Abstract 9857: Comparison of Late Gadolinium Enhancement Quantitation Methods in Cardiac Sarcoidosis to Predict Clinical Outcomes

Introduction: We sought to investigate the optimal method for quantifying late gadolinium enhancement (LGE) in patients with cardiac sarcoidosis (CS) undergoing cardiac magnetic resonance (CMR). Methods: We retrospectively studied 53 patients with CS. LGE quantitation was performed using (a) Semi-automated segmentation (SAS) using a Signal Threshold versus Reference Mean (STRM) cutoffs of >2, >3 and >5 standard deviations (SD); (b) full width half max (FWHM) method and (c) manual segmentation (MS) of affected myocardial segments. Primary outcome was a composite of cardiovascular death and ventricular tachyarrhythmias (VTA). A multivariate regression analysis was performed comparing techniques adjusting for age, gender, NYHA class and left ventricular ejection fraction (LVEF). Results: Mean age was 56.3 ± 12 years, 71.6% males, 66% white. Mean LVEF was 45.1% ± 14.7%. Over a median follow-up of 28.1 months, 2 patients had cardiac death (3.7%) and 8 (15.1%) had VTA. On multivariate analysis, MS, >2SD, >3SD, >5SD and FWHM had odds ratios of 1.99 [CI 1.19-3.25], 1.09 [CI 0.99-1.21], 1.15 [CI 1.03-1.29], 1.16 [CI 1.04-1.27] and 1.08 [CI 0.96-1.21], respectively, for predicting composite outcome. ROC curve analysis showed MS to have the highest AUC 0.89 followed by 0.81 for >3SD and >5SD, 0.75 for >2SD and lowest 0.69 for FWHM method. Reproducibility was lower for manual method (ICC 0.7) than for >3SD (ICC 0.83) and >5SD (ICC 0.82). Conclusion: In patients with CS, quantitation of LGE using either MS or SAS with STRM >3SD or >5SD was significantly associated with the composite outcome of cardiac death and VTA. SAS with STRM >3SD provided the best combination of accuracy and reproducibility.