Diastolic Left Ventricular Research Articles

Prognostic yield of echocardiographic measures of cardiac structure and function in HFrEF patients with vs without an ICD or CRT-D

Abstract Background Selected echocardiographic measures of cardiac structure and function are known to be associated with mortality in patients with Heart Failure with reduced Left Ventricular (LV) Ejection Fraction (HFrEF). Whether the predictive ability of measures of cardiac structure and function remain after implantation of an Implantable Cardioverter Defibrillator (ICD) or Cardiac Resynchronization Therapy-Defibrillator (CRT-D) is unknown among patients with HFrEF. Purpose To compare the predictive ability of echocardiographic measures of cardiac structure and function in HFrEF patients with or without an ICD/CRT-D. Methods Echocardiographic examinations were performed between 2003 and 2013 and retrieved from 2168 patients with HFrEF. Patients that had an ICD or CRT-D implanted during follow-up were identified through registries. The endpoint was all-cause mortality and follow-up was 100% to date. Images were analyzed offline in accordance with current guidelines. Associations were assessed by Cox multivariable regression and Cox univariable interaction models. Results After a median of 169 days, 677 patients had an ICD or CRT-D implanted. In total, 68% vs 80% of patients with and without an ICD, respectively, were men (p<0.001) and the median age were 70 vs 71 years (p=0.192). There was a significant difference in resting heart rate (median 74 vs 69, p<0.001) and frequency of ischemic heart disease (64% vs 81%, p<0.001) between the groups. Patients with an ICD had a higher mortality rate (69 per 1000 people/year vs 92 per 1000 people/year, p<0.001) and died significantly faster (median 9.3 vs 8.2 years, p<0.001). Patients with an ICD had higher Left Atrial (LA) End Systolic Volume (59.2 vs 67.3, p<0.001), LA Volume Index (28.5 vs 33.9, p<0.001), LV End Diastolic Volume (137.7 vs 153.7, p<0.001), and LV Mass Index (114.5 vs 124.5, p<0.001), as well as lower LA strain (9.8 vs 6.3, p<0.001) and TAPSE (2.0 vs 1.7, p<0.001). In patients without an ICD, Right Ventricular strain was associated with mortality (HR = 1.05 per 1% decrease mm/m2 [1.005, 1.11] when adjusting for covariates whereas in patients with an ICD, LA Volume Index (HR 1.14 per 1 increase [1.03, 1.25], and LV Ejection Fraction (HR 0.96 per 1% increase [0.92, 0.99]) were associated with mortality when adjusting for covariates. ICD/CRT-D implantation significantly modified the prognostic yield of LV End Diastolic Volume (HR per 1 ml increase: 0.99 without vs 1.01 with an ICD/CRT-D, p=0.005) and LV Mass Index (HR per 1 g/m2 increase: 1.00 without and 1.01 with an ICD/CRT-D, p=0.031). Conclusion Different echocardiographic measures were stronger prognosticators in HFrEF patients with and without an ICD or CRT-D, respectively, and ICD implantation modified the prognostic yield of LV End Diastolic Volume and LV Mass Index in HFrEF patients.Table 1Forest plot

Intact DNA repair in differentiated cardiomyocytes is essential for maintaining cardiac function in response to pressure overload in mice

Abstract Introduction DNA in every cell is continuously damaged and DNA repair mechanisms are essential for protection against DNA damage-induced aging-related diseases. For example, deficient repair of endogenously generated DNA damage in mice with cardiomyocyte-restricted inactivation of Xpg, is associated with progressive heart failure. Purpose Here we tested the hypothesis that unrepaired DNA damage in differentiated cardiomyocytes increases cardiac vulnerability in response to hemodynamic overload. Methods To increase the burden of spontaneous DNA damage, we generated mice with cardiomyocyte-restricted inactivation of DNA repair endonuclease XPG. At 8 weeks of age, αMHC-Xpgc/- and control (Ctrl) mice were subjected to pressure overload by transverse aortic constriction (TAC). Eight weeks after TAC, left ventricular (LV) function was assessed using echocardiography and hemodynamic measurements, followed by molecular and histological analyses. Results Cardiomyocyte-restricted inactivation of Xpg resulted in systolic as well as diastolic LV dysfunction (Table). TAC-induced LV hypertrophy is similar in both groups (Ctrl 38%; αMHC-Xpgc/- 34%). In Ctrl mice, LV hypertrophy was accompanied by minimal LV dilation and modest changes in systolic and diastolic LV function. Conversely, TAC in αMHC-Xpgc/- produced severe LV dysfunction and resulted in overt congestive heart failure, demonstrated by aggravation of LV dilation, and marked increases in LV end-diastolic pressure, left atrial weight and lung fluid weight, which was accompanied by further increases in the expression levels of the hypertrophic marker genes atrial natriuretic peptide and beta-myosin heavy chain (Table). Moreover, lectin staining revealed a decrease in capillary density and TUNEL staining revealed further elevated levels of myocardial apoptosis. In addition, a significant increase of myocardial collagen content was observed. Conclusion Cardiomyocyte-restricted loss of DNA repair protein XPG increases cardiac vulnerability to develop heart failure in response to pressure overload. These findings underscore the importance of genomic stability for maintenance of cardiac function, not only during basal conditions, but also in response to a pathological stimulus.

