Background Cardiovascular magnetic resonance (CMR) is the current reference standard for the quantitative assessment of ventricular function. Fast Strain-ENCoded (fSENC)-CMR imaging allows for the assessment of myocardial deformation within a single heartbeat. The aim of this pilot study was to identify obstructive coronary artery disease (oCAD) with fSENC-CMR in patients presenting with new onset of chest pain. Methods and results In 108 patients presenting with acute chest pain, we performed fSENC-CMR after initial clinical assessment in the emergency department. The final clinical diagnosis, for which cardiology-trained physicians used clinical information, serial high-sensitive Troponin T (hscTnT) values and—if necessary—further diagnostic tests, served as the standard of truth. oCAD was defined as flow-limiting CAD as confirmed by coronary angiography with typical angina or hscTnT dynamics. Diagnoses were divided into three groups: 0: non-cardiac, 1: oCAD, 2: cardiac, non-oCAD. The visual analysis of fSENC bull´s eye maps (blinded to final diagnosis) resulted in a sensitivity of 82% and specificity of 87%, as well as a negative predictive value of 96% for identification of oCAD. Both, global circumferential strain (GCS) and global longitudinal strain (GLS) accurately identified oCAD (area under the curve/AUC: GCS 0.867; GLS 0.874; p<0.0001 for both), outperforming ECG, hscTnT dynamics and EF. Furthermore, the fSENC analysis on a segmental basis revealed that the number of segments with impaired strain was significantly associated with the patient´s final diagnosis (p<0.05 for all comparisons). Conclusion In patients with acute chest pain, myocardial strain imaging with fSENC-CMR may serve as a fast and accurate diagnostic tool for ruling out obstructive coronary artery disease.

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 pathology (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 1 h 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 dysfunction (GLS-fSENC AUC: 0.882; GCS-fSENC AUC: 0.899; LVLAS AUC: 0.771; GLS-FT AUC: 0.740; GCS-FT: 0.688), while FT-derived strain did not allow for differentiation between ACS and non-cardiac patients. There was significant variability between the three techniques. Intra- and inter-observer variability (OV) was excellent for fSENC and FT, while 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 While reproducibility was excellent for both FT and fSENC, it was only fSENC and the LVLAS which allowed for significant identification of myocardial dysfunction, even before LVEF, and therefore might be used as rapid supporting parameters for assessment of left-ventricular function.

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Background In acute situations such as non-ST-elevation infarction (NSTEMI) or relevant coronary artery disease (CAD) CMR does not yet play a key role due to its lengthy protocols. fSENC is a new CMR technique which may detect subclinical signs of myocardial damage by measuring myocardial strain (change in length/ unit length). A whole-heart coverage is generated in 6 heart-beats and the information obtained is converted into a colour-coded map. fSENC does not require major post-processing, long breath-holds and the administration of contrast agents/medication. Purpose In this observational study fSENC is assessed in patients with chest pain and its capability to differentiate between an ischemic cause (NSTEMI, significant CAD), an underlying non-ischemic cardiac disease and non-cardiac chest pain. Additionally, we aim to identify the affected coronary arteries in the ischemic cohort. With fSENC it could be possible to successfully diagnose patients with suspected AMI in <1h after admission and also gain diagnostic information regarding the underlying pathology. Methods Patients with chest pain and an initial hscTnT level between 5pg/ml and 52 pg/ml are recruited. These patients then undergo an fSENC-CMR before 2nd hscTnT measurement. Additionally, a stress-induced fSENC-image is acquired (1-minute hyperventilation, followed by a single breath-hold). This breathing manoeuvre leads to an increase in oxygenation through vasodilation, therefore identifying ischemic areas. The fSENC analysis is later compared to the patient's final diagnosis and therapy. Results So far 50 patients have been analysed by fSENC in this observational study (26 female, aged 57±18). fSENC correctly identified 7 patients suffering from NSTEMI or significant CAD and their affected coronary arteries. 42 other patients were safely ruled-out by fSENC which was consistent with the serial hscTnT results. In 11 patients fSENC was able to detect generalized impaired myocardial deformation, implying an underlying cardiac disease (hypertrophic cardiomyopathy, myocarditis). fSENC currently exhibits a sensitivity of 100% and specificity of 97,7% for correct rule-in/-out of an ischemic cause. Conclusions At this stage fSENC allows correct identification of patients suffering from myocardial infarction and their affected coronary arteries. Additionally, fSENC can safely rule-out patients with chest pain but no underlying ischemic cause. This novel technique is a rapid additional diagnostic tool which assesses myocardial function non-invasively without radiation exposure.