, effects on higher age-related risk factors on relative risk of apixaban to warfarin is also investigated through subgroup analyses.

Detailed Description

This is a retrospective non-intervention observational study to evaluate the difference in safety and effectiveness between apixaban and warfarin using a database provided by Medical Data Vision Co. Ltd. (MDV Co. Ltd.). Eligible patients will be extracted from the database and allocated to the pre-defined cohorts based on the actual age, age of NVAF diagnosis and types of anticoagulant therapy.

Patient characteristics will be balanced by an Inverse probability of treatment weighting (IPTW) method, and risk of stroke/SE (primary effectiveness endpoint) and major bleeding (primary safety endpoint) will be compared.

Study Timeline

• Study First Submitted: 2022-06-25
• Study First Submitted QC: 2022-06-25
• Study First Posted: 2022-06-30
• Study Start: 2022-07-01
• Primary Completion: 2022-10-19
• Study Completion: 2022-10-19
• Status Verified: 2023-10
• Results First Submitted: 2023-10-02
• Results First Submitted QC: 2023-10-02
• Last Update Submitted: 2023-10-02
• Results First Posted: 2024-05-20
• Last Update Posted: 2024-05-20

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 77814

Inclusion Criteria

• Patients must meet all the following inclusion criteria to be eligible for inclusion in the study.

  1. Diagnosed with Atrial fibrillation (AF) anytime in the baseline period or on the index date, also have definitive diagnosis of AF anytime in the baseline period, on the index date, or post-index period.
  2. Prescribed apixaban or warfarin on or after the day of AF diagnosis. The first observed prescription will be used to identify the patient's index date and treatment cohort
  3. No use of the any Oral anticoagulants (OAC)s during the baseline period (the 180 days before the index date)
  4. Age of 18 years or older on the index date.
  5. Index date is at age 80 or older

Exclusion Criteria

• Patients meeting any of the following criteria will not be included in the study:

  1. Having a diagnosis of valvular atrial fibrillation, post-operative atrial fibrillation, rheumatic atrial fibrillation or mechanical-valvular atrial fibrillation during the baseline and post-index period
  2. Having a cardiac surgery procedure record during the baseline period
  3. Having a joint replacement procedure record during the baseline period
  4. Having a procedure of prosthetic heart valve during the baseline period
  5. Having a diagnosis of venous thromboembolism during the baseline period
  6. Female patients with pregnancy during the follow-up period
  7. Patients prescribed "off-label" doses of OACs (per Japanese package insert of each OAC) or patients treated with OAC but in "off-label" or "contraindicated" manners.

Study & Design

• Study Type: OBSERVATIONAL
• Study Design: Not specified

Arm && Interventions

Group	Intervention	Description
Warfarin cohort (Reference)	Warfarin	Patients with NVAF treated with warfarin
Apixaban cohort	Apixaban	Patients with NVAF treated with apixaban

Primary Outcome Measures

Name	Time	Method
Incidence Rate (Per 1,000 Participant-Year) of Composite of Stroke and Systemic Embolism (SE): Balanced Cohorts	Follow-up period during data observation period from 26-Feb-2013 to 31-Dec-2021 (approximately 8 years 10 months); extracted data evaluated in approximately 3.5 months of this study	Incidence rate per 1000 participant-years for the first occurrence of composite stroke and SE events after index date was reported. Stroke events included ischemic and hemorrhagic stroke. International Classification of Diseases 10th Revision (ICD-10) diagnosis code was used to label the events. Index date was defined as a date when participants initiated warfarin or apixaban. Follow-up period: the next day of the index date till occurrence of target outcome, discontinuation of the warfarin or apixaban, switching from the warfarin or apixaban, withdrawal from the database, whichever observed first.
Incidence Rate (Per 1,000 Participant-Year) of Major Bleeding: Balanced Cohorts	Follow-up period during data observation period from 26-Feb-2013 to 31-Dec-2021 (approximately 8 years 10 months); extracted data evaluated in approximately 3.5 months of this study	Incidence rate per 1000 participant-years for the first occurrence of major bleeding event after index date was reported. Major bleeding was defined as any bleeding that required hospitalization for treatment. ICD-10 diagnosis code was used to label the events. Index date was defined as a date when participants initiated warfarin or apixaban. Follow-up period: the next day of the index date till occurrence of target outcome, discontinuation of the warfarin or apixaban, switching from the warfarin or apixaban, withdrawal from the database, whichever observed first.

