Abstract 14366: Cardiac Magnetic Resonance Derived Late Gadolinium Enhancement Replacement Fibrosis and Extracellular Volume Significance in the Detection of Diastolic Dysfunction
Background: Cardiac magnetic resonance (CMR) with late gadolinium enhancement (LGE) is considered the gold standard for detection of replacement fibrosis (RF). Newer CMR techniques also allow assessment of interstitial fibrosis by measurement of extracellular volume fraction (ECV). Our goal was to assess the relationship of RF and ECV with diastolic dysfunction.
METHODS: This is a retrospective study of 57 subjects who had CMR with Modified Look-Locker inversion recovery, LGE, and transthoracic echocardiography (TTE) within 7days for clinical evaluation from June 2011 [[Unable to Display Character: –]] December 2012. ECV, RF percentage of myocardium, other CMR, TTE and clinical variables were collected. Patients with atrial fibrillation, more-than-moderate mitral regurgitation, surgical rings, incomplete studies for diastolic evaluation and heart rate >120bpm during TTE were excluded.
Results: The cohort with mean age of 59±16 years consisted of 40.4% (23) women. Median interval between CMR and TTE was 2 days. RF was present in 59.6% (34) of the cohort with mean RF burden of 10±11%. Of those with RF, 58.8% had a non-coronary artery disease pattern of RF. Comparison of selected variables is shown in table1. ECV was significantly lower in subjects with normal left ventricular ejection fraction (LVEF) by CMR (LVEF>58%) and normal diastolic function, as determined by TTE, when compared to those with normal LVEF and diastolic dysfunction and to the low LVEF group (p:0.009). ECV ≥ 28.85% is more sensitive (77.8% VS 66.7%) but less specific (71.4% VS 85.7%) than RF in the detection of diastolic dysfunction.
Conclusion: Myocardial extracellular volume fraction and replacement fibrosis are significantly different between subjects with normal systolic and diastolic function in comparison with subjects with abnormal LVEF or diastolic dysfunction. There is overlap between the lower ECV values in all three categories, suggesting that fibrosis may not be significant in some subjects with diastolic dysfunction.
- © 2013 by American Heart Association, Inc.