Signature of diabetic cardiomyopathy progression using high-fat diet and streptozotocin mouse model: from subclinical to clinical with three-hit mouse model

Abstract Background Diabetic cardiomyopathy (DbCM) is a pre-heart failure (pre-HF) condition that usually exhibits early diastolic dysfunction and evolving systolic dysfunction, along with left ventricular (LV) remodelling. Although DbCM shows distinct pathophysiology, the transition from the subclinical to the symptomatic stage is not straightforward and usually involves multifaceted processes which are not fully understood. Purpose To define the signature of DbCM progression in a novel mouse model using longitudinal echocardiography and multi-omics approaches. Methods Male mice (C57BL/6) were fed with high-fat diet (HFD) or control diet (CD) for 24 weeks, with single dose of streptozotocin (STZ) or vehicle injection at 8 weeks (n=10 each). Serial functional and metabolic parameters were measured prior to endpoint single nuclei RNA sequencing (snRNA-seq) and mass spectrometry-based proteomics analysis with comparison to cardiac remodelling to define detailed mechanisms underlying DbCM progression. Results HFD/STZ mice developed type 2 diabetes mellitus (T2DM) based on higher fasting blood glucose and HbA1C levels, insulin resistance and decreased beta-cell function (HOMA-IR and HOMA-beta, respectively) compared to controls. Progressive diastolic dysfunction was evident in HFD/STZ mice compared to CD mice based on enlarged LVPW;d from 12 weeks (P<0.05), reduced MV E/A ratio (P<0.01) and IVRT (P<0.05) from 16 weeks, and increased cardiac filling pressure (Left atrial (LA) area and LA volume) at 24 weeks, with preserved systolic function. This was paralleled by elevated collagen deposition (Picrosirius red), myocyte cross-sectional area and Col1a1 expression in HFD/STZ versus CD mice (all P<0.05). snRNA-seq analysis indicated preferential monocyte migration into diabetic hearts (P<0.01) whilst inflammatory pathways were activated across all cardiac cell types. Proteomics analysis revealed elevated expression of the established inflammation marker, plasma C-reactive protein (CRP), in HFD/STZ versus CD mice (P<0.05), which was correlated with worsening diastolic function (MV E/A ratio: r=-0.839, P<0.01) and LV hypertrophy (LVPW;d: r=0.861, P<0.01). Conclusion Our HFD/STZ mouse model offers a ‘three-hit’ approach which effectively captures key stages of clinical DbCM progression: 1) T2DM with insulin resistance, 2) progressive diastolic dysfunction with elevated chronic filling pressure and cardiac remodelling, and 3) systemic inflammation. This improved HFD/STZ mouse model is therefore appropriate to support a detailed study of mechanisms underlying DbCM progression and subsequent translation.

Novel clinical method: left ventricular diastolic pressure curve by echocardiography

