Feature-tracking Strain Analysis Research Articles

Right ventricular longitudinal strain on cardiovascular magnetic resonance imaging predicts outcome in patients undergoing transcatheter mitral valve repair

Abstract Background The prognostic value of left and right ventricular global longitudinal strain (LV and RV GLS) derived from cardiovascular magnetic resonance (CMR) feature tracking in patients with severe mitral regurgitation (MR) undergoing transcatheter mitral valve repair (TMVR) is unknown. Methods Consecutive patients scheduled for TMVR underwent pre-procedural and follow-up CMR imaging including feature tracking strain analysis. Kaplan-Meier estimates and multivariate Cox-regression analyses were used to identify the prognostic impact of LV and RV GLS on CMR using a composite of heart failure hospitalization and death. Results A total of 62 patients (78.3±7.0y/o, 45% female, EuroSCORE II: 9.7±7.2%) with severe MR underwent CMR prior to TMVR. 23 (37%) patients presented with right ventricular dysfunction (RVD) defined by RV GLS >−20% on CMR. At baseline, RVD was associated with NT-proBNP levels (9510 vs. 4064pg/mL, p=0.030). On CMR, RVD was associated with reduced left and RV ejection fraction (LVEF: 39.2 vs. 48.7%, p=0.011, RVEF: 35.1 vs. 46.7%, p<0.001), as well as increased LV GLS (−14.0 vs. −19.5%, p=0.003). A total of 18 events (12 deaths, 6 hospitalizations for heart failure) occurred during follow-up (mean 11.4±9.1months). While LV GLS was not significantly associated with outcome (HR 0.95, 95% CI: 0.90–1.01, p=0.082), RV GLS showed a strong and independent association with event-free survival by multivariate Cox-regression analysis (adj.HR 0.91, 95% CI: 0.83–0.99, p=0.033) after adjustment for relevant baseline and procedural data (EuroSCORE II, post-procedural residual MR), imaging parameters (TAPSE, LV and RVEF on CMR), and cardiac biomarkers (NT-proBNP). When compared with the “gold standard” RVEF on CMR (RVEF <45%: adj.HR 0.86, 95% CI: 0.23–3.20, p=0.825) and TAPSE on echo (TAPSE <17mm: adj.HR: 2.77, 95% CI: 0.72–10.70, p=0.140), only RVD (RV GLS >−20%: adj.HR 5.05, 95% CI: 1.23–20.63, p=0.024) was significantly associated with the composite endpoint (Figure 1). Follow-up CMR was performed in 21 (34%) patients. RV GLS significantly improved after TMVR (−20.6 to −25.2%, p=0.016, Figure 2). Conclusions RV rather than LV GLS, as determined on CMR, is an important predictor of outcome in patients undergoing TMVR. At 1 year follow-up, RV function significantly improved, and thus might add useful prognostic information on top of established risk factors. Funding Acknowledgement Type of funding sources: None. Figure 1Figure 2

The role of feature-tracking strain analysis in the differentiation of cardiac amyloidosis from hypertrophic cardiomyopathy

Abstract Cardiac magnetic resonance (CMR) examinations have an essential role in the differentiation of cardiac involvement of amyloidosis (CA) from hypertrophic cardiomyopathy (HCM). The CMR diagnosis is traditionally based on morphologic features and the pattern of late gadolinium enhancement (LGE). However, in patients contraindicated for contrast agent administration, the diagnosis can be challenging. Novel CMR techniques, including strain analysis, can help in the differentiation of these patients. The aim of our study was to investigate the differential diagnostic and prognostic importance of feature-tracking strain analysis in patients with left ventricular hypertrophy caused by CA or HCM. We investigated 89 HCM patients (48 males; 50±18 years) and 46 CA patients (29 males; 64±10 years) who underwent CMR examination. The left ventricular ejection fraction (LVEF), volumes (end-diastolic volume: LVEDV, end-systolic volume: LVESV, stroke volume: LVSV), mass (LVM), and the amount of LGE were quantified. Global longitudinal (GLS), circumferential (GCS) and radial (GRS) LV strain parameters, and basal, midventricular, and apical LS and CS were measured. The apex-to-base regional LS and CS ratios were calculated. The all-cause mortality of the patients was analyzed. The characteristics of groups were compared with an independent t-test or Mann-Whitney test, as appropriate. ROC curve analysis was performed to analyze the diagnostic accuracy of a parameter and to identify optimal cutoff values. The prognostic value of CMR parameters was assessed with Cox proportional hazard regression analyses. Survival probability was analyzed with Kaplan-Meier curves and compared by the log-rank test. CA patients had significantly lower LVEF (51±11 vs. 63±8%; p<0.0001), lower LVSVi (43±12 vs. 54±12 ml/m2; p<0.0001), higher LVMi (94±24 vs. 79±24 g/m2; p<0.001), higher amount of LGE (29±15 vs. 8±8%; p<0.0001), and more impaired global and regional strain values (GRS: 55±22 vs. 93±29%; GCS: −33±10 vs. −42±8%; GLS: −18±4 vs. −25±6%; basal CS: −26±9 vs. −39±7%; basal LS: −15±4 vs. −22±6%; p<0.0001) than HCM patients. The apex-to-base CS and LS ratios were higher in CA patients, suggestive of apical sparing (1.71±0.68 vs. 1.29±0.33; p<0.0001; 1.88±0.76 vs. 1.57±0.62; p<0.05; respectively). In the differentiation of CA and HCM, LGE, basal CS, basal LS, GRS, and GLS had the highest diagnostic accuracies (AUCs: 0.911, 0.866, 0.848, 0.859, 0.849). During the mean 2.1±2.0 years of follow-up, three HCM patients (3.4%) and 29 CA patients (63%) died (p<0.0001). The significant independent predictors of mortality were a diagnosis of CA, LVSVi and basal LS. Our results show that CMR-based strain analysis might be a useful method for differentiating cardiac involvement of amyloidosis from HCM. Furthermore, this technique provides additional information for the assessment of prognosis in this patient population. Funding Acknowledgement Type of funding sources: Public Institution(s). Main funding source(s): National Research, Development and Innovation Office of Hungary; Ministry for Innovation and Technology in Hungary, within the framework of the Therapeutic Development and Bioimaging programmes of the Semmelweis University

