POSTER PRESENTATION Open Access Left atrial scar burden determined by delayed enhancement cardiac magnetic resonance at post radiofrequency ablation: association with atrial fibrillation recurrence Gerd Brunner1,2*, Lucien Abboud2, Kamran A Shaikh2, Amish S Dave2, Joel Morrisett1, William A Zoghbi2, Miguel Valderrábano2, Dipan J Shah2 From 15th Annual SCMR Scientific Sessions Orlando, FL, USA. 2-5 February 2012 Background Left atrial (LA) radiofrequency (RF) ablation has become routine treatment for atrial fibrillation (AF) but still suf- fers from AF recurrence requiring a repeat procedure. LA-RF ablation success rates vary between 53% and 85%. Delayed-enhancement Cardiac Magnetic Reso- nance (DE-CMR) can be used to noninvasively visualize LA hyperenhancement (scar). We have utilized DE- CMR to quantify LA scar extent post LA-RF-ablation and related this measure to AF recurrence. Methods Twenty-seven patients (62.0±11.1 years, 20 males) with paroxysmal and chronic AF underwent LA-RF-ablation and subsequent DE-CMR, an average of 260.7±314.7 days post procedure. The DE-CMR procedure was per- formed utilizing a navigated 3D inversion recovery gra- dient echo sequence (Siemens 1.5T Avanto or 3.0T Verio) approximately 15 minutes after administration of 0.2 mmol/kg Diethylenetriaminepentaacetic Acid−Gado- linium (DTPA-Gd, Magnevist, Berlex Laboratories, Wayne, NJ). All scans were electrocardiographically (ECG)-gated and acquired during a 150 ms window in mid-diastole with navigator-gating and fat suppression. We have developed an image analysis method and gra- phical user interface to semi-automatically quantify hyperenhanced regions in the LA wall (scar). LA scar was quantified by a single experienced observer blinded to patient data. LA-scar measurements were normalized by LA size. The intra-class correlation coefficient (ICC) was used to assess intra-observer variability of 4 ran- domly selected scans which were re-read one week later. Variables were tested for normality with the Shapiro- Wilk test and a p-value<0.05 was considered statistically 1Section of Atherosclerosis and Vascular Medicine, Department of Medicine, Baylor College of Medicine, Houston, TX, USA Full list of author information is available at the end of the article Table 1 LA-scar quantification in AF patients. Variable AF-Recurrence [N=13, mean, std] AF-Free [N=14, mean, std] P-value LA-Volume [mL] 128.49 ± 44.0 96.0 ± 38.5 0.06 LVEF [%] 58.93 ± 12.1 64.85 ± 6.2.1 0.092 LA-scar [cm2] 11.40 ± 7.6 16.56 ± 5.25 0.036 Age [years] 61.67 ± 9.3 62.23 ± 12.8 0.891 Gender [no. males] 10 10 - LA= left atrium; LA scar (hyperenhanced area) was normalized by LA volume. N= number of patients; Std=standard deviation; RF= radio frequency; LVEF: left ventricle ejection fraction; AF: atrial fibrillation. Brunner et al. Journal of Cardiovascular Magnetic Resonance 2012, 14(Suppl 1):P204 http://www.jcmr-online.com/content/14/S1/P204 © 2012 Brunner et al; licensee BioMed Central Ltd. This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. http://creativecommons.org/licenses/by/2.0 significant (all tests were 2-sided). All patients provided informed consent. Results The DE-CMR scans were performed 260.7±314.7 days after the initial LA-RF- ablation procedure (Figure). AF recurrence was noted to occur in 13 (48%) patients whereas 14 (52%) patients demonstrated no AF recur- rence. There was a trend toward a larger LA-volume in the AF-recurrence group (128.49±44.0 ml vs. 96.0±38.5 ml; p=0.06, see Table 1). Left ventricle ejection fractions (LVEF) were smaller in the AF-recurrence group but the difference was not statistically significant (58.93±12.1% vs. 64.85±6.2.1%, p=0.092). Average analysis time per scan was 14.5±7 min and intra-observer variability was excellent (ICC=0.99). LA-scar was normally distributed (p=0.151). Average LA scar extent, quantified in post LA-RF-ablation DE-CMR scans, was significantly larger in recurrence-free AF patients (16.56±5.3 cm2) when compared with individuals with AF-recurrence (11.40 ±7.6 cm2; p=0.036). The results indicate that there is a significant inverse relationship between LA-scar burden and AF-recurrence. Conclusions LA scar extent can be reproducibly quantified with DE- CMR; and a lower scar burden post LA-RF-ablation is associated with AF recurrence. Funding This work was supported in part by NIH grant T32HL07812. Author details 1Section of Atherosclerosis and Vascular Medicine, Department of Medicine, Baylor College of Medicine, Houston, TX, USA. 2The Methodist DeBakey Heart & Vascular Center, Houston, TX, USA. Published: 1 February 2012 doi:10.1186/1532-429X-14-S1-P204 Cite this article as: Brunner et al.: Left atrial scar burden determined by delayed enhancement cardiac magnetic resonance at post radiofrequency ablation: association with atrial fibrillation recurrence. Journal of Cardiovascular Magnetic Resonance 2012 14(Suppl 1):P204. Submit your next manuscript to BioMed Central and take full advantage of: • Convenient online submission • Thorough peer review • No space constraints or color figure charges • Immediate publication on acceptance • Inclusion in PubMed, CAS, Scopus and Google Scholar • Research which is freely available for redistribution Submit your manuscript at www.biomedcentral.com/submit Figure 1 DE-CMR images of the left atrium (LA) obtained with a Siemens 1.5T Avanto (left and middle panels). The right panel shows the result of the semi-automated LA scar segmentation for the center panel. The left atrium is indicated by the red contour and the blue area highlights hyperenhanced regions (scar). Brunner et al. Journal of Cardiovascular Magnetic Resonance 2012, 14(Suppl 1):P204 http://www.jcmr-online.com/content/14/S1/P204 Page 2 of 2 Background Methods Results Conclusions Funding Author details