Abstract Background A non-invasive clinical method for construction of the systolic part of the left ventricular (LV) pressure curve was recently introduced. There is, however, no clinical method available to construct the LV diastolic pressure curve. Purpose The aim of this study was construction of patient-specific LV diastolic pressure curves from echocardiographic data and have initial validation against simultaneously acquired pressure curves by high-fidelity LV pressure catheters (micromanometers). Methods The study included 108 patients referred for diagnostic left heart catheterization due to suspected coronary artery disease. 81 patients were used as a training cohort. The construction of a diastolic pressure curve is based on a reference unitless pressure trace and seven key pressure-time diastolic events estimated in each patient. The reference diastolic pressure trace was generated from a group of 8 patients with LV pressures recorded by micromanometer. Each individual pressure trace from the reference cohort was first annotated with the occurrence of the key diastolic events: mitral valve (MV) opening, minimum LV pressure, peak of early-diastolic mitral flow velocity (E) and start and peak of atrial contraction-induced velocity (A), and MV closure. Then the temporal intervals between these events were normalized before calculating an averaged pressure curve (Figure 1, panels A-C). A patient-specific LV diastolic pressure curve was constructed by adjusting the standard curve according to estimated LV pressure at the key diastolic events (shown in Figure 1D). The estimation of the pressure-time instants is based on the LV volume temporal transient, used to estimate filling flow rate (Q=dV/dt) and flow acceleration and deceleration (dQ/dt=d2V/dt2), as well as a set of biomarkers including left atrial reservoir strain, peak systolic LV pressure, and body mass index. LV volume temporal traces were generated by combining global 2D volumes with global longitudinal strain. The ability to generate patient-specific diastolic LV pressure curves was validated in a second cohort of 7 patients studied with micromanometer-tipped catheters. Echocardiography and LV pressure were recorded from the same series of beats and recordings were done during breath-hold at end-expiration. The agreement was accessed qualitatively and considering the mean diastolic LV pressure. Results There was good agreement between measured and estimated LV diastolic pressure curves, qualitatively and quantitatively, via mean diastolic PLV: Bias 0.2 mmHg, limits of agreement <3.2 mmHg (Figure 1D-F). Conclusions The results suggest that the LV diastolic pressure curve can be estimated by echocardiography. The method needs validation in larger populations.Non-invasive diastolic LV pressure curve

Effect of stereotactic body radiation therapy on left ventricular diastole function in symptomatic patients with hypertrophic obstructive cardiomyopathy

Abstract Background We applied stereotactic body radiotherapy (SBRT) for the first time in the treatment of patients with hypertrophic obstructive cardiomyopathy (HOCM), and significant improvements in symptoms and diastolic function were observed after treatment. Objectives To evaluate the impact of SBRT on cardiac structure, function, and clinical indicators in patients with HOCM. Methods This study included 12 drug-refractory symptomatic HOCM patients (6 who underwent SBRT and 6 who received pharmacological treatment alone) and conducted a retrospective analysis of their clinical data. Transthoracic echocardiography was used to assess various ultrasound parameters, including interventricular septal thickness, left ventricular outflow tract diameter, peak pressure gradient and diastolic function before treatment and at 1, 3, and 6 months after treatment. Additionally, assessments were made for symptoms; laboratory test results (NT-proBNP, cTnT, CK-mb, and CRP); 6-minute walk test results; New York Heart Association (NYHA) functional classification; and Kansas score before and 6 months after treatment. Results HOCM patients showed significant improvement in mitral valve systolic anterior motion after SBRT. Compared to that at baseline, the interventricular septum thickness gradually decreased at 1, 3, and 6 months after treatment (-8.8%, -8.0%, -14.4%, respectively) (P<0.05). Compared to those in the drug group, the left ventricular diastolic function and structural parameters, including the interventricular septum thickness (mean change from baseline of -3 mm [95% CI: -5.2 to -0.8 mm] and 1.3 mm [95% CI: 0.5 to 2.2 mm]; P<0.05), and the LA GLS (change of 2.1% [-0.03% to 4.2%] and -0.9% [-3.1% to 1.3%]; P<0.05), were significantly improved in HOCM patients at 6 months posttreatment. Similarly, the clinical indicators, including KCCQ, increased from baseline (61 (range, 47.3-70) to 84 (range, 70-89.5) at 6 months posttreatment (P<0.05), and the 6-minute walk test score increased from 187 meters (range, 50-370) to 401 meters (range, 280-540) (P<0.05). Conclusion SBRT significantly improved left ventricular diastolic function and reduced interventricular septum thickness in HOCM patients. Symptoms, exercise capacity and clinical indicators improved after SBRT in HOCM patients.

Reproducibility of Cardiac Multifrequency MR Elastography in Assessing Left Ventricular Stiffness and Viscosity.