Value of Left Ventricular Feature Tracking Strain Analysis for Detection of Early Cardiac Involvement in Fabry Disease (FD).

Purpose: Detection of cardiac involvement in Fabry disease (FD) is of high importance for treatment management. Native T1 mapping especially showed great potential for detection of early cardiac manifestations. Echocardiographic studies showed strain abnormalities in FD patients, but data on MRI feature tracking strain analysis (FT-SA) is limited. Therefore, the aim of our study was to evaluate the potential of FT-SA compared to native T1 and the FD specific biomarker Globotriaosylsphingosine (LysoGb3). Methods: 28 consecutive FD patients (18 female; 47.8 years ± 17.4 standard deviation (SD)) and 28 control subjects (18 female; 46.6 years ± 18.2 SD) underwent cardiac MRI at 1.5 Tesla. Global native T1 times and left ventricular FT-SA were evaluated. Results were correlated to serum Lyso-Gb3-levels. Results: Native T1 times, global longitudinal (GLS) and global radial strain (GRS) were significantly reduced in FD patients (p < 0.0064, p = 0.0009 and p = 0.0184, respectively). Moreover, native T1 times and GLS were significantly lower in Lyso-Gb3 positive FD patients (p < 0.005 and p = 0.03). GLS, native T1 times showed significant moderate correlations to LysoGb3 (p = 0.002 and p < 0.001). Furthermore, GLS and native T1 times reduce when LysoGb3 was elevated and increasingly with presence of left ventricular hypertrophy (LVH) or late gadolinium enhancement (LGE). Conclusions: Native T1 times and strain values differ significantly between FD patients and control subjects and showed promising correlations to the FD specific biomarker LysoGb3. We therefore conclude that strain abnormalities occur early beside native T1 reductions in cardiac FD involvement. Large scale trials are needed to verify our findings.

Multichamber Dysfunction in Children and Adolescents With Severe Obesity: A Cardiac Magnetic Resonance Imaging Myocardial Strain Study.

In severe obesity, left ventricular (LV) and right ventricular (RV) remodeling and contractile dysfunction have been documented, but less is known regarding left atrial (LA) dysfunction and its association with LV/RV remodeling, especially in children. To assess the effects of severe childhood obesity on cardiac function by using multichamber strain analysis with MRI. Prospective. Forty-five children aged 7-18 years (including 20 with severe obesity, defined as a body mass index values above the 99th percentile). 5 T. Steady-state-free-precession (SSFP) images in short-axis views and longitudinal two- and four-chamber views. Cardiac strain measurements were derived from standard SSFP cine images by using a dedicated MR imaging feature tracking software. Inter- and intra-rater reliability were evaluated. Independent sample t test, Spearman's correlation coefficient, principal component analysis, Bland-Altman analysis, and intra-class correlation coefficients (ICC). A P value <0.05 was considered statistically significant. As compared to children without obesity, those with obesity showed significantly reduced LA reservoir function (22.2% ± 6.4% vs. 33.8% ± 9.0%) and contractile function (5.4% ± 3.2% vs. 13.3% ± 8.0%) as well as significantly decreased absolute values for LA longitudinal strain in reservoir and contraction phases and LA radial motion fraction in reservoir and contraction phases. Children with severe obesity showed significantly reduced absolute RV radial motion fraction (-10.6% ± 2.9% vs. -18.2% ± 2.9%) and circumferential strain (-10.6% ± 2.9% vs. -16% ± 2.5%) as well as higher LV mass index (28.7% ± 5.1% vs. 21.7 ± 4.6 g/m2 ) along with significantly reduced LV ejection fraction (56.4% ± 3.9% vs. 60% ± 4.1%), LV radial strain (56% ± 6% vs. 61.8% ± 11.3%), and longitudinal strain (-17.8% ± 1.8% vs. -20.3% ± 3.2%). Reliability was good to excellent, with ICC ranging from 79.1% to 97.7%. MR feature-tracking strain analysis revealed multichamber dysfunction in severely obese children with impaired LA reservoir and atrial contraction phases, which suggest an early loss in the compensatory ability of atrial contraction with severe obesity. 2 TECHNICAL EFFICACY STAGE: 3.

Left ventricular myocardial strain and tissue characterization by cardiac magnetic resonance imaging in immune checkpoint inhibitor associated cardiotoxicity.

