Abstract 20387: Evaluation of Left Atrial Fibrosis Progression Over Time in Atrial Fibrillation Patients using Delayed-Enhancement MRI
Background: The extent of this left atrial (LA) wall fibrosis can be detected and quantified by delayed enhancement MRI (DE-MRI) in patients with atrial fibrillation (AF). We sought to evaluate the relationship between LA fibrosis and its progressive change over time.
Methods and Results: Twenty-five patients had 2 DE-MRI scans at 2 different time points. Fourteen patients were excluded (3 due to prior ablation, 5 as a result of with poor quality MRI, and 6 pts with partial DE-MRI acquired); leaving an 11 patient cohort (male n=7) with comparable, quantifiable MRI's. Three-dimensional segmentation of the LA was performed and the extent of fibrosis was quantified using a semi-automated algorithm for each time point for comparison. The average time duration between the two MRI scans was 179±131 days. The mean LA fibrotic enhancement for scan 1 was 11.38±8.49% compared to 16.73±9.19%, with a mean change of 5.35±3.44%. The difference between the two time points was significant (p=0.0004). Figure 1 shows the two MRI scans per patient and graphically demonstrates the relationship that the longer time difference between the two scans, the greater the difference in fibrosis.
Conclusions: From our preliminary experience, AF patients appear to have quantifiable progressive LA fibrosis over time as detected by DE-MRI. New strategies for prevention and termination of AF should be built on further understanding the time course of AF-induced atrial remodeling.
- © 2010 by American Heart Association, Inc.