Abstract 14269: How Closely Left Atrial Volume and Circulating Natriuretic Peptides Levels Relate to the Duration of Atrial Fibrillation Recurrences. The Results of a GISSI-AF Trial Substudy
Objective: Atrial fibrillation recurrence (AFr) may be promoted by electrophysiological and structural changes secondary to underlying cardiovascular diseases and/or to AF itself. We evaluated whether AFr duration is associated with baseline left atrial (LA) volume and plasma concentrations of two cardiac natriuretic peptides (NP).
Methods: Echocardiographic maximal LA volumes/BSA (LAV) and two NP, (mid-regional proatrial NP (MR-proANP) and N-terminal proBNP (NT-proBNP)) were measured at baseline, in central core laboratories in pts enrolled in the GISSI-AF trial substudy. AFr was detected by the remote transmission of ECG signals sent weekly and in case of symptoms. Each event was verified by an ad hoc committee. The population (284 pts) was analyzed by considering pts without AFr (no AFr) and pts with at least 1 AFr divided into tertiles on the basis of AFr duration. The differences between categories of LAV and NP levels across AFr duration were tested with ANCOVA adjusting LAV for age, and NP levels by age, gender and serum creatinine.
Results: At least one episode of AFr over 12 months (mos) was present in 56% of pts. AFr was associated with a history of ≥2 episodes of AF in the previous 6 mos (p=0.0004). The median number of AFr was 2 [1–4] with a overall median duration of 19.5 [4–95] days over 12 mos. There was a linear relationship between tertiles of AFr duration and LAV (p<0.0001, Figure). A similar pattern was observed for the atrial and B-type NP. The most provocative finding was that pts without AFr had larger LAV (≥40 mL/m2, 53%) and higher NPs than expected. An analysis of pts with severely abnormal LAV, showed that those without AFr, presented a lower rate of ≥2 episodes of AF in the previous 6 mos and also were less smokers than pts with ≥1 AFr (all p<0.05).
Conclusions: The duration of AFr over a 12 mo observation is related to baseline LAV and NP levels. Since half of the pts with severe LA dilation had no recurrence, mechanisms other than remodeling are in play.
- © 2010 by American Heart Association, Inc.