Magnetic resonance tissue phase mapping of myocardial motion: new insight in age and gender

Sex Differences in Cardiac and Clinical Phenotypes and Their Relation to Outcomes in Patients with Heart Failure

Biological sex is one of the major factors characterizing the heart failure (HF) patient phenotype. Understanding sex-related differences in HF is crucial to implement personalized care for HF patients with various phenotypes. There are sex differences in left ventricular (LV) remodeling patterns in the HF setting, namely, more likely concentric remodeling and diastolic dysfunction in women and eccentric remodeling and systolic dysfunction in men. Recently supra-normal EF (snLVEF) has been recognized as a risk of worse outcome. This pathology might be more relevant in female patients. The possible mechanism may be through coronary microvascular dysfunction and sympathetic nerve overactivation from the findings of previous studies. Further, estrogen deficit might play a significant role in this pathophysiology. The sex difference in body composition may also be related to the difference in LV remodeling and outcome. Lower implementation in guideline-directed medical therapy (GDMT) in female HFrEF patients might also be one of the factors related to sex differences in relation to outcomes. In this review, we will discuss the sex differences in cardiac and clinical phenotypes and their relation to outcomes in HF patients and further discuss how to provide appropriate treatment strategies for female patients.

Unravelling the intricacies of left ventricular haemodynamic forces: age and gender-specific normative values assessed by cardiac MRI in healthy adults

AIMS

Haemodynamic forces (HDFs) provided a feasible method to early detect cardiac mechanical abnormalities by estimating the intraventricular pressure gradients. The novel advances in assessment of HDFs using routine cardiac magnetic resonance (CMR) cines shed new light on detection of preclinical dysfunction. However, definition of normal values for this new technique is the prerequisite for application in the clinic.

METHODS AND RESULTS

A total of 218 healthy volunteers [38.1 years ± 11.1; 111 male (50.9%)] were recruited and underwent CMR examinations with a 3.0T scanner. Balanced steady state free precession breath hold cine images were acquired, and HDF assessments were performed based on strain analysis. The normal values of longitudinal and transversal HDF strength [root mean square (RMS)] and ratio of transversal to longitudinal HDF were all evaluated in overall population as well as in both genders and in age-specific groups. The longitudinal RMS values (%) of HDFs were significantly higher in women (P < 0.05). Moreover, the HDF amplitudes significantly decreased with ageing in entire heartbeat, systole, diastole, systolic/diastolic transition, and diastolic deceleration, while increased in atrial thrust. In multivariable linear regression analysis, age, heart rate, and global longitudinal strain emerged as independent predictors of the amplitudes of longitudinal HDFs in entire heartbeat and systole, while left ventricular end-diastole volume index was also independently associated with longitudinal HDFs in diastole and diastolic deceleration (P < 0.05 for all).

CONCLUSION

Our study provided comprehensive normal values of HDF assessments using CMR as well as presented with specific age and sex stratification. HDF analyses can be performed with excellent intra- and inter-observer reproducibility.

Right Ventricular Remodeling Assessed by MRI in Duchenne Muscular Dystrophy

BACKGROUND

In Duchenne muscular dystrophy (DMD), the right ventricle (RV) tends to be relatively well preserved, but characterization remains difficult due to its complex architecture. Tissue phase mapping (TPM) is a phase contrast cine MRI technique that allows for multidirectional assessment of myocardial velocities.

PURPOSE

To use TPM to elucidate relationships between myocardial structure, function, and clinical variables in DMD.

STUDY TYPE

Retrospective.

SUBJECTS

A total of 20 patients with muscular dystrophy (median age: 16 years); 18 age-matched normal controls (median age: 15 years).

FIELD STRENGTH/SEQUENCE

Three-directional velocity encoded cine gradient echo sequence (TPM) at 1.5 T, balanced steady-state free procession (bSSFP), T1 mapping with extracellular volume (ECV), and late gadolinium enhancement (LGE).

ASSESSMENT

TPM in basal, mid, and apical short-axis planes was performed as part of a standard MRI study with collection of clinical data. Radial, circumferential, and longitudinal velocities (Vr, Vφ, and Vz, respectively) and corresponding time to peak (TTP) velocities were quantified from TPM and used to calculate RV twist as well as intraventricular and interventricular dyssynchrony. The correlations between TPM velocities, myocardial structure/function, and clinical variables were assessed.

STATISTICAL TEST

Unpaired t-test, Wilcoxon rank-sum test, Bland-Altman analyses were used for comparisons between DMD patients and controls and between DMD subgroups. Pearson's test was used for correlations (r). Significance level: P < 0.05.

RESULTS

Compared to controls, DMD patients had preserved RV ejection fraction (RVEF 53% ± 8%) but significantly increased interventricular dyssynchrony (Vφ: 0.49 ± 0.21 vs. 0.72 ± 0.17). Within the DMD cohort, RV dyssynchrony significantly increased with lower LV ejection fraction (intraventricular Vr and Vz: r = -0.49; interventricular Vz: r = 0.48). In addition, RV intraventricular dyssynchrony significantly increased with older age (Vz: r = 0.67).

DATA CONCLUSION

RV remodeling in DMD occurs in the context of preserved RVEF. Within DMD, this abnormal RV deformation is associated with older age and decreased LVEF.

EVIDENCE LEVEL

4.

TECHNICAL EFFICACY

Stage 2.

Myocardial strain imaging in Duchenne muscular dystrophy

Cardiomyopathy (CM) is the leading cause of death for individuals with Duchenne muscular dystrophy (DMD). While DMD CM progresses rapidly and fatally for some in teenage years, others can live relatively symptom-free into their thirties or forties. Because CM progression is variable, there is a critical need for biomarkers to detect early onset and rapid progression. Despite recent advances in imaging and analysis, there are still no reliable methods to detect the onset or progression rate of DMD CM. Cardiac strain imaging is a promising technique that has proven valuable in DMD CM assessment, though much more work has been done in adult CM patients. In this review, we address the role of strain imaging in DMD, the mechanical and functional parameters used for clinical assessment, and discuss the gaps where emerging imaging techniques could help better characterize CM progression in DMD. Prominent among these emerging techniques are strain assessment from 3D imaging and development of deep learning algorithms for automated strain assessment. Improved techniques in tracking the progression of CM may help to bridge a crucial gap in optimizing clinical treatment for this devastating disease and pave the way for future research and innovation through the definition of robust imaging biomarkers and clinical trial endpoints.

Differential Adaptation of Biventricular Myocardial Kinetic Energy in Patients With Repaired Tetralogy of Fallot Assessed by MR Tissue Phase Mapping

BACKGROUND

The myocardial kinetic energy (KE) and its association with pulmonary regurgitation (PR) have yet to be investigated in repaired tetralogy of Fallot (rTOF) patients.

PURPOSE

To evaluate the adaptation of myocardial KE in rTOF patients by tissue phase mapping (TPM).

STUDY TYPE

Prospective.

POPULATION

A total of 49 rTOF patients (23 ± 5 years old; male = 32), 47 normal controls (22 ± 1 year old; male = 29).

FIELD STRENGTH/SEQUENCE

3-T/2D dark-blood three-directional velocity-encoded gradient-echo sequence.

ASSESSMENT

Left and right ventricle (LV, RV) myocardial KE in radial (KE_r ), circumferential (KE_ø ), longitudinal (KE_z ) directions. The proportions of KE in each direction to the sum of all KE (KE_røz ): %KE_r , %KE_ø , %KE_z . PR fraction.

STATISTICAL TEST

Student's t test, multivariable regression. Statistical significance: P < 0.05.

RESULTS

In rTOF group, LV KE_z remained normal in systole (P = 0.565) and diastole (P = 0.210), whereas diastolic LV %KE_z (62% ± 14% vs. 72% ± 7%) and systolic LV %KE_ø (9% ± 6% vs. 20% ± 7%) were significantly decreased. The KE_r and %KE_r of both ventricles significantly increased in the rTOF group (RV in diastole: 6 ± 3 vs. 3 ± 1 μJ and 54% ± 13% vs. 27% ± 7%). The rTOF group exhibited significantly higher RV/LV ratios of %KE_r (systole: 1.3 ± 0.3 vs. 1.0 ± 0.3) and %KE_ø (systole: 1.6 ± 0.8 vs. 1.0 ± 0.3) and significantly lower ratios of %KE_z in systole (0.7 ± 0.2 vs. 1.0 ± 0.1) and diastole (0.5 ± 0.2 vs. 0.9 ± 0.1). In multivariable regression analysis, the RV peak systolic KE_røz , RV systolic KE_z , and LV diastolic %KE_ø were independently associated with PR fraction in the rTOF group (adjusted R²  = 0.479).

