Magnetic Resonance Feature Tracking Research Articles

Range Variability in CMR Feature Tracking Multilayer Strain across Different Stages of Heart Failure

Heart failure (HF) is associated with progressive ventricular remodeling and impaired contraction that affects distinctly various regions of the myocardium. Our study applied cardiac magnetic resonance (CMR) feature tracking (FT) to assess comparatively myocardial strain at 3 distinct levels: subendocardial (Endo-), mid (Myo-) and subepicardial (Epi-) myocardium across an extended spectrum of patients with HF. 59 patients with HF, divided into 3 subgroups as follows: preserved ejection fraction (HFpEF, N = 18), HF with mid-range ejection fraction (HFmrEF, N = 21), HF with reduced ejection fraction (HFrEF, N = 20) and a group of age- gender- matched volunteers (N = 17) were included. Using CMR FT we assessed systolic longitudinal and circumferential strain and strain-rate at Endo-, Myo- and Epi- levels. Strain values were the highest in the Endo- layer and progressively lower in the Myo- and Epi- layers respectively, this gradient was present in all the patients groups analyzed but decreased progressively in HFmrEF and further on in HFrEF groups. GLS decreased with the severity of the disease in all 3 layers: Normal > HFpEF > HFmrEF > HFrEF (Endo-: −23.0 ± 3.5 > −20.0 ± 3.3 > −16.4 ± 2.2 > −11.0 ± 3.2, p < 0.001, Myo-: −20.7 ± 2.4 > −17.5.0 ± 2.6 > −14.5 ± 2.1 > −9.6 ± 2.7, p < 0.001; Epi-: −15.7 ± 1.9 > −12.2 ± 2.1 > −10.6 ± 2.3 > −7.7 ± 2.3, p < 0.001). In contrast, GCS was not different between the Normal and HFpEF (Endo-: −34.5 ± 6.2 vs −33.9 ± 5.7, p = 0.51; Myo-: −21.9 ± 3.8 vs −21.3 ± 2.2, p = 0.39, Epi-: −11.4 ± 2.0 vs −10.9 ± 2.3, p = 0.54) but was, as well, markedly lower in the systolic heart failure groups: Normal > HFmrEF > HFrEF (Endo-: −34.5 ± 6.2 > −20.0 ± 4.2 > 12.3 ± 4.2, p < 0.001; Myo-: −21.9 ± 3.8 > −13.0 ± 3.4 > −8.0 ± 2.7. p < 0.001; Epi-: −11.4 ± 2.0 > −7.9 ± 2.3 > −4.5 ± 1.9. p < 0.001). CMR feature tracking multilayer strain assessment identifies large range differences between distinct myocardial regions. Our data emphasizes the importance of sub-endocardial myocardium for cardiac contraction and thus, its predilect role in imaging detection of functional impairment. CMR feature tracking offers a convenient, readily available, platform to evaluate myocardial contraction with excellent spatial resolution, rendering further details about discrete areas of the myocardium. Using this technique across distinct groups of patients with heart failure (HF), we demonstrate that subendocardial regions of the myocardium exhibit much higher strain values than mid-myocardium or subepicardial and are more sensitive to detect contractile impairment. We also show comparatively higher values of circumferential strain compared with longitudinal and a higher sensitivity to detect contractile impairment. A newly characterized group of patients, HF with mid-range ejection fraction (EF), shows similar traits of decompensation but has relatively higher strain values as patients with HF with reduced EF.

P5265Magnetic resonance multilayer assessment of strain in patients with heart failure

