The mechanism of reduced longitudinal left ventricular systolic function in hypertensive patients with normal ejection fraction

In-silico heart model phantom to validate cardiac strain imaging

The quantification of cardiac strains as structural indices of cardiac function has a growing prevalence in clinical diagnosis. However, the highly heterogeneous four-dimensional (4D) cardiac motion challenges accurate "regional" strain quantification and leads to sizable differences in the estimated strains depending on the imaging modality and post-processing algorithm, limiting the translational potential of strains as incremental biomarkers of cardiac dysfunction. There remains a crucial need for a feasible benchmark that successfully replicates complex 4D cardiac kinematics to determine the reliability of strain calculation algorithms. In this study, we propose an in-silico heart phantom derived from finite element (FE) simulations to validate the quantification of 4D regional strains. First, as a proof-of-concept exercise, we created synthetic magnetic resonance (MR) images for a hollow thick-walled cylinder under pure torsion with an exact solution and demonstrated that "ground-truth" values can be recovered for the twist angle, which is also a key kinematic index in the heart. Next, we used mouse-specific FE simulations of cardiac kinematics to synthesize dynamic MR images by sampling various sectional planes of the left ventricle (LV). Strains were calculated using our recently developed non-rigid image registration (NRIR) framework in both problems. Moreover, we studied the effects of image quality on distorting regional strain calculations by conducting in-silico experiments for various LV configurations. Our studies offer a rigorous and feasible tool to standardize regional strain calculations to improve their clinical impact as incremental biomarkers.

In-silico heart model phantom to validate cardiac strain imaging

The quantification of cardiac strains as structural indices of cardiac function has a growing prevalence in clinical diagnosis. However, the highly heterogeneous four-dimensional (4D) cardiac motion challenges accurate "regional" strain quantification and leads to sizable differences in the estimated strains depending on the imaging modality and post-processing algorithm, limiting the translational potential of strains as incremental biomarkers of cardiac dysfunction. There remains a crucial need for a feasible benchmark that successfully replicates complex 4D cardiac kinematics to determine the reliability of strain calculation algorithms. In this study, we propose an in-silico heart phantom derived from finite element (FE) simulations to validate the quantification of 4D regional strains. First, as a proof-of-concept exercise, we created synthetic magnetic resonance (MR) images for a hollow thick-walled cylinder under pure torsion with an exact solution and demonstrated that "ground-truth" values can be recovered for the twist angle, which is also a key kinematic index in the heart. Next, we used mouse-specific FE simulations of cardiac kinematics to synthesize dynamic MR images by sampling various sectional planes of the left ventricle (LV). Strains were calculated using our recently developed non-rigid image registration (NRIR) framework in both problems. Moreover, we studied the effects of image quality on distorting regional strain calculations by conducting in-silico experiments for various LV configurations. Our studies offer a rigorous and feasible tool to standardize regional strain calculations to improve their clinical impact as incremental biomarkers.

Complete spatiotemporal quantification of cardiac motion in mice through enhanced acquisition and super-resolution reconstruction

The quantification of cardiac motion using cardiac magnetic resonance imaging (CMR) has shown promise as an early-stage marker for cardiovascular diseases. Despite the growing popularity of CMR-based myocardial strain calculations, measures of complete spatiotemporal strains (i.e., three-dimensional strains over the cardiac cycle) remain elusive. Complete spatiotemporal strain calculations are primarily hampered by poor spatial resolution, with the rapid motion of the cardiac wall also challenging the reproducibility of such strains. We hypothesize that a super-resolution reconstruction (SRR) framework that leverages combined image acquisitions at multiple orientations will enhance the reproducibility of complete spatiotemporal strain estimation. Two sets of CMR acquisitions were obtained for five wild-type mice, combining short-axis scans with radial and orthogonal long-axis scans. Super-resolution reconstruction, integrated with tissue classification, was performed to generate full four-dimensional (4D) images. The resulting enhanced and full 4D images enabled complete quantification of the motion in terms of 4D myocardial strains. Additionally, the effects of SRR in improving accurate strain measurements were evaluated using an in-silico heart phantom. The SRR framework revealed near isotropic spatial resolution, high structural similarity, and minimal loss of contrast, which led to overall improvements in strain accuracy. In essence, a comprehensive methodology was generated to quantify complete and reproducible myocardial deformation, aiding in the much-needed standardization of complete spatiotemporal strain calculations.

Hypertension-specific association of cardio-ankle vascular index with subclinical left ventricular function in a Chinese population: Danyang study

The association of cardio-ankle vascular index (CAVI), with subclinical cardiac dysfunction in hypertensive patients is unclear. We aim to examine their relationship in hypertensive patients compared with that in normotensive subjects. Our study included 1887 subjects enrolled from Danyang between 2018 and 2019. CAVI was measured using VaSera VS-1500A device. We performed conventional echocardiography to measure ejection fraction (EF) and E/A, tissue Doppler to measure mitral annular early diastolic velocities (e'), and speckle-tracking to estimate left ventricular (LV) global longitudinal strain (GLS). LV mass index (76.3, 80.0, and 84.0 g/m2), and E/e' (7.6, 8.2, and 8.8) were increased and GLS (21.1, 21.0, and 20.4%), E/A (1.2, 1.0, and 0.8) and e' velocity (11.2, 9.4, and 8.2 cm/s) was decreased from tertiles 1-3 of CAVI on unadjusted analyses (P < .001). After adjustment for covariates, GLS, E/A, and e' were still significantly decreased from tertiles 1-3 of CAVI (P ≤ .04). Further sensitive analyses revealed a similar association pattern for diastolic function but not systolic function. Compared with the lowest tertile, subjects with a top tertile of CAVI were at higher risk of subclinical LV systolic dysfunction in hypertensive patients (OR = 2.61; P = .005). Increased CAVI is associated with worse subclinical diastolic function. However, this relationship of CAVI to subclinical systolic function was more prominent in hypertensive patients.