DATA CONCLUSION

In rTOF patients, the adaptation of the KE proportion occurred earlier than that of the KE amplitude, and the biventricular balance of %KE was disrupted. PR may cause differential KE adaptation in RV and LV. TPM-derived KE may be useful in investigation of myocardial adaptation in rTOF patients.

EVIDENCE LEVEL

2 TECHNICAL EFFICACY: Stage 3.

Hypertension in Women: A South-Asian Perspective

Introduction

Hypertension is an important contributor to cardiovascular disease related morbidity and mortality. Despite the magnitude of its negative impact on cardiovascular outcomes, treatment and control of hypertension remain suboptimal in both men and women.

Materials and Methods

Numerous databases, i.e., PubMed, ScienceDirect, etc., were searched using keywords to identify relevant studies to our narrative review. The findings from the most pertinent articles were summarized and integrated into our narrative review on hypertension in women.

Results

The pathophysiology of essential hypertension is still being delineated in both men and women; there are multiple sex specific factors in association with the development of hypertension in women, including age, combined oral contraceptives (COCs), polycystic ovarian syndrome (PCOS), preeclampsia, etc. There are several sex specific considerations in antihypertensives drug choices.

Discussion

Despite the magnitude of its negative impact on cardiovascular outcomes, treatment and control of hypertension remain suboptimal in women. Medical treatment and adherence is uniquely challenging for South Asian women due to a variety of socio-cultural-economic factors. Further research is warranted to identify optimal sex-specific treatment options that will improve the control of hypertension and decrease the risk of subsequent cardiovascular disease in both genders.

Dual-phase imaging of cardiac metabolism using hyperpolarized pyruvate

PURPOSE

Previous cardiac imaging studies using hyperpolarized (HP) [1-13 C]pyruvate were acquired at end-diastole (ED). Little is known about the interaction between cardiac cycle and metabolite content in the myocardium. In this study, we compared images of HP pyruvate and products at end-systole (ES) and ED.

METHODS

A dual-phase 13 C MRI sequence was implemented to acquire two sequential HP images within a single cardiac cycle at ES and ED during successive R-R intervals in an interleaved manner. Each healthy volunteer (N = 3) received two injections of HP [1-13 C]pyruvate for the dual-phase imaging on the short-axis and the vertical long-axis planes. Spatial distribution of HP 13 C metabolites at each cardiac phase was correlated to multiphase 1 H MRI to confirm the mechanical changes. Ratios of myocardial HP metabolites were compared between ES and ED. Segmental analysis was performed on the midcavity short-axis plane.

RESULTS

In addition to mechanical changes, metabolic profiles of the heart detected by HP [1-13 C]pyruvate differed between ES and ED. The myocardial signal of [13 C]bicarbonate relative to [1-13 C]lactate was significantly smaller at ED than the ratio at ES (p < .05), particularly in mid-anterior and mid-inferoseptal segments. The distinct metabolic profiles in the myocardium likely reflect the technical aspects of the imaging approach such as the coronary flow in addition to the cyclical changes in metabolism.

CONCLUSION

The study demonstrates that metabolic profiles of the heart, measured by HP [1-13 C]pyruvate, are affected by the cardiac cycle in which that the data are acquired.

Diastolic Cardiac Function by MRI-Imaging Capabilities and Clinical Applications

Most cardiac studies focus on evaluating left ventricular (LV) systolic function. However, the assessment of diastolic cardiac function is becoming more appreciated, especially with the increasing prevalence of pathologies associated with diastolic dysfunction like heart failure with preserved ejection fraction (HFpEF). Diastolic dysfunction is an indication of abnormal mechanical properties of the myocardium, characterized by slow or delayed myocardial relaxation, abnormal LV distensibility, and/or impaired LV filling. Diastolic dysfunction has been shown to be associated with age and other cardiovascular risk factors such as hypertension and diabetes mellitus. In this context, cardiac magnetic resonance imaging (MRI) has the capability for differentiating between normal and abnormal myocardial relaxation patterns, and therefore offers the prospect of early detection of diastolic dysfunction. Although diastolic cardiac function can be assessed from the ratio between early and atrial filling peaks (E/A ratio), measuring different parameters of heart contractility during diastole allows for evaluating spatial and temporal patterns of cardiac function with the potential for illustrating subtle changes related to age, gender, or other differences among different patient populations. In this article, we review different MRI techniques for evaluating diastolic function along with clinical applications and findings in different heart diseases.

Left Ventricular Diastolic Function Studied with Magnetic Resonance Imaging: A Systematic Review of Techniques and Relation to Established Measures of Diastolic Function

Purpose: In recent years, cardiac magnetic resonance (CMR) has been used to assess LV diastolic function. In this systematic review, studies were identified where CMR parameters had been evaluated in healthy and/or patient groups with proven diastolic dysfunction or known to develop heart failure with preserved ejection fraction. We aimed at describing the parameters most often used, thresholds where possible, and correlation to echocardiographic and invasive measurements. Methods and results: A systematic literature review was performed using the databases of PubMed, Embase, and Cochrane. In total, 3808 articles were screened, and 102 studies were included. Four main CMR techniques were identified: tagging; time/volume curves; mitral inflow quantification with velocity-encoded phase-contrast sequences; and feature tracking. Techniques were described and estimates were presented in tables. From published studies, peak change of torsion shear angle versus volume changes in early diastole (−dφ′/dV′) (from tagging analysis), early peak filling rate indexed to LV end-diastolic volume <2.1 s⁻¹ (from LV time-volume curve analysis), enlarged LA maximal volume >52 mL/m², lowered LA total (<40%), and lowered LA passive emptying fractions (<16%) seem to be reliable measures of LV diastolic dysfunction. Feature tracking, especially of the atrium, shows promise but is still a novel technique. Conclusion: CMR techniques of LV untwisting and early filling and LA measures of poor emptying are promising for the diagnosis of LV filling impairment, but further research in long-term follow-up studies is needed to assess the ability for the parameters to predict patient related outcomes.

Exploring gender differences in trajectories of clinical markers and symptoms after left ventricular assist device implantation

AIMS

Despite well-known gender differences in heart failure, it is unknown if clinical markers and symptoms differ between women and men after left ventricular assist device (LVAD) implantation. Our aim was to examine gender differences in trajectories of clinical markers (echocardiographic markers and plasma biomarkers) and symptoms from pre- to post-LVAD implantation.

METHODS AND RESULTS

This was a secondary analysis of data collected from a study of patients from pre- to 1, 3, and 6 months post-LVAD implantation. Data were collected on left ventricular internal end-diastolic diameter (LVIDd) and ejection fraction (LVEF), plasma N-terminal pro-B-type natriuretic peptide (NT-proBNP), and soluble suppressor of tumorigenicity (sST2). Physical and depressive symptoms were measured using the Heart Failure Somatic Perception Scale and Patient Health Questionnaire-9, respectively. Latent growth curve modelling was used to compare trajectories between women and men. The average age of the sample (n = 98) was 53.3 ± 13.8 years, and most were male (80.6%) and had non-ischaemic aetiology (65.3%). Pre-implantation, women had significantly narrower LVIDd (P < 0.001) and worse physical symptoms (P = 0.041) compared with men. Between pre- and 6 months post-implantation, women had an increase in plasma sST2 followed by a decrease, whereas men had an overall decrease (slope: P = 0.014; quadratic: P = 0.011). Between 1 and 6 months post-implantation, women had a significantly greater increase in LVEF (P = 0.045) but lesser decline in plasmoa NT-proBNP compared with men (P = 0.025).

CONCLUSION

Trajectories of clinical markers differed somewhat between women and men, but trajectories of symptoms were similar, indicating some physiologic but not symptomatic gender differences in response to LVAD.

Sex-Related Differences in Dynamic Right Ventricular-Pulmonary Vascular Coupling in Heart Failure With Preserved Ejection Fraction

BACKGROUND

Right ventricular (RV) dysfunction is associated with poorer outcomes in heart failure with preserved ejection fraction (HFpEF). Although female subjects are more likely to have HFpEF, male subjects have worse prognosis and resting RV function. The contribution of dynamic RV-pulmonary arterial (RV-PA) coupling between sex and its impact on peak exercise capacity (VO₂) in HFpEF is not known.

RESEARCH QUESTION

The goal of this study was to investigate the differential effects of sex on RV-PA coupling during maximum incremental exercise in patients with HFpEF.

