A Head-to-Head comparison of fast-SENC and Feature Tracking to LV long axis strain for assessment of myocardial deformation in chest pain patients

Background Myocardial strain imaging has gained importance in cardiac magnetic resonance (CMR) imaging in recent years as an even more sensitive marker of early left ventricular dysfunction than left-ventricular ejection fraction (LVEF). fSENC (fast strain encoded imaging) and FT (Feature Tracking) both allow for reproducible assessment of myocardial strain. However, left-ventricular long axis strain (LVLAS) might enable an equally sensitive measurement of myocardial deformation as global longitudinal or circumferential strain in a more rapid and simple fashion. Methods In this study we compared the diagnostic performance of fSENC, FT and LVLAS for identification of cardiac illness (ACS, cardiac-non-ACS) in patients presenting with chest pain (initial hscTnT 5- 52 ng/l). Patients were prospectively recruited from the chest pain unit in Heidelberg. The CMR scan was performed within 1h after patient presentation. Analysis of LVLAS was compared to the GLS and GCS as measured by fSENC and FT. Results In total 40 patients were recruited (ACS n=6, cardiac-non-ACS n=6, non-cardiac n=28). LVLAS was comparable to fSENC for differentiation between healthy myocardium and myocardial illness (GLS-fSENC AUC: 0.882; GCS-fSENC AUC: 0.899; LVLAS AUC: 0.771; GLS-FT AUC: 0.740; GCS-FT: 0.688). There was significant variability between the three techniques. Intra- and inter-observer variability (OV) was excellent for fSENC and FT, whilst for LVLAS the agreement was lower and levels of variability higher (intra-OV: Pearson >0.7, ICC>0.8; inter-OV: Pearson>0.65, ICC>0.8; CoV > 25%). Conclusions Although there was significant bias between the three deformation parameters, reproducibility was excellent for both FT and fSENC. Whilst LVLAS demonstrated lower levels of agreement and higher variability, it was comparable to FT and fSENC for identification of myocardial illness and might be used as a rapid supporting parameter for assessment of left-ventricular function.