Left ventricular ejection fraction: clinical, pathophysiological, and technical limitations

Risk stratification of cardiovascular death and treatment strategies in patients with heart failure (HF), the optimal timing for valve replacement, and the selection of patients for implantable cardioverter defibrillators are based on an echocardiographic calculation of left ventricular ejection fraction (LVEF) in most guidelines. As a marker of systolic function, LVEF has important limitations being affected by loading conditions and cavity geometry, as well as image quality, thus impacting inter- and intra-observer measurement variability. LVEF is a product of shortening of the three components of myocardial fibres: longitudinal, circumferential, and oblique. It is therefore a marker of global ejection performance based on cavity volume changes, rather than directly reflecting myocardial contractile function, hence may be normal even when myofibril's systolic function is impaired. Sub-endocardial longitudinal fibers are the most sensitive layers to ischemia, so when dysfunctional, the circumferential fibers may compensate for it and maintain the overall LVEF. Likewise, in patients with HF, LVEF is used to stratify subgroups, an approach that has prognostic implications but without a direct relationship. HF is a dynamic disease that may worsen or improve over time according to the underlying pathology. Such dynamicity impacts LVEF and its use to guide treatment. The same applies to changes in LVEF following interventional procedures. In this review, we analyze the clinical, pathophysiological, and technical limitations of LVEF across a wide range of cardiovascular pathologies.

The Use of Global Longitudinal Strain to Detect Subclinical Reduction in Left Ventricular Pump Function

BACKGROUND

Left ventricular (LV) ejection fraction (LVEF) is not a sensitive marker of LV systolic function in a subset of patients with preserved EF. The relation between LV pump function and global longitudinal strain (GLS) has not been elucidated well in patients with objectively preserved EF and no apparent heart failure (HF). We aimed to detect whether LV GLS can discover impaired LV pump function [presented as low stroke volume index (SVI) and low cardiac output (COP)] in patients with objectively preserved EF and no apparent clinical HF and its practice utility.

METHODS

In total, 100 participants with LVEF of ≥50% were studied for demographic and echocardiographic data, including LVEF, stroke volume, SVI, COP, LV longitudinal strain assessments, apical 4-, 3-, and 2-chamber views averaged for GLS, and were classified into 2 groups: group 1: normal GLS (more negative than -18%) and group 2: low GLS (less negative than -18%).

RESULTS

Reduced LV GLS was associated with lower SVI (35.6 ± 13.6 vs. 43.8 ± 12.7 mL/m 2 ; P = 0.01), lesser COP (5.4 ± 1.9 vs. 6.5 ± 2.1 l/min; P = 0.02), GLS had strong positive correlations with SVI ( r = 0.75; P < 0.001), and COP ( r = 0.66; P < 0.001). LV GLS at a cutoff value less negative than -15% is a strong predictor of SVI ≤35 mL/m 2 (76% sensitivity and 79% specificity) and at a cutoff value less negative than -13.5% it is a strong predictor of COP ≤4 L/min (76% sensitivity and 73% specificity). LV GLS was the best independent predictor of low SVI (<35 mL/m 2 ) and low COP (<4 L/min).

CONCLUSION

Impaired LV strain is associated with lower LV pump function, presented as lower COP and lower SVI in patients with preserved EF even in the absence of clinical HF. It is of great importance to incorporate GLS in the routine evaluation of LV function hand-by-hand with the noninvasive assessment of LV stroke volume and COP that can replace GLS on evaluation of LV pump function in old machines with no GLS modalities, for early pick-up of patients with impaired LV pump function before apparent HF.

Multi-Ethnic Study of Atherosclerosis: Relationship between Left Ventricular Shape at Cardiac MRI and 10-year Outcomes

Background Left ventricular (LV) subclinical remodeling is associated with adverse outcomes and indicates mechanisms of disease development. Standard metrics such as LV mass and volumes may not capture the full range of remodeling. Purpose To quantify the relationship between LV three-dimensional shape at MRI and incident cardiovascular events over 10 years. Materials and Methods In this retrospective study, 5098 participants from the Multi-Ethnic Study of Atherosclerosis who were free of clinical cardiovascular disease underwent cardiac MRI from 2000 to 2002. LV shape models were automatically generated using a machine learning workflow. Event-specific remodeling signatures were computed using partial least squares regression, and random survival forests were used to determine which features were most associated with incident heart failure (HF), coronary heart disease (CHD), and cardiovascular disease (CVD) events over a 10-year follow-up period. The discrimination improvement of adding LV shape to traditional cardiovascular risk factors, coronary artery calcium scores, and N-terminal pro-brain natriuretic peptide levels was assessed using the index of prediction accuracy and time-dependent area under the receiver operating characteristic curve (AUC). Kaplan-Meier survival curves were used to illustrate the ability of remodeling signatures to predict the end points. Results Overall, 4618 participants had sufficient three-dimensional MRI information to generate patient-specific LV models (mean age, 60.6 years ± 9.9 [SD]; 2540 women). Among these participants, 147 had HF, 317 had CHD, and 455 had CVD events. The addition of LV remodeling signatures to traditional cardiovascular risk factors improved the mean AUC for 10-year survival prediction and achieved better performance than LV mass and volumes; HF (AUC, 0.83 ± 0.01 and 0.81 ± 0.01, respectively; P < .05), CHD (AUC, 0.77 ± 0.01 and 0.75 ± 0.01, respectively; P < .05), and CVD (AUC, 0.78 ± 0.0 and 0.76 ± 0.0, respectively; P < .05). Kaplan-Meier analysis demonstrated that participants with high-risk HF remodeling signatures had a 10-year survival rate of 56% compared with 95% for those with low-risk scores. Conclusion Left ventricular event-specific remodeling signatures were more predictive of heart failure, coronary heart disease, and cardiovascular disease events over 10 years than standard mass and volume measures and enable an automatic personalized medicine approach to tracking remodeling. © RSNA, 2022 Online supplemental material is available for this article.

