Role of PR-Interval In Predicting the Occurrence of Atrial Fibrillation

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, not all studies were 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 range. The existence of a true U-shaped relationship could 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 three independent risk scores where model selection primarily was based on improvement in c-statistics. In one risk score, PR-interval improved the predictive value of the risk model, whereas it did not in the other two risk scores. 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.