Efstathios Pagourelias

Comparison of Feasibility, Accuracy, and Reproducibility of Layer-Specific Global Longitudinal Strain Measurements Among Five Different Vendors: A Report from the EACVI-ASE Strain Standardization Task Force

Background: Despite standardization efforts, vendors still use information from different myocardial layers to calculate global longitudinal strain (GLS). Little is known about potential advantages or disadvantages of using these different layers in clinical practice. The authors therefore investigated the reproducibility and accuracy of GLS measurements from different myocardial layers. Methods: Sixty‐three subjects were prospectively enrolled, in whom the intervendor bias and test‐retest variability of endocardial GLS (E‐GLS) and midwall GLS (M‐GLS) were calculated, using software packages from five vendors that allow layer‐specific GLS calculation (GE, Hitachi, Siemens, Toshiba, and TomTec). The impact of tracking quality and the interdependence of strain values from different layers were assessed by comparing test‐retest errors between layers. Results: For both E‐GLS and M‐GLS, significant bias was found among vendors. Relative test‐retest variability of E‐GLS values differed significantly among vendors, whereas M‐GLS showed no significant difference (range, 5.4%–9.5% [P = .032] and 7.0%–11.2% [P = .200], respectively). Within‐vendor test‐retest variability was similar between E‐GLS and M‐GLS for all but one vendor. Absolute test‐retest errors were highly correlated between E‐GLS and M‐GLS for all vendors. Conclusions: E‐GLS and M‐GLS measurements showed no relevant differences in robustness among vendors, although intervendor bias was higher for M‐GLS compared with E‐GLS. These data provide no technical argument in favor of a certain myocardial layer for global left ventricular functional assessment. Currently, the choice of which layer to use should therefore be based on the available clinical evidence in the literature.

Machine learning of the spatio-temporal characteristics of echocardiographic deformation curves for infarct classification

The aim of this study was to analyze the whole temporal profiles of the segmental deformation curves of the left ventricle (LV) and describe their interrelations to obtain more detailed information concerning global LV function in order to be able to identify abnormal changes in LV mechanics. The temporal characteristics of the segmental LV deformation curves were compactly described using an efficient decomposition into major patterns of variation through a statistical method, called Principal Component Analysis (PCA). In order to describe the spatial relations between the segmental traces, the PCA-derived temporal features of all LV segments were concatenated. The obtained set of features was then used to build an automatic classification system. The proposed methodology was applied to a group of 60 MRI-delayed enhancement confirmed infarct patients and 60 controls in order to detect myocardial infarction. An average classification accuracy of 87% with corresponding sensitivity and specificity rates of 89% and 85%, respectively was obtained by the proposed methodology applied on the strain rate curves. This classification performance was better than that obtained with the same methodology applied on the strain curves, reading of two expert cardiologists as well as comparative classification systems using only the spatial distribution of the end-systolic strain and peak-systolic strain rate values. This study shows the potential of machine learning in the field of cardiac deformation imaging where an efficient representation of the spatio-temporal characteristics of the segmental deformation curves allowed automatic classification of infarcted from control hearts with high accuracy.

Right ventricular remodelling after transcatheter pulmonary valve implantation

To define the optimal timing for percutaneous pulmonary valve implantation (PPVI) in patients with severe pulmonary regurgitation (PR) after Fallots Tetralogy (ToF) correction.

Functional and molecular correlative imaging in a patient with amyloidosis

A 74-year-old man with a history of sarcoidosis was referred for further investigations due to relapsing heart failure symptoms. Because of a previously implanted defibrillator, cardiac work-up with echocardiography and 18F-FDG PET/CT was done to evaluate cardiac function and disease activity, respectively. Echocardiography revealed left and right ventricular hypertrophy with severely impaired biventricular …

Long-term outcomes after percutaneous revascularization of complex coronary bifurcation lesions using a dedicated self-expanding biolimus-eluting stent system

