In a recent Danish population-based cohort study published within the journal British medical journal, researchers analyzed changes in the chance of atrial fibrillation (AF) and complications over the lifespan. They compared data from two periods: 2000–2010 and 2011–2022. They found that the lifetime risk of AF increased over the study period, and that individuals with AF had a big lifetime risk of heart failure (HF) and stroke.

Test: Time trends within the lifetime risk of atrial fibrillation and its complications from 2000 to 2022: a Danish, nationwide, population-based cohort study. Photo source: Magic Mine / Shutterstock

Background

AF is an increasing health problem worldwide as a consequence of the expected significant increase within the variety of affected populations. Although improvements in mortality rates have been observed, AF stays related to an increased risk of stroke, HF, and myocardial infarction (MI). Understanding and effective assessment of the chance of AF, including its long-term complications, are crucial in preventive measures. Residual lifetime risk, a measure of the cumulative risk of disease over the remaining period of life, provides helpful information for public health and patient education initiatives. Despite previous research examining the lifetime risk of AF, there may be an absence of knowledge on temporal trends and comprehensive risk of complications. Monitoring changes in AF burden is critical to assessing management strategies and preventive measures, especially as stroke prevention therapies evolve. On this study within the Danish population, researchers sought to evaluate the lifetime risk of AF and related complications and analyze its temporal trends from 2000 to 2022.

Concerning the study

Data were collected from national registers, including the Danish National Patient Register for hospital stays and outpatient contacts, the Civil Registration System for demographic data and vital status, and the Danish National Prescription Register for drug information. The study included 3,574,903 Danes without AF aged 45 or later between 2000 and 2022. Roughly 51.7% of participants were women. People aged 95 and older were excluded. Follow-up was led to the event of incident AF, death, age 95, emigration, or end of period. In the first evaluation, 45 years was used because the index age, and in secondary analyses, ages 55, 65, and 75 years or older were used. Incidental AF was diagnosed based on hospital diagnoses.

A complete of 362,721 people were followed up after newly diagnosed AF (46.4% women). After diagnosis, complications were recorded, including HF, stroke, myocardial infarction, or systemic embolism. Exclusions included pre-existing complications and events inside seven days of diagnosis. The diagnosis was made based on stringent International Classification of Diseases 10 (ICD-10) criteria with high predictive values. Analyzes were performed for age indicators of 45, 55, 65 and 75 years.

Study populations were characterised by assessing medical history, family income, and academic level. Statistical methods included use of the Aalen-Johansen estimator to find out cumulative incidence, pseudovalue regression, propensity rating adjustment using logistic regression, stabilized inverse propensity weighting, and subgroup evaluation with interaction testing.

Results and discussion

Age distribution was found to stay consistent across time periods, with the incidence of hypertension, dyslipidemia and diabetes increasing over time, while the incidence of HF and myocardial infarction decreased.

The lifetime risk of AF at age 45 years from 2000 to 2022 was 27.7%, with higher risks observed amongst men, those with a history of certain heart problems, and people with higher socioeconomic status. From 2000-2010 to 2011-2022, there was an absolute increase in lifetime risk from 24.2% to 30.9%. This trend continued across all subgroups, with barely greater increases amongst men, those with a history of HF or stroke, and people without dyslipidemia. At ages 55, 65, and 75, lifetime risk also trended upward, with absolute increases between these two periods.

Amongst those diagnosed with AF, probably the most common complication was HF, with a lifetime risk of 41.2%, followed by stroke (21.4%), myocardial infarction (11.5%), and diagnosed systemic embolism (1, 8%). Men were generally at higher risk of HF and heart attack in comparison with women, while women had a better risk of stroke after AF. The history of certain cardiovascular diseases significantly increased the chance of HF after AF. Over time, there was a slight decrease within the lifetime risk of stroke (-2.5%) and heart attack (-3.9%).

The study is the primary to explain temporal patterns of lifetime risk related to AF and its subsequent complications. Nonetheless, a limitation of the study is the potential underestimation of incident events as a consequence of the shortage of distinction between AF and atrial flutter and the shortage of knowledge on, amongst others, lifestyle aspects and causes of death.

Application

This Denmark-wide study shows a disturbing trend: the lifetime risk of AF has increased from one in 4 to at least one in three over the past twenty years. HF emerged as probably the most common complication after AF, with a lifetime risk twice that of stroke. Although there have been small improvements in the chance of stroke, ischemic stroke, and myocardial infarction after AF, these rates remained high. These findings highlight the urgent have to develop effective strategies to forestall HF and stroke in patients with AF.