Abstract 13960: Global Two-Dimensional Strain as a Robust Parameter of Myocardial Fibrosis in Patients With Hypertrophic Cardiomyopathy
Background: Myocardial fibrosis can lead to an increase in chamber stiffness, Resultsing in left ventricular (LV) systolic and diastolic dysfunction. Late gadolinium enhancement (LGE) on contrast-enhanced magnetic resonance imaging (MRI) in hypertrophic cardiomyopathy (HCM) has been reported to be associated with myocardial fibrosis, and the extent of LGE is correlated with cardiac events. In patients with HCM, 2D strain identified subclinical global systolic dysfunction despite normal LV systolic function as assessed by standard criteria. Therefore, this study tested our hypothesis that global 2D strain could detect myocardial fibrosis in patients with HCM.
Methods: Echocardiographic examination and MRI were performed in 47 consecutive patients with HCM (mean age: 64±12 years, men: 33). We measured the global longitudinal strain (GLS) from apical two-chamber, four-chamber and long-axis views using speckle tracking analysis. The extent of LGE (%LGE = LGE volume/ total LV volume) and LV mass index (LVMI) were calculated on the basis of Simpson's rule by MRI using custom software.
Results: LGE were observed in 35 patients (74%, mean %LGE = 5.3±3.3%). The patients with LGE had significantly higher GLS (−11.8 ± 2.9 vs −15.0 ± 1.7%, P = 0.002), higher LVMI (132 ± 30 vs 113 ± 18 g/m2, P = 0.043), lower e' (3.3 ± 1.3 vs 4.1 ± 1.2 cm/s, P = 0.048) and lower propagation velocity of LV early filling flow (Vp) (22 ± 6 vs 37 ± 12 cm/s, P < 0.001) than those without LGE. In contrast, ejection fraction was not different between the two groups (74 ± 9 vs 75 ± 9%, P = 0.645). %LGE was significantly correlated with GLS (r = 0.631, P < 0.001), LVMI (r = 0.492, P < 0.001), e' (r = −0.379, P = 0.012) and Vp (r = −0.582, P < 0.001). Multivariate analysis showed that GLS and Vp were independent predictors of %LGE (standard coefficient = 0.523, P = 0.001; and −0.325, p = 0.032, respectively).
Conclusions: These results suggest that global 2D strain can provide strong information on myocardial fibrosis in patients with HCM.
- © 2010 by American Heart Association, Inc.