Abstract Introduction Muscular architecture of the heart is three dimensionally complex and contractility parameters vary widely. Cardiac magnetic resonance (CMR) feature tracking is a largely available and facile method to assess myocardial strain at different layers of the myocardium. Purpose Assessing and compare the myocardial longitudinal (GLS) and circumferential strain (GCS) at three distinct layers of the myocardium in patients with heart failure (HF). Methods 59 patients with a clinical diagnosis of HF who were post-hoc subdivided according to the measured EF and echo assessment of diastolic impairment into 3 groups, following ESC guidelines, were included: (1) patients with HF with preserved ejection fraction (HFpEF) where EF &gt;50% and diastolic dysfunction (E/e' ratio) is present and plasma levels of natriuretic peptides are elevated, (2) patients with HF with mid-range ejection fraction (HFmrEF), where EF = 40–49% and similar additional criterias are present, (3) patients with HF with reduced ejection fraction (HFrEF) where EF &lt;40%. Exclusion criteria: valvulopathy, arrhythmias, insufficient acquisition and artefacts. Results Strain values are the highest in the Endo− and progressively lower in the Myo− and Epi− layers with a gradient present in all groups but decreasing in HFmEF and further in HFrEF. GLS decrease with the severity of the disease in all 3 layers Normal &gt; HFpEF &gt; HFmrEF &gt; HFrEF (Endo−: −23.0±3.5 vs −20.0±3.3 vs −16.4±2.2 vs −11.0±3.2, p&lt;0.001, Myo−: −20.7±2.4 vs −17.5.0±2.6 vs −14.5±2.1 vs −9.6±2.7, p&lt;0.001, Epi−: −15.7±1.9 vs −12.2±2.1 vs −10.6±2.3 vs −7.7±2.3, p&lt;0.001) (Figure A), GCS is not different between the Normal and HFpEF (Endo−: −34.5±6.2 vs −33.9±5.7, p=0.51; Myo−: −21.9±3.8 vs −21.3±2.2, p=0.39; Epi−: −11.4±2.0 vs −10.9±2.3, p=0.54) but markedly lower in systolic HF groups Normal &gt; HFmrEF &gt; HFrEF (Endo−: −34.5±6.2 vs −20.0±4.2 vs −12.3±4.2, p&lt;0.001; Myo−: −21.9±3.8 vs −13.0±3.4 vs −8.0±2.7, p&lt;0.001; Epi−: −11.4±2.0 vs −7.9±2.3 vs −4.5±1.9) (Figure B). ROC analysis renders Endo− GCS (AUC=0.89) and respectively Endo− GLS (AUC=0.74) as optimal to detect contractile impairment in HF with Youden's thresholds of −20.2 for Endo− GLS and, respectively, −28.1 for Endo− GCS. Endo− GCS is not different between control and HFpEF and GLS impairment is present only inconstantly in HFpEF. Conclusions Feature tracking CMR successfully assess layer-specific myocardial strain and emerges as a powerful tool in functional stratification of patients with HF. Strain amplitude varies consistently throughout the myocardium and its quantification warrants careful standardization. Sub-endocardial strain values of strain are comparatively the highest and show most predictive power to detect contractile impairment. Underlying systolic impairment is present only in a subgroup of patients with HFpEF and only GLS and not the GCS is for this purpose a useful diagnostic tool.

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.

P5253Does regional myocardial strain by cardiac magnetic resonance feature tracking reflect scar in ischemic heart disease?

Abstract Background Cardiac magnetic resonance (CMR) late gadolinium enhancement (LGE) is the gold standard for detection of myocardial scar. We hypothesized that CMR Feature Tracking (FT)-derived regional myocardial strain may reflect the presence of scar and could thus potentially be used instead of LGE imaging. Purpose The aim of this study was to determine the relationship between FT-derived regional myocardial strain and LGE in patients with coronary artery disease (CAD). Methods Seventy-five patients with CAD and typical ischemic LGE patterns on CMR (1.5T) were included (mean age 60±12 years, 70% males). Myocardial strain analysis and LGE identification were performed using dedicated commercial software. Scar was defined by presence of LGE in the same area of the myocardium in both short- and long-axis views. Peak systolic regional longitudinal and circumferential strain (RLS, RCS) values were calculated in the region of interest corresponding to the LGE area and also in a non-LGE myocardial region as a reference in each patient. These comparisons were repeated for a subgroup of 36 patients with left ventricular (LV) ejection fraction (EF) &lt;40% to determine whether the relationship between strain and LGE holds in the presence of reduced LV function, when strain measurements may be altered as a reflection of reduced LVEF itself. Results Both global longitudinal and circumferential strain values were abnormal (−12.8±5.1% and −11.4±4.1%, respectively), reflecting LV dysfunction in this CAD cohort (EF = 40±16%). The magnitude of both RLS and RCS was significantly reduced in areas of LGE, compared to those without LGE: RLS −10.0±5.8% versus −20.4±7.5% (p&lt;0.001); RCS −10.1±5.3±% versus −18.9±7.5%, respectively (p&lt;0.001). Same pattern was noted in the reduced EF subgroup: RLS −8.0±4.7% versus −16.9±6.6% (p&lt;0.001), RCS −7.7±4.3±% versus −16.0±7.9%, respectively (p&lt;0.001). The figure depicts 2 representative cases in long and short axis views, LGE detection and concomitant regional strain analysis. LGE and regional strain analysis. Conclusion Reduced magnitude of regional longitudinal and circumferential strain by CMR-FT correlates with presence of LGE. Pending further validation, this finding may constitute the basis for detection of scar without contrast enhanced imaging, and would result in reduced cost, scan time and risk associated with gadolinium. Acknowledgement/Funding ARP: Research support (software) from Neosoft and Philips