BACKGROUND To evaluate long-term clinical outcomes after treatment of complex bifurcation lesions with the AXXESS dedicated self-expanding biolimus A9-eluting bifurcation stent. METHODS Between 2004 and 2013, 123 patients with complex bifurcation lesions were treated in a single-center with the AXXESS stent in the proximal main vessel (MV) and additional drug-eluting stents in branches when required. Median follow-up was 5 years. Primary endpoint was the rate of major adverse cardiac events (MACE). Secondary endpoints included MACE components (cardiac death, non-periprocedural clinical myocardial infarction [MI], target lesion revascularization [TLR] and definite/probable stent thrombosis [ST]) as well as all-cause death, target vessel revascularization (TVR) and non-TVR. RESULTS During follow-up, 11 (8.9%) patients experienced a MACE, of whom 2 (1.6%) suffered cardiac death, 2 (1.6%) had a non-periprocedural clinical MI requiring TLR, and 7 (5.7%) underwent elective TLR. No definite/probable ST was observed. All-cause death occurred in 9 (7.3%) patients, TVR in 11 (8.9%) and non-TVR in 11 (8.9%). Patients treated for left main (LM) bifurcation lesions were more likely to experience MACE than non-LM bifurcation lesions (25% vs. 6.5%, p = 0.04). CONCLUSIONS Percutaneous revascularization of complex bifurcation lesions with the AXXESS stent is safe and provides excellent long-term results, especially in non-LM lesions.

Papillary muscles contribute significantly more to left ventricular work in dilated hearts

Aims Left ventricular (LV) dilatation results in increased sphericity and affects position and orientation of papillary muscles (PMs), which may influence their performed work. The aim of this study was to assess the contribution of PM to LV function and its changes with dilatation. Methods and results Fifteen sheep were investigated. Ten animals were subjected to 8 weeks of rapid (180 bpm) pacing, inducing LV dilatation. Five animals served as controls. High-resolution gated computed tomography was performed to assess LV volumes, left ventricular ejection fraction (LVEF), global longitudinal strain (GLS), sphericity index, and PM angle, width and fractional shortening. 18F-fluorodeoxyglucose positron emission tomography (PET) was used to measure glucose metabolism as surrogate of regional myocardial work. Spatial resolution of PET images was maximized by electrocardiogram- and respiratory-gating. 18F-fluorodeoxyglucose uptake was measured in PM and compared with remaining left ventricular myocardium (MYO) to obtain a PM/MYO ratio. Animals with dilated heart had a more spherical left ventricle, with reduced LVEF (P < 0.0001) and GLS (P < 0.0001). In dilated hearts, PET analysis revealed a higher contribution of both PM to LV myocardial work (P < 0.0001); and PM angle towards LV wall correlated with PM work, together with PM width and the LV sphericity index. Sphericity index and posterior PM angle were strongest determinants of posterior PM/MYO ratio (R2 = 0.754; P < 0.0001), while anterior PM/MYO was mostly determined by sphericity index and the PM width (R2 = 0.805; P < 0.0001). Conclusion In dilated hearts, PM contribute relatively more to LV myocardial work. We hypothesize that this is caused by the more cross-sectional orientation of the subvalvular apparatus, which leads to a higher stress on the PM compared with the spherical LV walls. The reduced cross-sectional area of the PM may further explain their increased stress.

A Left Atrial Appendage Phantom Structure

A 71-year-old female patient was referred for shock cardioversion following diagnosis of lone atrial fibrillation. Transesopageal echocardiography was performed as routine workup. Interestingly a circular membrane like structure in the left atrial appendage (LAA) was observed (Fig. 1A, Supplementary movie 1). Using 2D X plane imaging echocardiography, where an orthogonal view can be acquired through the midline of a primary image and displayed as a secondary image, an extra thin LAA wall was evidenced showing sigmoid anatomy (Fig. 1B). Local pericardial effusion was questioned implicating that this specific structure accounted for the thin LAA wall. 3D echocardiography evidenced the entrance of LAA, surrounded by the pericardial wall at a distance, due to the presence of pericardial effusion (Fig. 1C and D, Supplementary movies 2 and 3). The patient underwent uneventful direct current shock cardioversion and remains in sinus rhythm at nine months follow up. Fig. 1 2D and 3D echocardiography imaging. A: Circular structure into the LAA. B: 2D X plane imaging of the structure. C and D: 3D echocardiography delineating LAA entrance surrounded by pericardial fluid. AO: aorta, LAA: left atrial appendage, LA: left atrium, ... Cardiac magnetic resonance imaging confirmed the diagnosis of local pericardial effusion in the LAA area. No structure, thrombi or membrane were documented into the LAA (Supplementary movie 4). Local pericardial effusion in the LAA area is an extremely rare finding.1),2) It is clinically important to be aware of this benign clinical finding that should be differentiated from LAA obstructive or non-obstructive membranes or thrombi, especially in patients with atrial fibrillation undergoing cardioversion or planned for specific transcatheter therapies such as implantation of LAA closure devices.3),4),5)