STUDY DESIGN AND METHODS

This study examined rest and exercise invasive pulmonary hemodynamics in 22 male patients with HFpEF and 27 female patients with HFpEF. To further investigate the discrepancy in RV-PA response between sex, 26 age-matched control subjects (11 male subjects and 15 female subjects) were included. Single beat analysis of RV pressure waveforms was used to determine the end-systolic elastance (Ees) and pulmonary arterial elastance. RV-PA coupling was determined as the ratio of end-systolic elastance/PA elastance.

RESULTS

Both HFpEF groups experienced decreased peak VO₂ (% predicted). However, male patients with HFpEF experienced a greater decrement in peak VO₂ compared with female patients (58 ± 16% vs 70 ± 15%; P < .05). Male patients with HFpEF had a more pronounced increase in RV afterload, Ea (1.8 ± 0.6 mm Hg/mL/m² vs 1.3 ± 0.4 mm Hg/mL/m²; P < .05) and failed to increase RV contractility during exercise, resulting in dynamic RV-PA uncoupling (0.9 ± 0.4 vs 1.2 ± 0.4; P < .05) and subsequent reduced stroke volume index augmentation. In contrast, female patients with HFpEF were able to augment RV contractility in the face of increasing afterload, preserving RV-PA coupling during exercise.

INTERPRETATION

Male patients with HFpEF were more compromised regarding dynamic RV-PA uncoupling and reduced peak VO₂ compared with female patients. This finding was driven by both RV contractile impairment and afterload mismatch. In contrast, female patients with HFpEF had preserved RV-PA coupling during exercise and better peak exercise VO₂ compared with male patients with HFpEF.

Sex Differences in Cardiovascular Aging and Heart Failure

PURPOSE OF THE REVIEW

This review summarizes sex-related changes in the heart and vasculature that occur with aging, both in the presence and absence of cardiovascular disease (CVD).

RECENT FINDINGS

In the presence of CVD risk factors and/or overt CVD, sex-specific changes in the number of cardiomyocytes, extent of the myocardial extracellular matrix, and myocellular hypertrophy promote unique patterns of LV remodeling in men and women. In addition, age- and sex-specific vascular stiffening is also well established, driven by changes in endothelial dysfunction, elastin-collagen content, microvascular dysfunction, and neurohormonal signaling. Together, these changes in LV chamber geometry and morphology, coupled with heightened vascular stiffness, appear to drive both age-related increases in systolic function and declines in diastolic function, particularly in postmenopausal women. Accordingly, estrogen has been implicated as a key mediator, given its direct vasodilating properties, association with nitric oxide excretion, and involvement in myocellular Ca2+ handling, mitochondrial energy production, and oxidative stress. The culmination of the abovementioned sex-specific cardiac and vascular changes across the lifespan provides important insight into heart failure development, particularly of the preserved ejection fraction variety, while offering promise for future preventive strategies and therapeutic approaches.

Motion-compensated gradient waveforms for tensor-valued diffusion encoding by constrained numerical optimization

PURPOSE

Diffusion-weighted MRI is sensitive to incoherent tissue motion, which may confound the measured signal and subsequent analysis. We propose a "motion-compensated" gradient waveform design for tensor-valued diffusion encoding that negates the effects bulk motion and incoherent motion in the ballistic regime.

METHODS

Motion compensation was achieved by constraining the magnitude of gradient waveform moment vectors. The constraint was incorporated into a numerical optimization framework, along with existing constraints that account for b-tensor shape, hardware restrictions, and concomitant field gradients. We evaluated the efficacy of encoding and motion compensation in simulations, and we demonstrated the approach by linear and planar b-tensor encoding in a healthy heart in vivo.

RESULTS

The optimization framework produced asymmetric motion-compensated waveforms that yielded b-tensors of arbitrary shape with improved efficiency compared with previous designs for tensor-valued encoding, and equivalent efficiency to previous designs for linear (conventional) encoding. Technical feasibility was demonstrated in the heart in vivo, showing vastly improved data quality when using motion compensation. The optimization framework is available online in open source.

CONCLUSION

Our gradient waveform design is both more flexible and efficient than previous methods, facilitating tensor-valued diffusion encoding in tissues in which motion would otherwise confound the signal. The proposed design exploits asymmetric encoding times, a single refocusing pulse or multiple refocusing pulses, and integrates compensation for concomitant gradient effects throughout the imaging volume.

Biventricular myocardial adaptation in patients with repaired tetralogy of Fallot: Mechanistic insights from magnetic resonance imaging tissue phase mapping

BACKGROUND

The myocardial adaptive mechanism in patients with repaired tetralogy of Fallot (rTOF) is less understood. We aimed to investigate biventricular myocardial adaptive remodeling in rTOF patients.

METHODS

We recruited 32 rTOF patients and 38 age- and sex-matched normal controls. The pulmonary stenosis of rTOF patients was measured using catheterized pressure gradient between right ventricle (RV) and pulmonary artery (PGRVPA). rTOF patients with PGRVPA < 15 mmHg and ≥15 mmHg were classified as low pulmonary stenosis (rTOFlow, n = 19) and high pulmonary stenosis (rTOFhigh, n = 13) subgroups, respectively. Magnetic resonance imaging tissue phase mapping was employed to evaluate the voxelwise biventricular myocardial motion in longitudinal (Vz), radial (Vr), and circumferential (Vφ) directions.

RESULTS

The rTOFlow subgroup presented higher pulmonary regurgitation fraction than rTOFhigh subgroup (p < 0.001). Compared with the normal group, only rTOFlow subgroup presented a decreased RV ejection fraction (RVEF) (p < 0.05). The rTOFlow subgroup showed decreased systolic and diastolic Vz in RV and LV, whereas rTOFhigh subgroup showed such change only in RV. In rTOFlow subgroup, RVEF significantly correlated with RV systolic Vr (r = 0.56, p < 0.05), whereas LVEF correlated with LV systolic Vz (r = 0.51, p = 0.02). Prolonged QRS correlated with RV systolic Vr (r = -0.58, p < 0.01) and LV diastolic Vr (r = 0.81, p < 0.001). No such correlations occurred in rTOFhigh subgroup.

CONCLUSIONS

The avoidance of unfavorable functional interaction in RV and LV in rTOFhigh subgroup suggested that adequate pulmonary stenosis (PGRVPA ≥ 15 mmHg in this sereis) has a protective effect against pulmonary regurgitation.

Assessment of diastolic dysfunction: comparison of different cardiovascular magnetic resonance techniques

Aims

Heart failure with preserved ejection fraction is still a diagnostic and therapeutic challenge, and accurate non‐invasive diagnosis of left ventricular (LV) diastolic dysfunction (DD) remains difficult. The current study aimed at identifying the most informative cardiovascular magnetic resonance (CMR) parameters for the assessment of LVDD.

Methods and results

We prospectively included 50 patients and classified them into three groups: with DD (DD+, n = 15), without (DD−, n = 26), and uncertain (DD±, n = 9). Diagnosis of DD was based on echocardiographic E/E′, invasive LV end‐diastolic pressure, and N‐terminal pro‐brain natriuretic peptide. CMR was performed at 1.5 T to assess LV and left atrial (LA) morphology, LV diastolic strain rate (SR) by tissue tracking and tagging, myocardial peak velocities by tissue phase mapping, and transmitral inflow profile using phase contrast techniques. Statistics were performed only on definitive DD+ and DD− (total number 41). DD+ showed enlarged LA with LA end‐diastolic volume/height performing best to identify DD+ with a cut‐off value of ≥0.52 mL/cm (sensitivity = 0.71, specificity = 0.84, and area under the receiver operating characteristic curve = 0.75). DD+ showed significantly reduced radial (inferolateral E peak: DD−: −14.5 ± 6.5%/s vs. DD+: −10.9 ± 5.9%/s, P = 0.04; anterolateral A peak: DD−: −4.2 ± 1.6%/s vs. DD+: −3.1 ± 1.4%/s, P = 0.04) and circumferential (inferolateral A peak: DD−: 3.8 ± 1.2%/s vs. DD+: 2.8 ± 0.8%/s, P = 0.007; anterolateral A peak: DD−: 3.5 ± 1.2%/s vs. DD+: 2.5 ± 0.8%/s, P = 0.048) SR in the basal lateral wall assessed by tissue tracking. In the same segments, DD+ showed lower peak myocardial velocity by tissue phase mapping (inferolateral radial peak: DD−: −3.6 ± 0.7 ms vs. DD+: −2.8 ± 1.0 ms, P = 0.017; anterolateral longitudinal peak: DD−: −5.0 ± 1.8 ms vs. DD+: −3.4 ± 1.4 ms, P = 0.006). Tagging revealed reduced global longitudinal SR in DD+ (DD−: 45.8 ± 12.0%/s vs. DD+: 34.8 ± 9.2%/s, P = 0.022). Global circumferential and radial SR by tissue tracking and tagging, LV morphology, and transmitral flow did not differ between DD+ and DD−.

