Assessment of the Effectiveness and Safety Outcome in Patients With Atrial Fibrillation Treated by Apixaban in Belgium

The PROVECT study is a retrospective, multicentre study assessing the effectiveness and the safety outcomes in patients with non-valvular atrial fibrillation (NVAF) treated by apixaban between 2015 and 2019 (5 years follow up). The study will use harmonized and federated hospital electronic health records (EHRs) from 10 Belgian hospitals. Outcomes of interest are major bleeding events leading to hospitalization (safety), stroke and systemic thromboembolic events (effectiveness), and all-cause mortality (as an exploratory endpoint, and after confirming the data availability because the death events are not always recorded into hospital EHRs). The study will analyse the outcomes by patient characteristics including the age groups focusing on elderly, thromboembolism risk factors (CHAR2RDSR2R-VASc score), bleeding risk factors (HAS-BLED score), comorbidities (Deyo-Charlson Comorbidity Index, DCCI) score and frailty.

Apixaban is an antithrombotic agent that directly inhibits factor Xa, and which has obtained market authorization in the indication "prevention of stroke and systemic embolism in patients with non-valvular atrial fibrillation (AF), with one or more risk factors, such as prior stroke or transient ischaemic attack (TIA), age ≥75 years, hypertension, diabetes mellitus, and symptomatic heart failure (NYHA ≥ class II)." Among other direct oral anti-coagulants (DOACs) only apixaban has shown a triple beneficial profile (on stroke/systemic embolisms, major bleedings, and all-cause mortality) supported by data from pivotal randomized clinical trials (RCTs). This differentiation has been consistently found in multiple real-world data (RWD) studies including the NAXOS study in France5 and the ARISTOPHANES study in US particularly in terms of incidence of major bleedings for apixaban vs. others DOACs or vitamin K antagonists (VKAs). Although such data can be generalized to different populations, healthcare professionals in Belgium and healthcare authorities have been frequently requesting local scientific data to support the effectiveness and safety outcomes in patients treated by apixaban in local Belgium settings. This scientific data gap is particularly evident for routine care data allowing to understand the apixaban use patterns in the Belgian poly-medicated, frail and new patients starting an apixaban treatment. The PROVECT study aims to address this particular local data gap and its results may help to guide practical clinical decisions .

Eligibility Criteria:
Inclusion Criteria:

* is 18 years or older at the index date.
* had ≥1 apixaban prescription during the study period from January 1st, 2015 to December 31, 2019.
* had ≥1 medical diagnosis for Atrial Fibrillation, AF (International Classification of Diseases, 10th Revision, Clinical Modification \[ICD-10-CM\]10 diagnosis codes I48.0, I48.1X, I48.11, I48.19, I48.2X, I48.20, I48.21, I48.9X, I48.91, I49.1) any time before or on index date
* had \>1 encounter (visits, prescriptions, etc) within the EHRs.

Exclusion Criteria:

* Medical EHRs indicating a diagnosis code indicative of rheumatic mitral valvular heart disease, mitral valve stenosis (ICD-10-CM diagnosis codes I05.x, I06.x, I07.x, I08.x, I34.x, I35.x, I36.x, I37.x, I38.x, I39.x, I37.x, Q23.x) during the 12-month baseline period,
* Medical EHRs indicating a diagnosis code of VTE (DVT: ICD-10-CM codes: I80.xx, I81.xx, I82.xx, I82.40x, I82.41x, I82.42x, I82.43x, I82.44x, I82.49x, I82.4Yx, I82.4Zx, I82.5xx, I82.51x, I82.52x, I82.53x, I82.54x, I82.55x, I82.56x, I82.59x, I82.5Yx, I82.5Zx, I82.62x, I82.72x, O22.0x, O22.2x, O22.3x; or PE: ICD-10-CM codes I26.01, I26.02, I26.09, I26.90, I26.92, I26.93, I26.94, I26.99) during the 12-month baseline period,
* Medical EHRs indicating a diagnosis (ICD-10-CM) or procedure code (International Classification of Diseases, 10th Revision, Procedure Coding System \[ICD-10-PCS\]10) of transient AF, or cardiac surgery: Heart valve replacement/transplant: 02YA0Zxx, 02RF0xx, 02RJ0xx, 02RG0xx, 02RH0xx, Z95.2, Z95.3, Z95.4; Pericarditis: I00, I01, I02, I24.1, I30.x, I31.x, I32\*coding first the associated cause/etiology; Hyperthyroidism and Thyrotoxicity: E05.0, E05.1, E05.2, E05.3, E05.4, E05.8, E05.9) during the 12-month baseline period;
* Medical EHRs indicating pregnancy during the study period (ICD-10-CM diagnosis codes O00-O9A, Z31, Z32, Z33, Z34, Z36, Z37, Z38, O20-O29, ICD-10 CPS code 109xxx, 10Axxx, 10Dxxx, 10Exxx, 10Hxxx, 10Pxxx, 10Sxxx);
* Medical EHRs indicating diagnosis or procedure for hip/knee replacement surgery within 6 weeks prior to index date (0SR90xx, 0SRA0xx, 0SRB0xx, 0SRC0xx, 0SRD0xx, 0SRE0xx, 0SQ0xx, 0SQB0xx, 0SQB0xx, 0SQB0xx)
* Patients with a prescription for \>1 anticoagulants at index date.