P605Correlation of left atrial phasic transport function and arrhythmogenic substrate in patients with atrial fibrillation: cardiac magnetic resonance feature tracking and bipolar voltage mapping

Abstract Background Bipolar voltage mapping is a widely accepted approach to identify areas of arrhythmogenic substrate in patients presenting for atrial fibrillation (AF) ablation. However, until now little is known about the correlation of left atrial (LA) bipolar voltage distribution and LA transport function. Purpose To study the impact of LA low voltage zones (LVZ) on LA transport function. Methods 107 consecutive patients presenting for ablation of symptomatic AF (34 paroxysmal AF, 73 persistent AF) were prospectively enrolled. Each patient underwent cardiac magnetic resonance imaging (CMR) within 24 hours prior to the ablation procedure. 59 patients were in sinus rhythm (SR) and 48 in AF. LA phasic indexed volumes (LAVi) and ejection fractions were calculated using biplane area length formula. In addition LA phasic strains and strain rates were analyzed using dedicated software (Figure 1A &amp; B). LA bipolar voltage mapping was performed prior to beginning of ablation in sinus rhythm using a 3-dimensional mapping system and LVZ were defined as areas of bipolar voltage &lt;0.5mV. Results LVZ were present in 47 patients (23 in SR). The area of LVZ was 14.6cm2 (5.3–34.0). For patients in AF at the time of CMR only elevated minimal and maximal LAVi (p=0.001 and p=0.002 respectively) but no LA functional parameter was predictive for the occurrence of LVZ. In contrast for patients in SR all LA phasic volumes (endsystolic, pre atrial contraction and enddiastolic LAVi) and LA function parameters (passive, active and total ejection fraction (EF), reservoir, conduit and booster pump strains and strain rates) were predictive for the occurrence of LVZ. After clustered and pooled multivariate logistic regression only impaired booster pump strain rate was still predictive for occurrence of LVZ (OR 0.974, 95% CI 0.950–0.998, p=0.036). In addition Pearson correlation analysis revealed a strong link between LA booster pump functional parameters and cm2 expansion of LVZ areas: LA active EF, LA booster pump strain and SR (r=−0.42, p=0.044; r=−0.47, p=0.024; r=−0.65, p=0.001 [Figure 1C] respectively). Conclusion For patients in SR LA transport function is closely linked to the occurrence of LA LVZ and outperforms LA volumetric measurements for the prediction of LA LVZ. Furthermore LA booster pump function parameters show robust correlation to the extension of LA LVZ.

4937Global longitudinal strain by feature tracking predicts adverse remodeling in ST-elevation myocardial infarction incremental to

Abstract Objectives To evaluate the independent and incremental value of left ventricular (LV) strain assessed by cardiac magnetic resonance feature tracking (CMR-FT) for prediction of adverse LV remodeling following ST-elevation myocardial infarction (STEMI). Background The role of LV myocardial strain by CMR-FT for prediction of adverse remodeling after STEMI in comparison to LV ejection fraction and infarct severity is unclear. Methods STEMI patients treated with primary percutaneous coronary intervention within 24 hours after symptom onset were enrolled. CMR core laboratory analysis was performed to assess LV ejection fraction, infarct pathology and LV myocardial strain. The primary endpoint was adverse remodeling defined as ≥20% increase in LV end-diastolic volume from baseline to 4 months. Results From the 232 patients included, 38 (16.4%) reached the primary endpoint. Global longitudinal strain (GLS), global radial strain, and global circumferential strain were all predictive of adverse remodeling (p&lt;0.01 for all), but among strain values only GLS was an independent predictor of adverse remodeling (hazard ratio: 1.36 [1.03–1.78]; p=0.028) after adjustment for strain parameters, ejection fraction and CMR markers of infarct severity. A GLS &gt;-14% was associated with a 4-fold increase in risk for LV remodeling (hazard ratio: 4.16 [1.56–11.13]; p=0.005). Addition of GLS to a baseline model comprising ejection fraction, infarct size and microvascular obstruction resulted in net reclassification improvement of 0.26 ([0.13–0.38]; p&lt;0.001) and integrated discrimination improvement of 0.02 ([0.01–0.03]; p=0.006). Conclusions In STEMI survivors, determination of GLS using CMR-FT provides important prognostic information for the development of adverse remodeling that is incremental to LV ejection fraction and CMR markers of infarct severity.

Early detection of left atrial dysfunction assessed by CMR feature tracking in hypertensive patients.

