Left ventricular long axis strain: a new prognosticator in non-ischemic dilated cardiomyopathy?

Myocardial Transit Time Mapping by CMR: A Novel Indicator of Microcirculatory Dysfunction in Cardiac Amyloidosis

Cardiac amyloidosis (CA) is characterized by the deposition of amyloid fibrils within the myocardium, resulting in a restrictive physiology. Although microvascular dysfunction is a common feature, it is difficult to assess. This study aimed to explore myocardial transit time (MyoTT) by cardiovascular magnetic resonance (CMR) as a potential novel parameter of microcirculatory dysfunction in CA. This prospective study enrolled 20 CA patients and 20 control subjects. CMR acquisition included cine imaging, pre- and post-contrast T1 mapping, and MyoTT assessment, which was calculated from the time delay in contrast agent arrival between the aortic root and coronary sinus (CS). Compared to the control group, patients with CA exhibited significantly reduced left ventricular (LV) ejection fraction and myocardial strain, an increase in LV global peak wall thickness (LVGPWT), extracellular volume fraction (ECV), and prolonged MyoTT (14.4 ± 3.8 s vs. 7.7 ± 1.5 s, p < 0.001). Moreover, patients at Mayo stage III had a significantly longer MyoTT compared to those at stage I/II. MyoTT showed a positive correlation with the ECV, LVGPWT, and LV global longitudinal strain (LV-GLS) (p < 0.05). The area under the curve (AUC) for MyoTT was 0.962, demonstrating diagnostic performance comparable to that of the ECV (AUC 0.995) and LV-GLS (AUC 0.950) in identifying CA. MyoTT is significantly prolonged in patients with CA, correlating with fibrosis markers, remodeling, and dysfunction. As a novel parameter of coronary microvascular dysfunction (CMD), MyoTT has the potential to be an integral biomarker in multiparametric CMR assessment of CA.

Prognostic impact of MRI-derived feature tracking myocardial strain in patients with non-ischaemic dilated cardiomyopathy: a systematic review and meta-analysis

AIM

To evaluate the clinical utility of feature tracking (FT)-derived myocardial strain in patients with non-ischaemic dilated cardiomyopathy (NIDCM).

MATERIALS AND METHODS

Electronic database searches of PubMed, Web of Science Core Collection, Cochrane advanced search, and EMBASE were performed. Studies on NIDCM were divided into categories according to left ventricular ejection fraction (LVEF; <30%, 30-40%, >40%), and correlations between strains and prevalence of late gadolinium enhancement (LGE) were evaluated by weighted correlation coefficients. Global longitudinal strain (GLS) hazard ratios were also integrated for prediction of future adverse events.

RESULTS

The present meta-analysis analysed data from 5,767 patients with NIDCM from 30 eligible studies. GLS and global circumferential strain significantly differed across the three LVEF categories (all p<0.05); however, global radial strain did not. Only GLS showed a strong correlation with the prevalence of LGE (Spearman's correlation coefficient = 0.61). The pooled HR of GLS for predicting adverse events was 1.15 (95% confidence interval [CI]: 1.07-1.23, p<0.001).

CONCLUSION

In this meta-analysis, FT-derived GLS was strongly correlated with myocardial fibrosis and was an important predictor of future adverse events. These results suggest that FT-derived GLS may be useful in the pathological evaluation and risk stratification of NIDCM.

Derivation and validation of diagnostic models for myocardial fibrosis in duchenne muscular dystrophy: assessed by multi-parameter cardiovascular magnetic resonance

BACKGROUND

Gadolinium-enhanced cardiovascular magnetic resonance (CMR) is the most widely used approach for diagnosing myocardial fibrosis with late gadolinium enhancement (LGE) in cardiomyopathy associated with Duchenne muscular dystrophy. Given the limitations and safety of gadolinium use, we wanted to develop and evaluate multi-parametric pre-contrast CMR models for the diagnosis of LGE and investigate whether they could be utilised as surrogates for LGE in DMD patients.

METHODS

A total of 136 DMD patients were prospectively recruited and separated into LGE - and LGE + groups. In the first subset of patients (derivation cohort), regression models for the diagnosis of LGE were built by logistic regression using pre-contrast sequence parameters. In a validation cohort of other patients, the models' performances were evaluated.

RESULTS

EF, native T1 and longitudinal strain alone, as well as their combinations form seven models. The model that included EF, native T1 and longitudinal strain had the best diagnostic value, but there was no significant difference in diagnostic accuracy among the other models except EF. In the validation cohort, the diagnosis outcomes of models were moderate consistent with the existence of LGE. The longitudinal strain outperformed the other models in terms of diagnostic value (sensitivity: 83.33%, specificity: 54.55%).

CONCLUSIONS

Pre-contrast sequences have a moderate predictive value for LGE. Thus, pre-contrast parameters may be considered only in a specific subset of DMD patients who cannot cooperate for long-time examinations and have contradiction of contrast agent to help predict the presence of LGE.

TRIAL REGISTRATION NUMBER (TRN)

ChiCTR1800018340 DATE OF REGISTRATION: 20180107.

Potential Prognostic Relevance of Left-Ventricular Global Longitudinal Strain and of the Summation of the Mitral and Tricuspid Regurgitation Volume in Patients with Non-Ischemic Dilated Cardiomyopathy

BACKGROUND

The aim of this pilot study was to determine the potential prognostic relevance of novel multidirectional myocardial and volumetric echocardiographic parameters in patients with non-ischemic dilated cardiomyopathy (NIDCM).

METHODS

Multidirectional myocardial parameters (longitudinal, radial, and circumferential left-ventricular (LV) strain using speckle tracking echocardiography) and a new volumetric parameter (the sum of the mitral and tricuspid regurgitation volume (mitral-tricuspid regurgitation volume) were assessed. The cardiovascular (CV) outcome was a composite of cardiac death and hospitalization for heart failure (HF) at 1 year.

RESULTS

Approximately 102 patients were included in this pilot study. The mean LV ejection fraction (LVEF) was 28.4 ± 8.9%. During a follow-up of 1 year, the CV outcome occurred in 39 patients (10 HF deaths, and 36 hospitalizations for HF). The LV global longitudinal systolic strain (GLS) and mitral-tricuspid regurgitation volume were the main parameters that were seen to be significantly altered in the comparison of patients with events vs. those without events (GLS (absolute values) 7.4 ± 2.7% vs. 10.3 ± 2.6%; mitral-tricuspid regurgitation volume 61.1 ± 20.4 mL vs. 40.9 ± 22.9 mL, respectively; p-value < 0.01). In line with these findings, in a multivariate continuous logistic regression analysis, the GLS and mitral-tricuspid regurgitation volume were the main parameters associated with worse CV outcomes (GLS: OR 0.77 (95%CI 0.65-0.92); mitral-tricuspid regurgitation volume OR 1.09 (95%CI 1.01-1.25)), whereas the radial and circumferential LV global strain and mitral regurgitation volume and tricuspid regurgitation volume were not linked to the CV outcome. Furthermore, in a receiver operating characteristic curve analysis, a GLS cutoff of <7.5% and mitral-tricuspid regurgitation volume > 60 mL were the identified values for the parameters associated with worse CV outcomes.

CONCLUSIONS

The findings of this pilot study suggest that the GLS and a novel volumetric parameter (the sum of the mitral and tricuspid regurgitation volume) are linked to worse CV outcomes in patients with non-ischemic dilated cardiomyopathy. Hence, these promising results warrant further validation in larger studies.

Left atrial strain is associated with arrhythmia recurrence after atrial fibrillation ablation: Cardiac magnetic resonance rapid strain vs. feature tracking strain

PURPOSE

The present study assesses different left atrial (LA) strain approaches in relation to atrial fibrillation (AF) recurrence after ablation and compares LA feature tracking (FT) strain to novel rapid LA strain approaches in AF patients.

METHODS

This retrospective single-center study comprised of 110 prospectively recruited AF patients who underwent cardiac magnetic resonance (CMR) imaging in sinus rhythm prior to their first pulmonary vein isolation ablation. LA rapid strain (long axis strain and atrioventricular (AV)-junction strain), LA FT strain, and LA volumes were derived from 2-chamber and 4-chamber cine images. AF recurrence was followed up for 12 months using either 12‑lead ECGs or rhythm Holter monitoring.

RESULTS

Arrhythmia recurrence was observed in 39 patients (36%) after the 90-day blanking period, occurring at a median of 181 (122-286) days. LA long axis strain, AV-junction strain, and FT strain were all more impaired in patients with AF recurrence compared to patients without AF recurrence (long axis strain: P < 0.01; AV-junction strain: P < 0.001; FT strain: P < 0.01, respectively). Area under the curve (AUC) values for LA remodeling parameters in association with AF recurrence were 0.68 for long axis strain, 0.68 for AV-junction strain, 0.66 for FT strain, 0.66 for LA volume index. Phasic FT LA strain demonstrated that contractile strain had the highest AUC (0.70).