Cardiac magnetic resonance elastography (MRE) shows promise in assessing the mechanofunctional properties of the heart but faces clinical challenges, mainly synchronization with cardiac cycle, breathing, and external harmonic stimulation. To determine the reproducibility of in vivo cardiac multifrequency MRE (MMRE) for assessing diastolic left ventricular (LV) stiffness and viscosity. Prospective. This single-center study included a total of 28 participants (mean age, 56.6 ± 23.0 years; 16 male) consisting of randomly selected healthy participants (mean age, 44.6 ± 20.1 years; 9 male) and patients with aortic stenosis (mean age, 78.3 ± 3.8 years; 7 male). 3 T, 3D multifrequency MRE with a single-shot spin-echo planar imaging sequence. Each participant underwent two cardiac MMRE examinations on the same day. Full 3D wave fields were acquired in diastole at frequencies of 80, 90, and 100 Hz during a total of three breath-holds. Shear wave speed (SWS) and penetration rate (PR) were reconstructed as a surrogate for tissue stiffness and inverse viscous loss. Epicardial and endocardial ROIs were manually drawn by two independent readers to segment the LV myocardium. Shapiro-Wilk test, Bland-Altman analysis and intraclass correlation coefficient (ICC). P-value <0.05 were considered statistically significant. Bland-Altman analyses and intraclass correlation coefficients (ICC = 0.96 for myocardial stiffness and ICC = 0.93 for viscosity) indicated near-perfect test-retest repeatability among examinations on the same day. The mean SWS for scan and re-scan diastolic LV myocardium were 2.42 ± 0.24 m/s and 2.39 ± 0.23 m/s; the mean PR were 1.24 ± 0.17 m/s and 1.22 ± 0.14 m/s. Inter-reader variability showed good to excellent agreement for myocardial stiffness (ICC = 0.92) and viscosity (ICC = 0.85). Cardiac MMRE is a promising and reproducible method for noninvasive assessment of diastolic LV stiffness and viscosity. 2 TECHNICAL EFFICACY: 1.

Sacubitril/valsartan improves diastolic left ventricular stiffness with increased titin phosphorylation via cGMP-PKG activation in diabetic mice

Titin, a giant sarcomeric protein, regulates diastolic left ventricular (LV) passive stiffness as a molecular spring and could be a therapeutic target for diastolic dysfunction. Sacubitril/valsartan (Sac/Val), an angiotensin receptor neprilysin inhibitor, has been shown to benefit patients with heart failure with preserved ejection fraction. The effect of Sac/Val is thought to be due to the enhancement of the cGMP/PKG pathway via natriuretic peptide. In this study, the effects of Sac/Val on LV diastolic dysfunction are demonstrated in a mouse diabetic cardiomyopathy model focusing on titin phosphorylation. Sac/Val-treated diabetic mice showed a greater increase in myocardial levels of cGMP-PKG than Val-treated and control mice. Conductance catheter analysis showed a significant reduction in LV stiffness in diabetic mice, but not in non-diabetic mice. Notably, diastolic LV stiffness was significantly reduced in Sac/Val-treated diabetic hearts compared with Val-treated or vehicle-treated diabetic mice. The phosphorylation level of titin (N2B), which determines passive stiffness and modulates active contraction, was higher in Sac/Val-treated hearts compared with Val-treated hearts in diabetic mice. Given that alteration of titin phosphorylation through PKG contributes to myocardial stiffness, the beneficial effects of Sac/Val in heart failure might be partly attributed to the induction of titin phosphorylation.

The Management Outcome of Heart Failure Reduced Ejection Fraction with or without Angiotensin Receptor Neprilysin Inhibitor

INTRODUCTION: Heart failure is associated with recurrent admission, higher mortality and low quality of life. Angiotensin receptor neprilysin inhibitor (ARNI) is a novel agent that has been used for treating heart failure reduced ejection fraction (HFrEF) patients. Thus, it is interesting to evaluate the effect of ARNI on the reverse cardiac remodelling, rehospitalization, cardiac biomarker and quality of life in HFrEF patients. MATERIALS AND METHODS: A case controlled study was conducted to assess the treatment outcome of HFrEF with or without ARNI. During the study, the patients’ basic demography, co-morbidities, baseline echocardiography (ECHO) findings, NYHA classification, NT-pro BNP levels and KCCQ score were evaluated. The patients’ admission history within 90 days from initiation of ARNI or non ARNI were obtained retrospectively. A follow up ECHO was obtained after at least 3 months of intervention. RESULTS: A total of 81 patients were recruited in which 54 patients were on ARNI and 27 were on non ARNI treatment. There was a statistically significant improvement of ejection fraction, left ventricular internal diameter end diastole and systole, and left ventricular end-systolic volume in ARNI group. The NYHA class was also noted to improve after ARNI treatment. The NT-proBNP value was lower whereas the KCCQ score was higher in ARNI group compared to non ARNI group. CONCLUSION: HFrEF patients with ARNI treatment had better reverse cardiac remodelling effect, cardiac biomarker and quality of life compared to non ARNI treatment. Furthermore, patient received ARNI demonstrated improved heart failure classification after treatment

Epicardial Fat in Heart Failure with Preserved Ejection Fraction Compared with Reduced Ejection Fraction.