To evaluate whether early left atrial (LA) dysfunction in hypertension (HTN), with or without left ventricular hypertrophy (LVH), can be detected by cardiovascular magnetic resonance feature tracking (CMR-FT). Seventy-three HTN patients and 29 healthy controls were retrospectively recruited. HTN patients were divided into the LVH (n = 29) and non-LVH group (n = 44). LA performance was analysed using CMR-FT in 2- and 4-chamber cine images, including LA reservoir function (total ejection fraction [EF], total strain [εs], peak positive strain rate [SRs]), conduit function (passive EF, passive strain [εe], peak early negative strain rate [SRe]) and booster pump function (booster EF, active strain [εa], late peak negative strain rate [SRa]). One-way analysis of variance with post hoc LSD tests, Spearman analysis, receiver operating characteristic curve and intra-class correlation coefficient analysis were applied for statistical analyses. Compared with healthy controls, LA reservoir (LA total EF, εs, SRs) and conduit function (LA passive EF, εe, SRe) were significantly impaired in HTN patients with or without LVH, and these parameters significantly correlated with mitral E/A < 1 (all p < 0.05). However, LA booster pump function was relatively preserved in non-LVH patients, representing an intermediate stage between the LVH group and controls. Among LA deformation parameters, εe showed the highest diagnostic value for differentiation of HTN patients with healthy controls (AUC, 0.82; sensitivity, 80.82%; specificity, 72.41%). Observer reproducibility was good-excellent (ICC, 0.83-0.97) for all CMR-FT derived parameters. CMR-FT is a promising tool for quantification of LA function. LA reservoir and conduit dysfunction might be detected early by CMR-FT in HTN patients before the presence of LVH. • CMR-FT is a promising tool in quantifying LA function, including deformation and volumetric parameters. • LA reservoir and conduit dysfunction might be detected early by CMR-FT in HTN patients with or without LVH. • The LA booster pump function was relatively preserved in non-LVH patients.

Assessment of Global Longitudinal and Circumferential Strain Using Computed Tomography Feature Tracking: Intra-Individual Comparison with CMR Feature Tracking and Myocardial Tagging in Patients with Severe Aortic Stenosis.

In this study, we used a single commercially available software solution to assess global longitudinal (GLS) and global circumferential strain (GCS) using cardiac computed tomography (CT) and cardiac magnetic resonance (CMR) feature tracking (FT). We compared agreement and reproducibility between these two methods and the reference standard, CMR tagging (TAG). Twenty-seven patients with severe aortic stenosis underwent CMR and cardiac CT examinations. FT analysis was performed using Medis suite version 3.0 (Leiden, The Netherlands) software. Segment (Medviso) software was used for GCS assessment from tagged images. There was a trend towards the underestimation of GLS by CT-FT when compared to CMR-FT (19.4 ± 5.04 vs. 22.40 ± 5.69, respectively; p = 0.065). GCS values between TAG, CT-FT, and CMR-FT were similar (p = 0.233). CMR-FT and CT-FT correlated closely for GLS (r = 0.686, p < 0.001) and GCS (r = 0.707, p < 0.001), while both of these methods correlated moderately with TAG for GCS (r = 0.479, p < 0.001 for CMR-FT vs. TAG; r = 0.548 for CT-FT vs. TAG). Intraobserver and interobserver agreement was excellent in all techniques. Our findings show that, in elderly patients with severe aortic stenosis (AS), the FT algorithm performs equally well in CMR and cardiac CT datasets for the assessment of GLS and GCS, both in terms of reproducibility and agreement with the gold standard, TAG.

Early Left Ventricular Involvement Detected by Cardiovascular Magnetic Resonance Feature Tracking in Arrhythmogenic Right Ventricular Cardiomyopathy: The Effects of Left Ventricular Late Gadolinium Enhancement and Right Ventricular Dysfunction.

BackgroundLeft ventricular (LV) involvement is common in arrhythmogenic right ventricular cardiomyopathy (ARVC). We aim to evaluate LV involvement in ARVC patients by cardiovascular magnetic resonance feature tracking.Methods and ResultsSixty‐eight patients with ARVC and 30 controls were prospectively enrolled. ARVC patients were divided into 2 subgroups: the preserved LV ejection fraction (LVEF) group (LVEF ≥55%, n=27) and the reduced LVEF group (LVEF <55%, n=41). Cardiovascular magnetic resonance with late gadolinium enhancement (LGE) and cardiovascular magnetic resonance feature tracking were performed in all subjects. LV global and regional (basal, mid, apical) peak strain (PS) in radial, circumferential and longitudinal directions were assessed, respectively. Right ventricular global PS in three directions were also analyzed. Compared with the controls, LV global and regional PS were all significantly impaired in the reduced LVEF group (all P<0.05). However, only LV global longitudinal PS as well as mid and apical longitudinal PS were impaired in the preserved LVEF group (all P<0.05), and all these parameters were significantly associated with right ventricular global radial PS (r=−0.47, −0.47, and −0.49, respectively, all P<0.001). The reduced LVEF group showed significantly higher prevalence of LGE (95.10% versus 63.00%, P=0.002) than the preserved LVEF group. Moreover, LV radial PS was significantly reduced in LV segments with LGE (33.15±20.42%, n=46) than those without LGE (41.25±15.98%, n=386) in the preserved LVEF group (P=0.016).ConclusionsIn patients with ARVC, cardiovascular magnetic resonance feature tracking could detect early LV dysfunction, which was associated with LV myocardial LGE and right ventricular dysfunction.