Subclinical systolic dysfunction by speckle tracking echocardiography in patients with systemic lupus erythematosus

BACKGROUND

We aimed to compare the prevalence of subclinical left ventricular systolic dysfunction in Hispanic systemic lupus erythematosus (SLE) patients versus healthy controls.

MATERIAL AND METHODS

This cross-sectional study included 46 SLE patients who fulfilled the 2019 European League Against Rheumatism and American College of Rheumatology (EULAR/ACR) classification criteria for SLE and with age ≥ 18 years. For comparison, we included a control group with 46 non-SLE subjects matched by age (±5 years) and gender. A transthoracic echocardiogram was performed on every participant. The echocardiographic measurements evaluated were left ventricular ejection fraction (LVEF), relative wall thickness (RWT), and tricuspid annular plane systolic excursion (TAPSE). Left ventricular-Global Longitudinal Strain (GLS) was evaluated, and a value higher than -18% was classified as subclinical left ventricular systolic dysfunction. Comparisons between groups were made using the Chi-square test or Fisher's exact test for qualitative variables, and Student's t-test or the Mann-Whitney's U test for quantitative variables. A p-value <.05 was considered significant.

RESULTS

We found a significant difference in the presence of subclinical left ventricular systolic dysfunction between SLE-patients and controls (37.0% vs 8.7%, p = .001). We also found that SLE patients had a lower left ventricular GLS (-18.90% vs -20.51%, p = .011), TAPSE (21.63 mm vs 23.60 mm, p = .009), and LVEF (57.17% vs 62.47%, p = <.001) than controls. Systemic lupus erythematosus diagnosis was independently associated with the presence of subclinical left ventricular systolic dysfunction with an OR of 6.068 (CI 95% 1.675-21.987) (p = .006). Subclinical systolic dysfunction was more common in men (29.4% vs 3.4%, p = .020), patients with obesity (17.6% vs 0%, p = .045), or hypertension (47.1% vs 6.9%, p = .001).

CONCLUSION

Systemic lupus erythematosus Hispanic patients had a higher prevalence of subclinical left ventricular systolic dysfunction, and worse left ventricular GLS, LVEF, and TAPSE values than matched healthy controls. Additionally, we found that male gender, obesity, and hypertension are associated with the presence of subclinical left ventricular systolic dysfunction in SLE patients. The inclusion of speckle tracking echocardiography as part of the cardiovascular evaluation of SLE patients may help identify high cardiovascular risk patients.

Longitudinal systolic dysfunction in hypertensive cardiomyopathy with normal ejection fraction

BACKGROUND

The left ventricle (LV) journey in their transition from hypertrophy to heart failure is marked by many subcellular events partially understood yet. The moment in which the structural abnormalities reach the umbral to induce myocardial dysfunction remains elusive.

AIMS

To evaluate the anatomic-functional relationship between LV wall thickness and longitudinal systolic dysfunction.

MATERIAL AND METHODS

We prospectively performed clinical assessment and transthoracic echocardiogram on healthy individuals and hypertensive patients with left ventricle ejection fraction (LVEF) ≥50% and absence of heart failure symptoms.

RESULTS

A total of 226 patients and 101 healthy individuals were recruited. The distribution for sex was similar between groups. The mean age was 67±13 years old in the patients, and 44% had concentric LV hypertrophy. LVEF was identical in both groups (63±6%); in contrast, global longitudinal strain (GLS) (-18.8±2.5% vs -20.4±2%) and mitral annulus plane systolic excursion (MAPSE) (13.8±2.8 vs 15.5±2 mm) were lower. ROC curve optimally classified decreased GLS with LV septum thickness ≥13 mm and decreased MAPSE with thickness ≥14 mm. Multivariable logistic regression found that LV septum thickness is the only variable associated with longitudinal systolic dysfunction (OR = 1.1, CI_95%  =  1.05 - 1.15, P = 0.001, R squared = .38).

DISCUSSION

A progressive increase in LV wall thickness due to myocyte hypertrophy and interstitial expansion is associated with LV systolic longitudinal dysfunction.

CONCLUSIONS

Patients with moderate or severe ventricular hypertrophy (septum ≥13 mm) had longitudinal systolic dysfunction, GLS decreases with minor structural change than MAPSE, and LVEF is insensitive in detecting longitudinal myocardial dysfunction in patients with hypertension.

Clinical factors associated with reduced global longitudinal strain in subjects with normal left ventricular ejection fraction

Characteristics of subjects with reduced GLS but no overt left ventricular dysfunction have been poorly characterized. We sought to find clinical factors associated with reduced GLS despite having normal LVEF. Subjects without documented cardiovascular disease who underwent measurement of GLS using 2D speckle-tracking echocardiography were retrospectively reviewed. All subjects had normal LVEF (≥ 55%). Because GLS is a negative value, we took the absolute value |x| for a simpler interpretation. Reduced GLS was defined as < 18%, and normal GLS was defined as ≥ 18%. Of 690 study subjects (mean age, 58 years and females, 51.2%), 208 (30.1%) had reduced GLS. Subjects with reduced GLS were more frequently male, and had more cardiovascular risk factors than those with normal GLS. In multivariable binary logistic regression analysis, male sex (odds ratio [OR] 3.02; 95% confidence interval [CI] 2.02‒4.50; P < 0.001), hypertension (OR 1.52; 95% CI 1.02‒2.28; P = 0.043) and cigarette smoking (OR 1.80; 95% CI 1.14‒2.85; P = 0.012) were independently associated with reduced GLS. The greater the number of these 3 risk factors (male sex, hypertension and cigarette smoking), the higher the probability of having reduced GLS (P < 0.001). In subjects without overt cardiovascular disease who had normal LVEF, a relevant proportion (30.1%) of subjects had reduced GLS. Male sex, hypertension and cigarette smoking were independently associated with reduced GLS. GLS measurement should be emphasized for subjects with these clinical characteristics.

