Abstract 11559: The Relative Atrial Index - A Transthoracic Echocardiographic Indicator of Intracardiac Shunt Status Pre and Post Amplatzer Atrial Septal Defect Closure
INTRODUCTION: The Relative Atrial Index (RAI) has been shown to be a reliable indicator of intracardiac shunting. The suggested normal cut-off is RAI <0.92, with values >0.92 highly predictive of atrial septal defects (ASDs). This study validates this cut-off in patients with ASDs and assesses the utility of the RAI to assess atrial remodeling following percutaneous ASD closure. It was hypothesized that the RAI would reliably predict the presence of ASDs in patients undergoing percutaneous ASD closure, and that the RAI would normalize following ASD closure as cardiac remodeling occurred.
METHODS: A patient population with secundum ASDs (n=79; mean age 47 y17.4; 26 men) underwent TTE prior to percutaneous Amplatzer ASD closure. Following closure, patients underwent sequential TTEs at day 1 post closure (n=72) and at follow up (n=69).
RESULTS: The mean RAI prior to closure was 1.110.27 with 75% of patients correctly classified as having ASDs. Patients incorrectly classified (RAI<0.92) had smaller ASDs requiring significantly smaller closure devices (mean Amplatzer size 185.8; p<0.05) compared to those correctly classified (mean Amplatzer size 225.1). At day 1, the RAI fell significantly to 0.940.11 (p <0.001). At follow up (mean 174 days, range 14-1055), the RAI fell further to 0.78 0.13 (p <0.00001) and had normalized in the majority of cases (81%).
CONCLUSION: The RAI accurately predicted the presence of ASDs in the majority of this population, with incorrect classification explained by the presence of small ASDs. Furthermore, there was a rapid reduction of the RAI immediately after closure and normalization at follow up, indicating resolution of intracardiac shunting.
- Adult congenital heart disease
- Atrial septal defect
- Percutaneous coronary intervention
- Cardiac imaging
- © 2011 by American Heart Association, Inc.