Young Investigator Award session: Basic Science311Intraventricular flow patterns after percutaneous mitral valve repair with MitraClip implantation312Papillary muscles contribute significantly to shortening of dilated left ventricles313Relationship between cardiac uptake by 99mTc-DPD scintigraphy and left ventricular longitudinal strain in patients with transthyretin-related cardiac amyloidosis314Premature ventricular contraction in resynchronized patients with short atrio-ventricular delay: hemodynamic impact beyond A-wave truncation

# 311 Intraventricular flow patterns after percutaneous mitral valve repair with MitraClip implantation {#article-title-2} Background: Percutaneous Mitral valve repair using MitraClip implantation has become a valid alternative for patients with severe mitral regurgitation (MR) and high surgical risk. After mitral valve (MV) replacement with mechanical prosthesis, vortex reversal flow and increase in energy dissipation was observed by Echo-PIV analysis. Aim of the present study was to evaluate if the revised valve anatomy with a generated double or multi-orifice configuration after MitraClip implantation may alter intraventricular flow patterns during diastole. Methods: From May 2015 to April 2016, 13 consecutive patients with severe MR undergoing MitraClip implantation were enrolled. All pts underwent contrast echocardiography before and after the procedure (2±1 days) for Echo-PIV analysis and vortex quantification. Acute procedural success (APS) was defined as successful clip implantation with residual MR grade ≤2+. Following parameters were evaluated by 2D/3D echocardiography: the etiology of MR (functional, ischemic and degenerative), MV anatomic characteristics, tricuspid regurgitation (TR) and pulmonary artery systolic pressure (PASP), LV dimension and function. Following parameters were evaluated by Echo-PIV analysis: vortex area, intensity and geometry, energy dissipation, flow force momentum (φ) and flow force dispersion. Results: Study population was divided in two groups according to the success of the procedure (APS in 7 and failure in 6 pts). No difference in MR etiology and severity, leaflets’ length and valve area was found. Patients with APS presented with a less pre-interventional PASP (28±6 vs 53±11 mmHg, p=0.005). By comparing vortex data before and after the procedure, in all patients vortex area and intensity were significantly lower after MitraClip implantation (0.39±0.07 vs 0.32±0.11; p=0.006 and -0.53±0.1 vs-0.30±0.34; p=0.009), confirmed in both sub-groups analysis. Contrary to what observed after MV replacement with mechanical prosthesis, vortex reversal flow was not detected. Finally, only in APS subgroup, a significant flow force dispersion reduction (50±3.4 vs 45±5; p=0.01) was found. Conclusion: The results of this study showed significant changes in intraventricular flow patterns following MitraClip implantation with different characteristics as compared to patients undergoing surgical MV replacement. A significant reduction of flow turbulence (flow force dispersion) in APS group was found. Further longitudinal studies are necessary to assess the impact of these intraventricular flow patterns on functional outcome. # 312 Papillary muscles contribute significantly to shortening of dilated left ventricles {#article-title-3} Background: Dilated left ventricles (LV) have a more spherical shape and displaced papillary muscles (PM). We hypothesized that this altered geometry may influence the contribution of PM to LV function. We therefore assessed the regional myocardial work by measuring the myocardial glucose uptake by 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) in an animal model of normal and dilated LVs. Methods: Fifteen animals were included in the study. Ten sheep were subjected to 8 weeks of rapid (180 bpm) pacing to induce LV dilatation. Five sheep served as control. Imaging was performed at a heart rate of 110 bpm. Cardiac magnetic resonance imaging (MRI) was performed in all animals to assess end-diastolic (EDV), end-systolic (ESV) volumes and LV ejection fraction (LVEF). LV sphericity index was defined as mid-ventricular septal-to-lateral width divided by LV length. Mitral regurgitation (MR) was graded visually on the MRI cine images as no (0), minimal (0.5), mild (1), moderate (2), moderate to severe (3), severe (4). ECG- and respiratory gating was used to obtain high resolution PET images. Regional metabolism was measured in the PM and compared to the remaining LV myocardium (MYO) (Figure). Results: Animals subjected to rapid pacing had a higher EDV and ESV compared to controls (105±20 vs. 76±7 ml and 76±16 vs. 41±6 ml, resp., both p<0.01), a lower LVEF (28±5 vs. 46±6 %, p<0.01), a higher MR score (1.6±0.8 vs. 0.2±0.4, p<0.01), and a higher LV sphericity index (0.61±0.03 vs. 0.47±0.02, p<0.01). The ratio of total PM FDG-uptake over total MYO uptake was significantly higher in dilated LVs compared to controls (0.54±0.05 vs. 0.39±0.03, p<0.01). The PM/MYO ratio correlated significantly with LVEF