Myocardial strain in hypertension: a meta-analysis of two-dimensional speckle tracking echocardiographic studies

AIM

Available evidence on systolic dysfunction in systemic hypertension, as assessed by left ventricular (LV) mechanics, is still based on single studies. Thus, we performed a systematic meta-analysis of two-dimensional speckle-tracking studies in order to provide an updated comprehensive information on this issue.

METHODS

The PubMed, OVID-MEDLINE, and Cochrane library databases were analyzed to search English language articles published from the inception up to 31 December 2020. Studies were identified by using MeSH terms and crossing the following search items: 'myocardial strain', 'left ventricular mechanics', 'speckle tracking echocardiography', 'systolic dysfunction', 'hypertensive heart disease', 'systemic hypertension', 'essential hypertension'.

RESULTS

Data from 4276 individuals (2089 normotensive controls and 2187 mostly uncomplicated hypertensive patients) were included. Left ventricular (LV) mass index, relative wall thickness, left atrial volume index and E/e' ratio were significantly higher in hypertensive patients than in normotensive controls. LV ejection fraction did not differ in the two pooled groups (SMD -0.048 ± 0.054, 95% CI -0.20 to 0.10, P = 0.30), whereas LV global longitudinal strain (GLS) was significantly impaired in the hypertensive group (SMD: 1.07 ± 0. 15, 95% CI 0.77-1.36, P < 0.0001). Similar findings were obtained in a sub-analysis restricted to 15 studies in which mean age was similar in cases and controls (SMD 1.21 ± 0.23, 95% CI 0.76-1.67, P = 0.002).

CONCLUSION

The present meta-analysis suggests that GLS assessment unmasks systolic dysfunction undetected by conventional ejection fraction in the uncomplicated hypertension setting and that this parameter should be incorporated into routine work-up aimed to identify hypertension-mediated cardiac damage.

Inter-vendor variability and reproducibility of subcostal left ventricular longitudinal strain

Left ventricular longitudinal strain (LVLS) performed using subcostal windows is a novel alternative for patients who require strain imaging but have poor apical windows. We investigated the reproducibility and inter-vendor variability of subcostal LVLS. One hundred and twenty-four echocardiographic studies were analysed from 73 women with early stage HER2-positive breast cancer. Speckle tracking strain was performed offline using EchoPAC and TomTec on subcostal 4-chamber and 3-chamber views to obtain subcostal 4-chamber (SC4_LS) and 3-chamber (SC3_LS) LVLS which was then averaged (SCav_LS). Reproducibility of subcostal single chamber and averaged LVLS were assessed. Measurements between platforms were compared. Strain was reported in absolute magnitude. EchoPAC measurements of SC3_LS (20.5 ± 2.4% vs. 21.2 ± 2.5%, p = 0.002) and SCav_LS (20.9 ± 2.1% vs. 21.2 ± 2.1%, p = 0.02) were lower than TomTec measurements while SC4_LS was similar (21.3 ± 2.7% vs. 21.3 ± 2.5%, p = 0.94). Mean differences between EchoPAC and TomTec were ≤ 0.6% strain units for all subcostal LVLS measurements; SCav_LS showed the narrowest limits of agreement (LOA) (mean difference - 0.3%, LOA - 3.2 to 2.6%). EchoPAC and TomTec measurements of SCav_LS showed good correlation (r = 0.76, p < 0.001). Intra-observer and inter-observer analysis showed good reproducibility. Inter-observer variability was lower than inter-vendor variability; SCav_LS was most reproducible: inter-observer relative mean error was 3.6% for EchoPAC and 4.3% for TomTec and inter-observer LOA were ± 2.1% for EchoPAC and ± 2.6% for TomTec. Averaged subcostal LVLS was highly reproducible with inter-observer variability comparable to GLS. Inter-vendor differences in averaged subcostal LVLS were small but statistically significant.

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.

Association of urine albumin-to-creatinine ratio with subclinical systolic dysfunction in hypertensive patients but not normotensive subjects: Danyang study

The association of albuminuria, as measured by urine albumin-to-creatinine ratio (UACR) concentration, with subclinical cardiac dysfunction in hypertensive patients is unclear. Our study aimed to examine its relationship in hypertensive patients compared with that in normotensive patients. The study participants were recruited from Danyang, a city of Jiangsu Province from 2017 to 2019. Categorical and continuous analyses were performed with sex-specific UACR tertiles and natural logarithmically transformed UACR, respectively. Comprehensive echocardiography including conventional imaging, tissue Doppler imaging, and 2D speckle tracking was performed using Philips CX50 device. The 2857 participants (mean age = 52.7 ± 11.8 years) included 1673 (58.6%) women, 1125 (39.4%) hypertensive patients, 546 (19.1%) patients with microalbuminuria, and 38 (1.3%) patients with macroalbuminuria. Comorbidities were increasingly prevalent across the tertiles of UACR. Increased left ventricular (LV) mass index, decreased global longitudinal strain (GLS) and LV ejection fraction, lower E/A ratio and e' velocity, and higher E/e' ratio were significantly associated with higher UACR on unadjusted analyses (p ≤ .01). After adjustment for covariates, UACR was only independently associated with lower GLS (tertile 3 = 20.7% vs. tertile 1 = 20.9%; p = .04). The results of hypertensive patients (p ≤ .04) but not normotensive patients (p ≥ .16) were similar to those of the total cohort. Subgroup analyses revealed similar results in patients without coronary artery disease, or without LV hypertrophy, or without diabetes. In conclusion, increased UACR is associated with worse subclinical systolic function in Chinese hypertensive patients but not in normotensive participants.