CONCLUSION

Both LA rapid strain and LA FT strain are associated with arrhythmia recurrence after ablation in AF patients. LA rapid strain can be a convenient and reproducible alternative for LA FT strain to assess LA function in clinical practice.

The value of CMR Left ventricular strain analysis in evaluating ICM

The purpose of this article is to investigate the value of cardiac magnetic resonance imaging (CMR) derived left ventricular strain parameters in evaluation of ischemic cardiomyopathy (ICM). Thirty-one ICM patients and nineteen non-cardiomyopathy (non-CM) patients who performed CMR examinations during the same period were selected for this retrospective study. The basic clinical data, CMR left ventricular function parameters, left ventricular strain parameters were compared among the left ventricular ejection fraction (LVEF) preserved ICM group, the LVEF impaired ICM group and the non-CM group. The differences of MyoGCS (-21.9 ± 1.9 vs. -18.9 ± 2.7 P<0.001), MyoGLS (-20.8 ± 2.3 vs. -17.0 ± 2.9 P<0.001) and EndoGLS (-22.2 ± 3.1 vs. -17.6 ± 3.7 P<0.001) between LVEF preserved ICM group and non-CM group were statistically significant, while the differences of left heart function parameters between the two groups were not statistically significant (P > 0.05). The left ventricular strain analysis can be used to assess cardiac functional and morphological alterations in ICM patients prior to changes of left ventricular function parameters, which has high clinical significance.

Helical structure of the ventricular myocardium. A narrative review of cardiac mechanics

To date, the ventricular myocardial band is the anatomical-functional model that best explains cardiac mechanics during systolic-diastolic phenomena in the cardiac cycle. The implications of the model fundamentally affect the anatomical interpretation of the ventricular myocardium, giving meaning to the direction that muscle fibers take, turning them into an object of study with potential clinical, imaging, and surgical applications. Re-interpreting the anatomy of the ventricular muscle justifies changes in the physiological interpretation, from its functional focus as a fiber unraveling the mechanical phenomena carried out during systole and diastole. We identify the functioning of the heart from the electrical and hemodynamic point of view, but it is necessary to delve into the mechanics that originate the hemodynamic changes observed flowmetrically, and that manifested during the pathology. In this review, the mechanical phenomena that the myocardium performs in each phase of the cardiac cycle are broken down in detail, emphasizing the physical displacements that each of the muscle segments presents, as well as a vision of their alteration and in which pathologies they are mainly identified. Visually, an anatomical correlation to the echocardiogram is provided, pointing out the direction of the segmental myocardial displacement by the strain velocity vector technique.

Cardiac Magnetic Resonance Imaging in Appraising Myocardial Strain and Biomechanics: A Current Overview

Subclinical alterations in myocardial structure and function occur early during the natural disease course. In contrast, clinically overt signs and symptoms occur during late phases, being associated with worse outcomes. Identification of such subclinical changes is critical for timely diagnosis and accurate management. Hence, implementing cost-effective imaging techniques with accuracy and reproducibility may improve long-term prognosis. A growing body of evidence supports using cardiac magnetic resonance (CMR) to quantify deformation parameters. Tissue-tagging (TT-CMR) and feature-tracking CMR (FT-CMR) can measure longitudinal, circumferential, and radial strains and recent research emphasize their diagnostic and prognostic roles in ischemic heart disease and primary myocardial illnesses. Additionally, these methods can accurately determine LV wringing and functional dynamic geometry parameters, such as LV torsion, twist/untwist, LV sphericity index, and long-axis strain, and several studies have proved their utility in prognostic prediction in various cardiovascular patients. More recently, few yet important studies have suggested the superiority of fast strain-encoded imaging CMR-derived myocardial strain in terms of accuracy and significantly reduced acquisition time, however, more studies need to be carried out to establish its clinical impact. Herein, the current review aims to provide an overview of currently available data regarding the role of CMR in evaluating myocardial strain and biomechanics.

Association of Late-Gadolinium Enhancement in Cardiac Magnetic Resonance with Mortality, Ventricular Arrhythmias, and Heart Failure in Patients with Non-Ischemic Cardiomyopathy: A Systematic Review and Meta-Analysis

Background

Late gadolinium enhancement (LGE) on cardiac magnetic resonance is a predictor of adverse events in patients with nonischemic cardiomyopathy (NICM).

Objective

This meta-analysis evaluated the correlation between LGE and mortality, ventricular arrhythmias (VAs) and sudden cardiac death (SCD), and heart failure (HF) outcomes.

Methods

A literature search was conducted for studies reporting the association between LGE in NICM and the study endpoints. The primary endpoint was mortality. Secondary endpoints included VA and SCD, HF hospitalization, improvement in left ventricular ejection fraction (LVEF) to >35%, and heart transplantation referral. The search was not restricted to time or publication status. The minimum follow-up duration was 1 year.

Results

A total of 46 studies and 10,548 NICM patients (4610 with LGE, 5938 without LGE) were included; mean follow-up was 3 years (range 13-71 months). LGE was associated with increased mortality (odds ratio [OR] 2.9; 95% confidence interval [CI] 2.3-3.8; P < .01) and VA and SCD (OR 4.6; 95% CI 3.5-6.0; P < .01). LGE was associated with an increased risk of HF hospitalization (OR 3.4; 95% CI 2.3-5.0; P < .01), referral for transplantation (OR 5.1; 95% CI 2.5-10.4; P < .01), and decreased incidence of LVEF improvement to >35% (OR 0.2; 95% CI 0.03-0.85; P = .03).

Conclusion

LGE in NICM patients is associated with increased mortality, VA and SCD, and HF hospitalization and heart transplantation referral during long-term follow up. Given these competing risks of mortality and HF progression, prospective randomized controlled trials are required to determine if LGE is useful for guiding prophylactic implantable cardioverter-defibrillator placement in NICM patients.

Prognostic value of myocardial strain by magnetic resonance imaging in nonischemic dilated cardiomyopathy: a systematic review and meta-analysis

Aim    This study was aimed at performing a systematic review and meta-analysis to investigate the prognostic role of left ventricular (LV) myocardial strain variables as determined by magnetic-resonance imaging in non-ischemic dilated cardiomyopathy.Material and methods    A search was performed in PubMed (MEDLINE), Google Scholar, and EMBASE databases for studies on the prognostic role of LV myocardial strain based on MR feature-tracking in non-ischemic dilated cardiomyopathy. Uncorrected odds ratio (OR) values reported by the studies where similar evaluation criteria of myocardial strain were available, were combined for a meta-analysis.Results    Nine studies were selected from 351 publications for this systematic review and meta-analysis. The analysis included a totality of 2139 patients (mean age, 52.3 years; mean follow-up duration, 42.5 months). The meta-analysis showed that the worsening of the LV global longitudinal strain (GLS), global circumferential strain (GCS), and global radial strain (GRS) was associated with increased risk of major adverse cardiovascular events (MACE): OR, 1.13  per each % of GLS; 95 % CI: 1.050–1.225; p=0.001; OR, 1.16 per each % of GCS; 95 % CI: 1.107–1.213; p<0.0001; OR, 0.95 per each % of GRS; 95 % CI: 0.92–0.97; p<0.0001.Conclusion    The LV GLS, GCS, and GRS variables by MR feature-tracking data are powerful predictors for the development of MACE. Evaluation of myocardial strain can be used as an effective instrument for risk stratification in patients with non-ischemic dilated cardiomyopathy.

 

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 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.

Feasibility of one breath-hold cardiovascular magnetic resonance compressed sensing cine for left ventricular strain analysis

Objective

To investigate the feasibility of 3D left ventricular global and regional strain by using one breath-hold (BH) compressed sensing cine (CSC) protocol and determine the agreement between CSC and conventional cine (CC) protocols.

Methods

A total of 30 volunteers were enrolled in this study. Cardiovascular magnetic resonance (CMR) images were acquired using a 1.436 T magnetic resonance imaging (MRI) system. The CSC protocols included one BH CSC and the shortest BH CSC protocols with different parameters and were only performed in short-axis (SA) view following CC protocols. Left ventricular (LV) end-diastole volume (EDV), end-systole volume (ESV), stroke volume (SV), and ejection fraction (EF) global and regional strain were calculated by CC, one BH CSC, and shortest BH CSC protocols. The intraclass correlation coefficient (ICC) and coefficient of variance (CV) of these parameters were used to determine the agreement between different acquisitions.

Results

The agreement of all volumetric variables and EF between the CC protocol and one BH CSC protocol was excellent (ICC &gt; 0.9). EDV, ESV, and SV between CC and shortest BH CSC protocols also had a remarkable coherence (ICC &gt; 0.9). The agreement of 3D LV global strain assessment between CC protocol and one BH CSC protocol was good (ICC &gt; 0.8). Most CVs of variables were also good (CV &lt; 15%). ICCs of all variables were lower than 0.8. CVs of all parameters were higher than 15% except global longitudinal strain (GLS) between CC and shortest BH CSC protocols. The agreement of regional strain between CC and BH CSC protocols was heterogeneous (-0.2 &lt; ICC &lt; 0.7). Many variables of CVs were poor.