Background: The role of epicardial adipose tissue (EAT) in heart failure with preserved ejection fraction (HFpEF) remains to be defined. Methods: A consecutive series of outpatients with chronic heart failure-heart failure with reduced ejection fraction (HFrEF) and HFpEF and/or diastolic dysfunction-had EAT assessed by echocardiographic measurement and related to indices of cardiac structure and function. Results: Epicardial fat thickness was significantly (p < 0.05) greater in HFpEF (N = 141) with a mean of 6.7 ± 1.6 mm compared with a mean of 5.1 ± 1.0 mm in HFrEF (n = 40). After adjusting for the relationship with BMI, in HFpEF, epicardial fat was significantly (p < 0.05) negatively correlated with left ventricular internal diameter end diastole (LVIDd), left ventricular internal diameter end systole (LVIDs), left ventricular (LV) end-diastolic volume (EDV) index, lateral e', septal e', right atrial (RA) volume index, and hemoglobin (Hgb). The association with Hgb was no longer significant after adjusting for the effect of age. HFpEF was associated with smaller LVIDd, LVIDs, LV EDV indexes, and left atrial (LA) and RA volume indexes. Conclusions: Epicardial fat is significantly (p < 0.05) greater in HFpEF than HFrEF. Epicardial fat is associated with smaller cardiac chamber sizes in HFpEF suggesting that epicardial fat acts as a constraint to cardiac dilation.

The preferable position for quantifying left ventricular diameter by transthoracic echocardiography.

In quantifying left ventricular (LV) diameter, which position for echocardiographic measurements, mitral valve tip level (MV-tip) or LV mid level (LV-mid), more accurately represents the LV volume is unclear. Furthermore, which factor affects the measurement error also has not been elucidated. We enrolled 150 patients without myocardial infarction and local asynergy who underwent echocardiography and cardiac magnetic resonance imaging (CMRI). Echocardiographic LV diastolic diameter (LVDD) and LV systolic diameter (LVDS) were measured at both MV-tip and LV-mid, and the LV end-diastolic volume (LVEDV) and end-systolic volume (LVESV) were quantified using CMRI. We quantified the degree of aortic wedging as the angle between the anterior wall of the aorta and the ventricular septal surface (ASA). The average LVDD was smaller and average LVDS larger when measured at the MV-tip than at the LV-mid. In regression analyses, the correlation coefficient between LVDD and LVEDV was larger at LV-mid (R = 0.89) than at MV-tip (R = 0.82), and the correlation coefficient between LVDS and LVESV also larger at LV-mid (R = 0.93) than MV-tip (R = 0.87). ASA, Valsalva diameter, left atrial diameter, patient height, and LV mass significantly affected the echocardiographic measurement error, but no factor affected the measurement error when quantifying LVDD at the LV-mid level. The echocardiographic LV diameter measured at LV-mid has a stronger correlation with LV chamber size derived from CMRI than measurements at MV-tip. The LVDD measured at the LV-mid level is not affected by other factors.

Prevalence and patterns of echocardiographic abnormalities among people living with HIV on anti-retroviral therapy in Kumasi, Ghana

BackgroundEchocardiography can be used to screen, confirm, and assist in the management of some cardiovascular diseases in people living with human immunodeficiency virus (HIV) (PLWH). Thus, complications from subclinical cardiovascular conditions or more apparent conditions, such as massive pericardial effusion with tamponade, can be promptly identified and managed to minimize cardiovascular morbidity and mortality associated with HIV infection. Since the introduction of antiretroviral therapy (ART) in Ghana approximately two decades ago, studies on the prevalence and patterns of echocardiographic abnormalities among PLWH on ART have been limited. This study was designed to assess the prevalence and patterns of echocardiographic abnormalities among PLWH on ART.MethodsThis was a cross-sectional study. PLWH on ART (cases) attending the HIV clinic at Komfo Anokye Teaching Hospital (KATH) and HIV-negative blood donors (controls) were consecutively recruited and enrolled in this study. The interviews were performed via a standardized questionnaire. After a clinical examination was performed, all patients underwent two-dimensional (2D) and Doppler transthoracic echocardiograms. The prevalence and patterns of echocardiographic abnormalities were characterized.ResultsThere were 117 patients in each arm of the study. There were more females than males among both the cases (92 (78.6%) and controls (80 (68.4%)); however, the sex distribution was similar between the two groups (p = 0.075). For clinical characteristics such as age, weight, height and blood pressure, there were no statistically significant differences between the cases and controls. Echocardiographic abnormalities were more frequently observed and demonstrated a statistically significant difference between cases and controls, with an overall prevalence of 35.0% among cases and 19.7% among controls (p = 0.008). The echocardiographic abnormalities that demonstrated significant differences between the cases and controls were left ventricular (LV) diastolic dysfunction (28.2% versus 8.6%; p = 0.000) and LV hypertrophy (7% versus 0.9%; p = 0.017).ConclusionNearly 1 in 3 PLWH on ART had an echocardiographic abnormality in this Ghanaian study. Echocardiograms are recommended as helpful screening modalities for diagnosing cardiac abnormalities among PLWH on ART.