Cardiac Magnetic Resonance Left Ventricular Mechanical Uniformity Alterations for Risk Assessment After Acute Myocardial Infarction

BackgroundDespite limitations as a stand‐alone parameter, left ventricular (LV) ejection fraction is the preferred measure of myocardial function and marker for postinfarction risk stratification. LV myocardial uniformity alterations may provide superior prognostic information after acute myocardial infarction, which was the subject of this study.Methods and ResultsConsecutive patients with acute myocardial infarction (n=1082; median age: 63 years; 75% male) undergoing cardiac magnetic resonance at a median of 3 days after infarction were included in this multicenter observational study. Circumferential and radial uniformity ratio estimates were derived from cardiac magnetic resonance feature tracking as markers of mechanical uniformity alterations (values between 0 and 1 with 1 reflecting perfect uniformity). The clinical end point was the 12‐month rate of major adverse cardiac events, consisting of all‐cause death, reinfarction, and new congestive heart failure. Patients with major adverse cardiac events (n=73) had significantly impaired circumferential uniformity ratio estimates (0.76 [interquartile range: 0.67–0.86] versus 0.84 [interquartile range: 0.76–0.89]; P<0.001) and radial uniformity ratio estimates (0.69 [interquartile range: 0.60–0.79] versus 0.76 [interquartile range: 0.67–0.83]; P<0.001) compared with patients without events. Although uniformity estimates did not provide independent prognostic information in the overall cohort, a circumferential uniformity ratio estimate below the median of 0.84 emerged as an independent predictor of outcome in postinfarction patients with LV ejection fraction >35% (n=959), even after adjustment for established risk factors (hazard ratio: 1.99; 95% CI, 1.06–3.74; P=0.033 in multivariable Cox regression analysis). In contrast, LV ejection fraction was not associated with adverse events in this subgroup of patients with acute myocardial infarction.ConclusionsCardiac magnetic resonance–derived estimates of mechanical uniformity alterations are novel markers for risk assessment after acute myocardial infarction, and the circumferential uniformity ratio estimate provides independent prognostic information for patients with preserved or only moderately reduced LV ejection fraction.

Normal left atrial strain and strain rate using cardiac magnetic resonance feature tracking in healthy volunteers.

The aim of our study was to establish normal ranges for left atrial (LA) strain and strain rate using cardiac magnetic resonance feature tracking (CMR-FT), LA sphericity index, and to compare LA strain using CMR-FT with 2D-speckle tracking echocardiography (STE) in a healthy population. A total of 112 volunteers (45 male, 67 female) had adequate tracking for analysis on CMR-FT (Circle Cardiovascular Imaging, Calgary, Canada). The median age was 42 years (range 19-79 years, interquartile range 30-53 years). LA reservoir, conduit, booster strain, strain rate using CMR-FT, and sphericity index were evaluated. Of the 112 volunteers, 91 patients had adequate tracking on 2D-STE using three commonly applied zero-baseline time reference methods: R-R gating, P-P gating, and volume gating (defining end-systole at the LA maximum and end-diastole at the LA minimum). The LA strain, strain rate using CMR-FT, and sphericity index were reported and comparable between both genders (P > 0.05 for all). The LA booster function including strain and strain rate increased significantly with age (P < 0.001 for all), while the LA conduit function gradually decreased. In comparison with STE, the LA reservoir strain was comparable between CMR and volume-gating methods (38.48 ± 9.31 vs. 36.77 ± 6.46; P = 0.13) but not with R-R and P-P gating methods (P < 0.001 for all). LA strain, strain rate, and sphericity index using CMR-FT had good intraobserver and interobserver reproducibility. LA strain, strain rate using CMR-FT, and sphericity index can be quickly assessed with good intraobserver and interobserver reproducibility.

P162Segmental left ventricular strain measurements using cardiac magnetic resonance feature tracking - reproducibility and accuracy among four vendors

P162Segmental left ventricular strain measurements using cardiac magnetic resonance feature tracking - reproducibility and accuracy among four vendors

232Evaluation of left ventricular strain assessment cardiac magnetic resonance-feature tracking in STEMI patients at different time points during a long term follow-up

232Evaluation of left ventricular strain assessment cardiac magnetic resonance-feature tracking in STEMI patients at different time points during a long term follow-up

Fast manual long-axis strain assessment provides optimized cardiovascular event prediction following myocardial infarction.