BackgroundImmune checkpoint inhibitors (ICIs) are highly effective in treating cancer; however, cardiotoxicity can occur, including myocarditis. Cardiac magnetic resonance (CMR) imaging is useful for evaluation of myocarditis, although it has not been well studied in ICI cardiotoxicity.MethodsWe identified patients referred for CMR evaluation of ICI cardiotoxicity from September 2015 through September 2019. We assessed structural and functional parameters, feature tracking (FT) left ventricular and atrial strain, T2- weighted ratios and quantitative late gadolinium enhancement (LGE). We also applied the Updated Lake Louise Criteria for diagnosis of myocarditis.ResultsOf the 20 patients referred, the median left ventricular ejection fraction (LVEF) was 52.5% ± 19.1 and 50% had a normal LVEF (≥53%). FT strain analysis revealed an average abnormal global longitudinal strain (GLS) of −9.8%± 4.2%. In patients with a normal LVEF, the average GLS remained depressed at −12.3%± 2.4%. In all patients, GLS demonstrated a significant negative correlation with LVEF (rs = −0.64, p 0.002). Sixteen patients (80%) had presence of LGE (14 non-ischemic pattern and 2 ischemic). Percent LGE did not correlate with any CMR parameters and notably did not correlate with LVEF (rs = −0.29, p = 0.22) or GLS (rs = 0.10, p = 0.67), highlighting the value of tissue characterization beyond functional assessment. Nine patients (45%) met full Updated Lake Louise Criteria and 85% met at least one criterion, suggestive of myocarditis in the correct clinical context. Thirteen patients (65%) were treated for ICI-associated myocarditis and, of these, 54% (n = 7) had recovery of LVEF to normal. There was no correlation between LVEF (p = 0.47), GLS (0.89), or % LGE (0.15) and recovery of LVEF with treatment.ConclusionIn patients with suspected ICI cardiotoxicity, CMR is an important diagnostic tool, even in the absence of overt left ventricular dysfunction, as abnormalities in left ventricular strain, T2 signal and LGE can identifying disease.

Prognostic significance of cardiac magnetic resonance-based markers in patients with hypertrophic cardiomyopathy

The prognosis of patients with hypertrophic cardiomyopathy (HCM) varies greatly. Cardiac magnetic resonance (CMR) is the gold standard method for assessing left ventricular (LV) mass and volumes. Myocardial fibrosis can be noninvasively detected using CMR. Moreover, feature-tracking (FT) strain analysis provides information about LV deformation. We aimed to investigate the prognostic significance of standard CMR parameters, myocardial fibrosis, and LV strain parameters in HCM patients. We investigated 187 HCM patients who underwent CMR with late gadolinium enhancement and were followed up. LV mass (LVM) was evaluated with the exclusion and inclusion of the trabeculae and papillary muscles (TPM). Global LV strain parameters and mechanical dispersion (MD) were calculated. Myocardial fibrosis was quantified. The combined endpoint of our study was all-cause mortality, heart transplantation, malignant ventricular arrhythmias and appropriate implantable cardioverter defibrillator (ICD) therapy. The arrhythmia endpoint was malignant ventricular arrhythmias and appropriate ICD therapy. The LVM index (LVMi) was an independent CMR predictor of the combined endpoint independent of the quantification method (p < 0.01). The univariate predictors of the combined endpoint were LVMi, global longitudinal (GLS) and radial strain and longitudinal MD (MDL). The univariate predictors of arrhythmia events included LVMi and myocardial fibrosis. More pronounced LV hypertrophy was associated with impaired GLS and increased MDL. More extensive myocardial fibrosis correlated with impaired GLS (p < 0.001). LVMi was an independent CMR predictor of major events, and myocardial fibrosis predicted arrhythmia events in HCM patients. FT strain analysis provided additional information for risk stratification in HCM patients.

Diagnostic and prognostic impact of cardiac magnetic resonance, including scar quantification and strain imaging in patients with malignant ventricular arrhythmias and nonobstructed coronary arteries

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Development and Innovation Fund of Hungary, National Research, Development and Innovation Office Background In case of malignant ventricular arrhythmias (VA) and nonobstructed coronary arteries, the differential diagnosis of the underlying diseases is still challenging, due to the board spectrum of possible causes. Cardiac magnetic resonance (CMR) provides functional, morphological and tissue specific information, including necrotic and scar-tissue. Aims We aimed to assess the diagnostic and prognostic implications of CMR parameters including global strain values and myocardial scar in patients after ventricular fibrillation (VF) or sustained ventricular tachycardia (SVT) and nonobstructed coronary arteries. Methods Between 2011 and 2019, 99 patients (42 ±17 years, 54 male) presenting with VF or SVT and nonobstructed coronary arteries, who underwent CMR examination before secondary prevention implantable cardioverter defibrillator (ICD) implantation were included in our study. Post-processing included feature-tracking strain analysis and left ventricular (LV) scar quantification. Patients were followed for the combined endpoint of all-cause-mortality and appropriate ICD therapy. Results CMR examination proved structural myocardial disease in 72%: dilated (n = 21), arrhythmogenic (n = 11), hypertrophic cardiomyopathy (n = 7) and other cardiomyopathies (n = 3). We found LGE patterns showing chronic myocardial infarction (n = 4), suggesting chronic myocarditis (n = 4) and aspecific nonischemic scar formation (n = 14). In 7 cases aspecific structural alterations without scar formation were detected. Overall, myocardial scar was found in 52%, with an average extent of 12 ± 8% of the LV myocardium. The CMR examination changed the clinical diagnosis in 55% of the patients. During a median follow-up at 2 years, 6 patients died and 42 experienced appropriate ICD therapy. We found an association between cardiac events and the presence of structural abnormality and myocardial scar (logrank: 4,553, p &amp;lt; 0.05 and 8.375, p &amp;lt;0.01). On Cox proportional-hazards modell LV ejection fraction, LV stroke volume index, the presence of structural abnormality, the presence and extent of myocardial scar, global LV strain parameters including longitudinal and circumferential strain, and a global left ventricular dssynchrony parameter (mechanical dispersion) were univariate predictors of the combined endpoint of all-cause-mortality and appropriate ICD therapy(p &amp;lt; 0.05). Conclusion CMR performed in patients after malignant VA and nonobstructed coronary arteries not only establishes the diagnosis in a high proportion of patients, but may also provide additional prognostic factors. This may indicate that CMR could play a complementary role in the risk stratification in this patient population. Abstract Figure.

