The identification of
individuals at high risk of developing atrial fibrillation (AF) is important to
prevent potentially lethal and invalidating complications of this arrhythmia. Recently,
several studies have investigated the association between PR-interval and the
risk of AF and have tested the value of PR-interval in personalized risk scores
for AF. However, the results of these studies are generally conflicting. When looking
for an association between a prolonged PR-interval (first-degree
atrioventricular [AV] block vs. normal PR-interval) and an increased risk of AF,
the majority of studies were not able to find a consistent and statistically
significant association. In two recent studies, however, the investigators were
able to show an increased risk of AF for individuals with PR-intervals in the
short range compared with individuals in the middle rage. The existence of a
true U-shaped relationship might potentially explain part of the conflicting
results from investigators only looking for an increased risk for longer
PR-intervals. However, regardless of these speculations, the association seems
relatively weak. The significance of PR-interval in risk prediction of AF has
been tested in two independent risk scores where model selection primarily was based
on improvement in c-statistics. In one risk score, PR-interval improved the
discriminative value of the risk model, whereas it did not in the other risk
score. Further studies are warranted before any final conclusion can be drawn,
although based on the current evidence, it is reasonable to conclude that the
predictive value of PR-interval in AF risk prediction is limited.
Credits: Signe Bidstrup; Morten Salling Olesen; Jesper Hastrup Svendsen; Jonas Bille Nielsen