Secondary Outcome Measures

Name	Time	Method
Incidence Rate (Per 1,000 Participant-Year) of Cardiogenic Cerebral Embolism: Balanced Cohorts	Follow-up period during data observation period from 26-Feb-2013 to 31-Dec-2021 (approximately 8 years 10 months); extracted data evaluated in approximately 3.5 months of this study	Incidence rate per 1000 participant-years for the first occurrence of cardiogenic cerebral embolism events after index date was reported. ICD-10 diagnosis code was used to label the events. Index date was defined as a date when participants initiated warfarin or apixaban. Follow-up period: the next day of the index date till occurrence of target outcome, discontinuation of the warfarin or apixaban, switching from warfarin or apixaban, withdrawal from the database, whichever observed first.
Incidence Rate (Per 1,000 Participant-Year) of Ischemic Stroke (Cerebral Infarction): Balanced Cohorts	Follow-up period during data observation period from 26-Feb-2013 to 31-Dec-2021 (approximately 8 years 10 months); extracted data evaluated in approximately 3.5 months of this study	Incidence rate per 1000 participant-years for the first occurrence of ischemic stroke event after index date was reported. ICD-10 diagnosis code was used to label the events. Index date was defined as a date when participants initiated warfarin or apixaban. Follow-up period: the next day of the index date till occurrence of target outcome, discontinuation of the warfarin or apixaban, switching from warfarin or apixaban, withdrawal from the database, whichever observed first.
Incidence Rate (Per 1,000 Participant-Year) of Intracranial Hemorrhage: Balanced Cohorts	Follow-up period during data observation period from 26-Feb-2013 to 31-Dec-2021 (approximately 8 years 10 months); extracted data evaluated in approximately 3.5 months of this study	Incidence rate per 1000 participant-years for the first occurrence of intracranial hemorrhage event after index date was reported. ICD-10 diagnosis code was used to label the events. Index date was defined as a date when participants initiated warfarin or apixaban. Follow-up period: the next day of the index date till occurrence of target outcome, discontinuation of the warfarin or apixaban, switching from warfarin or apixaban, withdrawal from the database, whichever observed first.
Incidence Rate (Per 1,000 Participant-Year) of Gastrointestinal Bleeding: Balanced Cohorts	Follow-up period during data observation period from 26-Feb-2013 to 31-Dec-2021 (approximately 8 years 10 months); extracted data evaluated in approximately 3.5 months of this study	Incidence rate per 1000 participant-years for the first occurrence of major GI bleeding event after index date was reported. ICD-10 diagnosis code was used to label the events. Index date was defined as a date when participants initiated warfarin or apixaban. Follow-up period: the next day of the index date till occurrence of target outcome, discontinuation of the warfarin or apixaban, switching from warfarin or apixaban, withdrawal from the database, whichever observed first.
Incidence Rate (Per 1,000 Participant-Year) of Intraocular Bleeding: Balanced Cohorts	Follow-up period during data observation period from 26-Feb-2013 to 31-Dec-2021 (approximately 8 years 10 months); extracted data evaluated in approximately 3.5 months of this study	Incidence rate per 1000 participant-years for the first occurrence of intraocular bleeding event after index date was reported. ICD-10 diagnosis code was used to label the events. Index date was defined as a date when participants initiated warfarin or apixaban. Follow-up period: the next day of the index date till occurrence of target outcome, discontinuation of the warfarin or apixaban, switching from warfarin or apixaban, withdrawal from the database, whichever observed first.

Trial Locations

Locations (1)

Pfizer Site; 🇯🇵 Tokyo, Japan