Conclusion

Notably, one BH CSC protocol can be used for 3D global strain analysis, along with a good correlation with the CC protocol. The regional strain should continue to be computed by the CC protocol due to poor agreement and a remarkable variation between the protocols. The shortest BH CSC protocol was insufficient to replace the CC protocol for 3D global and regional strain.

CMR-derived myocardial strain analysis differentiates ischemic and dilated cardiomyopathy-a propensity score-matched study

Left ventricular (LV) longitudinal, circumferential, and radial motion can be measured using feature tracking of cardiac magnetic resonance (CMR) images. The aim of our study was to detect differences in LV mechanics between patients with dilated cardiomyopathy (DCM) and ischemic cardiomyopathy (ICM) who were matched using a propensity score-based model. Between April 2017 and October 2019, 1224 patients were included in our CMR registry, among them 141 with ICM and 77 with DCM. Propensity score matching was used to pair patients based on their indexed end-diastolic volume (EDVi), ejection fraction (EF), and septal T1 relaxation time (psmatch2 module L Feature tracking provided six parameters for global longitudinal, circumferential, and radial strain with corresponding strain rates in each group. Strain parameters were compared between matched pairs of ICM and DCM patients using paired t tests. Propensity score matching yielded 72 patients in each group (DCM mean age 58.6 ± 11.6 years, 15 females; ICM mean age 62.6 ± 13.2 years, 11 females, p = 0.084 and 0.44 respectively; LV-EF 32.2 ± 13.5% vs. 33.8 ± 12.1%, p = 0.356; EDVi 127.2 ± 30.7 ml/m2 vs. 121.1 ± 41.8 ml/m2, p = 0.251; native T1 values 1165 ± 58 ms vs. 1167 ± 70 ms, p = 0.862). There was no difference in global longitudinal strain between DCM and ICM patients (- 10.9 ± 5.5% vs. - 11.2 ± 4.7%, p = 0.72), whereas in DCM patients there was a significant reduction in global circumferential strain (- 10.0 ± 4.5% vs. - 12.2 ± 4.7%, p = 0.002) and radial strain (17.1 ± 8.51 vs. 21.2 ± 9.7%, p = 0.039). Our data suggest that ICM and DCM patients have inherently different myocardial mechanics, even if phenotypes are similar. Our data show that GCS is significantly more impaired in DCM patients. This feature may help in more thoroughly characterizing cardiomyopathy patients.

Beyond Ejection Fraction: Novel Clinical Approaches Towards Sudden Cardiac Death Risk Stratification in Patients with Dilated Cardiomyopathy

Implantable Cardioverter-Defibrillator (ICD) therapy is indicated for patients at risk for sudden cardiac death due to ventricular tachyarrhythmia. The most commonly used risk stratification algorithms use Left Ventricular Ejection Fraction (LVEF) to determine which patients qualify for ICD therapy, even though LVEF is a better marker of total mortality than ventricular tachyarrhythmias mortality. This review evaluates imaging tools and novel biomarkers proposed for better risk stratifying arrhythmic substrate, thereby identifying optimal ICD therapy candidates.

Myocardial mechanics in dilated cardiomyopathy: prognostic value of left ventricular torsion and strain

BACKGROUND

Data on the prognostic value of left ventricular (LV) morphological and functional parameters including LV rotation in patients with dilated cardiomyopathy (DCM) using cardiovascular magnetic resonance (CMR) are currently scarce. In this study, we assessed the prognostic value of global longitudinal strain (GLS), global circumferential strain (GCS), global radial strain (GRS) and LV torsion using CMR feature tracking (FT).

METHODS

CMR was performed in 350 DCM patients and 70 healthy subjects across 5 different European CMR Centers. Myocardial strain parameters were retrospectively assessed from conventional balanced steady-state free precession cine images applying FT. A combined primary endpoint (cardiac death, heart transplantation, aborted sudden cardiac death) was defined for the assessment of clinical outcome.

RESULTS

GLS, GCS, GRS and LV torsion were significantly lower in DCM patients than in healthy subjects (all p < 0.001). The primary endpoint occurred in 59 (18.7%) patients [median follow-up 4.2 (2.0-5.6) years]. In the univariate analyses all strain parameters showed a significant prognostic value (p < 0.05). In the multivariate model, LV strain parameters, particularly GLS provided an incremental prognostic value compared to established CMR parameters like LV ejection fraction and late gadolinium enhancement. A scoring model including six categorical variables of standard CMR and strain parameters differentiated further risk subgroups.

CONCLUSION

LV strain assessed with CMR FT has a high prognostic value in patients with DCM, surpassing routine and dedicated functional parameters. Thus, CMR strain imaging may contribute to the improvement of risk stratification in DCM.

CMR-Based Risk Stratification of Sudden Cardiac Death and Use of Implantable Cardioverter-Defibrillator in Non-Ischemic Cardiomyopathy

Non-ischemic cardiomyopathy (NICM) is one of the most important entities for arrhythmias and sudden cardiac death (SCD). Previous studies suggest a lower benefit of implantable cardioverter–defibrillator (ICD) therapy in patients with NICM as compared to ischemic cardiomyopathy (ICM). Nevertheless, current guidelines do not differentiate between the two subgroups in recommending ICD implantation. Hence, risk stratification is required to determine the subgroup of patients with NICM who will likely benefit from ICD therapy. Various predictors have been proposed, among others genetic mutations, left-ventricular ejection fraction (LVEF), left-ventricular end-diastolic volume (LVEDD), and T-wave alternans (TWA). In addition to these parameters, cardiovascular magnetic resonance imaging (CMR) has the potential to further improve risk stratification. CMR allows the comprehensive analysis of cardiac function and myocardial tissue composition. A range of CMR parameters have been associated with SCD. Applicable examples include late gadolinium enhancement (LGE), T1 relaxation times, and myocardial strain. This review evaluates the epidemiological aspects of SCD in NICM, the role of CMR for risk stratification, and resulting indications for ICD implantation.

Multivendor comparison of global and regional 2D cardiovascular magnetic resonance feature tracking strains vs tissue tagging at 3T

BACKGROUND

Cardiovascular magnetic resonance (CMR) 2D feature tracking (FT) left ventricular (LV) myocardial strain has seen widespread use to characterize myocardial deformation. Yet, validation of CMR FT measurements remains scarce, particularly for regional strain. Therefore, we aimed to perform intervendor comparison of 3 different FT software against tagging.

METHODS

In 61 subjects (18 healthy subjects, 18 patients with chronic myocardial infarction, 15 with dilated cardiomyopathy, and 10 with LV hypertrophy due to hypertrophic cardiomyopathy or aortic stenosis) were prospectively compared global (G) and regional transmural peak-systolic Lagrangian longitudinal (LS), circumferential (CS) and radial strains (RS) by 3 FT software (cvi42, Segment, and Tomtec) among each other and with tagging at 3T. We also evaluated the ability of regional LS, CS, and RS by different FT software vs tagging to identify late gadolinium enhancement (LGE) in the 18 infarct patients.

RESULTS

GLS and GCS by all 3 software had an excellent agreement among each other (ICC = 0.94-0.98 for GLS and ICC = 0.96-0.98 for GCS respectively) and against tagging (ICC = 0.92-0.94 for GLS and ICC = 0.88-0.91 for GCS respectively), while GRS showed inconsistent agreement between vendors (ICC 0.10-0.81). For regional LS, the agreement was good (ICC = 0.68) between 2 vendors but less vs the 3rd (ICC 0.50-0.59) and moderate to poor (ICC 0.44-0.47) between all three FT software and tagging. Also, for regional CS agreement between 2 software was higher (ICC = 0.80) than against the 3rd (ICC = 0.58-0.60), and both better agreed with tagging (ICC = 0.70-0.72) than the 3rd (ICC = 0.57). Regional RS had more variation in the agreement between methods ranging from good (ICC = 0.75) to poor (ICC = 0.05). Finally, the accuracy of scar detection by regional strains differed among the 3 FT software. While the accuracy of regional LS was similar, CS by one software was less accurate (AUC 0.68) than tagging (AUC 0.80, p < 0.006) and RS less accurate (AUC 0.578) than the other two (AUC 0.76 and 0.73, p < 0.02) to discriminate segments with LGE.

CONCLUSIONS

We confirm good agreement of CMR FT and little intervendor difference for GLS and GCS evaluation, with variable agreement for GRS. For regional strain evaluation, intervendor difference was larger, especially for RS, and the diagnostic performance varied more substantially among different vendors for regional strain analysis.

Quantification of Myocardial Deformation Applying CMR-Feature-Tracking-All About the Left Ventricle?

Purpose of Review

Cardiac magnetic resonance-feature-tracking (CMR-FT)-based deformation analyses are key tools of cardiovascular imaging and applications in heart failure (HF) diagnostics are expanding. In this review, we outline the current range of application with diagnostic and prognostic implications and provide perspectives on future trends of this technique.

