Abstract 18655: Impact of New Guidelines on Atrial Fibrillation Pattern Classification: The Women’s Health Study

Abstract

Background: Recent US guidelines have updated atrial fibrillation (AF) pattern definitions, reclassifying patients who undergo successful cardioversion within 7 days of AF onset as paroxysmal rather than persistent. The impact of this reclassification on AF pattern designation and risk factor profiles in patients with AF is unknown. Methods: We examined all participants with confirmed, new-onset AF among 34,636 women who were aged ≥45 years and free of AF and cardiovascular disease at baseline within the Women’s Health Study. All women were classified by AF type using both 2006 and 2014 ACC/AHA AF guideline definitions. AF type was classified as the most sustained form within 2 years of initial diagnosis. Risk factor profiles of patients reclassified by the 2014 guidelines were then compared to patients where AF pattern classification remained unchanged. Results: During a median follow-up of 19.2 years, 1493 women developed incident AF. Application of the 2006 AF guidelines identified 998, 313 and 182 women with paroxysmal, persistent and permanent AF, respectively. Using the 2014 AF guidelines, 107 women with persistent AF (34.2%) were reclassified to paroxysmal. Compared to women classified as persistent by both guidelines, those reclassified to paroxysmal by the 2014 guidelines were younger and had a lower prevalence of hypertension; but had similar weight and BMI (Table). Compared to women classified as paroxysmal by both guidelines, the women reclassified to paroxysmal were again younger but had a higher weight and BMI. Other cardiac risk factors did not differ significantly across AF patterns (Table). Conclusions: Using 2014 AF guidelines definitions, AF pattern was reclassified in a significant number of persistent AF patients. The risk factor profile of the reclassified women differed with respect to age, hypertension and BMI; known risk factors for AF progression. Selected AF pattern definition may influence results of future studies on AF progression.