Conclusions

Left atrial size and regional quantitative myocardial deformation applying CMR identified best patients with DD.

Evaluating Biventricular Myocardial Velocity and Interventricular Dyssynchrony in Adult Patients During the First Year After Heart Transplantation

BACKGROUND

Magnetic resonance tissue phase mapping (TPM) measures three-directional myocardial velocities of the left and right ventricle (LV, RV). This noninvasive technique may supplement endomyocardial biopsy (EMB) in monitoring grafts post-heart transplantation (HTx).

PURPOSE

To assess biventricular myocardial velocity alterations in grafts and investigate the relationship between velocities and acute cellular rejection (ACR) episodes.

STUDY TYPE

Prospective.

SUBJECTS

Twenty-seven patients within 1 year post-HTx (49 ± 13 years, 19 M) and 18 age-matched controls (49 ± 15 years, 12 M).

FIELD STRENGTH/SEQUENCE

1.5T, 2D balanced steady-state free precession, and TPM.

ASSESSMENT

Ventricular function: end-diastolic and end-systolic volumes, stroke volumes, ejection fraction (EF), and myocardial mass. TPM velocities: peak-systolic and peak-diastolic velocities, cardiac twist, and interventricular dyssynchrony. ACR rejection episodes: International Society for Heart and Lung Transplantation grading of EMB specimens.

STATISTICAL TESTS

The Lilliefors test for normality, unpaired t-tests, and Wilcoxon rank-sum tests for normally and nonnormally distributed data, respectively, were used, as well as multivariate regression for confounding variables and Pearson's correlation for associations between TPM velocities and global function.

RESULTS

Compared to controls, HTx patients demonstrated reduced biventricular systolic longitudinal velocities (LV: 5.2 ± 2.1 vs. 4.0 ± 1.5 cm/s, P < 0.05; RV: 4.2 ± 1.3 vs. 3.1 ± 1.2 cm/s, P < 0.01). Correlation analysis revealed significant positive relationships for biventricular EF with radial peak velocities of the same ventricle in both systole and diastole (LV systole: r = 0.48, P < 0.01; LV diastole: r = 0.28, P < 0.05; RV systole: r = 0.35, P < 0.01; RV diastole: r = 0.36, P < 0.01). Segmentally, longitudinal velocities were impaired in 7/16 LV segments and 5/10 RV segments in systole and 7/10 RV segments in diastole. TPM analysis in studies with >4 preceding ACR episodes showed globally reduced RV and LV systolic radial velocity, and segmentally reduced radial and longitudinal systolic velocities.

DATA CONCLUSION

Biventricular global and segmental velocities were reduced in HTx patients. Patients with >4 rejection episodes showed reduced myocardial velocities. The TPM sequence may add functional information for monitoring graft dysfunction.

LEVEL OF EVIDENCE

2 TECHNICAL EFFICACY STAGE: 2 J. Magn. Reson. Imaging 2020;52:920-929.

Donor and Recipient Characteristics in Heart Transplantation Are Associated with Altered Myocardial Tissue Structure and Cardiac Function

PURPOSE

To use structure-function cardiac MRI in the evaluation of relationships between donor and heart transplantation (HTx) recipient characteristics and changes in cardiac tissue structure and function. HTx candidates and donor hearts are evaluated for donor-recipient matches to improve survival, but the impact of donor and recipient characteristics on changes in myocardial tissue and function in the transplanted heart is not fully understood.

MATERIALS AND METHODS

Cardiac MRI at 1.5 T was performed from August 2014 to June 2017 in 58 HTx recipients (mean age, 51.1 years ± 12.6 [standard deviation], 26 female patients) and included T2 mapping (to evaluate edematous and/or inflammatory changes), precontrast and postcontrast T1 mapping (allowing the calculation of extracellular volume fraction [ECV] to estimate interstitial expansion), and tissue phase mapping (allowing the calculation of myocardial velocities and twist). Donor and recipient demographics (age, sex, height, weight, and body mass index [BMI]) and comorbidities (hypertension, diabetes, and smoking history) were evaluated for relationships with cardiac MRI measures.

RESULTS

Sex-influenced cardiac MRI measures of myocardial tissue and function are as follows: Female HTx recipients demonstrated increased precontrast T1 (P = .002) and reduced systolic peak long-axis velocities (P = .015). Increased age of the donor heart was associated with elevated T2 (r = 0.32; P < .05) and ECV (r = 0.47; P < .01), indicating increased edema and interstitial expansion, as well as impaired diastolic peak long-axis velocities (r = 0.41; P < .01). Recipient-donor differences in age, weight, and BMI were significantly associated with elevated ECV (r = 0.36-0.48; P < .05). Hypertension in donors resulted in increased ECV (31.0% ± 4.2 vs 26.0% ± 3.3; P = .001).

CONCLUSION

Donor and HTx recipient characteristics were significantly associated with cardiac MRI-derived measures of myocardial tissue structure and function.© RSNA, 2019.

Effects of Sacubitril-Valsartan Versus Valsartan in Women Compared With Men With Heart Failure and Preserved Ejection Fraction: Insights From PARAGON-HF

BACKGROUND

Unlike heart failure with reduced ejection fraction, there is no approved treatment for heart failure with preserved ejection fraction, the predominant phenotype in women. Therefore, there is a greater heart failure therapeutic deficit in women compared with men.

METHODS

In a prespecified subgroup analysis, we examined outcomes according to sex in the PARAGON-HF trial (Prospective Comparison of ARNI With ARB Global Outcomes in Heart Failure With Preserved Ejection Fraction), which compared sacubitril-valsartan and valsartan in patients with heart failure with preserved ejection fraction. The primary outcome was a composite of first and recurrent hospitalizations for heart failure and death from cardiovascular causes. We also report secondary efficacy and safety outcomes.

RESULTS

Overall, 2479 women (51.7%) and 2317 men (48.3%) were randomized. Women were older and had more obesity, less coronary disease, and lower estimated glomerular filtration rate and NT-proBNP (N-terminal pro-B-type natriuretic peptide) levels than men. For the primary outcome, the rate ratio for sacubitril-valsartan versus valsartan was 0.73 (95% CI, 0.59-0.90) in women and 1.03 (95% CI, 0.84-1.25) in men (P interaction = 0.017). The benefit from sacubitril-valsartan was attributable to reduction in heart failure hospitalization. The improvement in New York Heart Association class and renal function with sacubitril-valsartan was similar in women and men, whereas the improvement in Kansas City Cardiomyopathy Questionnaire clinical summary score was less in women than in men. The difference in adverse events between sacubitril-valsartan and valsartan was similar in women and men.

CONCLUSIONS

As compared with valsartan, sacubitril-valsartan seemed to reduce the risk of heart failure hospitalization more in women than in men. Whereas the possible sex-related modification of the effect of treatment has several potential explanations, the present study does not provide a definite mechanistic basis for this finding.

CLINICAL TRIAL REGISTRATION

https://www.clinicaltrials.gov. Unique identifier: NCT01920711.

Sex Differences in Cardiovascular Pathophysiology: Why Women Are Overrepresented in Heart Failure With Preserved Ejection Fraction

Consistent epidemiological data demonstrate that patients with heart failure with preserved ejection fraction (HFpEF) are more likely to be women than men. Exploring mechanisms behind this sex difference in heart failure epidemiology may enrich the understanding of underlying HFpEF pathophysiology and phenotypes, with the ultimate goal of identifying therapeutic approaches for the broader HFpEF population. In this review we evaluate the influence of sex on the key domains of cardiac structure and function, the systemic and pulmonary circulation, as well as extracardiac factors and comorbidities that may explain the predisposition of women to HFpEF. We highlight the potential role of factors exclusive to or more prevalent in women such as pregnancy, preeclampsia, and iron deficiency. Finally, we discuss existing controversies and gaps in knowledge, as well as the clinical importance of known sex differences in the context of the potential need for sex-specific diagnostic criteria, improved risk stratification models, and targeted therapies.