Cardiac mechanics in heart failure with preserved ejection fraction

Heart failure with preserved ejection fraction (HFpEF) is a complex clinical entity associated with significant morbidity and mortality. Common comorbidities including hypertension, coronary artery disease, diabetes, chronic kidney disease, obesity, and increasing age predispose to preclinical diastolic dysfunction that often progresses to frank HFpEF. Clinical HFpEF is typically associated with some degree of diastolic dysfunction, but can occur in the absence of many conventional diastolic dysfunction indices. The exact biologic links between risk factors, structural changes, and clinical manifestations are not clearly apparent. Innovative approaches including deformation imaging have enabled deeper understanding of HFpEF cardiac mechanics beyond conventional metrics. Furthermore, predictive analytics through data-driven platforms have allowed for a deeper understanding of HFpEF phenotypes. This review focuses on the changes in cardiac mechanics that occur through preclinical myocardial dysfunction to clinically apparent HFpEF.

Subclinical Systolic and Diastolic Dysfunction Is Evident in Youth With Elevated Blood Pressure

Hypertension is associated with cardiovascular events in adults. Subclinical changes to left ventricular strain and diastolic function have been found before development of decreased left ventricular ejection fraction and cardiovascular events. Our objective was to study effects of blood pressure (BP) on ventricular function in youth across the BP spectrum. Vital signs and labs were obtained in 346 participants aged 11 to 19 years who had BP categorized as low-risk (N=144; systolic BP <75th percentile), mid-risk (N=83; systolic BP ≥80th and <90th percentile), and high-risk (N=119; systolic BP ≥90th percentile). Echocardiography was performed to assess left ventricular strain and diastolic function. Differences between groups were analyzed by ANOVA. General linear models were constructed to determine independent predictors of systolic and diastolic function. Mid-risk and high-risk participants had greater adiposity and more adverse metabolic labs (lower HDL [high-density lipoprotein], higher glucose, and higher insulin) than the low-risk group. Mid-risk and high-risk participants had significantly lower left ventricular ejection fraction and peak global longitudinal strain than the low-risk group (both P≤0.05). The E/e' ratio was higher in the high-risk group versus the low-risk and mid-risk groups, and the e'/a' ratio was lower in the high-risk versus the low-risk group (both P≤0.05). BP and adiposity were statistically significant determinants of left ventricular systolic and diastolic function. Subclinical changes in left ventricular systolic and diastolic function can be detected even at BP levels below the hypertensive range as currently defined.

Asymptomatic Left Ventricle Systolic Dysfunction

Heart failure is a common debilitating illness, associated with significant morbidity and mortality, rehospitalisation and societal costs. Current guidelines and position statements emphasise the management of patients with overt symptomatic disease, but the increasing prevalence of congestive heart failure underscores the need to identify and manage patients with early left ventricular dysfunction prior to symptom onset. Asymptomatic left ventricular systolic dysfunction (ALVSD), classified as stage B heart failure, is defined as depressed left ventricular systolic function in the absence of clinical heart failure. Early initiation of therapies in patients with presumed ALVSD has been shown to lead to better outcomes. In this article, the authors clarify issues surrounding the definition and natural history of ALVSD, outline clinical tools that may be of value in identifying patients with ALVSD and highlight potential opportunities for future investigations to better address aspects of our understanding of this complex syndrome.

Myocardial Strain in the Assessment of Patients With Heart Failure: A Review

Importance

The cornerstones of imaging in heart failure (HF) are the measurement of systolic and diastolic function and left ventricular (LV) filling pressure.

Observations

Ejection fraction and the assessment of LV filling pressure and diastolic dysfunction using the ratio of early transmitral flow and LV relaxation (E/e') are conventional imaging markers of LV function. Despite their extensive use in HF guidelines, both have significant detractions, especially in an era when HF with preserved ejection fraction is becoming the dominant presentation. In contrast, strain imaging has provided a new window into myocardial mechanics. Myocardial strain is now well validated, robust, and can easily be performed on most modern echocardiography machines. This Review summarizes the evidence in 9 situations across the stages of HF where LV global longitudinal strain and other strain parameters may provide information on risk prediction, diagnosis, assessment of treatment response, and follow-up.

Conclusions and Relevance

The evolution of myocardial deformation imaging from research tool to clinical practice will provide clinicians with a useful additional imaging parameter to facilitate the assessment and risk evaluation of patients with HF.

Left ventricular systolic dysfunction potentially contributes to the symptoms in heart failure with preserved ejection fraction

AIMS

Left ventricular diastolic dysfunction (LVDD) is considered a key factor associated with heart failure (HF) symptoms in patients with preserved ejection fraction (HFpEF). However, LV systolic performance, including LV systolic function and synchrony, has not been well characterized in these patients. The aims of this study were to assess to investigate the underlying relationship and differences between subclinical LVDD and HFpEF.

METHODS

Eighty-six patients with LVDD were recruited (58 with HFpEF and 28 with subclinical LVDD). Systolic left ventricular (LV) longitudinal strain (LS), systolic longitudinal strain rate (LSrS), early diastolic longitudinal strain rate (LSrE), and late diastolic longitudinal strain rate (LSrA) were measured using speckle tracking echocardiography. LV diastolic and systolic dyssynchrony (Te-SD and Ts-SD) were calculated. Forty age- and sex-matched healthy individuals were enrolled as a control group.

RESULTS

LV global LS and LSrS were decreased in patients with HFpEF than in normal controls and subclinical LVDD patients (P < .05). Te-SD and Ts-SD were significantly more prolonged in subclinical LVDD and HFpEF patients than in the control group (P < .05). Reduced LS was associated with HF symptoms in LVDD patients, and a cutoff value of -18% for LS could differentiate HFpEF from subclinical LVDD with 73% sensitivity and 69% specificity.

CONCLUSION

LV systolic function and mechanical dyssynchrony were impaired in HFpEF patients. Deteriorated LV longitudinal systolic function was likely correlated with the symptoms of HFpEF.

Speckle tracking derived reference values of myocardial deformation and impact of cardiovascular risk factors - Results from the population-based STAAB cohort study

AIMS

We aimed to provide reference values for speckle-tracking derived systolic and diastolic myocardial deformation markers, and to determine their relation with age, sex, and cardiovascular risk factors.