Recent Findings

By applying CMR-FT in different cardiovascular diseases, increasing evidence proves CMR-FT-derived parameters as powerful diagnostic and prognostic imaging biomarkers within the HF continuum partly outperforming traditional clinical values like left ventricular ejection fraction. Importantly, HF diagnostics and deformation analyses by CMR-FT are feasible far beyond sole left ventricular performance evaluation underlining the holistic nature and accuracy of this imaging approach.

Summary

As an established and continuously evolving technique with strong prognostic implications, CMR-FT deformation analyses enable comprehensive cardiac performance quantification of all cardiac chambers.

Strain parameters for predicting the prognosis of non-ischemic dilated cardiomyopathy using cardiovascular magnetic resonance tissue feature tracking

BACKGROUND

A considerable number of non-ischemic dilated cardiomyopathy (NDCM) patients had been found to have normalized left ventricular (LV) size and systolic function with tailored medical treatments. Accordingly, we aimed to evaluate if strain parameters assessed by cardiovascular magnetic resonance (CMR) feature tracking (FT) analysis could predict the NDCM recovery.

METHODS

79 newly diagnosed NDCM patients who underwent baseline and follow-up CMR scans were enrolled. Recovery was defined as a current normalized LV size and systolic function evaluated by CMR.

RESULTS

Among 79 patients, 21 (27%) were confirmed recovered at a median follow-up of 36 months. Recovered patients presented with faster heart rates (HR) and larger body surface area (BSA) at baseline (P < 0.05). Compared to unrecovered patients, recovered pateints had a higher LV apical radial strain divided by basal radial strain (RSapi/bas) and a lower standard deviation of time to peak radial strain in 16 segments of the LV (SD16-TTPRS). According to a multivariate logistic regression model, RSapi/bas (P = 0.035) and SD16-TTPRS (P = 0.012) resulted as significant predictors for differentiation of recovered from unrecovered patients. The sensitivity and specificity of RSapi/bas and SD16-TTPRS for predicting recovered conditions were 76%, 67%, and 91%, 59%, with the area under the curve of 0.75 and 0.76, respectively. Further, Kaplan Meier survival analysis showed that patients with RSapi/bas ≥ 0.95% and SD16-FTPRS ≤ 111 ms had the highest recovery rate (65%, P = 0.027).

CONCLUSIONS

RSapi/bas and CMR SD16-TTPRS may be used as non-invasive parameters for predicting LV recovery in NDCM. This finding may be beneficial for subsequent treatments and prognosis of NDCM patients. Registration number: ChiCTR-POC-17012586.

Prognostic Value of Feature-Tracking Circumferential Strain in Dilated Cardiomyopathy Patients with Severely Reduced Ejection Fraction Incremental to Late Gadolinium Enhancement

Myocardial fiber deformation measurements have been reported to be associated with adverse outcomes in patients with acute heart failure and those with myocardial infarction. However, few studies have addressed the prognostic value of global circumferential strain (GCS) in dilated cardiomyopathy (DCM) patients with severely impaired systolic function. This study aimed to evaluate the prognostic value of cardiac magnetic resonance (CMR)-derived GCS in DCM patients with severely reduced ejection. Consecutive DCM patients with severely reduced ejection fraction (EF <35%) who underwent CMR were included. GCS was calculated from CMR cine images. The clinical endpoint was a composite of all-cause mortality, heart transplantation, implantable cardioverter defibrillator (ICD) implantation and aborted sudden cardiac death (SCD). A total of 129 patients with a mean EF of 15.33% (11.36%-22.27%) were included. During a median follow-up of 518 days, endpoint events occurred in 50 patients. Patients with GCS ≥ the median (-5.17%) had significantly reduced event-free survival as compared with those with GCS < the median (P<0.01). GCS was independently associated with adverse events after adjusting for clinical and imaging risk factors including extent of late gadolinium enhancement (LGE) (P<0.05). Adding GCS into the model including the extent of LGE resulted in significant improvements in the C-statistic (from 0.706 to 0.742; P<0.05) with a continuous net reclassification improvement (NRI) of 29.71%. It was concluded that GCS derived from CMR could be useful for risk stratification in DCM patients with severely reduced EF, which may increase common imaging risk factors including LGE.

Predicting outcome in children with dilated cardiomyopathy: the use of repeated measurements of risk factors for outcome

Aims

We aimed to determine whether in children with dilated cardiomyopathy repeated measurement of known risk factors for death or heart transplantation (HTx) during disease progression can identify children at the highest risk for adverse outcome.

Methods and results

Of 137 children we included in a prospective cohort, 36 (26%) reached the study endpoint (SE: all‐cause death or HTx), 15 (11%) died at a median of 0.09 years [inter‐quartile range (IQR) 0.03–0.7] after diagnosis, and 21 (15%) underwent HTx at a median of 2.9 years [IQR 0.8–6.1] after diagnosis. Median follow‐up was 2.1 years [IQR 0.8–4.3]. Twenty‐three children recovered at a median of 0.6 years [IQR 0.5–1.4] after diagnosis, and 78 children had ongoing disease at the end of the study. Children who reached the SE could be distinguished from those who did not, based on the temporal evolution of four risk factors: stunting of length growth (−0.42 vs. −0.02 length Z‐score per year, P < 0.001), less decrease in N‐terminal pro‐B‐type natriuretic peptide (NT‐proBNP) (−0.26 vs. −1.06 2log pg/mL/year, P < 0.01), no decrease in left ventricular internal diastolic dimension (LVIDd; 0.24 vs. −0.60 Boston Z‐score per year, P < 0.01), and increase in New York University Pediatric Heart Failure Index (NYU PHFI; 0.49 vs. −1.16 per year, P < 0.001). When we compared children who reached the SE with those with ongoing disease (leaving out the children who recovered), we found similar results, although the effects were smaller. In univariate analysis, NT‐proBNP, length Z‐score, LVIDd Z‐score, global longitudinal strain (%), NYU PHFI, and age >6 years at presentation (all P < 0.001) were predictive of adverse outcome. In multivariate analysis, NT‐proBNP appeared the only independent predictor for adverse outcome, a two‐fold higher NT‐proBNP was associated with a 2.8 times higher risk of the SE (hazard ratio 2.78, 95% confidence interval 1.81–3.94, P < 0.001).

Conclusions

The evolution over time of NT‐proBNP, LVIDd, length growth, and NYU PHFI identified a subgroup of children with dilated cardiomyopathy at high risk for adverse outcome. In this sample, with a limited number of endpoints, NT‐proBNP was the strongest independent predictor for adverse outcome.

Age- and gender-related reference values of cardiac morphology and function in cardiovascular magnetic resonance

Cardiovascular magnetic resonance (CMR) is the reference standard for the quantitative assessment of cardiac morphology and function. The aim of the study was to determine age- and gender-related reference values for cardiac morphology and function according to current recommendations. 454 healthy volunteers (235 men, median age 52.0 (44.0-59.0) years) underwent a standard CMR scan and were divided into six groups of nearly equal size with regard to sex (male, female) and age (21-47 years, 48-57 years, 58-84 years). Left ventricular end-diastolic (LV-EDV) and end-systolic (LV-ESV) volumes and LV mass (LV-M) were measured at end-diastole and end-systole in steady-state free precession series with including papillary muscles and trabecular tissue in the LV-M. Absolute and indexed volumetric parameters were significantly different between gender groups with higher values in men compared to women (all p < 0.001). Furthermore, a significant age-dependent decline could be observed for left ventricular and right ventricular volumes (all p < 0.001), while LV-M did not show differences between the different age-groups. Parameters of longitudinal function for the left and right ventricle were higher in female compared to male subjects with a significant age-dependent decline. We provided normal values for cardiac volumes, function, and mass derived in accordance with current guidelines from a large population of healthy subjects, which can be implemented in clinical routine as a standard of reference.

Exercise Stress Real-Time Cardiac Magnetic Resonance Imaging for Noninvasive Characterization of Heart Failure With Preserved Ejection Fraction: The HFpEF-Stress Trial

BACKGROUND

Right heart catheterization using exercise stress is the reference standard for the diagnosis of heart failure with preserved ejection fraction (HFpEF) but carries the risk of the invasive procedure. We hypothesized that real-time cardiac magnetic resonance (RT-CMR) exercise imaging with pathophysiologic data at excellent temporal and spatial resolution may represent a contemporary noninvasive alternative for diagnosing HFpEF.

METHODS

The HFpEF-Stress trial (CMR Exercise Stress Testing in HFpEF; URL: https://www.clinicaltrials.gov; Unique identifier: NCT03260621. URL: https://dzhk.de/; Unique identifier: DZHK-17) prospectively recruited 75 patients with echocardiographic signs of diastolic dysfunction and dyspnea on exertion (E/e'>8, New York Heart Association class ≥II) to undergo echocardiography, right heart catheterization, and RT-CMR at rest and during exercise stress. HFpEF was defined according to pulmonary capillary wedge pressure (≥15 mm Hg at rest or ≥25 mm Hg during exercise stress). RT-CMR functional assessments included time-volume curves for total and early (1/3) diastolic left ventricular filling, left atrial (LA) emptying, and left ventricular/LA long axis strain.