Multiparametric Cardiac Magnetic Resonance Imaging Can Detect Acute Cardiac Allograft Rejection After Heart Transplantation

OBJECTIVES

The purpose of this study was to evaluate the sensitivity of multiparametric cardiac magnetic resonance imaging (CMR) for the detection of acute cardiac allograft rejection (ACAR).

BACKGROUND

ACAR is currently diagnosed by endomyocardial biopsy, but CMR may be a noninvasive alternative because of its capacity for regional myocardial structure and function characterization.

METHODS

Fifty-eight transplant recipients (mean age 47.0 ± 14.7 years) and 14 control subjects (mean age 47.7 ± 16.7 years) were prospectively recruited from August 2014 to May 2017 and underwent 97 CMR studies (83 transplant recipients, 14 control subjects) for assessment of global left ventricular function and myocardial T2, T1, and extracellular volume fraction (ECV). CMR studies were divided into 4 groups on the basis of biopsy grade: control subjects (n = 14), patients with no ACAR (no history of ACAR; n = 36), patients with past ACAR (history of ACAR; n = 24), and ACAR+ patients (active grade ≥1R ACAR; n = 23).

RESULTS

Myocardial T2 was significantly higher in patients with past ACAR compared with those with no ACAR (51.0 ± 3.8 ms vs. 49.2 ± 4.0 ms; p = 0.02) and in patients with no ACAR compared with control subjects (49.2 ± 4.0 ms vs. 45.2 ± 2.3 ms; p < 0.01). ACAR+ patients demonstrated increased T2 compared with the no ACAR group (52.4 ± 4.7 ms vs. 49.2 ± 4.0 ms, p < 0.01) but not compared with the past ACAR group. In contrast, ECV was significantly elevated in ACAR+ patients compared with transplant recipients without ACAR regardless of history of ACAR (no ACAR: 31.5 ± 3.9% vs. 26.8 ± 3.3% [p < 0.01]; past ACAR: 31.5 ± 3.9% vs. 26.8 ± 4.0% [p < 0.01]). Receiver operating characteristic curve analysis revealed that a combined model of age at CMR, global T2, and global ECV was predictive of ACAR (area under the curve = 0.84).

CONCLUSIONS

The combination of CMR-derived myocardial T2 and ECV has potential as a noninvasive tissue biomarker for ACAR. Larger studies during acute ACAR are needed for continued development of multiparametric CMR for transplant recipient surveillance.

Impact of age and cardiac disease on regional left and right ventricular myocardial motion in healthy controls and patients with repaired tetralogy of fallot

The assessment of both left (LV) and right ventricular (RV) motion is important to understand the impact of heart disease on cardiac function. The MRI technique of tissue phase mapping (TPM) allows for the quantification of regional biventricular three-directional myocardial velocities. The goal of this study was to establish normal LV and RV velocity parameters across a wide range of pediatric to adult ages and to investigate the feasibility of TPM for detecting impaired regional biventricular function in patients with repaired tetralogy of Fallot (TOF). Thirty-six healthy controls (age = 1-75 years) and 12 TOF patients (age = 5-23 years) underwent cardiac MRI including TPM in short-axis locations (base, mid, apex). For ten adults, a second TPM scan was used to assess test-retest reproducibility. Data analysis included the calculation of biventricular radial, circumferential, and long-axis velocity components, quantification of systolic and diastolic peak velocities in an extended 16 + 10 LV + RV segment model, and assessment of inter-ventricular dyssynchrony. Biventricular velocities showed good test-retest reproducibility (mean bias ≤ 0.23 cm/s). Diastolic radial and long-axis peak velocities for LV and RV were significantly reduced in adults compared to children (19-61%, p < 0.001-0.02). In TOF patients, TPM identified significantly reduced systolic and diastolic LV and RV long-axis peak velocities (20-50%, p < 0.001-0.05) compared to age-matched controls. In conclusion, tissue phase mapping enables comprehensive analysis of global and regional biventricular myocardial motion. Changes in myocardial velocities associated with age underline the importance of age-matched controls. This pilot study in TOF patients shows the feasibility to detect regionally abnormal LV and RV motion.

Impact of Age and Diastolic Function on Novel, 4D flow CMR Biomarkers of Left Ventricular Blood Flow Kinetic Energy

Two-dimensional (2D) methods of assessing mitral inflow velocities are pre-load dependent, limiting their reliability for evaluating diastolic function. Left ventricular (LV) blood flow kinetic energy (KE) derived from four-dimensional flow cardiovascular magnetic resonance imaging (4D flow CMR) may offer improvements. It remains unclear whether 4D LV blood flow KE parameters are associated with physiological factors, such as age when compared to 2D mitral inflow velocities. Fifty-three healthy volunteers underwent standard CMR, plus 4D flow acquisition. LV blood flow KE parameters demonstrated good reproducibility with mean coefficient of variation of 6 ± 2% and an accuracy of 99% with a precision of 97%. The LV blood flow KEi_EDV E/A ratio demonstrated good association to the 2D mitral inflow E/A ratio (r = 0.77, P < 0.01), with both decreasing progressively with advancing age (P < 0.01). Furthermore, peak E-wave KEi_EDV and A-wave KEi_EDV displayed a stronger association to age than the corresponding 2D metrics, peak E-wave and A-wave velocity (r = −0.51 vs −0.17 and r = 0.65 vs 0.46). Peak E-wave KEi_EDV decreases whilst peak A-wave KEi_EDV increases with advancing age. This study presents values for various LV blood flow KE parameters in health, as well as demonstrating that they show stronger and independent correlations to age than standard diastolic metrics.

Cardiac Structure-Function MRI in Patients After Heart Transplantation

BACKGROUND

Following heart transplantation (Tx), recipients are closely monitored using endomyocardial biopsy, which is limited by cost and invasiveness, and echocardiography, which is limited regarding detailed structural and functional evaluation.

PURPOSE

To test the feasibility of comprehensive structure-function cardiac MRI as a noninvasive modality to assess changes in myocardial structure and function.

STUDY TYPE

Prospective.

SUBJECTS

MR was performed in 61 heart transplant recipients (age 47.9 ± 16.3 years, 39% female) and 14 age-matched healthy controls (age 47.7 ± 16.7 years, 36% female).

FIELD STRENGTH/SEQUENCE

1.5T; 2D CINE steady state free precession (SSF)P imaging, T₂ -mapping, pre- and postgadolinium contrast T₁ -mapping, and tissue-phase mapping (TPM).

ASSESSMENT

Quantification of myocardial T₂ (as a measure of edema), pre- and post-Gd T₁ (allowing calculation of extracellular volume (ECV) to estimate interstitial expansion), and TPM-based assessment of peak regional left ventricular (LV) velocities, dyssynchrony, and twist.

STATISTICAL TESTS

Comparisons between transplant recipients and controls were performed using independent samples t-tests. Relationships between structural (T₂ , T₁ , ECV) and functional measures (myocardial velocities, dyssynchrony, twist) were assessed using Pearson correlation analysis.

RESULTS

T₂ and T₁ were significantly elevated in transplant recipients compared to controls (global T₂ : 50.5 ± 3.4 msec vs. 45.2 ± 2.3 msec, P < 0.01; global T₁ : 1037.8 ± 48.0 msec vs. 993.8 ± 34.1 msec, P < 0.01). Systolic longitudinal function was impaired in transplant recipients compared to controls (reduced peak systolic longitudinal velocities, 2.9 ± 1.1 cm/s vs. 5.1 ± 1.2 cm/s, P < 0.01; elevated systolic longitudinal dyssynchrony, 60.2 ± 30.2 msec vs. 32.1 ± 25.1 msec, P < 0.01). Correlation analysis revealed a significant positive relationship between T₂ and ECV (r = 0.45,P < 0.01). In addition, peak systolic longitudinal velocities demonstrated a significant inverse relationship with T₂ (global r = -0.29, P = 0.02), and systolic radial dyssynchrony was positively associated with peak T₂ and peak T₁ (r = 0.26,P = 0.04; r = 0.27,P = 0.03).

DATA CONCLUSION

MR techniques are sensitive to structural and functional differences in transplant recipients compared to controls. Structural (T₂ , T₁ ) and functional (peak myocardial velocities, dyssynchrony) measures were significantly associated, suggesting a structure-function relationship of cardiac abnormalities following heart transplant.

