Testing a gene-guided warfarin dose tool in people with atrial fibrillation

Trial details

Who runs it

University of Pernambuco

Trial code

NCT06789588

Record updated

4 June 2025

Original description

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.Read full original descriptionShow less

Pharmacogenetic Algorithm for Warfarin Dose Predictor: Protocol for Improvement and Effectiveness of Therapy Anticoagulant

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.

Inclusion: Be greater than or equal to 18 years old; Patients using warfarin or indicated to start therapy; Patients with AF in its various etiologies and in paroxysmal, persistent or permanent clinical presentations, with a diagnosis established through clinical examination confirmed by conventional electrocardiographic recording or by 24-hour ambulatory electrocardiographic recording (Holter).

Exclusion: Patients with liver disease or cancer of any etiology; Patients who are not able to understand the explanations about the exams, as well as clarifications inherent to their participation in the research; Patients who stop following the instructions provided by researchers or whose questionnaires are incomplete.

ClinicalTrials.gov NCT06789588