RESULTS

Patients with HFpEF (n=34; median pulmonary capillary wedge pressure at rest, 13 mm Hg; at stress, 27 mm Hg) had higher E/e' (12.5 versus 9.15), NT-proBNP (N-terminal pro-B-type natriuretic peptide; 255 versus 75 ng/L), and LA volume index (43.8 versus 36.2 mL/m²) compared with patients with noncardiac dyspnea (n=34; rest, 8 mm Hg; stress, 18 mm Hg; P≤0.001 for all). Seven patients were excluded because of the presence of non-HFpEF cardiac disease causing dyspnea on imaging. There were no differences in RT-CMR left ventricular total and early diastolic filling at rest and during exercise stress (P≥0.164) between patients with HFpEF and noncardiac dyspnea. RT-CMR revealed significantly impaired LA total and early (P<0.001) diastolic emptying in patients with HFpEF during exercise stress. RT-CMR exercise stress LA long axis strain was independently associated with HFpEF (adjusted odds ratio, 0.657 [95% CI, 0.516-0.838]; P=0.001) after adjustment for clinical and imaging measures and emerged as the best predictor for HFpEF (area under the curve at rest 0.82 versus exercise stress 0.93; P=0.029).

CONCLUSIONS

RT-CMR allows highly accurate identification of HFpEF during physiologic exercise and qualifies as a suitable noninvasive diagnostic alternative. These results will need to be confirmed in multicenter prospective research studies to establish widespread routine clinical use. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03260621. URL: https://dzhk.de/; Unique identifier: DZHK-17.

Emerging Techniques for Risk Stratification in Nonischemic Dilated Cardiomyopathy: JACC Review Topic of the Week

Dilated cardiomyopathy (DCM) is a common condition, which carries significant mortality from sudden cardiac death and pump failure. Left ventricular ejection fraction has conventionally been used as a risk marker for sudden cardiac death, but has performed poorly in trials. There have been significant advances in the areas of cardiac magnetic resonance imaging and genetics, which are able to provide useful rick prediction in DCM. Biomarkers and cardiopulmonary exercise testing are well validated in the prediction of risk in heart failure; however, they have been tested less specifically in the DCM setting. This review will discuss these methods with a view toward multiparametric risk assessment in DCM with the hope of creating parametric risk models to predict sudden cardiac death and pump failure in the DCM population.

Effects of Levosimendan on cardiac function, size and strain in heart failure patients

Levosimendan improves cardiac function in heart failure populations; however, its exact mechanism is not well defined. We analysed the short-term impact of levosimendan in heart failure patients with ischemic and non-ischemic cardiomyopathy (CMP) using multiparametric cardiac magnetic resonance (CMR). We identified 33 patients with ischemic or non-ischemic CMP who received two consecutive CMR scans prior to and within one week after levosimendan administration. Changes in LV ejection fraction (LVEF) and LV volumes, as well as changes in strain rates, were measured prior to and within one week after levosimendan infusion. LV scarring, based on late gadolinium enhancement (LGE), was correlated to changes in LV size and strain rates. Both LV endiastolic (EDV) and endsystolic volumes (ESV) significantly decreased (EDV: p=0,001; ESV: p=0,002) after levosimendan administration, with no significant impact on LVEF (p=0.41), cardiac output (p=0.61), and strain rates. Subgroup analyses of ischemic or non-ischemic CMP showed no significant differences between the groups in terms of short-term LV reverse remodeling. The presence and extent of scarring in LGE did not correlate with changes in LV size and strain rates. CMR is able to monitor cardiac effects of levosimendan infusion. Short-term follow-up of a single levosimendan infusion using CMR shows a significant decrease in LV size, but no impact on LVEF or strain measurements. There was no difference between patients with ischemic or non-ischemic CMP. Quantification of LV scarring in CMR is not able to predict changes in LV size and strain rates in response to levosimendan.

Prognostic value of multiple cardiac magnetic resonance imaging parameters in patients with idiopathic dilated cardiomyopathy

PURPOSE

Our study aimed to comprehensively explore efficient prognostic indicators in idiopathic dilated cardiomyopathy (IDCM) patients with reduced left ventricular ejection fraction (LVEF<40%).

BACKGROUND

Prognostic value of cardiac magnetic resonance(CMR) parameters for IDCM have been inconsistent.

METHODS

126 IDCM patients with reduced LVEF (<40%) were retrospectively enrolled. Cardiac function parameters, myocardial strain indices and myocardial fibrosis were evaluated. Laboratory data also were analyzed. The endpoint was a combination of major adverse cardiac events (MACEs), including cardiac death, heart transplantation, and rehospitalization. Prognostic value was evaluated by the Kaplan-Meier method and Cox regression.

RESULTS

During a median follow-up of 31 months, 44 patients experienced MACEs, including 9 deaths, 1 heart transplantation, and 34 rehospitalizations due to heart failure. Univariate and multivariate Cox analyses showed that cardiac function and myocardial strain indexes were not associated with the prognosis of IDCM (all p>0.05). NT-proBNP (HR 1.5, 95%CI: 1.053 to 2.137), Late‑gadolinium enhancement(LGE) mass (HR 1.022, 95%CI: 1.005 to 1.038), and LGE mass/left ventricle mass were significant predictors (HR 1.027, 95%CI: 1.007 to 1.046) for MACEs, all p < 0.05. Besides, poorest prognosis was observed in IDCM patients with positive LGE combined with NT-proBNP (log-rank = 27.261, p ≤ 0.001).

CONCLUSION

NT-proBNP and extent of LGE were reliable predictors in IDCM patients with reduced LVEF. Additionally, presence of LGE combined with NT-proBNP showed the strongest prognostic value in IDCM with reduced LVEF. Myocardial strain parameters seemed to have no prognostic value in IDCM patients with reduced LVEF.

Left ventricular strain and fibrosis in adults with repaired tetralogy of Fallot: A case-control study

BACKGROUND

Left ventricular (LV) systolic dysfunction and myocardial fibrosis have prognostic implications in repaired tetralogy of Fallot (rTOF), but their relationship with myocardial strain is not well understood. We evaluated systolic strain and fibrosis (extracellular volume fraction, ECV) of the left ventricle (LV) using feature tracking with magnetic resonance and determine their association with each other and clinical outcome.

METHOD

Adults with rTOF and age-matched controls underwent CMR to measure LV-ECV. Feature-tracking was used to quantify radial, circumferential, and longitudinal strain in both 2 and 3 dimensions. Clinical events (death, arrhythmia and heart-failure hospitalization) were obtained through chart review. Associations between strain, ECV and clinical events were explored.

RESULTS

48 rTOF subjects (age 40.5 ± 14.3, 42% female) and 20 healthy controls were included. Both LV 2D and 3D global circumferential strain (GCS) and global longitudinal strain (GLS) were lower in rTOF subjects (p ≤0.01 for all). There was no association between strain and LV-ECV. Strain parameters correlated with ventricular volumes and function. After a median follow-up of 8.5 years (range 1-10.9 years) there were 5 deaths, 6 hospitalizations and 9 new arrhythmias. By multivariate Cox-regression, GLS was an independent predictor of both hospitalization and death, whereas LV-ECV was an independent predictor of arrhythmia.

CONCLUSION

While both LV strain abnormalities and fibrosis are present in rTOF, they are associated with different types of clinical outcome, and not to each other. The findings suggest that these measures reflect different long-term adverse adaptations to abnormal hemodynamics.

Updating the Risk Stratification for Sudden Cardiac Death in Cardiomyopathies: The Evolving Role of Cardiac Magnetic Resonance Imaging. An Approach for the Electrophysiologist

The prevention of sudden cardiac death (SCD) in cardiomyopathies (CM) remains a challenge. The current guidelines still favor the implantation of devices for the primary prevention of SCD only in patients with severely reduced left ventricular ejection fraction (LVEF) and heart failure (HF) symptoms. The implantation of an implantable cardioverter-defibrillator (ICD) is a protective barrier against arrhythmic events in CMs, but the benefit does not outweigh the cost in low risk patients. The identification of high risk patients is the key to an individualized prevention strategy. Cardiac magnetic resonance (CMR) provides reliable and reproducible information about biventricular function and tissue characterization. Furthermore, late gadolinium enhancement (LGE) quantification and pattern of distribution, as well as abnormal T1 mapping and extracellular volume (ECV), representing indices of diffuse fibrosis, can enhance our ability to detect high risk patients. CMR can also complement electro-anatomical mapping (EAM), a technique already applied in the risk evaluation and in the ventricular arrhythmias ablation therapy of CM patients, providing a more accurate assessment of fibrosis and arrhythmic corridors. As a result, CMR provides a new insight into the pathological substrate of CM. CMR may help identify high risk CM patients and, combined with EAM, can provide an integrated evaluation of scar and arrhythmic corridors in the ablative therapy of ventricular arrhythmias.