METHODS AND RESULTS

The Characteristics and Course of Heart Failure STAges A/B and Determinants of Progression (STAAB) cohort study recruited a representative sample of the population of Würzburg, Germany, aged 30-79 years. In a sample of 1818 participants (52% female, mean age 54±12 years) global longitudinal peak systolic strain (GL-PSS, n = 1218), systolic (GL-SSR, n = 1506), and early (GL-EDSR, n = 1506) and late diastolic strain rates (GL-LDSR, n = 1500) were derived from 2D speckle tracking analysis. From a subgroup of 323 individuals without any cardiovascular risk factor, sex- and age-specific reference values were computed. GL-PSS, GL-SSR, and GL-EDSR were associated with sex, GL-EDSR decreased and GL-LDSR increased with age. In the total sample, dyslipidemia was associated with altered GL-PSS, GL-SSR, and GL-EDSR in women but not in men, whereas obesity was associated with less favorable GL-PSS and GL-EDSR in either sex. Hypertension impacted more adversely on systolic and diastolic myocardial deformation in women compared to men (all p<0.01).

CONCLUSION

The female myocardium appeared more vulnerable to high blood pressure and dyslipidemia when compared to men, while obesity was associated with adverse myocardial deformation in either sex. The reference values for echocardiographic myocardial deformation provided for a non-diseased population and their here reported associations with cardiovascular risk factors will inform future observational and intervention studies regarding i) effect sizes and power calculation, ii) cross-study comparisons, and iii) categorization of myocardial deformation in specific patient groups.

Impaired Left Ventricular Global Longitudinal Strain among Patients with Chronic Kidney Disease and End-Stage Renal Disease and Renal Transplant Recipients

BACKGROUND

Although heart failure is the most prevalent cardiovascular disease associated with adverse outcome in chronic kidney disease (CKD) and after kidney transplantation, left ventricular (LV) systolic function is often preserved in renal patients. The aim of this study was to evaluate global longitudinal strain (GLS), which is reportedly a more accurate tool for detecting subclinical LV systolic dysfunction, in patients with various degrees of renal function impairment, including kidney transplant recipients (KTRs).

METHODS

This prospective study evaluated demographic, clinical, and ultrasound data, including the assessment of LV GLS and mitral E peak velocity and averaged ratio of mitral to myocardial early velocities (E/e'), of 70 consecutive renal patients (20 with stage 2-4 CKD, 25 with end-stage renal disease on hemodialysis [HD], and 25 KTRs). All patients had an LV ejection fraction ≥50% and no history of heart failure or coronary artery disease. We used multivariable logistic analysis to assess the risk of compromised GLS. One hundred and twenty control subjects with or without hypertension served as controls.

RESULTS

A compromised GLS <-18% was shown in 55% of patients with stage 2-4 CKD, 60% of HD patients, and 28% of KTRs, while it was 32% in hypertensive controls and 12% in non-hypertensive controls (p < 0.0001). Patients with HD had higher systolic pressure and a significantly greater prevalence of increased LV mass and diastolic dysfunction. In renal patients, E/e' (p = 0.025), and LV mass index (p = 0.063) were independent predictors of compromised GLS at logistic regression analysis. E/e', systolic artery pressure, and LV mass also exhibited the greatest areas under the curve on receiver operating characteristic analysis to identify a compromised GLS.

CONCLUSIONS

Renal disease proved to be associated with early and subclinical impairment of LV systolic function, which persists after starting dialysis and even in spite of successful kidney transplantation. An increased E/e' resulted to be the most powerful independent predictor of abnormal GLS.

Noninvasive Cardiac Imaging and the Prediction of Heart Failure Progression in Preclinical Stage A/B Subjects

Heart failure (HF) continues to grow as a cause of morbidity and mortality in our community and presents a significant public health problem, predominantly in individuals ≥65 years of age. Early intervention in asymptomatic HF subjects (Stage A/B) at risk of progression to symptomatic HF (Stage C/D) may provide an opportunity to halt this epidemic. The ability of cardiac imaging to assess cardiac structure and function permits early identification of those at increased risk of developing symptomatic HF. Systolic, diastolic, and structural left ventricular parameters each predict symptomatic HF, but no single parameter has sufficient sensitivity for screening to identify individuals with Stage A/B HF who are at increased risk of disease progression. Transthoracic echocardiography (TTE) has the advantage over other imaging modalities in being able to measure systolic, diastolic, and structural left ventricular parameters, and it identified at least 1 abnormal parameter in >50% of individuals with Stage A/B HF ≥65 years of age. Moreover, identification of at least 1 abnormality according to TTE in individuals with Stage A/B HF ≥65 years of age had 72% to 82% sensitivity for detection of those who subsequently developed symptomatic HF. Therefore, a case can be made for cardiac imaging by using TTE for community-dwelling populations with Stage A/B HF ≥65 years of age to identify those with increased risk of symptomatic HF who can be offered preventative therapies. Further studies are required to determine the best strategy for identifying the risk of symptomatic HF in younger individuals.

