P5253Does regional myocardial strain by cardiac magnetic resonance feature tracking reflect scar in ischemic heart disease?

Abstract

Abstract Background Cardiac magnetic resonance (CMR) late gadolinium enhancement (LGE) is the gold standard for detection of myocardial scar. We hypothesized that CMR Feature Tracking (FT)-derived regional myocardial strain may reflect the presence of scar and could thus potentially be used instead of LGE imaging. Purpose The aim of this study was to determine the relationship between FT-derived regional myocardial strain and LGE in patients with coronary artery disease (CAD). Methods Seventy-five patients with CAD and typical ischemic LGE patterns on CMR (1.5T) were included (mean age 60±12 years, 70% males). Myocardial strain analysis and LGE identification were performed using dedicated commercial software. Scar was defined by presence of LGE in the same area of the myocardium in both short- and long-axis views. Peak systolic regional longitudinal and circumferential strain (RLS, RCS) values were calculated in the region of interest corresponding to the LGE area and also in a non-LGE myocardial region as a reference in each patient. These comparisons were repeated for a subgroup of 36 patients with left ventricular (LV) ejection fraction (EF) <40% to determine whether the relationship between strain and LGE holds in the presence of reduced LV function, when strain measurements may be altered as a reflection of reduced LVEF itself. Results Both global longitudinal and circumferential strain values were abnormal (−12.8±5.1% and −11.4±4.1%, respectively), reflecting LV dysfunction in this CAD cohort (EF = 40±16%). The magnitude of both RLS and RCS was significantly reduced in areas of LGE, compared to those without LGE: RLS −10.0±5.8% versus −20.4±7.5% (p<0.001); RCS −10.1±5.3±% versus −18.9±7.5%, respectively (p<0.001). Same pattern was noted in the reduced EF subgroup: RLS −8.0±4.7% versus −16.9±6.6% (p<0.001), RCS −7.7±4.3±% versus −16.0±7.9%, respectively (p<0.001). The figure depicts 2 representative cases in long and short axis views, LGE detection and concomitant regional strain analysis. LGE and regional strain analysis. Conclusion Reduced magnitude of regional longitudinal and circumferential strain by CMR-FT correlates with presence of LGE. Pending further validation, this finding may constitute the basis for detection of scar without contrast enhanced imaging, and would result in reduced cost, scan time and risk associated with gadolinium. Acknowledgement/Funding ARP: Research support (software) from Neosoft and Philips