The combined effects of cardiac geometry, microcirculation, and tissue characteristics on cardiac systolic and diastolic function in subclinical diabetes mellitus-related cardiomyopathy

BACKGROUND

Diabetes mellitus-related cardiomyopathy has recently been described as a distinct progression of left ventricular (LV) systolic and diastolic dysfunction. Pathological changes in the myocardium may explain the development of two different phenotypes. We evaluated the effects of LV geometry, myocardial microcirculation, and tissue characteristics on cardiac deformation in patients with subclinical type 2 diabetes mellitus (T2DM) utilizing multiparametric cardiac magnetic resonance (CMR) imaging.

METHODS

A total of 135 T2DM patients and 55 matched controls were prospectively enrolled and performed multiparametric CMR examination. CMR-derived parameters including cardiac geometry, function, microvascular perfusion, T1 mapping, T2 mapping, and strain were analyzed and compared between T2DM patients and controls.

RESULTS

The univariable and multivariable analysis of systolic and diastolic function revealed that longer duration of diabetes was associated with decreased longitudinal peak systolic strain rate (PSSR-L) (β = 0.195, p = .013), and higher remodeling index and higher extracellular volume (ECV) tended to correlate with decreased longitudinal peak diastolic strain rate (PDSR-L) (remodeling index, β = -0.339, p = .000; ECV, β = -0.172, p = .026), whereas microvascular perfusion index and T2 value affected both PSSR-L (perfusion index, β = -0.328, p = .000; T2 value, β = 0.306, p = .000) and PDSR-L (perfusion index, β = 0.209, p = .004; T2 value, β = -0.275, p = .000) simultaneously.

CONCLUSIONS

The LV concentric remodeling and myocardial fibrosis correlated with diastolic function, and perfusion function and myocardial edema were associated with both LV systolic and diastolic function.

Left Ventricular Geometry and Replacement Fibrosis Detected by cMRI Are Associated with Major Adverse Cardiovascular Events in Nonischemic Dilated Cardiomyopathy

To investigate the relationship between left ventricular (LV) long-axis strain (LAS) and LV sphericity index (LVSI) and outcomes in patients with nonischemic dilated cardiomyopathy (NIDCM) and myocardial replacement fibrosis confirmed by late gadolinium enhancement (LGE) using cardiac magnetic resonance imaging (cMRI), we conducted a prospective study on 178 patients (48 ± 14.4 years; 25.2% women) with first NIDCM diagnosis. The evaluation protocol included ECG monitoring, echocardiography and cMRI. LAS and LVSI were cMRI-determined. Major adverse cardiovascular events (MACEs) were defined as a composite outcome including heart failure (HF), ventricular arrhythmias (VAs) and sudden cardiac death (SCD). After a median follow-up of 17 months, patients with LGE+ had increased risk of MACEs. Kaplan-Meier curves showed significantly higher rate of MACEs in patients with LGE+ (p < 0.001), increased LVSI (p < 0.01) and decreased LAS (p < 0.001). In Cox analysis, LAS (HR = 1.32, 95%CI (1.54–9.14), p = 0.001), LVSI [HR = 1.17, 95%CI (1.45–7.19), p < 0.01] and LGE+ (HR = 1.77, 95%CI (2.79–12.51), p < 0.0001) were independent predictors for MACEs. In a 4-point risk scoring system based on LV ejection fraction (LVEF) < 30%, LGE+, LAS > −7.8% and LVSI > 0.48%, patients with 3 and 4 points had a significantly higher risk for MACEs. LAS and LVSI are independent predictors of MACEs and provide incremental value beyond LVEF and LGE+ in patients with NIDCM and myocardial fibrosis.

The application of exercise stress cardiovascular magnetic resonance in patients with suspected dilated cardiomyopathy

OBJECTIVES

The imaging features of dilated cardiomyopathy (DCM) overlap with physiological exercise-induced cardiac remodeling in active and otherwise healthy individuals. Distinguishing the two conditions is challenging. This study examined the diagnostic and prognostic roles of exercise stress imaging in asymptomatic patients with suspected DCM.

METHODS

Exercise stress cardiovascular magnetic resonance (CMR) was performed in 60 asymptomatic patients with suspected DCM (dilated left ventricle and/or impaired systolic function on CMR), who also underwent DNA sequencing for DCM-causing genetic variants. Confirmed DCM was defined as genotype- and phenotype-positive (G+P+). Another 100 healthy subjects were recruited to establish normal exercise capacities (peak exercise cardiac index; PeakCI). The primary outcome was a composite of all-cause mortality, cardiac decompensation and ventricular arrhythmic events.

RESULTS

No patients with confirmed G+P+ DCM had PeakCI exceeding the 35th percentile specific for age and sex. Applying this threshold in G-P+ patients, those with PeakCI below 35th percentile had characteristics similar to confirmed DCM while patients with higher PeakCI were younger, more active and higher longitudinal strain. Adverse cardiovascular events occurred only in patients with low exercise capacity (P = 0.004).

CONCLUSIONS

In individuals with suspected DCM, exercise stress CMR demonstrates diagnostic and prognostic potential in distinguishing between pathological DCM and physiological exercise-induced cardiac remodeling.

Left Ventricular Strain and Rotation in Patients with Dilated Cardiomyopathy and Severe Systolic Dysfunction

INTRODUCTION

In dilated cardiomyopathy (DCM) left ventricular (LV) strain and twist are significantly decreased. However, the rate of attenuation has not been investigated well in patients with varying degrees of systolic dysfunction.

AIM

The present study aimed to investigate the relationship between LV deformational and rotational mechanics and conventional and tissue Doppler imaging (TDI) parameters, and to search for a constellation of findings distinguishing patients with severe systolic dysfunction (SSD) in DCM.

METHODS

Fifty-two patients with heart failure NYHA class III-IV and ejection fraction (EF) ≤45% were prospectively enrolled (mean age 61.8 ± 13.4 years; 36 males, 69%). Severe systolic LV dysfunction was considered as EF <30%. Echocardiography with 2D-speckle tracking analysis was performed.

RESULTS

The relationships of global longitudinal strain (GLS) with EF, circumferential strain at mid-level (CSmid), and systolic medial mitral annulus velocity were strong (r = -0.53, 0.67, and -0.56, respectively, p < 0.0001 for all). A good correlation was found between CSmid and EF (r = -0.50, p < 0.0001). There were weak correlations between basal endocardial rotation (BRendo) and EF and CSmid. Multiple regression analysis found GLS (p < 0.0001) and BRendo (p = 0.04) to be predictors of the change of EF. In ROC curve analysis, the cut-off values of GLS -7.2% (AUC 0.81, p < 0.0001), CSmid -7.5% (AUC 0.76, p = 0.002), and BRendo -2.43° (AUC 0.68, p = 0.03) identified SSD.

CONCLUSIONS

Parameters of LV mechanics were related to conventional and TDI systolic parameters in patients with DCM. The degree of alterations of LV longitudinal and circumferential deformation and basal rotation may identify patients with SSD and a higher risk, and may help in therapeutic decision making.

Prognostic value of novel imaging parameters derived from standard cardiovascular magnetic resonance in high risk patients with systemic light chain amyloidosis

BACKGROUND

The differentiated assessment of functional parameters besides morphological changes is essential for the evaluation of prognosis in systemic immunoglobulin light chain (AL) amyloidosis.

METHODS

Seventy-four subjects with AL amyloidosis and presence of late gadolinium enhancement (LGE) pattern typical for cardiac amyloidosis were analyzed. Long axis strain (LAS) and myocardial contraction fraction (MCF), as well as morphological and functional markers, were measured. The primary endpoint was death, while death and heart transplantation served as a composite secondary endpoint.

RESULTS

After a median follow-up of 41 months, 29 out of 74 patients died and 10 received a heart transplant. Left ventricular (LV) functional parameters were reduced in patients, who met the composite endpoint (LV ejection fraction 51% vs. 61%, LAS - 6.9% vs - 10%, GLS - 12% vs - 15% and MCF 42% vs. 69%; p <  0.001 for all). In unadjusted univariate analysis, LAS (HR = 1.05, p <  0.001) and MCF (HR = 0.96, p <  0.001) were associated with reduced transplant-free survival. Kaplan-Meier analyses showed a significantly lower event-free survival in patients with reduced MCF. MCF and LAS performed best to identify high risk patients for secondary endpoint (Log-rank test p <  0.001) in a combined model. Using sequential Cox regression analysis, the addition of LAS and MCF to LV ejection fraction led to a significant increase in the predictive power of the model (χ2 (df = 1) = 28.2, p <  0.001).

CONCLUSIONS

LAS and MCF as routinely available and robust CMR-derived parameters predict outcome in LGE positive AL amyloidosis. Patients with impaired LV function in combination with reduced LAS and MCF are at the highest risk for death and heart transplantation.

The prognostic value of biventricular long axis strain using standard cardiovascular magnetic resonance imaging in patients with hypertrophic cardiomyopathy

BACKGROUND

Long axis strain (LAS) is a parameter derived from standard cardiovascular magnetic resonance imaging. However, the prognostic value of biventricular LAS in hypertrophic cardiomyopathy (HCM) is unknown.