reduction (r=0.79, p<0.01), the MR score (r=0.61, p=0.01), and the LV sphericity index (r=0.86, p<0.01) (Figure). The LV sphericity index remained the strongest determinant of increased PM/MYO ratio after multiple regression analysis (model R²=0.86, p<0.01). Conclusions: Our data show that papillary muscles contribute more to LV shortening in dilated compared to normal hearts. We hypothesize that their higher workload is due to geometric abnormalities in dilated LVs which make papillary muscles work more diametral through the LV and less parallel to the LV wall. The increased contribution of papillary muscles to LV work in dilated hearts may further strengthen the argument of their preservation during MV repair/replacement in DCM. Funding Acknowledgements: KU Leuven research grant (OT/12/084). ![Figure][1] Abstract 312 Figure. # 313 Relationship between cardiac uptake by 99mTc-DPD scintigraphy and left ventricular longitudinal strain in patients with transthyretin-related cardiac amyloidosis {#article-title-4} Background: Pathophysiology of 99mTc-3,3-diphosphono-1,2-propanodicarboxylic acid (99mTc-DPD) uptake by scintigraphy in transthyretin-related (TTR) amyloidosis remains unclear. Impact of cardiac uptake on cardiac function is unknown. Purpose: The aim of this study was to explore the relationship between cardiac uptake by 99mTc-DPD scintigraphy and longitudinal myocardial strain assessed by echocardiography. Methods: Forty patients with TTR cardiac amyloidosis underwent 99mTc-DPD scintigraphy and echocardiography with measure of left ventricular segmental and global longitudinal strain (GLS). Cardiac retention was assessed by visual scoring and the heart/whole body (H/B) ratio was calculated by dividing counts in the heart by counts in late whole body images. Results: The mean population age was 79±10 years. Most of the patients (88%) were male. Visual score was 2 and 3 for 6 (15%) and 34 (85%) patients, respectively. Mean H/B ratio was 12±7. Mean left ventricular ejection fraction (LVEF) and GLS were 50±10% and -10±3%, respectively. H/B ratio was correlated with GLS (R = 0.490, P=0.001) but not with LVEF (R=-0,097, P=0.558). Segmental myocardial uptake normalized by H/B ratio was correlated with segmental longitudinal strain (n = 480 segments, R = 0.155, P<0.001). Conclusion: In patients with TTR cardiac amyloidosis, myocardial uptake by 99mTc-DPD scintigraphy is correlated with decrease of myocardial longitudinal strain. On behalf of: Department of Cardiology, Rangueil University Hospital, Toulouse, France. # 314 Premature ventricular contraction in resynchronized patients with short atrio-ventricular delay: hemodynamic impact beyond A-wave truncation {#article-title-5} Introduction: Optimization of atrio-ventricular delay (AVD) is one of the interventions that has been suggested to improve response to resynchronization therapy in heart failure patients. Excessively short AVD leads to A-wave truncation and, consequently, compromises left ventricular (LV) end-diastolic volume. Previous studies of intracardiac flow have suggested that atrial contraction impacts LV flow dynamics beyond its filling by generating a vortex that redirects flow towards the LV outflow tract, minimizing energy dissipation and facilitating initial ejection. In this study we assess the consequences of A-wave truncation on LV flow mechanics through LV flow mapping. Methods: Patients under cardiac resynchronization therapy (CRT) and in sinus rhythm underwent echocardiographic AVD optimization with transmitral flow assessment. Using intracardiac flow mapping, we measured Kinetic Energy Dissipation (KED) with automated software comparing flow direction and velocity in each pixel with its neighbouring points and integrates it into an image displaying energy loss in bright colours compared to dark areas with minimal energy dissipation. We also measured the angle between the longitudinal axis of the LV and the vector of early ejection flow (axis-flow angle, or AFA). Results: 25 patients (67% male, aged 72 ±11.7, LVEF 39.2±10.8) were included in the study. KED and AFA were measured in all patients in optimal AVD (Opt) and short AVD (Opt – 60 ms). Student’s t test showed a significant difference in KED between short (48,76 ± 8,33 J/m*s) and optimal AVD (24,32 ± 8,61 J/m*s, p<0,0001) in early ejection. The Flow – LV-Axis Angle was significantly narrower in short AVD vs. optimal AVD (20,2 ± 1,9° vs. 10,1 ± 1,3°, p<0.01), which implied that flow collided with the mitral valve and mitro-aortic junction before being ejected, with consequent energy dissipation, in short but not in optimal AVD. See Figure 1. Conclusions: Premature ventricular contraction due to short atrio-ventricular delay impacts LV flow dynamics causing higher kinetic energy dissipation due to impaired flow redirection to the LV outflow tract, which adds to the compromise of LV filling due to A wave truncation in explaining poor response to CRT in patients with suboptimal AVD programming. ![Figure][1] Abstract 314 Figure. [1]: pending:yes