Impact of chest wall deformity on cardiac function by CMR and feature-tracking strain analysis in paediatric patients with Marfan syndrome

ObjectivesTo evaluate systolic cardiac dysfunction in paediatric MFS patients with chest wall deformity using cardiac magnetic resonance (CMR) imaging and feature-tracking strain analysis.MethodsForty paediatric MFS patients (16 ± 3 years, range 8−22 years) and 20 age-matched healthy controls (16 ± 4 years, range 11−24 years) were evaluated retrospectively. Biventricular function and volumes were determined using cine sequences. Feature-tracking CMR was used to assess global systolic longitudinal (GLS), circumferential (GCS) and radial strain (GRS). A dedicated balanced turbo field echo sequence was used to quantify chest wall deformity by measuring the Haller index (HI).ResultsLV volumes and ejection fraction (EF) were similar in MFS patients and controls. There was a trend for lower right ventricular (RV) volume (75 ± 17 vs. 81 ± 10 ml/m2, p = 0.08), RV stroke volume (41 ± 12 vs. 50 ± 5 ml/m2, p < 0.001) and RVEF (55 ± 10 vs. 62 ± 6%, p < 0.01) in MFS patients. A subgroup of MFS patients had an increased HI compared to controls (4.6 ± 1.7 vs. 2.6 ± 0.3, p < 0.001). They demonstrated a reduced RVEF compared to MFS patients without chest wall deformity (50 ± 11% vs. 58 ± 8%, p = 0.01) and controls (p < 0.001). LV GLS was attenuated when HI ≥ 3.25 (- 16 ± 2 vs. - 18 ± 3%, p = 0.03), but not GCS and GRS. LV GLS (p < 0.01) and GCS (p < 0.0001) were attenuated in MFS patients compared to controls, but not GRS (p = 0.31). RV GLS was attenuated in MFS patients compared to controls (- 21 ± 3 vs. - 23 ± 3%, p < 0.05).ConclusionChest wall deformity in paediatric MFS patients is associated with reduced RV volume, ejection fraction and GLS. Feature-tracking CMR also indicates impairment of systolic LV function in paediatric MFS patients.Key Points• Paediatric Marfan patients demonstrate reduced RV volume and ejection fraction compared to healthy controls.• A concordant attenuation in RV global longitudinal strain was observed in Marfan patients, while the RV global circumferential strain was increased, indicating a possible compensatory mechanism.• Subgroup analyses demonstrated alterations in RV ejection fraction and RV/LV global strain parameters, indicating a possible association of severe chest wall deformity with biventricular dysfunction in paediatric Marfan patients.

Chronic coronary syndromes lead to reduced strain parameters compared to patients without myocardial ischemia in a propensity score-matched cohort assessed by cardiac magnetic resonance imaging

Abstract Background Vasodilator perfusion cardiac magnetic resonance (CMR) has evolved as gold standard in detecting myocardial perfusion deficits (MPD). Even reversible chronic MPD in chronic coronary syndromes can lead to impaired myocardial contractility similar to hibernating myocardium. Feature tracking strain analysis (FTS) provides the opportunity to detect these subclinical alterations of myocardial function before ejection fraction (EF) is impaired. It was therefore the aim of this study to investigate, if subtle changes in myocardial mechanics can be detected by FT strain analysis in patients with MPD. Methods Between April 2017 and October 2019 we identified 226 patients with MPD by vasodilator stress CMR out of 1500 patients included in our tertiary care center registry. Propensity score matching was used to identify patients without MPD with similar myocardial characteristics defined by EF, enddiastolic volume indexed by body surface area (EDVi) and native T1-mapping. Steady state free precession cine CMR sequences were analyzed by FTS retrospectively generating three global strain parameters: global longitudinal, circumferential and radial strain (GLS, GCS, GRS). Results Propensity score matching yielded 104 patients in each group (MPD mean age 63.6±12.8 years, 25 females; no MPD mean age 67.7±10.6 years, 26 females; LV-EF 51.3±16.0% vs. 52.6±15.2%, p=0.2307; EDVi 88.3±32.7 ml/m2 vs. 82.6±29.3 ml/m2, p=0.1533; native T1 values 1139±60 ms vs. 1125±63 ms, p=0.118). All global strain parameters were significantly reduced in MPD patients compared to patients with no MPD (global longitudinal strain −15.5±4.9 vs. −17.1±4.9, p=0.0046, global circumferential strain −18.0±5.4 vs. −19.4±5.6, p=0.0298; global radial strain 35.4±14.8 vs. 39.4±15.6, p=0.0127). Conclusion Chronic Coronary Syndromes cause subtle changes of myocardial mechanics, which are not reflected by EF but can be detected with FTS. Funding Acknowledgement Type of funding source: None

The influence of vigorous training on the structure and cardiorespiratory fitness in adolescent athletes