Cardiovascular magnetic resonance feature tracking (CMR-FT) global longitudinal strain (GLS) provides incremental prognostic value following acute myocardial infarction (AMI) but requires substantial post-processing. Alternatively, manual global long-axis strain (LAS) can be easily assessed from standard steady state free precession images. We aimed to define the prognostic value of LAS in a large multicentre study in patients following AMI. A total of 1235 patients with myocardial infarction [n = 795 with ST-elevation myocardial infarction (STEMI) and 440 with non-ST-elevation myocardial infarction (NSTEMI)] underwent cardiovascular magnetic resonance imaging after primary percutaneous coronary intervention in eight centres across Germany. Assessment of LAS was performed in a blinded core-laboratory measuring the systolic shortening between the epicardial apical border and the middle of a line connecting the origins of the mitral leaflets. Primary clinical endpoint was the occurrence of major adverse clinical events (MACE) including death, reinfarction, and congestive heart failure within 1 year after AMI. During 1-year follow-up, 76 patients suffered from MACE. Impaired LAS was associated with higher MACE occurrence both in STEMI (P < 0.001) and NSTEMI (P = 0.001) patients. Association of LAS remained significant (P = 0.017) after correction for univariate significant parameters for MACE prediction. C-statistics revealed incremental value of additional LAS assessment for optimized event prediction compared with left ventricular ejection fraction (MACE P = 0.044; mortality P = 0.013) and a combination of established clinical and imaging parameters (MACE P = 0.084; mortality P = 0.027), but not CMR-FT GLS (MACE P = 0.075; mortality P = 0.380). LAS provides software independent, widely available, easy and fast approximation of longitudinal left ventricular shortening early after reperfused AMI with incremental prognostic value beyond established risk stratification parameters. NCT00712101 and NCT01612312.

Right and Left Ventricular Strain Patterns After the Atrial Switch Operation for D-Transposition of the Great Arteries-A Magnetic Resonance Feature Tracking Study.

Introduction: Adult survivors of the atrial switch operation for transposition of the great arteries present with a systemic morphologic right ventricle and a subpulmonary morphologic left ventricle. This physiology can be considered a model for the effects of long-term right ventricular pressure overload and of decreased left ventricular afterload. We aimed to determine the impact of these chronically altered loading conditions on myocardial deformation of the ventricles.Materials and methods: Two-dimensional steady state free precession cine images of 29 patients after atrial repair (age 29 ± 7 years) and 19 controls (24 ± 10 years; n.s.) were post-processed with feature tracking software (TomTec 2D CPA). Volumes, ejection fractions, global and free wall longitudinal and circumferential strains of both ventricles were compared between both groups.Results: Systemic right ventricular global longitudinal strain was decreased in patients compared to controls (−12.9 ± 3.3% vs. −18.9 ± 4.6%, p < 0.001), while right ventricular circumferential strain was unchanged (−15.8 ± 3.4% vs. −15.1 ± 5%; n.s.). Left ventricular longitudinal strain was similar in both groups (−17 ± 5.6% vs. −17.5 ± 4.6%; n.s.), but global left ventricular circumferential strain was lower in patients (−20.7 ± 4.1% vs. −27.3 ± 4.5%, p < 0.001). The systemic right ventricle, compared to the systemic left ventricle, showed decreased global longitudinal (p < 0.001) and circumferential strain (p < 0.001). The subpulmonary left ventricle, compared to the subpulmonary right ventricle, demonstrated similar longitudinal (p = 0.223) but higher circumferential strain (p < 0.001).Conclusions: In patients after atrial switch repair for transposition of the great arteries, the systemic right ventricle shows poor longitudinal strain, but maintains normal right ventricular circumferential strain. The left ventricle shows higher circumferential strain than the right ventricle, in both systemic and subpulmonary positions.

Two-dimensional and three-dimensional cardiac magnetic resonance feature-tracking myocardial strain analysis in acute myocarditis patients with preserved ejection fraction.