Sheep can be used as animal model of regional myocardial remodelling and controllable work

BACKGROUND A-V-sequential pacing has been shown to induce reversible conduction delay and subsequent asymmetric remodelling of the left ventricle (LV) in dogs and pigs. Both species have disadvantages in animal experiments. Therefore aim of this study focusses at developing a more feasible and easy-to-use animal model in sheep. METHODS Dual-chamber pacing (DDD) pacemakers (right atrium + right ventricular free wall) were surgically implanted in 13 sheep. All animals underwent 8 weeks of chronic rapid pacing at 180 bpm. Reported observations were made at 110 bpm. RESULTS DDD pacing acutely induced a left bundle branch block (LBBB) - like pattern with almost doubling in QRS width and septal flash, indicating mechanical dyssynchrony. Atrial pacing (AAI) resulted in normal ventricular conduction and function. During 8 weeks of rapid DDD pacing, animals developed LV remodelling (confirmed with histology) with septal wall thinning (-30%, p < 0.05), lateral wall thickening (+22%, p < 0.05), LV volume increase (+32%, p < 0.05), decrease of LV ejection fraction (-31%, p < 0.05), and functional mitral regurgitation. After 8 weeks, segmental pressure-strain-loops, representing regional myocardial work, were recorded. Switching from AAI to DDD decreased immediately work in the septum and increased it in the lateral wall (-69 and +41%, respectively, p < 0.05). Global LV stroke work and dP/dtmax decreased (-27% and -25%, respectively, p < 0.05). CONCLUSIONS Herein is developed a new sheep model with an asymmetrically remodelled LV. Simple pacemaker programming allows direct modulation of regional myocardial function and work. This model provides a new and valuable alternative for canine or porcine models and has the potential to become instrumental for investigating regional function and loading conditions on regional LV remodelling.