Abstract Introduction The functional and morphological adaptation of the cardiovascular system to vigorous exercise in adolescents is less understood compared to adult athletes. Therefore, the differential diagnosis of normal cardiovascular adaptation from the possible pathological alterations is challenging. Cardiovascular magnetic resonance is an important method for assessing ventricular function and morphology. Maximal oxygen uptake (VO2 max) has been established as a reliable measure of the maximal ability to produce metabolic power aerobically. Aims The aim of this study was to examine left (LV) and right (RV) ventricular morphologic and functional remodeling in elite adolescent athletes using cardiac magnetic resonance imaging (CMR) and cardiopulmonary exercise test (CPET). Methods Between 2017 and 2019 116 asymptomatic adolescent (14–20 years) athletes (&amp;gt;6 training hour/week) underwent CMR and CPET as part of a detailed sports cardiology screening. Cine movie images were performed for the quantification of the LV and RV volumes, masses and ejection fraction, and advanced post processing included feature-tracking strain analysis. CPET was performed on a dedicated athlete protocol. Results All athletes participated in sports with a high dynamic component. Male athletes (n=74, 16±1 years) demonstrated higher LV and RV end –diastolic volume index (EDVi), stroke volume index (SVi) and mass index (Mi) compared with female athletes (p&amp;lt;0.001). We found significant difference regarding the global circumferential strain (GCS) and mechanical dispersion (MD) of male and female athletes (GCS −34±4 vs. −31±5%; MD 4±2 vs. 7±4% p&amp;lt;0.05). VO2 showed positive correlation with the LV and RV volumetric parameters (EDVi, SVi) and Mi (p&amp;lt;0.001) and the absolute value of GCS (p&amp;lt;0.05), and negative correlation with the MD (p&amp;lt;0.001). In 36 athletes the VO2 max exceeded the age-adjusted expected VO2 max by 130%, which was categorized as excellent. Besides gender, age, and body surface area CMR based LVEDVi and LVMi were independent predictors of VO2 max. Conclusion The functional and morphological adaptation of the adolescent cardiovascular system shows noteworthy differences between male and female athletes. VO2 max correlates with several CMR based values including LV and RV volumetric parameters, masses and strain parameters such as GCS and MD. Strain analysis of an adolescent athlete Funding Acknowledgement Type of funding source: Public grant(s) – National budget only. Main funding source(s): Project no. NVKP_16-1-2016-0017 has been implemented with the support provided from the National Research, Development and Innovation Fund of Hungary, financed under the NVKP_16 funding scheme. ÚNKP-19-3-I New National Excellence Program of the Ministry for Innovation and Technology.

Multi-Modality Imaging in Dilated Cardiomyopathy: With a Focus on the Role of Cardiac Magnetic Resonance.

Heart failure (HF) is recognized as a leading cause of morbidity and mortality worldwide. Dilated cardiomyopathy (DCM) is a common phenotype in patients presenting with HF. Timely diagnosis, appropriate identification of the underlying cause, individualized risk stratification, and prediction of clinical response to treatment have improved the prognosis of DCM over the last few decades. In this article, we reviewed the current evidence on available imaging techniques used for DCM patients. In this direction, we evaluated appropriate scenarios for the implementation of echocardiography, nuclear imaging, and cardiac computed tomography, and we focused on the primordial role that cardiac magnetic resonance (CMR) holds in the diagnosis, prognosis, and tailoring of therapeutic options in this population of special clinical interest. We explored the predictive value of CMR toward left ventricular reverse remodeling and prediction of sudden cardiac death, thus guiding the decisions for device therapy. Principles underpinning the use of state-of-the-art CMR techniques such as parametric mapping and feature-tracking strain analysis are also provided, along with expectations for the anticipated future advances in this field. We also attempted to correlate the evidence with clinical practice, with the intent to address questions on selecting the optimal imaging method for different indications and clinical needs. Overall, we recommend a comprehensive assessment of DCM patients at baseline and at follow-up intervals depending on the clinical status, with the addition of CMR as a second-line modality to other imaging techniques. We also provide an algorithm to guide the detailed imaging approach of the patient with DCM. We expect that future guidelines will upgrade their clinical recommendations for the utilization of CMR in DCM, which is expected to further improve the quality of care and the outcomes. This review provides an up-to-date perspective on the imaging of dilated cardiomyopathy patients and will be of clinical value to training doctors and physicians involved in the area of heart failure.

Advanced myocardial characterization in hypertrophic cardiomyopathy: feasibility of CMR-based feature tracking strain analysis in a case-control study.

This study aimed to evaluate the feasibility and reproducibility of using cardiovascular magnetic resonance feature tracking (CMR-FT) for analysis of bi-ventricular strain and strain rate (SR) in hypertrophic cardiomyopathy (HCM) patients as well as to explore the correlation between right ventricular (RV) and left ventricular (LV) deformation. A total of 60 HCM patients and 48 controls were studied. Global and segmental peak values of bi-ventricular longitudinal, circumferential, radial strain, and systolic SR were analyzed. Pearson analysis was performed to investigate the correlation of RV and LV deformation. Intra-observer and inter-observer reproducibility were also assessed. LV mass in the HCM group was significantly higher than that in the control group. LV end-systolic and end-diastolic volume and RV end-systolic and end-diastolic volume in the HCM group were all significantly lower than the correlated parameters in the control group (p < 0.001, respectively), whereas no statistical difference was found in ejection fraction (p > 0.05). Global longitudinal strain (GLS), global longitudinal strain rate (GLSR), global circumferential strain (GCS), global circumferential strain rate (GCSR), global radial strain (GRS), and global radial strain rate (GRSR) of the LV and RV were all significantly lower than the control group, and segmental strain and SR were also true (p < 0.001, respectively). Bi-ventricular strain and SR measurements were highly reproducible at both intra- and inter-observer levels. Additionally, Pearson analysis showed RV GCS, GLS, and GRS positively correlated with LV GCS, GLS, and GRS (r = 0.713, p < 0.001; r = 0.728, p < 0.001; r = 0.730, p < 0.001, respectively). CMR-FT is a promising approach to analyze impairment of global and segmental myocardium deformation in HCM patients non-invasively and quantitatively. • CMR-FT allows for advanced myocardial characterization with high reproducibility. • As compared with controls, HCM patients have significant differences in CMR-FT strain analysis while ejection fraction was similar. • CMR-FT may serve as an early biomarker of HCM in subjects at risk.