To explore the potential role of two- (2D) and three-dimensional (3D) cardiac magnetic resonance (CMR) feature tracking (FT) myocardial strain analysis in identifying sub-clinical myocardial systolic and diastolic dysfunction in acute myocarditis patients with preserved ejection fraction (EF). Prospective two centre study-control study. Thirty patients (9 female, 37.2 ± 11.8years.) with a CMR diagnosis of acute myocarditis according to the Lake Louise Criteria and preserved EF (≥ 55%) were included in the analysis. CMR data from 24 healthy volunteers (11 female, 36.2 ± 12.5years.) served as control. 2D and 3D LV tissue tracking analysis were performed in a random fashion by two double-blinded operators. Variables were checked for normality and analysed with parametric test. The baseline characteristics of myocarditis patients with preserved EF and the healthy volunteers were perfectly comparable, except for the LV mass index and T1 and T2 mapping values (p < 0.001). The results of the interobserver variability in the 2D and 3D LV CMR FT myocardial strain analysis were p > 0.42, ICC > 0.80 and η2 > 0.98. There was no statistical difference in 2D and 3D global radial, circumferential and longitudinal strain peak (%) and both systolic and diastolic strain rate (1/s) between acute myocarditis with preserved EF and healthy volunteers (all p = ns). There were no difference in 2D and 3D global radial, circumferential and longitudinal strain peak and both systolic and diastolic strain rate of the LV between acute myocarditis patients with preserved ejection fraction and healthy volunteers.

Prognostic Value of Left Ventricular Function and Mechanics in Pulmonary Hypertension: A Pilot Cardiovascular Magnetic Resonance Feature Tracking Study.

Background and objective: Cardiovascular magnetic resonance (CMR) - based feature tracking (FT) can detect left ventricular (LV) strain abnormalities in pulmonary hypertension (PH) patients, but little is known about the prognostic value of LV function and mechanics in PH patients. The aim of this study was to evaluate LV systolic function by conventional CMR and LV global strains by CMR-based FT analysis in precapillary PH patients, thereby defining the prognostic value of LV function and mechanics. Methods: We prospectively enrolled 43 patients with precapillary PH (mean pulmonary artery pressure (mPAP) 55.91 ± 15.87 mmHg, pulmonary arterial wedge pressure (PAWP) ≤15 mmHg) referred to CMR for PH evaluation. Using FT software, the LV global longitudinal strain (GLS) and global circumferential strain (GCS), also right ventricular (RV) GLS were analyzed. Results: Patients were classified into two groups according to survival (survival/non-survival). LV GLS was significantly reduced in the non-survival group (−12.4% [−19.0–(−7.8)] vs. −18.4% [−22.5–(−15.5)], p = 0.009). By ROC curve analysis, LV GLS > −14.2% (CI: 3.229 to 37.301, p < 0.001) was found to be robust predictor of mortality in PH patients. Univariable analysis using the Cox model showed that severely reduced LV GLS > −14.2%, with good sensitivity (77.8%) and high specificity (93.5%) indicated an increase of the risk of death by 11-fold. LV GLS significantly correlated in PH patients with RV ESVI (r = 0.322, p = 0.035), RV EF (r = 0.444, p < 0.003). Conclusions: LV systolic function and LV global longitudinal strain measurements using CMR-FT correlates with RV dysfunction and is associated with poor clinical outcomes in precapillary PH patients.

Additional Prognostic Value of 2D Right Ventricular Speckle-Tracking Strain for Prediction of Survival in Heart Failure and Reduced Ejection Fraction: A Comparative Study With Cardiac Magnetic Resonance

ObjectivesThis study sought to compare the prognostic value of 2-dimensional (2D) right ventricular (RV) speckle tracking (STE) against cardiac magnetic resonance (CMR) RV ejection fraction (EF) and feature tracking (FT) and conventional echocardiographic parameters on overall and cardiovascular (CV) survival in patients with heart failure with reduced EF (HFrEF). BackgroundPrior works showed that RV systolic function predicts prognosis in HFrEF. 2D RVSTE had recently been proposed as new echocardiographic method to evaluate RV dysfunction. MethodsA total of 266 patients with HFrEF (mean LVEF 23 ± 7%, 60 ± 14 years of age; 29% women) underwent RV function assessment using CMR and 2D echocardiography and were followed for a primary endpoint of overall death and secondary endpoint of CV death. ResultsAverage CMR-RVEF was 42 ± 15%, average STE RV global longitudinal strain (STE-RVGLS) was −18.0 ± 4.9%, and average CMR-FT-RVGLS was −11.8 ± 4.3%. After a median follow-up of 4.7 years, 102 patients died, 84 of a CV cause. RVEF, FT-RVGLS, tricuspid annulus plane systolic excursion (TAPSE), fractional area change (FAC), and STE-RVGLS were significant univariate predictors of overall and cardiac death. In multivariate Cox regression, age, ischemic etiology, diabetes, New York Heart Association functional class III to IV, and beta-blocker treatment were independent clinical predictors of overall mortality. CMR-RVEF (chi-square to enter = 3.9; p < 0.05), FT-RVGLS (chi-square to enter 3.7; p = 0.05), FAC (chi-square to enter 6.2; p = 0.02), and TAPSE (chi-square to enter = 4.1; p = 0.04) provided additional prognostic value over these baseline parameters, but the additional predictive value of STE-RVGLS (chi-square to enter = 10.8; p < 0.001) was significantly (p < 0.05) higher than the other tests. Additional hazard ratio to predict overall mortality was 2.5 (95% confidence interval [CI]: 1.6 to 3.9) for STE-RVGLS <−19%, 2.15 (95% CI: 1.34 to 3.43) for TAPSE >15 mm, 1.6 (95% CI: 1.02 to 2.49) for FAC >39%, 1.93 (95% CI: 1.25 to 2.99) for RVEF >41%, and 1.87 (95% CI: 1.10 to 3.19) for CMR-FT-RVGLS <−15%. Conclusions2D RVGLS provides strong additional prognostic value to predict overall and CV mortality in HFrEF, with higher predictive value than CMR-RVEF, CMR-FT-RVGLS, TAPSE, or FAC. This supports use of STE-RVGLS to identify higher-risk HFrEF patients.