Layer-specific systolic and diastolic strain in hypertensive patients with and without mild diastolic dysfunction

This study sought to examine layer-specific longitudinal and circumferential systolic and diastolic strain, strain rate (SR) and diastolic time intervals in hypertensive patients with and without diastolic dysfunction. Fifty-eight treated hypertensive patients were assigned to normal diastolic function (NDF, N = 39) or mild diastolic dysfunction (DD, N = 19) group. Layer-specific systolic and diastolic longitudinal and circumferential strains and SR were assessed. Results showed no between-group difference in left ventricular mass index (DD: 92.1 ± 18.1 vs NDF: 88.4 ± 16.3; P = 0.44). Patients with DD had a proportional reduction in longitudinal strain across the myocardium (endocardial for DD -13 ± 4%; vs NDF -17 ± 3, P < 0.01; epicardial for DD -10 ± 3% vs NDF -13 ± 3%, P < 0.01; global for DD: -12 ± 3% vs NDF: -15 ± 3, P = 0.01), and longitudinal mechanical diastolic impairments as evidenced by reduced longitudinal strain rate of early diastole (DD 0.7 ± 0.2 L/s vs NDF 1.0 ± 0.3 L/s, P < 0.01) and absence of a transmural gradient in the duration of diastolic strain (DD endocardial: 547 ± 105 ms vs epicardial: 542 ± 113 ms, P = 0.24; NDF endocardial: 566 ± 86 ms vs epicardial: 553 ± 77 ms, P = 0.03). Patients with DD also demonstrate a longer duration of early circumferential diastolic strain (231 ± 71 ms vs 189 ± 58 ms, P = 0.02). In conclusion, hypertensive patients with mild DD demonstrate a proportional reduction in longitudinal strain across the myocardium, as well as longitudinal mechanical diastolic impairment, and prolonging duration of circumferential mechanical relaxation.

Left ventricular diastolic and systolic dyssynchrony and dysfunction in heart failure with preserved ejection fraction and a narrow QRS complex

Aims: Mechanical dyssynchrony has been reported in heart failure with preserved ejection fraction (HFpEF), with a majority of patients having a narrow QRS complex; however, whether any benefit is observed with restoration of dyssynchrony remains unclear. We sought to assess left ventricular (LV) dyssynchrony and function in HFpEF and elucidate the underlying mechanisms that may account for HFpEF. Methods: Seventy-eighty patients with a narrow QRS complex including 47 with HFpEF, 31 with heart failure with reduced ejection fraction (HFrEF) patients, and 29 with asymptomatic left ventricular diastolic dysfunction (LVDD) were recruited. Forty-five normal subjects acted as controls. Systolic LV longitudinal strain (LS), systolic longitudinal strain rate (LSrS), early diastolic longitudinal strain rate (LSrE), and late diastolic longitudinal strain rate (LSrA) were measured using speckle tracking echocardiography. LV diastolic and systolic dyssynchrony (Te-SD and Ts-SD) were calculated. Results: Te-SD and Ts-SD were prolonged in HFpEF and HFrEF patients than in the control group (p<0.05). However, Ts-SD was shorter in HFpEF patients compared to HFrEF patients despite a narrow QRS complex (p<0.05). LV global LS, LSrS, and LSrE were decreased in patients with HFpEF and HFrEF compared to other groups, with HFrEF being even more reduced than HFpEF (p<0.05). Reduced LS, LSrS, and LSrE could effectively differentiate HF from asymptomatic LVDD patients (p<0.05). Conclusion: HFrEF exhibited increased systolic dyssynchrony compared to HFpEF despite a narrow QRS complex in addition to the more reduced diastolic and systolic function. Therefore, targeting to improve diastolic and systolic function instead of managing systolic dyssynchrony might be of great importance in the treatment of HFpEF.

Influence of Aging on Level and Layer-Specific Left Ventricular Longitudinal Strain in Subjects Without Structural Heart Disease

Values for level- (apical, mid, and basal) and layer-based (endocardial, mid-myocardial, and epicardial) left ventricular (LV) longitudinal strain across age are scarce. The present study evaluates the effect of aging on level- and layer-specific LV longitudinal strain in subjects without structural heart disease. A total of 408 subjects (mean age 58 years [range 16 to 91]; 49% men) were evaluated retrospectively. Subjects were divided into equal groups based on age and gender. Subjects with evidence of structural heart disease or arrhythmias were excluded. Mean LV ejection fraction was 62 ± 6.2%. A gradual increase in magnitude of level LV longitudinal strain was observed from basal to mid and apical levels (-16.7 ± 2.1%, -18.8 ± 2.0%, -22.6 ± 3.8%; p <0.001, respectively). Across age groups, there was a borderline significant decrease in magnitude of basal longitudinal strain in older subjects, whereas the magnitude in the apical level significantly increased. On layer-based analysis, the magnitude of longitudinal strain increased from epicardium to endocardium across all age groups. On multivariable analysis, only diabetes mellitus was associated with more impaired longitudinal strain in the endocardium, and male gender was associated with more impaired longitudinal strain at the epicardium layer. In conclusion, with increasing age, the magnitude of LV longitudinal strain at the basal level declines while the apical LV longitudinal strain increases. In contrast, layer-specific LV longitudinal strain remains unchanged with aging. The presence of diabetes mellitus modulated the effect of age on the LV endocardial layer, and male gender was associated with more impaired longitudinal strain at the epicardial layer.

Stem cell therapy restores viscoelastic properties of myocardium in rat model of hypertension

Extensive remodeling of the myocardium is seen in a variety of cardiovascular diseases, including systemic hypertension. Stem cell therapy has been proposed to improve the clinical outcomes of hypertension, and we hypothesized that changes in mechanical properties of the myocardium would accompany the progression of disease and the results of treatment conditions. Using spontaneously hypertensive rats (SHR) as a model of hypertension, we treated 13-week-old hypertensive rats with a single injection of adipose-derived stem cells (ADSC) isolated from a normotensive control. We indented the isolated ventricles of control, untreated sham-injected SHR, and ADSC-treated SHR hearts with a custom cantilever-based system and fit the resulting data to a standard linear solid model. SHR animals had higher blood pressure (198.4±25.9mmHg) and lower ejection fraction (69.9±4.2%) than age-matched control animals (109.0±1.6mmHg, 88.2±1.3%), and increased viscoelastic properties accompanied these clinical changes (right ventricle effective stiffness, SHR: 21.97±5.10kPa, Control: 13.14±3.48kPa). ADSC-treated animals saw improvement in clinical parameters compared to the untreated SHR group, which was also accompanied by a significant restoration of viscoelastic properties of the myocardium (ACSD-treated SHR: 9.77±6.96kPa).