P5288Slice position vulnerability in the basal and apical parts for right ventricular circumferential strain measurement with feature tracking cardiac magnetic resonance

Abstract Background Strain is a more sensitive and precise parameter than ejection fraction (EF) for detection and characterization of subclinical left ventricular (LV) dysfunction and remodeling. Similar relationship is expected for right ventricle (RV); however RV functional parameters are less validated. Feature tracking strain analysis based on standard cardiac magnetic resonance (CMR) cine imaging is available for both ventricles. We experience a large slice-to-slice variation for RV global circumferential strain (GCS), possibly making the parameter vulnerable to minute position changes. Purpose To evaluate slice-to-slice differences in RV GCS for identification of the least variation region in a patient group without regional RV disease, in order to achieve a robust method for measurement. Hypothesis The slice-to-slice difference in peak GCS is lower in the mid-ventricular part of the RV than in the basal and apical parts. Methods 50 patients 6–72 months after pulmonary embolism without other major cardiopulmonary disease were included; mean age 60 years (range: 18–75 years); 68% men. Standard 2D cine CMR was obtained in longitudinal planes and in 10–12 consecutive 10 mm short axis planes for complete coverage of the RV. RV free wall and the inner contour of the septum were manually segmented on every end-diastolic and end-systolic slice from the pulmonary valve to the apex for feature tracking strain analysis. Peak RV GCS for every short axis slice and GCS difference (absolute percentage points) between adjacent slices were calculated. RV EF and peak RV GLS from the 4-chamber image were measured for correlation to RV GCS. Wilcoxon signed rank test and Pearson correlation were performed. Confidence intervals of means are based on 1000 bootstrap samples. Results RV EF was 46.6% (95% CI: 44.3; 48.8), RV peak GLS was −17.6% (95% CI: −18.6; −16.6). RV mid-ventricular GCS was −10.9% (95% CI: −12.0; −9.9). RV peak GCS slice-to-slice difference was 6.8 absolute percentage points (95% CI: 6.0; 7.6) in the basal part, 2.7 (95% CI: 2.4; 3.0) in the mid-ventricular part and 4.6 (95% CI: 3.9; 5.3) apically. Difference was significantly lower in mid-ventricular (p&lt;0.001) compared to both basal and apical. RV EF correlated to RV peak GLS (r: −0.397, p=0.004) and mid-ventricular peak GCS (r: −0.356, p=0.01) but not to basal or apical peak GCS. RV peak GLS correlated to basal and mid-ventricular peak GCS (r: 0.313, p=0.03 and r: 0.301, p=0.03 respectively) but not to apical peak GCS. Figure 1 shows slice-to-slice difference (expressed in absolute percentage points) in right ventricular peak GCS. Conclusion Slice-to-slice difference in RV peak GCS was significantly lower in the mid-ventricular region. Large differences in the basal and apical parts indicate that measurements largely depend on slice positioning.

P5282Comparison of cardiovascular magnetic resonance ejection fraction and left ventricular volumes by long axis feature tracking strain analysis versus standard short axis stack contour tracing

Abstract Introduction Cardiovascular magnetic resonance (CMR) feature tracking (FT) is based on the recognition of endocardial features obtained during standard CMR cine imaging to be tracked and followed throughout the cardiac cycle. Global longitudinal strain (GLS) has been proposed as a superior measure for diagnosis and prognosis than ejection fraction (EF). However, EF remains an important primary parameter to describe cardiac function. A rapid determination of GLS based on three long axis views (LAX) allows for a simultaneous calculation of EF without additional imaging or post-processing promising a significant reduction of scan and post-processing time. Purpose The purpose of this work is to compare the LV volumes and EF obtained during assessment of GLS based on CMR feature tracking with standard analysis of a short axis (SAX) stack used as the reference standard. Methods 75 consecutive patients underwent a routine clinical scan obtaining a full SAX stack as well as 3 standard LAX views using either 3-Tesla or 1,5-Tesla clinical scanners. We determined LV volumes and EF based on the reference standard as well as feature tracking analysis with additional GLS. A p value &lt;0.01 was considered statistically significant. Results Mean EF was 45.9% using standard SAX (range, 13%-72%) and 51.1% using triplanar feature tracking (r=0.950; p&lt;0.0001, figure 1A). Bland-Altman analysis showed a systematic bias of 5,27%; without proportional bias (figure 1B). End-diastolic volumes (r=0,975; p&lt;0.0001) and end-systolic volumes (r=0.985; p&lt;0.0001) demonstrated similar results. Mean GLS was −17.3% (range: −30,7% to −3,3%) and was significantly correlated with standard EF (r=−0,884; p&lt;0.0001). Classification of EF into categories: reduced, mid-range or preserved (&lt;40%, 40–49%, ≥50%) remain unchanged in 79% of patients when using EF by feature tracking analysis. Twelve of 16 reclassifications occurred in the mid-range category. Figure 1 Conclusion There is a good correlation between EF obtained by rapid post-processing of GLS with EF based on a full SAX stack resulting in an identical categorization in 79% of patients. Reduction of EF within the mid-range might be best assesses by the standard SAX stack.

