Ashkan Akhavan Malayeri MD, Presenter: Nothing to Disclose

Rob J. Van Der Geest MS, Abstract Co-Author: Nothing to Disclose

Aditya Jain MBBS, MPH, Abstract Co-Author: Nothing to Disclose

Gordon Tomaselli, Abstract Co-Author: Nothing to Disclose

Kathryn Wagner, Abstract Co-Author: Nothing to Disclose

Joao A.C. Lima MD, Abstract Co-Author: Grant, Toshiba Corporation Grant, Bracco Group Grant, Astellas Group

David A. Bluemke MD, PhD, Abstract Co-Author: Nothing to Disclose

Saman Nazarian MD, Abstract Co-Author: Nothing to Disclose

00030490-DMT et al, Abstract Co-Author: Nothing to Disclose

The role of delayed enhancement magnetic resonance imaging (DE-MRI) in quantitative evaluation of ischemic myocardial scar has been established, but quantification of diffuse fibrosis remains challenging. We evaluated the role of DE-MRI for diffuse myocardial fibrosis in patients with myotonic muscular dystrophy (MMD).

In 41 patients with MMD (33 with type I and 8 with type II, 51% males, mean age 49.3 ± 12.8 years), inversion recovery fast gradient imaging was performed 10 minutes after 0.2 mmol/kg gadolinium injection. We quantified the hyper-enhanced area based on a threshold algorithm at 2 to 8 standard deviations above baseline signal using Qmass software. Hyperenhancement (as a percentage of myocardial tissue) was compared to myocardial function and QRS duration based on electrophysiological testing using linear regression and receiver operating receiver operating characteristic (ROC) curve analysis.

The percent hyper-enhanced myocardial area showed a significant inverse association with left ventricular ejection fraction (LVEF) in both univariate and multivariate analyses after adjusting for age and body mass index (p<0.05). The magnitude of this association was linearly related to the SD of percent hyper-enhanced area, with eight SD above baseline showing the highest association with LVEF in univariate [-1.31% (95% CI -2.45 to -0.17), p= 0.03] as well as multivariate analysis [-1.06% (95% CI -1.80 to -0.33), p= 0.01]. Four (≥ 26.18%) and five SD (≥17.14%) showed the most optimum combination of sensitivity and specificity (85.7%, 80.9% respectively, each) to detect low LVEF (LVEF < 45%). Longer QRS duration (>120 msec) in these patients was not associated with percent-enhanced myocardium or LVEF.

There is a significant inverse association between area of hyperenhancement with left ventricular ejection fraction in both univariate and multivariate analyses after adjusting for age and body mass index.

Quantification of the area of patchy fibrosis can predict the functional impairment of the heart in patients with MMD and other cardiomyopathies.  

Malayeri, A, Van Der Geest, R, Jain, A, Tomaselli, G, Wagner, K, Lima, J, Bluemke, D, Nazarian, S, et al, 0, Novel Technique for Quantification of Diffuse Myocardial Fibrosis by Magnetic Resonance Imaging: Relationship to Cardiac Function.  Radiological Society of North America 2009 Scientific Assembly and Annual Meeting, November 29 - December 4, 2009 ,Chicago IL. http://archive.rsna.org/2009/8013335.html