Abstract 14546: Cardiovascular Magnetic Resonance Imaging With Late Gadolinium Enhancement and Histopathological Correlation in Hypertrophic Cardiomyopathy
Background: Cardiac MRI with Late Gadolinium Enhancement (CMR-LGE) is a well established tool for the assessment of scar in ischemic heart disease. Its role in the assessment of Hypertrophic Cardiomyopathy (HCM) has become evident in recent years and an association with non-sustained VT has been shown. In this study we sought to explore the relationship between CMR-LGE signal intensity measured at 2 and 5SD (from remote normal myocardium) and various histopathological parameters including interstitial fibrosis, replacement fibrosis (scar), Small Intramural Coronary Arteriole Dysplasia (SICAD), and myocardial disarray.
Methods: Symptomatic HCM patients with LVOT obstruction who underwent septal myectomy (2004-2010) and had CMR-LGE < 6 months (2± 2months) prior to surgery were selected. Patients with significant coronary artery disease and LV dysfunction were excluded. 30 patients (mean age 49±14, 63% male) met these criteria. Histopathological assessment of the myectomy specimens included quantitative digital morphometric analysis (interstitial and replacement fibrosis) and semi-quantitative assessment using standardized grading criteria (SICAD and disarray). Correlations between CMR-LGE at 2 and 5SD at the myectomy site and interstitial fibrosis, scar, and their sum (fibrosis+scar) in the pathological samples were evaluated.
Results: Statistically significant correlations between CMR-LGE (at 2SD and 5SD) and both interstitial fibrosis and scar were found (correlation between 2SD and scar was not significant). Correlation was consistently stronger with 5SD measurements. Interstitial fibrosis displayed stronger correlations than scar. The strongest correlation (r=0.86, P<0.0001) was between interstitial fibrosis+scar and CMR-LGE at 5 SD. In addition, SICAD showed strong and statistically significant correlation with scar (P = 0.007), scar+fibrosis (P = 0.02), and CMR-LGE at 5SD (P = 0.02). No significant correlation was found between disarray and these parameters.
Conclusion: CMR-LGE at 5SD displays highly significant correlation to histopathological fibrosis, scarring, and SICAD. These findings confirm the accuracy of CMR-LGE as a technique for reliable identification of fibrosis and scar in patients with HCM.
- © 2011 by American Heart Association, Inc.