# Incidência e Preditores de Desfechos Clínicos em Pacientes com Fibrilação Atrial Valvar e Não Valvar em uso de Antagonistas da Vitamina K

## TL;DR

This study identifies risk factors for adverse outcomes in patients with atrial fibrillation using vitamin K antagonists in Brazil.

## Contribution

The study provides real-world evidence on predictors of clinical outcomes in patients with valvular and nonvalvular AF using VKA.

## Key findings

- Prior thromboembolism and reduced time in therapeutic range were linked to higher risk of thromboembolic events.
- Reduced glomerular filtration rate and prior bleeding predicted higher rates of major bleeding.
- Enlarged left atrium and poor anticoagulation control were associated with the composite outcome of thromboembolism or bleeding.

## Abstract

Figura Central:Incidência e Preditores de Desfechos Clínicos em Pacientes com Fibrilação Atrial Valvar e Não Valvar em uso de Antagonistas da Vitamina K
AVK: antagonista da vitamina K; RNI: relação normalizada internacional; TFG: taxa de filtração glomerular; TFT: tempo na faixa terapêutica.

Antagonistas da vitamina K (AVK) representam uma importante estratégia terapêutica oferecida pelo Sistema Único de Saúde no Brasil aos pacientes com fibrilação atrial (FA). Entretanto, os preditores de desfechos clínicos relevantes são pouco estudados no mundo real.

Determinar a incidência e os preditores independentes de desfechos clínicos em pacientes com FA valvar e não valvar tratados com AVK.

Coorte prospectivo de pacientes com FA valvar e não valvar em uso ≥ 1 ano de AVK. Desfechos primários foram morte cardiovascular, eventos tromboembólicos, sangramento maior e não maior clinicamente relevante, separadamente e como desfecho composto, e adjudicados de modo independente. Valores de p < 0,05 foram considerados estatisticamente significantes.

Incluídos 1.350 pacientes, idade média de 69,2 (± 11.8) anos e 53,6% do sexo feminino, seguidos por 17 (15 - 19) meses. Incidência anual de eventos tromboembólicos e morte cardiovascular foi 4,4% e preditores foram tromboembolismo prévio (
hazard ratio
[HR] 2,12; intervalo de confiança [IC] de 95% 1,22 - 3,67), tempo na faixa terapêutica (TFT) < 50% (HR 1,98; IC95% 1,16 - 3,37), e taxa de filtração glomerular (TFG) < 45 mL/min/1.73 m2 (HR 2,76; IC95% 4,82 - 1,58). Taxa de sangramento maior e não maior clinicamente relevante foram 3,24% por ano (IC95% 2,47 - 4,14) e preditores foram sangramento prévio (HR 2,60; IC95% 1,47 - 4,61) e prótese mecânica (HR 1,91; IC95% 1,15 - 3,15). O desfecho composto foi 8,7% por ano e preditores foram sangramento prévio (HR 1,70; IC95% 1,07 - 2,70), TFT < 41% (HR 1,79; IC95% 1,11 - 2,86) e diâmetro do átrio esquerdo > 44 mm (HR 1,97; IC95% 3,26 - 1,19).

Tromboembolismo ou sangramento prévios, TFG e TFT reduzidos e átrio esquerdo aumentado foram preditores de desfechos clínicos em pacientes com FA tratados com AVK.

Central Illustration:Incidence and Predictors of Clinical Outcomes in Patients with Valvular and Nonvalvular Atrial Fibrillation Using Vitamin K Antagonists
GFR: glomerular filtration rate; INR: international normalized ratio; TTR: time in therapeutic range; VKA: vitamin K antagonist.

Vitamin K antagonists (VKA) represent an important therapeutic strategy offered by the Brazilian Unified Public Health System to patients with atrial fibrillation (AF). However, predictors of relevant clinical outcomes are understudied in the real world.

To determine the incidence and independent predictors of clinical outcomes in patients with valvular and nonvalvular AF treated with VKA.

This prospective cohort included patients with valvular and nonvalvular AF receiving VKA for ≥ 1 year. The primary outcomes were cardiovascular death, thromboembolic events, and major and clinically relevant non-major bleeding, separately and as a composite outcome. The outcomes were independently adjudicated. P values < 0.05 were considered statistically significant.

The study included 1,350 patients, with a mean age of 69.2 (± 11.8) years, 53.6% female, followed up for 17 (15 - 19) months. The annual incidence of thromboembolic events and cardiovascular death was 4.4%, and predictors were prior thromboembolism (hazard ratio [HR] 2.12; 95% confidence interval [CI] 1.22 - 3.67), time in therapeutic range (TTR) < 50% (HR 1.98; 95% CI 1.16 - 3.37), and glomerular filtration rate (GFR) < 45 mL/min/1.73 m2(HR 2.76; 95% CI 4.82 - 1.58). The rate of major and clinically relevant non-major bleeding was 3.24% per year (95% CI 2.47 - 4.14), and predictors were prior bleeding (HR 2.60; 95% CI 1.47 - 4.61) and mechanical prosthesis (HR 1.91; 95% CI 1.15 - 3.15). The composite outcome was 8.7% per year, and predictors were prior bleeding (HR 1.70; 95% CI 1.07 - 2.70), TTR < 41% (HR 1.79; 95% CI 1.11 - 2.86), and left atrial diameter > 44 mm (HR 1.97; 95% CI 3.26 - 1.19).

Prior thromboembolism or bleeding, reduced GFR and TTR levels, and enlarged left atrium were predictors of clinical outcomes in patients with AF treated with VKA.