LEVEL OF EVIDENCE

2 Technical Efficacy Stage: 2 J. Magn. Reson. Imaging 2019;49:678-687.

A new look at the heart-novel imaging techniques

The development and successful implementation of cutting-edge imaging technologies to visualise cardiac anatomy and function is a key component of effective diagnostic efforts in cardiology. Here, we describe a number of recent exciting advances in the field of cardiology spanning from macro- to micro- to nano-scales of observation, including magnetic resonance imaging, computed tomography, optical mapping, photoacoustic imaging, and electron tomography. The methodologies discussed are currently making the transition from scientific research to routine clinical use, albeit at different paces. We discuss the most likely trajectory of this transition into clinical research and standard diagnostics, and highlight the key challenges and opportunities associated with each of the methodologies.

Segmental biventricular analysis of myocardial function using high temporal and spatial resolution tissue phase mapping

OBJECTIVE

Myocardial dysfunction of the right ventricle (RV) is an important indicator of RV diseases, e.g. RV infarction or pulmonary hypertension. Tissue phase mapping (TPM) has been widely used to determine function of the left ventricle (LV) by analyzing myocardial velocities. The analysis of RV motion is more complicated due to the different geometry and smaller wall thickness. The aim of this work was to adapt and optimize TPM to the demands of the RV.

MATERIALS AND METHODS

TPM measurements were acquired in 25 healthy volunteers using a velocity-encoded phase-contrast sequence and kt-accelerated parallel imaging in combination with optimized navigator strategy and blood saturation. Post processing was extended by a 10-segment RV model and a detailed biventricular analysis of myocardial velocities was performed.

RESULTS

High spatio-temporal resolution (1.0 × 1.0 × 6 mm³, 21.3 ms) and the optimized blood saturation enabled good delineation of the RV and its velocities. Global and segmental velocities, as well as time to peak velocities showed significant differences between the LV and RV. Furthermore, complex timing of the RV could be demonstrated by segmental time to peak analysis.

CONCLUSION

High spatio-temporal resolution TPM enables a detailed biventricular analysis of myocardial motion and might provide a reliable tool for description and detection of diseases affecting left and right ventricular function.

Direct comparison of high-temporal-resolution CINE MRI with Doppler ultrasound for assessment of diastolic dysfunction in mice

Diastolic dysfunction is a sensitive early indicator of heart failure and can provide additional data to conventional measures of systolic function. Transmitral Doppler ultrasound, which measures the one-dimensional flow of blood through the mitral valve, is currently the preferred method for the measurement of diastolic function, but the measurement of the left ventricular volume changes using high-temporal-resolution cinematic magnetic resonance imaging (CINE MRI) is an alternative approach which is emerging as a potentially more robust and user-independent technique. Here, we investigated the performance of high-temporal-resolution CINE MRI and compared it with ultrasound for the detection of diastolic dysfunction in a mouse model of myocardial infarction. An in-house, high-temporal-resolution, retrospectively gated CINE sequence was developed with a temporal resolution of 1 ms. Diastolic function in mice was assessed using a custom-made, open-source reconstruction package. Early (E) and late (A) left ventricular filling phases were easily identifiable, and these measurements were compared directly with high-frequency, pulsed-wave, Doppler ultrasound measurements of mitral valve inflow. A repeatability study established that high-temporal-resolution CINE MRI and Doppler ultrasound showed comparable accuracy when measuring E/A in normal control mice. However, when applied in a mouse model of myocardial infarction, high-temporal-resolution CINE MRI indicated diastolic heart failure (E/A = 0.94 ± 0.11), whereas ultrasound falsely detected normal cardiac function (E/A = 1.21 ± 0.11). The addition of high-temporal-resolution CINE MRI to preclinical imaging studies enhances the library of sequences available to cardiac researchers and potentially identifies diastolic heart failure early in disease progression.

Magnetic resonance imaging of myocardial strain: A review of current approaches

Contraction of the heart is central to its purpose of pumping blood around the body. While simple global function measures (such as the ejection fraction) are most commonly used in the clinical assessment of cardiac function, MRI also provides a range of approaches for quantitatively characterizing regional cardiac function, including the local deformation (or strain) within the heart wall. While they have been around for some years, these methods are still undergoing further technical development, and they have had relatively little clinical evaluation. However, they can provide potentially useful new ways to assess cardiac function, which may be able to contribute to better classification and treatment of heart disease. This article provides some basic background on the physical and physiological factors that determine the motion of the heart, in health and disease and then reviews some of the ways that MRI methods are being developed to image and quantify strain within the myocardium.

LEVEL OF EVIDENCE

4 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2017;46:1263-1280.

Magnetic resonance tissue phase mapping demonstrates altered left ventricular diastolic function in children with chronic kidney disease

BACKGROUND

Echocardiographic examinations have revealed functional cardiac abnormalities in children with chronic kidney disease.

OBJECTIVE

To assess the feasibility of MRI tissue phase mapping in children and to assess regional left ventricular wall movements in children with chronic kidney disease.

MATERIALS AND METHODS

Twenty pediatric patients with chronic kidney disease (before or after renal transplantation) and 12 healthy controls underwent tissue phase mapping (TPM) to quantify regional left ventricular function through myocardial long (Vz) and short-axis (Vr) velocities at all 3 levels of the left ventricle.

RESULTS

Patients and controls (age: 8 years-20 years) were matched for age, height, weight, gender and heart rate. Patients had higher systolic blood pressure. No patient had left ventricular hypertrophy on MRI or diastolic dysfunction on echocardiography. Fifteen patients underwent tissue Doppler echocardiography, with normal z-scores for mitral early diastolic (V_E), late diastolic (V_A) and peak systolic (V_S) velocities. Throughout all left ventricular levels, peak diastolic Vz and Vr (cm/s) were reduced in patients: Vz_base -10.6 ± 1.9 vs. -13.4 ± 2.0 (P < 0.0003), Vz_mid -7.8 ± 1.6 vs. -11 ± 1.5 (P < 0.0001), Vz_apex -3.8 ± 1.6 vs. -5.3 ± 1.6 (P = 0.01), Vr_base -4.2 ± 0.8 vs. -4.9 ± 0.7 (P = 0.01), Vr_mid -4.7 ± 0.7 vs. -5.4 ± 0.7 (P = 0.01), Vr_apex -4.7 ± 1.4 vs. -5.6 ± 1.1 (P = 0.05).

CONCLUSION

Tissue phase mapping is feasible in children and adolescents. Children with chronic kidney disease show significantly reduced peak diastolic long- and short-axis left ventricular wall velocities, reflecting impaired early diastolic filling. Thus, tissue phase mapping detects chronic kidney disease-related functional myocardial changes before overt left ventricular hypertrophy or echocardiographic diastolic dysfunction occurs.

The prognostic impact of gender in patients with acute heart failure - An evaluation of the age of female patients with severely decompensated acute heart failure

BACKGROUND

The gender differences in the prognosis of Asian patients with acute heart failure (AHF) remain to be elucidated.

METHODS AND RESULTS

One thousand fifty AHF patients were enrolled. The patients were assigned to a female group (n=354) and a male group (n=696). A Kaplan-Meier curve showed that the cardiovascular survival rate of the female group was significantly lower than that of the male group (p=0.005). A multivariate Cox regression model identified female gender [hazard ratio (HR): 1.381, 95% CI: 1.018-1.872] as an independent predictor of 730-day cardiovascular death. In subgroup analysis by age, in patients over 79 years, female gender significantly increased the cardiovascular death (HR: 1.715, 95% CI: 1.088-2.074, p<0.001) with a significant interaction (p-value for interaction<0.001). The prognosis, including cardiovascular death, was significantly poorer among elderly female patients (≥79 years) than among elderly male patients (p=0.019). The multivariate Cox regression model identified female gender as an independent predictor of 730-day cardiovascular death in patients who were older than 79 years of age (HR, 1.943; 95% CI, 1.192-3.167).

CONCLUSIONS

Female gender was associated with poor prognosis in AHF patients. In particular, old age (≥79 years) was associated with adverse outcomes in female patients with AHF.

On the influence of respiratory motion in radial tissue phase mapping cardiac MRI

PURPOSE

To investigate the impact of respiratory motion on radial tissue phase mapping (TPM) measurements, and to improve image quality and scan efficiency without compromising velocity fidelity by increasing the respiratory acceptance window with and without motion correction.

MATERIALS AND METHODS

A radial golden angle TPM sequence was measured in 10 healthy volunteers in three short axis slices at 3T. Ungated ( CFREE), self-gated with a single acceptance window ( CREF), motion-corrected averaging using all ( CMCall), or selected ( CMC) data reconstructions were compared by means of various image quality measures and resulting velocities.