METHODS

Patients with HCM (n = 384) and healthy volunteers (n = 150) were included in the study. Left ventricular (LV)-LAS was defined as the percentage change in the length measured from the epicardial border of the LV apex to the midpoint of a line connecting the mitral annulus at end-systole and end-diastole. Right ventricular (RV)-LAS represented the percentage change of length between epicardial border of the LV apex to the midpoint of a line connecting the tricuspid annulus at end-systole and end-diastole. The primary endpoint was a combination of all-cause death and sudden cardiac death aborted by appropriate implantable cardioverter-defibrillator discharge and cardiopulmonary resuscitation after syncope. The secondary endpoint was a combination of the primary endpoint and hospitalization for congestive heart failure.

RESULTS

Twenty-nine patients (7.6%) achieved the primary endpoint, and the secondary endpoint occurred in 66 (17.2%) patients. In multivariate Cox regression analysis, RV-LAS was an independent prognostic factor for the primary (hazard ratio (HR), 1.13) and secondary (HR, 1.11) endpoints. In the subgroup of patients with a normal RV ejection fraction (EF) (>45.0%, n = 345), impaired RV-LAS was associated with adverse outcomes and might add incremental prognostic value to RVEF and tricuspid annular plane systolic excursion (TAPSE) (p < 0.01).

CONCLUSIONS

RV-LAS is an independent predictor of adverse prognosis in HCM in addition to RVEF and TAPSE.

The feasibility of a novel limited field of view spiral cine DENSE sequence to assess myocardial strain in dilated cardiomyopathy

Objective

Develop an accelerated cine displacement encoding with stimulated echoes (DENSE) cardiovascular magnetic resonance (CMR) sequence to enable clinically feasible myocardial strain evaluation in patients with dilated cardiomyopathy (DCM).

Materials and methods

A spiral cine DENSE sequence was modified by limiting the field of view in two dimensions using in-plane slice-selective pulses in the stimulated echo. This reduced breath hold duration from 20RR to 14RR intervals. Following phantom and pilot studies, the feasibility of the sequence to assess peak radial, circumferential, and longitudinal strain was tested in control subjects (n = 18) and then applied in DCM patients (n = 29).

Results

DENSE acquisition was possible in all participants. Elements of the data were not analysable in 1 control (6%) and 4 DCM r(14%) subjects due to off-resonance or susceptibility artefacts and low signal-to-noise ratio. Peak radial, circumferential, short-axis contour strain and longitudinal strain was reduced in DCM patients (p < 0.001 vs. controls) and strain measurements correlated with left ventricular ejection fraction (with circumferential strain r = − 0.79, p < 0.0001; with vertical long-axis strain r = − 0.76, p < 0.0001). All strain measurements had good inter-observer agreement (ICC > 0.80), except peak radial strain.

Discussion

We demonstrate the feasibility of CMR strain assessment in healthy controls and DCM patients using an accelerated cine DENSE technique. This may facilitate integration of strain assessment into routine CMR studies.

Electronic supplementary material

The online version of this article (10.1007/s10334-019-00735-5) contains supplementary material, which is available to authorized users.

Journal of Cardiovascular Magnetic Resonance 2017

There were 106 articles published in the Journal of Cardiovascular Magnetic Resonance (JCMR) in 2017, including 92 original research papers, 3 reviews, 9 technical notes, and 1 Position paper, 1 erratum and 1 correction. The volume was similar to 2016 despite an increase in manuscript submissions to 405 and thus reflects a slight decrease in the acceptance rate to 26.7%. The quality of the submissions continues to be high. The 2017 JCMR Impact Factor (which is published in June 2018) was minimally lower at 5.46 (vs. 5.71 for 2016; as published in June 2017), which is the second highest impact factor ever recorded for JCMR. The 2017 impact factor means that an average, each JCMR paper that were published in 2015 and 2016 was cited 5.46 times in 2017.In accordance with Open-Access publishing of Biomed Central, the JCMR articles are published on-line in continuus fashion and in the chronologic order of acceptance, with no collating of the articles into sections or special thematic issues. For this reason, over the years, the Editors have felt that it is useful to annually summarize the publications into broad areas of interest or theme, so that readers can view areas of interest in a single article in relation to each other and other contemporary JCMR articles. In this publication, the manuscripts are presented in broad themes and set in context with related literature and previously published JCMR papers to guide continuity of thought within the journal. In addition, I have elected to use this format to convey information regarding the editorial process to the readership.I hope that you find the open-access system increases wider reading and citation of your papers, and that you will continue to send your very best, high quality manuscripts to JCMR for consideration. I thank our very dedicated Associate Editors, Guest Editors, and Reviewers for their efforts to ensure that the review process occurs in a timely and responsible manner and that the JCMR continues to be recognized as the forefront journal of our field. And finally, I thank you for entrusting me with the editorship of the JCMR as I begin my 3rd year as your editor-in-chief. It has been a tremendous learning experience for me and the opportunity to review manuscripts that reflect the best in our field remains a great joy and highlight of my week!

Clinical applications of feature-tracking cardiac magnetic resonance imaging

Cardiovascular diseases represent the leading cause of mortality and morbidity in the western world. Assessment of cardiac function is pivotal for early diagnosis of primitive myocardial disorders, identification of cardiac involvement in systemic diseases, detection of drug-related cardiac toxicity as well as risk stratification and monitor of treatment effects in patients with heart failure of various etiology. Determination of ejection fraction with different imaging modalities currently represents the gold standard for evaluation of cardiac function. However, in the last few years, cardiovascular magnetic resonance feature tracking techniques has emerged as a more accurate tool for quantitative evaluation of cardiovascular function with several parameters including strain, strain-rate, torsion and mechanical dispersion. This imaging modality allows precise quantification of ventricular and atrial mechanics by directly evaluating myocardial fiber deformation. The purpose of this article is to review the basic principles, current clinical applications and future perspectives of cardiovascular magnetic resonance myocardial feature tracking, highlighting its prognostic implications.

Prognostic Implications of Mitral Annular Plane Systolic Excursion in Patients with Hypertension and a Clinical Indication for Cardiac Magnetic Resonance Imaging: A Multicenter Study

OBJECTIVES

This study sought to evaluate the prognostic value of cardiac magnetic resonance (CMR)-derived mitral annular plane systolic excursion (MAPSE) in a large multicenter population of patients with hypertension.

BACKGROUND

In patients with hypertension, cardiac abnormalities are powerful predictors of adverse outcomes. Long-axis mitral annular movement plays a fundamental role in cardiac mechanics and is an early marker for a number of pathological processes. Given the adverse consequences of cardiac involvement in hypertension, the authors hypothesized that lateral MAPSE may provide incremental prognostic information in these patients.

METHODS

Consecutive patients with hypertension and a clinical indication for CMR at 4 U.S. medical centers were included in this study (n = 1,735). Lateral MAPSE was measured in the 4-chamber cine view. The primary endpoint was all-cause death. Cox proportional hazards regression modeling was used to examine the association between lateral MAPSE and death. The incremental prognostic value of lateral MAPSE was assessed in nested models.

RESULTS

Over a median follow-up period of 5.1 years, 235 patients died. By Kaplan-Meier analysis, risk of death was significantly higher in patients with a lateral MAPSE < median (10 mm) (log-rank; p < 0.0001). Lateral MAPSE was associated with risk of death after adjustment for clinical and imaging risk factors (hazard ratio [HR]: 1.402-per-millimeter decrease; p < 0.001). Addition of lateral MAPSE in this model resulted in significant improvement in the C-statistic (0.735 to 0.815; p < 0.0001). Continuous net reclassification improvement was 0.739 (95% confidence interval: 0.601 to 0.902). Lateral MAPSE remained significantly associated with death even after adjustment for feature tracking global longitudinal strain (HR: 1.192-per-millimeter decrease; p < 0.001). Lateral MAPSE was independently associated with death among the subgroups of patients with preserved ejection fraction (HR = 1.339; p < 0.001) and in those without history of myocardial infarction (HR: 1.390; p < 0.001).

CONCLUSIONS

CMR-derived lateral MAPSE is a powerful, independent predictor of mortality in patients with hypertension and a clinical indication for CMR, incremental to common clinical and CMR risk factors. These findings may suggest a role for CMR-derived lateral MAPSE in identifying hypertensive patients at highest risk of death.

What Is the Heart? Anatomy, Function, Pathophysiology, and Misconceptions

Cardiac dynamics are traditionally linked to a left ventricle, right ventricle, and septum morphology, a topography that differs from the heart's five-century-old anatomic description of containing a helix and circumferential wrap architectural configuration. Torrent Guasp's helical ventricular myocardial band (HVMB) defines this anatomy and its structure, and explains why the heart's six dynamic actions of narrowing, shortening, lengthening, widening, twisting, and uncoiling happen. The described structural findings will raise questions about deductions guiding "accepted cardiac mechanics", and their functional aspects will challenge and overturn them. These suppositions include the LV, RV, and septum description, timing of mitral valve opening, isovolumic relaxation period, reasons for torsion/twisting, untwisting, reasons for longitudinal and circumferential strain, echocardiographic sub segmentation, resynchronization, RV function dynamics, diastolic dysfunction's cause, and unrecognized septum impairment. Torrent Guasp's revolutionary contributions may alter future understanding of the diagnosis and treatment of cardiac disease.