Cardiac biomarkers for screening and prognostication of cardiac dysfunction in critically ill patients.

This study aimed to assess the use of high-sensitivity troponin T (hsTNT) and N-terminal pro-brain natriuretic peptide (NT-proBNP) in screening for cardiac dysfunction [left ventricular (LV) systolic or diastolic dysfunction or right ventricular (RV) dysfunction] in mixed intensive care unit (ICU) patients and establish whether these biomarkers are independently associated with an increased risk of death. We performed a secondary analysis of a single-centre prospective observational study in which consecutive ICU patients were examined with transthoracic echocardiography (TTE) and cardiac biomarkers. Patients with systolic or diastolic LV dysfunction, RV dysfunction or a combination of these were compared with patients with normal cardiac function. Sensitivity and specificity for different cut-off levels were calculated using receiver operating characteristic curves. Regression models were used to evaluate the associations between cardiac biomarkers, sepsis, renal failure and mortality. A total of 276 patients were included. Most of the patients had cardiac dysfunction on TTE (64%). Combined cardiac dysfunction was most prevalent (71 patients, 26%), followed by isolated diastolic LV dysfunction (40 patients, 15%). Levels of hsTNT and NT-proBNP were higher in all types of cardiac dysfunction versus patients with normal cardiac function. The area under the curve (AUC) for hsTNT to detect any cardiac dysfunction was 0.75. An optimal cut-off at 30.5ng/L rendered a positive predictive value (PPV) of 80% and a negative predictive value (NPV) of 58%. The AUC for NT-proBNP to detect any cardiac dysfunction was 0.788. Using an optimal cut-off at 1145ng/L rendered a PPV of 86% and an NPV of 58%. Using a clinically relevant 90% sensitivity for detecting cardiac dysfunction put the cut-offs at 14.1ng/L for hsTNT and 247ng/L for NT-proBNP, resulting in a specificity of 48% and 46%, respectively. Levels of NT-proBNP were associated with sepsis and renal failure (P<0.001), while levels of hsTNT were associated with renal failure only (P<0.001) after adjustment for cardiac dysfunction. Levels of biomarkers were associated with an increased risk of 90day mortality after adjustments for age, Simplified Acute Physiology Score 3, cardiac dysfunction and factors independently associated with biomarker increase (sepsis and renal failure) (P=0.048 for hsTNT and P<0.006 for NT-proBNP). Cardiac biomarkers, hsTNT and NT-proBNP, are strongly correlated to cardiac dysfunction in ICU patients and have a robust association with increased mortality. However, the relatively low NPV and the low specificity at relevant sensitivity levels of the biomarkers make them unsuitable for use in screening for cardiac dysfunction.

Flow inefficiencies in non-obstructive HCM revealed by kinetic energy and hemodynamic forces on 4D-flow CMR.

Patients with non-obstructive hypertrophic cardiomyopathy (HCM) exhibit myocardial changes which may cause flow inefficiencies not detectable on echocardiogram. We investigated whether left ventricular (LV) kinetic energy (KE) and hemodynamic forces (HDF) on 4D-flow cardiovascular magnetic resonance (CMR) can provide more sensitive measures of flow in non-obstructive HCM. Ninety participants (70 with non-obstructive HCM and 20 healthy controls) underwent 4D-flow CMR. Patients were categorized as phenotype positive (P+) based on maximum wall thickness (MWT) ≥ 15 mm or ≥13 mm for familial HCM, or pre-hypertrophic sarcomeric variant carriers (P-). LV KE and HDF were computed from 4D-flow CMR. Stroke work was computed using a previously validated non-invasive method. P+ and P- patients and controls had comparable diastolic velocities and LV outflow gradients on echocardiography, LV ejection fraction, and stroke volume on CMR. P+ patients had greater stroke work than P- patients, higher systolic KE compared with controls (5.8 vs. 4.1 mJ, P = 0.0009), and higher late diastolic KE relative to P- patients and controls (2.6 vs. 1.4 vs. 1.9 mJ, P < 0.0001, respectively). MWT was associated with systolic KE (r = 0.5, P < 0.0001) and diastolic KE (r = 0.4, P = 0.005), which also correlated with stroke work. Systolic HDF ratio was increased in P+ patients compared with controls (1.0 vs. 0.8, P = 0.03) and correlated with MWT (r = 0.3, P = 0.004). Diastolic HDF was similar between groups. Sarcomeric variant status was not associated with KE or HDF. Despite normal flow velocities on echocardiography, patients with non-obstructive HCM exhibited greater stroke work, systolic KE and HDF ratio, and late diastolic KE relative to controls. 4D-flow CMR provides more sensitive measures of haemodynamic inefficiencies in HCM, holding promise for clinical trials of novel therapies and clinical surveillance of non-obstructive HCM.