RESULTS

Using all data ( CFREE) resulted in significantly higher perceived signal-to-noise ratio (SNR) (P < 0.001), but significantly reduced sharpness (P < 0.001) and contrast (P = 0.02), when compared to CREF. Coefficient of variation (CV) and perceived sharpness were not significantly different (P > 0.05). With motion-correction, perceived sharpness could be significantly improved ( CMC: P = 0.002; CMCall: P = 0.002) in comparison to CFREE. Velocity peaks of CFREE were significantly reduced compared to CREF (all peaks: P < 0.001; except the longitudinal "E" peak: P = 0.03). The peak velocities in CMC and CMCall were not significantly different from CREF (all peaks: P > 0.08; except longitudinal "E"/"A" peaks: P > 0.01).

CONCLUSION

Free-breathing reconstruction results in good perceived image sharpness and velocity information with slightly, but significantly, reduced peak velocities. For achieving velocities and image quality comparable to data from a single acceptance window, but higher gating efficiency, selected motion-corrected TPM (CMC) can be applied. J. Magn. Reson. Imaging 2016;44:1218-1228.

Myocardial dysfunction in patients with aortic stenosis and hypertensive heart disease assessed by MR tissue phase mapping

PURPOSE

To identify abnormalities of myocardial velocities in patients with left ventricular pressure overload using magnetic resonance tissue phase mapping (TPM).

MATERIAL AND METHODS

Thirty-three patients (nine with hypertensive heart disease [HYP], 24 with aortic stenosis [AS]) and 41 healthy controls were enrolled. To assess left ventricular motion, a basal, midventricular, and apical slice were acquired using three-directional velocity-encoded phase-contrast MR with a 3T system. Target parameters were peak longitudinal (Vz ) and radial (Vr ) velocity in systole and diastole (Peaksys , Peakdias ). Analysis was done on each myocardial segment. In a subgroup (n = 7 HYP, n = 12 AS, n = 24 controls), measurement was repeated during handgrip exercise.

RESULTS

AS had significantly lower Vz -Peaksys in the inferolateral and inferoseptal wall (P = 0.003-0.029) and Vr -Peaksys in the septum and anterior wall (P = 0.001-0.013) than controls. Vz -Peakdias and Vr -Peakdias were lower in AS than in controls in almost all segments (P < 0.001-0.028). HYP showed reduced Vz -Peakdias compared to controls in all basal segments as well as in the lateral midventricular wall (P < 0.001-0.045), and reduced Vr -Peakdias compared to controls predominantly in the midventricular and apical segments (P = 0.004-0.042). AS patients with focal fibrosis had significantly reduced myocardial velocities (P = 0.001-0.047) in segments without late enhancement. During exercise, Vz -Peaksys , Vr -Peaksys , and Vz -Peakdias remained unchanged in AS and HYP, but decreased in the lateral wall in controls (P < 0.001-0.043).

CONCLUSION

Even with preserved left ventricle (LV) ejection fraction, peak longitudinal and radial velocities of the LV are reduced in AS and HYP, indicating early functional impairment. J. Magn. Reson. Imaging 2016;44:168-177.

Sex Differences in the Management and Outcomes of Heart Failure With Preserved Ejection Fraction in Patients Presenting to the Emergency Department With Acute Heart Failure

BACKGROUND

Heart failure (HF) with preserved ejection fraction (HFpEF) is more common in women than in men; data characterizing sex differences in the management and outcomes of HFpEF patients presenting to the emergency department (ED) are limited.

METHODS AND RESULTS

Using Acute Decompensated Heart Failure National Registry Emergency Module data linked to Medicare claims, we conducted a retrospective analysis of acute HF patients in the ED, identifying HFpEF (ejection fraction [EF] ≥40%) patients and stratifying by sex to compare baseline characteristics, ED therapies, hospital length of stay (LOS), in-hospital mortality, and post-discharge outcomes. Of 4161 HFpEF patients, 2808 (67%) were women, who were more likely to be older and hypertensive, but less likely to be diabetic or smokers (all P < .01). Women more often presented with systolic blood pressure >140 mm Hg (62.5% vs 56.4%; P = .0001) and higher EF. There were no sex differences in ED therapies, adjusted 30- and 180-day all-cause mortality, in-hospital mortality, or 30- and 180-day readmissions. After adjustment, women had longer LOS (0.40 days, 95% confidence interval [CI] 0.10-0.70; P = .008).

CONCLUSIONS

Women with HFpEF presenting to the ED were more likely to have elevated systolic blood pressure, but overall ED management strategies were similar to those in men. We observed adjusted differences in hospital LOS, but no differences in 30- and 180-day outcomes.

Effects of sex and hypertension subtype on haemodynamics and left ventricular diastolic function in older patients with stage 1 hypertension

BACKGROUND

Hypertension is associated with cardiovascular stiffening and left ventricular diastolic dysfunction, leading to comorbidities such as heart failure with preserved ejection fraction (HFpEF). It is unknown whether sex and hypertension subtype affect haemodynamics and left ventricular function in older individuals.

METHODS

Ninety-five older patients with Stage 1 hypertension (ambulatory awake SBP135-159 mmHg) and 56 normotensive controls were enrolled. Patients were stratified prospectively into isolated systolic hypertension (ISH, DBP <85 mmHg) or systolic-diastolic hypertension (SDH, DBP ≥85 mmHg). Haemodynamics and Doppler variables including early filling (E) and averaged mitral annular (E'mean) velocities were measured during supine rest.

RESULTS

Ambulatory awake blood pressures (BPs) were the highest in SDH, whereas supine SBP was similar in both hypertensive groups. No sex difference was observed in supine or ambulatory awake BPs in all groups. Stroke volume was similar among groups within the same sex, but smaller in women. Women exhibited faster E, slower E'mean and greater E/E'mean, whereas no group difference was observed in E within the same sex. In women, E'mean was significantly slower in SDH (5.9 ± 1.6 vs. 7.4 ± 1.1 cm/s, P < 0.01) and ISH (6.6 ± 1.6 cm/s, P = 0.07) than controls, resulting in the highest E/E'mean in SDH. In men, E'mean and E/E'mean were similar among the three groups.

CONCLUSION

These results suggest that elderly hypertensive women may have left ventricular early diastolic dysfunction and higher estimated filling pressure, consistent with their susceptibility to HFpEF. Women with SDH seemed to have more left ventricular diastolic dysfunction, which might be explained by the greater cumulative afterload when ambulatory.

Cardiovascular magnetic resonance phase contrast imaging

Cardiovascular magnetic resonance (CMR) phase contrast imaging has undergone a wide range of changes with the development and availability of improved calibration procedures, visualization tools, and analysis methods. This article provides a comprehensive review of the current state-of-the-art in CMR phase contrast imaging methodology, clinical applications including summaries of past clinical performance, and emerging research and clinical applications that utilize today's latest technology.

Imaging of cardiovascular complications in patients with systemic lupus erythematosus

In the long-term survival of patients with systemic lupus erythematosus (SLE), cardiovascular disease (CVD) is a leading cause of death. Recently, multimodality cardiovascular imaging methods have been adopted for the evaluation of cardiovascular risk, which has shown to be associated with both traditional cardiovascular risk factors and SLE-specific conditions. Quantitative imaging biomarkers, which can describe both morphological and functional abnormalities in the heart, are expected to provide new insights to stratify cardiovascular risks and to guide SLE management by assessing individual responses to therapies either protecting the cardiovascular system or suppressing the autoimmune reactions. In this review, we will discuss cutting-edge cardiovascular imaging techniques and potential clinical applications and limitations of those techniques for the evaluation of major SLE-related heart disorders.

Sex differences in the prevalence of diastolic dysfunction in cardiac surgical patients

OBJECTIVES

The mortality from diastolic dysfunction is approximately 9% to 28%. In patients with ischemic heart disease, female sex and advanced age are associated with increases in ventricular diastolic stiffness. Clinical studies have found higher rates of diastolic dysfunction in women, despite higher ejection fractions, than in men post-myocardial infarction. Therefore, we hypothesized that female patients undergoing cardiac surgery have higher degrees of diastolic dysfunction and experience more adverse outcomes, such as prolonged hospitalization.

METHODS

We prospectively enrolled 153 patients undergoing cardiac surgery. Diastolic function was assessed using early transmitral velocity (E) and early diastolic lateral mitral annular tissue velocity (e'). Left ventricular diastolic dysfunction was defined as binary and a continuous outcome (E/e').

RESULTS

Females were more likely than males to present with higher E/e' (11.5 vs. 7.9, p = 0.001) and higher left ventricular diastolic dysfunction (71% vs. 36%, p < 0.001). The addition of sex to the model for left ventricular diastolic dysfunction was significant. The relationship between sex and E/e' ratio showed the biggest difference between males and females in the 56-72-year-old age brackets, where women were much more likely to have a higher E/e' than males.