Feature-tracking myocardial strain in healthy adults- a magnetic resonance study at 3.0 tesla

We analyzed feature-tracking derived circumferential and longitudinal strain in healthy volunteers who underwent cardiac magnetic resonance imaging (CMR) at 3.0 T. 88 healthy adults (44.6 ± 18.0 years old, 49% male), without prior cardiovascular disease, underwent CMR at 3.0 T including cine, and late gadolinium enhancement in subjects >45 years. LV functional analysis and feature-tracking strain analyses were carried out. Global strain had better reproducibility than segmental strain. There was a sex specific difference global longitudinal strain (mean ± SD, −18.48 ± 3.65% (male), −21.91 ± 3.01% (female), p < 0.001), but not global circumferential strain (mean ± SD, −25.41 ± 4.50% (male), −27.94 ± 3.48% (female), p = 0.643). There was no association of strain with ageing after accounting for sex for both global longitudinal and circumferential strain. Feature-tracking strain analysis is feasible at 3.0 T. Healthy female volunteers demonstrated higher magnitudes of global longitudinal strain when compared to male counterparts. Whilst global cine-strain has good reproducibility, segmental strain does not.

Non-invasive evaluation of the relationship between electrical and structural cardiac abnormalities in patients with myotonic dystrophy type 1.

Cardiac involvement in myotonic dystrophy type 1 (MD1) includes conduction disease, arrhythmias, and left-ventricular (LV) systolic dysfunction leading to an increased sudden cardiac death risk. An understanding of the interplay between electrical and structural myocardial changes could improve the prediction of adverse cardiac events. We aimed to explore the relationship between signs of cardiomyopathy by conventional and advanced cardiovascular magnetic resonance (CMR), and electrical abnormalities in MD1. Fifty-seven MD1 patients (43 ± 13 years, 46% male) and 15 matched controls (41 ± 7 years, 53% male) underwent CMR including cine-imaging with feature-tracking strain analysis, late gadolinium enhancement (LGE), and native/post-contrast T1-mapping with extracellular volume calculation. Standard 12-lead and long-term ECG monitoring were performed as screening for rhythm and/or conduction abnormalities. Abnormal ECGs were recorded in 40% of MD1; a pathologic CMR was found in 44%: 21% had an impaired LV-EF and 32% showed non-ischemic LGE. When looking at MD1 patients with available long-term ECG monitoring (n = 39), those with atrial fibrillation (Afib)/flutter(Afl) episodes had lower LV-EF (52 ± 7 vs. 60 ± 5%, p = 0.002), lower global longitudinal strain (- 17 ± 3 vs. - 20 ± 3%, p = 0.034), a trend to lower left atrial emptying fraction (LA-EF) (44 ± 14 vs. 55 ± 8%, p = 0.08), and higher prevalence of LGE (88% vs. 23%, p = 0.001) with an intramural (75% vs. 23%, p = 0.01) and septal (63% vs. 13%, p = 0.009) pattern. In a model including LV-EF (OR 0.8, 95% CI 0.7-1.0, p = NS) and LGE presence (OR 14.8, 95% CI 1.4-159.0, p = 0.026), only LGE was independently associated with the occurrence of Afib/Afl episodes. Myocardial abnormalities depicted by non-ischemic LGE-CMR were the only independent predictor for the occurrence of Afib/Afl on ECG monitoring, previously shown to predict adverse cardiac events in MD1.

Associations of Infarct Size and Regional Myocardial Function Examined by Cardiac Magnetic Resonance Feature Tracking Strain Analysis with the Infarct Location in Patients with Acute ST-Segment Elevation Myocardial Infarction

ObjectiveTo quantitatively evaluate the associations of infarct size, regional myocardial function examined by cardiac magnetic resonance feature tracking (CMR-FT) strain analysis with infarct location in patients with ST-segment elevation myocardial infarction (STEMI) treated by primary percutaneous coronary intervention. MethodsCardiac magnetic resonance images were retrospectively analyzed in 95 consecutive STEMI patients with successful reperfusion. The patients were divided into the anterior wall myocardial infarction (AWMI) and nonanterior wall myocardial infarction (NAWMI) groups. Infarct characteristics were assessed by late gadolinium enhancement. Global and regional strains and associated strain rates in the radial, circumferential and longitudinal directions were assessed by CMR-FT based on standard cine images. The associations of infarct size, regional myocardial function examined by CMR-FT strain analysis with infarct location in STEMI patients were evaluated by the Spearman or Pearson method. ResultsThere were 44 patients in the AWMI group and 51 in the NAWMI group. The extent of left ventricular enhanced mass was significantly larger in patients with AWMI compared with the NAWMI group (24.47+11.89, 21.06+12.08 %LV; t = 3.928, P = 0.008). In infarct zone analysis, strains in the radial, circumferential and longitudinal directions were remarkably declined in the AWMI group compared with the NAWMI group (z = -20.873, -20.918, -10.357, all P < 0.001). The volume (end-systolic volume index), total enhanced mass and extent of enhanced mass of the left ventricular were correlated best with infarct zone strain in the AWMI group (all P < 0.001). ConclusionIn STEMI patients treated by percutaneous coronary intervention, myocardial damage is more extensive and regional myocardial function in the infarct zone is lower in the AWMI group compared with the NAWMI group.