ß-2 microglobulin level is negatively associated with global left ventricular longitudinal peak systolic strain and left atrial volume index in patients with chronic kidney disease not on dialysis

Objective:

There are many factors related to high left atrial volume index (LAVI) and global left ventricular longitudinal peak systolic strain (GLS-%) decline in chronic kidney disease. The purpose of our study is to investigate the relation between the β-2 microglobulin (β-2µ) and GLS-% and LAVI in patients with chronic kidney disease not yet on dialysis.

Methods:

Our study was a non-randomized, controlled, prospective study. We included 87 consecutive patients with eGFR levels below 60 ml/min/m² not on dialysis and 82 normal healthy individuals with complaints of atypical chest pain and negative stress tests as control group in our study. Patients with hospitalization related to dialysis or heart failure attacks within 3 months, active malignancy, malnutrition, pregnancy, and uncontrolled hypertension were excluded. Brachial pulse wave velocity (PWV), augmentation index, augmentation pressure and central hemodynamics, and PWV analysis were performed in order to assess the arterial stiffness and blood pressure. According to the distribution of data, Spearman and Pearson correlations and multiple linear regression were used to determine significant and independent factor associated with high LAVI and low GLS-%.

Results:

There were significant correlations between β-2µ with LAVI (r=0.313, p=0.004) and with GLS-% (r=–0.222, p=0.04). In multiple linear regression, the relationship between β-2µ with GLS-% [β=–0.037, 95% CI (–0.062, –0.013), p=0.004] and LAVI [β=4.522, 95% CI (2.806, 6.238), p<0.001] was independent of age, PWV, central and peripheral blood pressures, parathormone, CalciumXPhospor, Hgb levels, and eGFR.

Conclusion:

Increasing β-2µ levels were found to be associated with increased LAVI and decreased GLS-%. Additional experimental studies are needed to clarify these relationships.

Pathophysiological effects of different risk factors for heart failure

Background

Hypertension and type 2 diabetes mellitus (T2DM) are important causes of non-ischaemic heart failure (HF). Understanding the pathophysiology of early HF may guide screening. We hypothesised that the underlying physiology differed according to aetiology.

Methods

In this cross-sectional study of 521 asymptomatic community-based subjects ≥65 years with ≥1 HF risk factors, 187 participants (36%) had T2DM and hypertension (T2DM+/HTN+), 109 (21%) had T2DM with no hypertension (T2DM+/HTN−) and 72 (14%) had neither T2DM nor hypertension (T2DM−/HTN−). In 153 patients (29%), clinic blood pressure was ≥140/90 mm Hg, defined as active hypertension (T2DM−/HTN+). All underwent a comprehensive echocardiogram, including conventional parameters for systolic and diastolic function as well as global longitudinal strain (GLS), diastolic strain (DS) and DS rate (DSR). A 6 min walk (6MW) test was used to assess functional capacity.

Results

GLS in T2DM−/HTN+ group (−18.9±2.7%) was similar to that in T2DM−/HTN− group (−19.4±2.4%) and greater than T2DM+/HTN− (−18.0±2.8%, p=0.005). DS in T2DM−/HTN− (0.47±0.15%) exceeded that in T2DM−/HTN+ (0.43±0.14%) and T2DM+/HTN− (0.43±0.13%). 6MW distance was preserved in T2DM−/HTN+ (482±85 m) and reduced in T2DM+/HTN− (469±93, p<0.001). Those with T2DM and active hypertension had worst GLS, DS, DSR and shortest 6MW distance (p<0.002). In multivariable analysis, GLS was associated with T2DM but neither active hypertension nor a history of hypertension. Diastolic markers and left ventricular (LV) mass were associated with hypertension and T2DM. Thus, patients with HF risk factors show different functional disturbances according to aetiology.

Conclusions

Patients with hypertension had relatively less impaired GLS and preserved 6MW distance but more impaired diastolic function.

Cardiac function in BRCA1/2 mutation carriers with history of breast cancer treated with anthracyclines

Animal data suggest that defects in BRCA1/2 genes significantly increase the risk of heart failure and mortality in mice exposed to doxorubicine. Women with BRCA1/2 mutations who develop breast cancer (BC) may receive anthracyclines but their risk of cardiac dysfunction has not been investigated. Our study tested the hypothesis that women with history of BRCA1/2 mutation-associated BC treated with anthracyclines have impaired parameters of cardiac function compared to similarly treated women with history of sporadic BC. Women with history of BC and anthracycline treatment underwent an echocardiographic exam for assessment of primary outcomes, left ventricular ejection fraction (LVEF) and global longitudinal strain (GLS). The sample size of 81 provided 79 % power with two-sided two-sample t test and alpha of 0.05 to detect a clinically meaningful difference in cardiac function of absolute 5 % points difference for LVEF and 2 % points difference for GLS. Of 81 normotensive participants, 39 were BRCA1/2 mutation carriers and 42 in the sporadic group. Mean age was 50 ± 9 years in both groups (P = 0.99) but BRCA1/2 mutation carriers had longer anthracycline treatment-to-enrollment time (7.5 ± 5.3 vs. 4.2 ± 3.3 years, P = 0.001). There were no significant differences in LVEF (P = 0.227) or GLS (P = 0.53) between the groups. LVEF was normal in 91 % of women and subclinical cardiac dysfunction defined as absolute GLS value <18.9 % was seen in 4 (10 %) BRCA1/2 mutation carriers and 7 (17 %) sporadic participants. In this first prospective examination of cardiac function in BRCA1/2 mutation carriers, we found no significant differences in sensitive echocardiographic parameters of cardiac function between BRCA1/2 mutation carriers and women with history of sporadic BC who received anthracycline treatment. In contrast to laboratory animal data, our findings indicate lack of elevated cardiac risk with the use of standard-doses of adjuvant anthracyclines in treatment of BRCA1/2 mutation carriers with early stage BC.