Protocol for Improvement of Therapy With Warfarin

Summary

Atrial Fibrillation (AF) is the most common supraventricular arrhythmia in clinical practice. The presence of AF, as an independent factor, increases mortality by up to two times. One in every six cerebrovascular accidents (CVA) occurs in patients with AF, generating an annual risk of around 7% per year, which represents an increase of up to seven times in relation to the risk in the general population, leading to the need for start anticoagulant therapy. Warfarin is still the Oral Anticoagulant (OC) of choice, being the most used in several clinical situations. The variability of response to anticoagulants is related to pharmacokinetic and pharmacodynamic factors, adherence to treatment, age, diet, body mass index (BMI), liver function, body deposition of vitamin K, individual drug metabolism, drug interactions, comorbidities, in addition to of genetic factors. It is estimated that the annual risks associated with the use of OCs are between 2% and 8% for bleeding. The clinical benefit and risk of OAC therapy are associated with the time in which the values of therapeutic - TTR (time in therapeutic range). Measuring the quality of anticoagulation assesses whether therapy is being maintained within this range. Increased TTR is associated with a decrease in thromboembolic and/or hemorrhagic events. In the context of OCs, pharmacogenetics is the science that predicts the response to drugs, based on individual genetic markers. By understanding the relationship between the genotype and the response to a drug, pharmacogenomics has the potential to help healthcare professionals to predict the therapeutic dose of warfarin by genotyping patients for several Single Nucleotide Polymorphisms (SNPs) that affect metabolism or sensitivity to warfarin. Therefore, the main objectives of genotype-guided therapy are to improve the safety and efficacy of anticoagulant therapy. In Brazil, more specifically in the Brazilian Northeast, the use of a dose predictor algorithm is not common, which leads to high rates of complications and consequently increases the length of hospital stay. As a result, there is an increasing need to implement therapeutic technologies applied to precision health, explore studies on genetic polymorphisms and therapies guided by pharmacogenomics, aiming to understand the individual genetic effect on the metabolism of drugs such as warfarin.

Conditions

• Atrial Fibrillation (AF)

Interventions

DRUG

pharmacogenetic algorithm

The dose predictor algorithm proposed in this work aims to maintain and quality treatment in an individualized and effective manner. In the routine use protocol, warfarin is prescribed based only on the INR collected within 5 days. The proposed intervention protocol is based on the patient's clinical and genetic factors, such as genetic polymorphisms, age, weight, height, race, use of amiodarone, statins, antifungals or antibiotics, tobacco use, clinical indication and what the RNI target.

DRUG

Clinical treatment

Patients with AF indicated for OAC therapy guided by institutional protocol.

Sponsors & Collaborators

• Universidade Federal de Pernambuco

  collaborator OTHER

• University of Pernambuco

  lead OTHER

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

SINGLE

Model

PARALLEL

Eligibility

Min Age

18 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2024-10-21

Primary Completion

2026-07-31

Completion

2027-07-31

Countries

• Brazil

Study Locations