Prognostic value of left atrial function by cardiovascular magnetic resonance feature tracking in hypertrophic cardiomyopathy.

Left atrium (LA) size has an important role in determining prognosis and risk stratification in hypertrophic cardiomyopathy (HCM). Cardiovascular magnetic resonance myocardial feature tracking (CMR-FT) is a novel technique for the quantification of LA function. Our aim was first to evaluate LA function by CMR-FT and volumetric analysis in patients with HCM; and secondly we sought to determine the association of LA-longitudinal strain (LA-LS) with major cardiovascular outcomes, particularly all cause mortality and heart failure. 75 patients with HCM and 75 control subjects underwent a conventional CMR study including assessment of LA function by CMR-FT (LA-LS) and volumetric analysis. A primary endpoint of all-cause mortality and secondary combined endpoint of hospital admission related to heart failure, lethal ventricular arrhythmias or cardiovascular death were defined. Compared to controls, LA-LS and all volumetric indices of LA function were significantly impaired in HCM even in patients with normal LA volume and normal LV filling pressures. LA-LS showed moderate-high correlation with LA-emptying fraction (total, active and passive LA-EF, r = 0.68, r = 0.67, r = 0.31, p < 0.001 for all) and with parameters of diastolic function (E/é, r = 0.4, p < 0.001). The age, minimum LA volume and % of LGE were independent predictors of LA-LS (p < 0.01 for all). During a mean follow-up of 3.3 ± 1.2years LA-LS was associated with the primary (HR: 0.85 (0.73-0.98), p = 0.02) and the secondary end-point (HR: 0.88 (0.82-0.96), p = 0.003). LA-LS by CMR-FT provides accurate measurements of LA function in HCM patients. LA-LS may become a novel potential predictor of poor cardiac outcomes, particularly cardiovascular mortality and HF.

Cardiovascular magnetic resonance imaging feature tracking: Impact of training on observer performance and reproducibility

BackgroundCardiovascular magnetic resonance feature tracking (CMR-FT) is increasingly used for myocardial deformation assessment including ventricular strain, showing prognostic value beyond established risk markers if used in experienced centres. Little is known about the impact of appropriate training on CMR-FT performance. Consequently, this study aimed to evaluate the impact of training on observer variance using different commercially available CMR-FT software.MethodsIntra- and inter-observer reproducibility was assessed prior to and after dedicated one-hour observer training. Employed FT software included 3 different commercially available platforms (TomTec, Medis, Circle). Left (LV) and right (RV) ventricular global longitudinal as well as LV circumferential and radial strains (GLS, GCS and GRS) were studied in 12 heart failure patients and 12 healthy volunteers.ResultsTraining improved intra- and inter-observer reproducibility. GCS and LV GLS showed the highest reproducibility before (ICC >0.86 and >0.81) and after training (ICC >0.91 and >0.92). RV GLS and GRS were more susceptible to tracking inaccuracies and reproducibility was lower. Inter-observer reproducibility was lower than intra-observer reproducibility prior to training with more pronounced improvements after training. Before training, LV strain reproducibility was lower in healthy volunteers as compared to patients with no differences after training. Whilst LV strain reproducibility was sufficient within individual software solutions inter-software comparisons revealed considerable software related variance.ConclusionObserver experience is an important source of variance in CMR-FT derived strain assessment. Dedicated observer training significantly improves reproducibility with most profound benefits in states of high myocardial contractility and potential to facilitate widespread clinical implementation due to optimized robustness and diagnostic performance.