Myocardial Work Indices Predict Hospitalization in Patients with Advanced Heart Failure.

An increasing proportion of heart failure (HF) patients progress to the advanced stage (AdHF) with high event rates and limited treatment options. Echocardiography, particularly Speckle Tracking-derived myocardial work (MW), is useful for HF diagnosis and prognosis. We aimed to assess MW's feasibility in the prognostic stratification of AdHF. We retrospectively screened patients with AdHF who accessed our hospital in 2018-2022. We excluded subjects with inadequate acoustic windows; unavailable brachial artery cuff pressure at the time of the echocardiography; atrial fibrillation; and mitral or aortic regurgitation. We measured standard parameters and left ventricular (LV) strain (LS) and MW. The population was followed up to determine the composite outcomes of all-cause mortality, left ventricular assist device implantation and heart transplantation (primary endpoint), as well as unplanned HF hospitalization (secondary endpoint). We enrolled 138 patients, prevalently males (79.7%), with a median age of 58 years (IQR 50-62). AdHF etiology was predominantly non-ischemic (65.9%). Thirty-five patients developed a composite event during a median follow-up of 636 days (IQR 323-868). Diastolic function, pulmonary pressures, and LV GLS and LV MW indices were not associated with major events. Contrarily, for the secondary endpoint, the hazard ratio for each increase in global work index (GWI) by 50 mmHg% was 0.90 (p = 0.025) and for each increase in global constructive work (GCW) by 50 mmHg% was 0.90 (p = 0.022). Kaplan-Meier demonstrated better endpoint-free survival, with an LV GWI ≥ 369 mmHg%. GWI and GCW, with good feasibility, can help in the better characterization of patients with AdHF at higher risk of HF hospitalization and adverse events, identifying the need for closer follow-up or additional HF therapy.

DIASTOLIC DYSFUNCTION EVALUATION IN CARDIAC AMYLOIDOSIS: BEYOND TRADITIONAL PARAMETERS TO DISCRIMINATE BETWEEN TRUE HEART FAILURE WITH PRESERVED EJECTION FRACTION AND MIMICS

Abstract Background Diastolic dysfunction in cardiac amyloidosis (CA), according to current guidelines, can be classified using mitral flow velocities, mitral annular e’ velocity, E/e’ ratio, tricuspid regurgitation jet and left atrial (LA) maximal volume. However, LA minimal volume and the ratio between LA and left ventricular (LV) volumes at end–diastole, known as left atrio–ventricular coupling index (LACI), have recently been proposed to refine prognosis and peak atrial longitudinal strain (PALS) has been demonstrated to better stratify diastolic dysfunction. Aim of the Study To evaluate, in patients with CA: 1) the role of LACI as marker of LV diastolic dysfunction; 2) whether LACI could discriminate cardiomyopathy from normal cardiac function; 3) whether LACI and/or PALS could help discriminate between true heart failure with preserved ejection fraction (HFpEF) and amyloidotic cardiomyopathy (HFpEF–mimic). Methods We retrospectively analyzed 63 patients with CA and compared them with 80 true HFpEF patients and 70 healthy people; echocardiography was performed at the time of the diagnosis and diastolic function was characterized according to current guidelines. Results In patients with CA, LACI significantly increased as diastolic dysfunction worsened (P for trend &amp;lt; 0.0001) and significantly correlated with LV filling pressures estimated by E/e’ ratio (beta = 0.65, P &amp;lt; 0.0001) and pulmonary artery systolic pressure (beta = 0.63, P &amp;lt; 0.0001). LACI, after adjustment for age, gender and body mass index (BMI), was significantly higher in CA [0.62 (95%CI 0.52–0.70)] and in HFpEF [0.61 (95%CI 0.55–0.68)] than in controls [0.29 (95%CI 0.19–0.39)], while the difference between the two diseased populations was not statistically significant; a cut–off value of 0.45 was able to discriminate between controls and diseased patients (sensitivity = 95%, specificity = 94%, area under ROC curve = 0.98). PALS, after adjustment for age, gender and BMI, was significantly lower in CA [11.1 (95%CI 8.4–13.8%) and 8.4 (95%CI 3.5–13.3%) respectively in ATTR and AL] than in HFpEF [17.4 (95%CI 15.6–19.3%)], and a cut–off value of 9.9% was able to discriminate between them (sensitivity = 89%, specificity = 73%, area under ROC curve = 0.86). Conclusions LACI is a novel index able to discriminate between normal and diseased patients. In CA, it shows good correlation with diastolic dysfunction and LV filling pressures. PALS can be used to discriminate between true HFpEF and CA.

