Abstract 12512: Combination of Global Longitudinal Strain and Late Gadolinium Enhancement Predicts Improvement of Systolic Function After Aortic Valve Replacement in Patients With Severe Aortic Stenosis

Abstract

Introduction: Myocardial fibrosis correlates with post-operative prognosis in patients with severe aortic stenosis (AS). There were a few reports that global longitudinal strain (GLS) by echocardiography decreased and correlated with myocardial fibrosis and/or late gadolinium enhancement (LGE) by MRI in patients with AS. However, it remains unclear whether GLS and LGE are possible to predict improvement of myocardial function after aortic valve replacement (AVR). Hypothesis: The combination of GLS and LGE identify the systolic dysfunction including myocardial fibrosis in severe AS, and predicts the improvement of systolic function after AVR. Methods: In 27 patients with severe AS before AVR, we examined GLS by 2D speckle tracking echocardiography and LGE by MRI for assessment of myocardial fibrosis, i.e., LGEcore(g): >mean of normal area +5SD, LGEgray(g): mean of normal area +2~5SD, and LGEcore+gray(g): LGEcore+LGEgray. In addition, fibrosis index (FI, %), as the percentage of fibrosis in myocardial specimen, was calculated in 11 patients. We evaluated the relationship among the GLS, the LGEs and the FI. Moreover, at 1 year after AVR, we assessed which indices in pre-operative period related to the improvement of GLS. Results: The mean values of indices were: GLS -15.6±0.9%, LGEcore 5.0±1.3g (4.5±1.2%), LGEgray 12.5±1.9g (11.5±1.4%), LGEcore+gray 17.5±3.0g (16.1±2.4%) and FI 7.1±1.4%. The FI related with the GLS (R=0.60, P<0.05), the LGEcore (R=0.58, P<0.05), and the LGEcore+gray (R=0.54, P<0.05). On the other hand, the GLS related to the LGEcore (R=0.50, P<0.05), LGEgray (R=0.52, P<0.05) and the LGEcore+gray (R=0.60, P<0.01). After AVR, the GLS was significantly improved (-15.0±1.2 to -18.6±1.1%, P<0.05). The LGE core before AVR was significantly smaller in the improvement group (GLS≥-19.0%) than the un-improvement group (GLS<-19.0%) (1.3±0.4 vs 7.1±2.5g, P<0.05). Conclusions: In patients with severe AS, GLS before AVR related with the mild to severe myocardial fibrosis. Moreover, the patients with severe fibrosis did not show the improvement of GLS in follow-up period. The combination of GLS and LGE will identify the potential systolic dysfunction including myocardial fibrosis, and predicts the improvement of systolic function after AVR.