MRI feature tracking strain is prognostic for all-cause mortality in AL amyloidosis

Objectives: Cardiac involvement is a major determinate of mortality in light chain (AL) amyloidosis. Cardiac magnetic resonance imaging (MRI) feature tracking (FT) strain is a new method for measuring myocardial strain. This study retrospectively evaluated the association of MRI FT strain with all-cause mortality in AL amyloidosis.Materials and methods: Seventy-six patients with newly diagnosed AL amyloidosis underwent cardiac MRI. 75 had images suitable for MRI FT strain analysis. MRI delayed enhancement, morphologic and functional evaluation, cardiac biomarker staging and transthoracic echocardiography were also performed. Subjects’ charts were reviewed for all-cause mortality. Cox proportional hazards analysis was used to evaluate survival in univariate and multivariate analysis.Results: There were 52 deaths. Median follow-up of surviving patients was 1.7 years. In univariate analysis, global radial (Hazard Ratio (HR) = 0.95, p <.01), circumferential (HR = 1.09, p < .01) and longitudinal (HR = 1.08, p < .01) strain were associated with all-cause mortality. In separate multivariate models, radial (HR = 0.96, p = .02), circumferential (HR = 1.09, p = .03) and longitudinal strain (HR = 1.07, p = .04) remained prognostic when combined with presence of biomarker stage 3.Conclusions: MRI FT strain is associated with all-cause mortality in patients with AL amyloidosis.

Cardiac Magnetic Resonance Feature Tracking Biventricular Two-Dimensional and Three-Dimensional Strains to Evaluate Ventricular Function in Children After Repaired Tetralogy of Fallot as Compared with Healthy Children.

Cardiac magnetic resonance imaging is an important tool to evaluate cardiac anatomy and ventricular size and function after repaired tetralogy of Fallot. Magnetic resonance tissue tagging is the gold standard for evaluation of myocardial strain. However, myocardial tagging strain requires tagged images to be obtained prospectively, during the scan and with limited temporal resolution. Cardiac magnetic resonance feature tracking is a new tool that allows the retrospective analysis of cine images. There is limited experience with cardiac magnetic resonance feature tracking strain analysis in children. The medical records of patients with repaired tetralogy of Fallot that had a cardiac magnetic resonance (CMR) study from December 2013 to June 2015 were reviewed. The control group included patients who underwent a CMR with normal cardiac anatomy and ventricular function. Global longitudinal, circumferential and radial strain parameters (2D and 3D) were obtained by retrospectively contouring cine images from ventricular short axis, two chamber and four chamber views using post-processing software (Circle CVi42, Calgary, Canada). The correlation between conventional ventricular function parameters and ventricular strain was performed using Pearson's correlation. The mean age of tetralogy of Fallot and control subjects was 12.4 and 14.1years, respectively. In patients after repaired tetralogy of Fallot, the mean left ventricular global 2D and 3D circumferential strains were -17.4±2.9 and -10.1±3, respectively. The mean indexed right ventricular end-diastolic volume was 135.4ccm2±46 compared to 75.7ccm2±17 in control subjects (P=0.0001, CI 95%). Left ventricular global circumferential 3D strain showed a statistically significant difference in patients after TOF repair compared to normal subjects (-10.1±3 vs. -14.71±1.9, P=0.00001). A strong correlation between left ventricular global circumferential 3D strain and right ventricular end-diastolic volume (P≤0.0001) was noted. We found a strong correlation between left ventricular circumferential 3D strain and indexed right ventricular end-diastolic volume, as well as a strong correlation between left ventricular longitudinal 2D strain and right ventricular ejection fraction. Circumferential 3D strain may be a suitable tool to detect early abnormalities of ventricular myocardium even before the ejection fraction becomes compromised. Large-scale prospective studies are recommended.

Evaluation of Myocardial Strain in Patients With Amyloidosis Using Cardiac Magnetic Resonance Feature Tracking

PurposeTo study the use of cardiac magnetic resonance (CMR) feature tracking technique in evaluation of myocardial amyloidosis. Materials and MethodsCMR scans of 28 patients with biopsy proven myocardial amyloidosis and 35 controls were reviewed. Conventional short axis, vertical long axis, and 4-chamber cine steady-state free precession images from CMR scans were used to generate radial, circumferential, and longitudinal myocardial strain maps using feature tracking software. Global and regional peak radial, circumferential, and longitudinal strain values were computed. ResultsThere were significant decreases in radial, circumferential, and longitudinal strains in patients with myocardial amyloidosis globally and across layers (all P < 0.001). Strain was relatively preserved for the apex and most affected for the basal level. The area under the receiver operating characteristic curve for base peak radial, circumferential, and longitudinal strain 0.899, 0.884, and 0.866 and cut offs of 22.9, −13.3, and −10.9, respectively, were determined by receiver operating characteristic analysis. CMR feature tracking strain analysis of base-level strain parameters was able to differentiate patients with myocardial amyloidosis from those without myocardial amyloid with high sensitivity (82.5%) and specificity (82.9%) particularly for radial strain. The maximum sensitivity (89.3%) was achieved if any of the 3 parameters were abnormal, and the maximum specificity (88.6%) when all 3 parameters were abnormal. ConclusionMyocardial amyloidosis produces significant changes in regional and global strain parameters, and the peak radial and circumferential strain are the most affected at the basal layer.