CONCLUSIONS

We identified a significantly higher prevalence of diastolic dysfunction among females presenting for elective cardiac surgery compared to males. This finding is more pronounced with age. Additionally, we found that female sex is at higher risk of prolonged ICU and hospital length of stay.

Extracellular volume fraction is more closely associated with altered regional left ventricular velocities than left ventricular ejection fraction in nonischemic cardiomyopathy

BACKGROUND

Nonischemic cardiomyopathy is a common cause of left ventricular (LV) dysfunction and myocardial fibrosis. The purpose of this study was to noninvasively evaluate changes in segmental LV extracellular volume (ECV) fraction, LV velocities, myocardial scar, and wall motion in nonischemic cardiomyopathy patients.

METHODS AND RESULTS

Cardiac MRI including pre- and postcontrast myocardial T1 mapping and velocity quantification (tissue phase mapping) of the LV (basal, midventricular, and apical short axis) was applied in 31 patients with nonischemic cardiomyopathy (50±18 years). Analysis based on the 16-segment American Heart Association model was used to evaluate the segmental distribution of ECV, peak systolic and diastolic myocardial velocities, scar determined by late gadolinium enhancement, and wall motion abnormalities. LV segments with scar or impaired wall motion were significantly associated with elevated ECV (rs =0.26; P<0.001) and reduced peak systolic radial velocities (r=-0.43; P<0.001). Regional myocardial velocities and ECV were similar for patients with reduced (n=12; ECV=0.28±0.06) and preserved left ventricular ejection fraction (n=19; ECV=0.30±0.09). Patients with preserved left ventricular ejection fraction showed significant relationships between increasing ECV and reduced systolic (r=-0.19; r=-0.30) and diastolic (r=0.34; r=0.26) radial and long-axis peak velocities (P<0.001). Even after excluding myocardial segments with late gadolinium enhancement, significant relationships between ECV and segmental LV velocities were maintained indicating the potential of elevated ECV to identify regional diffuse fibrosis not visible by late gadolinium enhancement, which was associated with impaired regional LV function.

CONCLUSIONS

Regionally elevated ECV negatively affected myocardial velocities. The association of elevated regional ECV with reduced myocardial velocities independent of left ventricular ejection fraction suggests a structure-function relationship between altered ECV and segmental myocardial function in nonischemic cardiomyopathy.

Sex-dependent pathophysiological mechanisms in hypertrophic cardiomyopathy: implications for rhythm disorders

Differences in cardiac physiology are seen between men and women in terms of health and disease. Sex differences start to develop at puberty and are maintained during aging. The prevalence of almost all cardiovascular diseases is found to be higher in men than in women, and disease progression tends to be more rapid in male than in female patients. In cohorts of patients with hypertrophic cardiomyopathy (HCM), the most common autosomal inherited cardiac disease, men are overrepresented, suggesting increased penetrance of HCM-causing mutations in male patients. Cardiac remodeling in patients with HCM is higher in men than in women, the same is seen in HCM animal models. Patients with HCM are at increased risk of sudden cardiac death (SCD) and developing rhythm disorders. There seems to be no sex effect on the risk of SCD or arrhythmias in patients with HCM; however, animal studies suggest that certain mutations predispose men to SCD.

Gender differences in hypertension: myths and reality

Life expectancy is longer in women compared to men, and cardiovascular events occur at a lower rate and at a later age in females than males. The impact of gender on the prevalence, the presentation, and the long-term outcome of cardiovascular disease has long been a topic of active research. Gender differences have been found in several studies but opposite findings also exist. The impact of gender in hypertension and antihypertensive therapy remains poorly clarified. The prevalence, awareness, treatment, and control rates of hypertension exhibit some differences between the two sexes, which are age-dependent. The female advantage in the cardiovascular risk of hypertensive patients might be attenuated by comorbidities and target organ damage. Another aspect of major clinical importance is whether gender differences exist on the effects of antihypertensive agents in blood pressure reduction and cardiovascular morbidity and mortality. The aim of this review is to critically evaluate recent data regarding gender differences in hypertension and incorporate new data into the body of existing knowledge.

Sex-specific cardiovascular structure and function in heart failure with preserved ejection fraction

AIMS

Women are more likely to develop heart failure with preserved ejection fraction (HFpEF) than men. We studied the relationship between sex and cardiovascular structure and function in patients with HFpEF.

METHODS AND RESULTS

The study included 279 participants from the PARAMOUNT study (57% women) with analysable baseline echocardiograms (mean age 71 years, 94% hypertensive, 38% diabetic). We assessed sex-based differences in baseline clinical characteristics and measures of cardiovascular structure/function. Coronary artery disease was less common in women than in men. Women were more obese and symptomatic, and less likely to have albuminuria. Women had higher indexed left ventricular (LV) wall thicknesses, worse diastolic function (lower E', P = 0.002; higher E/E', P < 0.001), while LV mass and LV volumes indexed for height(2.7) were similar. Nonetheless, female sex was associated with a trend towards higher prevalence of abnormal LV geometry (defined as concentric hypertrophy, or eccentric hypertrophy, or concentric remodelling) at baseline (unadjusted P = 0.028, adjusted P = 0.056) and 12 weeks' follow up (unadjusted P = 0.001, adjusted P = 0.006), but not at 36 weeks' follow up (unadjusted P = 0.81, adjusted P = 0.99). Despite higher LV ejection fraction in women, global LV strain was similar between the sexes, while Tissue Doppler Imaging S' mitral velocity was lower in women. Both LV diastolic and systolic stiffness were higher in women than men (P < 0.001), even adjusting for LV concentricity and clinical covariates. We observed no sex differences in systolic arterial-LV coupling, as women also had higher absolute arterial elastance compared with men, although this difference was not significant after adjusting for height(2.7) .

CONCLUSION

More pronounced diastolic dysfunction may contribute to the greater predisposition for HFpEF in women compared with men.

Normal values of regional and global myocardial wall motion in young and elderly individuals using navigator gated tissue phase mapping

The purpose of this study was to evaluate normal values for regional and global myocardial wall motion parameters in young and elderly individuals, as detected by navigator gated high temporal resolution tissue phase mapping. Radial, longitudinal and circumferential ventricular wall motion, as well as ventricular torsion and longitudinal strain rates, were assessed in two age groups of volunteers, 23 ± 3 (n = 14) and 66 ± 7 years old (n = 9), respectively. All subjects were healthy, non-smokers without known cardiac disease. An increased global left ventricular (LV) torsion rate (peak systolic torsion rate 20.6 ± 2.0 versus 14.5 ± 1.0°/s/cm, peak diastolic torsion rate -25.2 ± 1.8 versus -14.1 ± 1.3°/s/cm) and a decrease in longitudinal LV motion (peak systolic values at mid-ventricle 5.9 ± 0.5 versus 8.5 ± 0.8 cm/s, peak diastolic values -10.7 ± 0.7 versus -15.2 ± 0.9 cm/s) in the older age group were the most prominent findings. Lower peak diastolic radial velocities with a longer time-to-peak values, most pronounced at the apex, are consistent with reduced diastolic function with ageing. Lower peak clockwise and counter-clockwise velocities at all LV levels revealed limitations in resting LV rotational motions in the older group. Significant changes in the undulating pattern of the rotational motions of the left ventricle were also observed. The results demonstrate distinct changes in regional and global myocardial wall motion in elderly individuals. Increased LV torsion rate and reduced LV longitudinal motion were particularly prominent in the older group. These parameters may have a role in the assessment of global LV contractility and help differentiate age-related changes from cardiac disease.

Heart failure with preserved ejection fraction

Progressive aging of the population and prolongation of life expectancy have led to the rising prevalence of heart failure (HF). Despite the improvements in medical therapy, the mortality rate of this condition has remained unacceptably high, becoming the primary cause of death in the elderly population. Almost half of patients with signs and symptoms of HF are found to have a nearly normal ejection fraction, which delineates a distinct clinical syndrome, known as HF with preserved ejection fraction (HF-PEF). While early research focused on the importance of diastolic dysfunction, more recent studies reported the pathophysiological complexity of the disease with multiple cardiovascular abnormalities contributing to its development and progression. HF-PEF is a challenging major health problem with yet no solution as there is no evidence-based treatment which improves clinical outcomes. This review summarizes the state of current knowledge on diagnosis, prognosis and treatment of HF-PEF, with particular insights on the pathological characteristics in the elderly population.