Review of Journal of Cardiovascular Magnetic Resonance (JCMR) 2015-2016 and transition of the JCMR office to Boston

The Journal of Cardiovascular Magnetic Resonance (JCMR) is the official publication of the Society for Cardiovascular Magnetic Resonance (SCMR). In 2016, the JCMR published 93 manuscripts, including 80 research papers, 6 reviews, 5 technical notes, 1 protocol, and 1 case report. The number of manuscripts published was similar to 2015 though with a 12% increase in manuscript submissions to an all-time high of 369. This reflects a decrease in the overall acceptance rate to <25% (excluding solicited reviews). The quality of submissions to JCMR continues to be high. The 2016 JCMR Impact Factor (which is published in June 2016 by Thomson Reuters) was steady at 5.601 (vs. 5.71 for 2015; as published in June 2016), which is the second highest impact factor ever recorded for JCMR. The 2016 impact factor means that the JCMR papers that were published in 2014 and 2015 were on-average cited 5.71 times in 2016.In accordance with Open-Access publishing of Biomed Central, the JCMR articles are published on-line in the order that they are accepted with no collating of the articles into sections or special thematic issues. For this reason, over the years, the Editors have felt that it is useful to annually summarize the publications into broad areas of interest or themes, so that readers can view areas of interest in a single article in relation to each other and other recent JCMR articles. The papers are presented in broad themes with previously published JCMR papers to guide continuity of thought in the journal. In addition, I have elected to open this publication with information for the readership regarding the transition of the JCMR editorial office to the Beth Israel Deaconess Medical Center, Boston and the editorial process.Though there is an author publication charge (APC) associated with open-access to cover the publisher's expenses, this format provides a much wider distribution/availability of the author's work and greater manuscript citation. For SCMR members, there is a substantial discount in the APC. I hope that you will continue to send your high quality manuscripts to JCMR for consideration. Importantly, I also ask that you consider referencing recent JCMR publications in your submissions to the JCMR and elsewhere as these contribute to our impact factor. I also thank our dedicated Associate Editors, Guest Editors, and reviewers for their many efforts to ensure that the review process occurs in a timely and responsible manner and that the JCMR continues to be recognized as the leading publication in our field.

Sudden Cardiac Death in Genetic Cardiomyopathies

Sudden cardiac death (SCD) caused by ventricular arrhythmias is common in patients with genetic cardiomyopathies (CMs) including dilated CM, hypertrophic CM, and arrhythmogenic right ventricular CM (ARVC). Phenotypic features can identify individuals at high enough risk to warrant placement of an implantable cardioverter-defibrillator, although risk stratification schemes remain imperfect. Genetic testing is valuable for family cascade screening but with few exceptions (eg, LMNA mutations) do not identify higher risk for SCD. Although randomized trials are lacking, observational data suggest that ICDs can be beneficial. Vigorous exercise can exacerbate ARVC disease progression and increase likelihood of ventricular arrhythmias.

Influence of longitudinal position on the evolution of steady-state signal in cardiac cine balanced steady-state free precession imaging

Background

Emerging quantitative cardiac magnetic resonance imaging (CMRI) techniques use cine balanced steady-state free precession (bSSFP) to measure myocardial signal intensity and probe underlying physiological parameters. This correlation assumes that steady-state is maintained uniformly throughout the heart in space and time.

Purpose

To determine the effects of longitudinal cardiac motion and initial slice position on signal deviation in cine bSSFP imaging by comparing two-dimensional (2D) and three-dimensional (3D) acquisitions.

Material and Methods

Nine healthy volunteers completed cardiac MRI on a 1.5-T scanner. Short axis images were taken at six slice locations using both 2D and 3D cine bSSFP. 3D acquisitions spanned two slices above and below selected slice locations. Changes in myocardial signal intensity were measured across the cardiac cycle and compared to longitudinal shortening.

Results

For 2D cine bSSFP, 46% ± 9% of all frames and 84% ± 13% of end-diastolic frames remained within 10% of initial signal intensity. For 3D cine bSSFP the proportions increased to 87% ± 8% and 97% ± 5%. There was no correlation between longitudinal shortening and peak changes in myocardial signal. The initial slice position significantly impacted peak changes in signal intensity for 2D sequences (P < 0.001).

Conclusion

The initial longitudinal slice location significantly impacts the magnitude of deviation from steady-state in 2D cine bSSFP that is only restored at the center of a 3D excitation volume. During diastole, a transient steady-state is established similar to that achieved with 3D cine bSSFP regardless of slice location.

Left Ventricular Long-Axis Function Assessed with Cardiac Cine MR Imaging Is an Independent Predictor of All-Cause Mortality in Patients with Reduced Ejection Fraction: A Multicenter Study

Purpose To evaluate the prognostic value of a simple index of left ventricular (LV) long-axis function-lateral mitral annular plane systolic excursion (MAPSE)-in a large multicenter population of patients with reduced ejection fraction (EF) who were undergoing cardiac magnetic resonance (MR) imaging. Materials and Methods This retrospective study included 1040 consecutive patients (mean age, 59.5 years ± 15.8) at four U.S. medical centers who were undergoing cardiac MR imaging for assessment of LV dysfunction with EF less than 50%. Lateral MAPSE was measured in the four-chamber cine view. The primary end point was all-cause death. Cox proportional hazards regression modeling was used to examine the independent association between lateral MAPSE and death. The incremental prognostic value of lateral MAPSE was assessed in nested models. Results During a median follow-up of 4.4 years, 132 patients died. With Kaplan-Meier analysis, the risk of death increased significantly with decreasing tertiles of lateral MAPSE (log-rank P = .0001). Patients with relatively preserved lateral MAPSE (>9 mm) had very few deaths, regardless of whether their EF was above or below 35%. Patients with late gadolinium enhancement (LGE) and low lateral MAPSE had significantly reduced survival compared to those with LGE and high lateral MAPSE (log-rank P < .0001). Lateral MAPSE was independently associated with risk of death after adjustment for clinical and imaging risk factors, which were univariate predictors (age, body mass index, diabetes, LV end-diastolic volume index, LGE, EF) (hazard ratio = 2.051 per mm decrease; 95% confidence interval [CI]: 1.520, 2.768; P < .001). Inclusion of lateral MAPSE in this model resulted in significant improvement in model fit (likelihood ratio test P < .0001) and C statistic (increasing from 0.675 to 0.844; P < .0001). Continuous net reclassification improvement was 1.036 (95% CI: 0.878, 1.194). Conclusion Lateral MAPSE measured during routine cine cardiac MR imaging is a significant independent predictor of mortality in patients with LV dysfunction, incremental to common clinical and cardiac MR risk factors-including EF and LGE. ^© RSNA, 2017.

Diagnostic and Prognostic Value of Long-Axis Strain and Myocardial Contraction Fraction Using Standard Cardiovascular MR Imaging in Patients with Nonischemic Dilated Cardiomyopathies

Purpose To assess the utility of established functional markers versus two additional functional markers derived from standard cardiovascular magnetic resonance (MR) images for their incremental diagnostic and prognostic information in patients with nonischemic dilated cardiomyopathy (NIDCM). Materials and Methods Approval was obtained from the local ethics committee. MR images from 453 patients with NIDCM and 150 healthy control subjects were included between 2005 and 2013 and were analyzed retrospectively. Myocardial contraction fraction (MCF) was calculated by dividing left ventricular (LV) stroke volume by LV myocardial volume, and long-axis strain (LAS) was calculated from the distances between the epicardial border of the LV apex and the midpoint of a line connecting the origins of the mitral valve leaflets at end systole and end diastole. Receiver operating characteristic curve, Kaplan-Meier method, Cox regression, and classification and regression tree (CART) analyses were performed for diagnostic and prognostic performances. Results LAS (area under the receiver operating characteristic curve [AUC] = 0.93, P < .001) and MCF (AUC = 0.92, P < .001) can be used to discriminate patients with NIDCM from age- and sex-matched control subjects. A total of 97 patients reached the combined end point during a median follow-up of 4.8 years. In multivariate Cox regression analysis, only LV ejection fraction (EF) and LAS independently indicated the combined end point (hazard ratio = 2.8 and 1.9, respectively; P < .001 for both). In a risk stratification approach with classification and regression tree analysis, combined LV EF and LAS cutoff values were used to stratify patients into three risk groups (log-rank test, P < .001). Conclusion Cardiovascular MR-derived MCF and LAS serve as reliable diagnostic and prognostic markers in patients with NIDCM. LAS, as a marker for longitudinal contractile function, is an independent parameter for outcome and offers incremental information beyond LV EF and the presence of myocardial fibrosis. ^© RSNA, 2017 Online supplemental material is available for this article.