Intact DNA Repair in Differentiated Cardiomyocytes Is Essential for Maintaining Cardiac Function in Response to Pressure Overload in Mice

Introduction: DNA in every cell is continuously damaged and DNA repair mechanisms are essential for protection against DNA damage-induced aging-related diseases. For example, deficient repair of endogenously generated DNA damage in mice with cardiomyocyte-restricted inactivation of Xpg, is associated with progressive heart failure (de Boer et al. Aging Cell 2023). Here we tested the hypothesis that unrepaired DNA damage in differentiated cardiomyocytes increases cardiac vulnerability in response to hemodynamic overload. Methods: At 8 weeks of age, αMHC-Xpgc/- and control (Ctrl) mice were subjected to pressure overload by mild transverse aortic constriction (TAC). Eight weeks after TAC, left ventricular (LV) function was assessed using echocardiography and hemodynamic measurements, followed by histological and molecular analyses. Results: Cardiomyocyte-restricted inactivation of Xpg resulted in systolic as well as diastolic LV dysfunction. TAC-induced LV hypertrophy was similar in both groups (Ctrl 38%; αMHC-Xpgc/- 34%). In Ctrl mice, LV hypertrophy was accompanied by minimal LV dilation and only modest changes in systolic and diastolic LV function. Conversely, TAC in αMHC-Xpgc/- produced severe LV dilation and dysfunction and resulted in overt backward failure, demonstrated by marked increases in LV end-diastolic pressure, left atrial weight and lung fluid weight. These changes were accompanied by further increases in the expression levels of the hypertrophic marker genes atrial natriuretic peptide and beta-myosin heavy chain. Moreover, lectin staining revealed a decrease in capillary density and TUNEL staining revealed further elevated levels of myocardial apoptosis in αMHC-Xpgc/--TAC mice as compared to Ctrl-TAC mice. In addition, a significant increase of myocardial collagen content was observed in αMHC-Xpgc/--TAC but not in Ctrl-TAC mice. Conclusion: Cardiomyocyte-restricted loss of DNA repair protein Xpg increases cardiac vulnerability to develop heart failure in response to pressure-overload. These findings underscore the importance of genomic stability for maintenance of cardiac function, not only under basal conditions, but also during increased cardiac loading conditions. Supported by the Dutch Heart Foundation [Grants 2017B018-ARENA-PRIME; 2021B008-RECONNEXT]. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Left atrial appendage closure in conjunction with radiofrequency ablation: Effects on left atrial functioning in patients with paroxysmal atrial fibrillation.

In the present study, we investigated the impact of left atrial appendage closure (LAAC) following catheter ablation (CA) on the left atrial structure and functioning of patients with paroxysmal atrial fibrillation (AF). Patients with paroxysmal AF were enrolled in this single-center prospective cohort study between April 2015 and July 2021; 353 patients received CA alone, while 93 patients received CA in combination with Watchman LAAC. We used age, gender, CHA2DS2-VASc, and HAS-BLED scores as well as other demographic variables to perform propensity score matching. Patients with paroxysmal AF were randomly assigned to the CA combined with Watchman LAAC group (combined treatment group) and the simple CA group, with 89 patients in each group. The left atrial structure, reserve, ventricular diastole, and pump functions and their changes in patients were assessed using routine Doppler echocardiography and 2D speckle tracking echocardiography over the course of a 1-year follow-up. At 1-week follow-up, the reserve, ventricular diastole, and pump functions of the left atrium (LA) increased in both groups; these functions were gradually restored at the 1- to 3-month follow-up; they were close to or returned to their pre-operative levels at the 3-month follow-up; and no significant differences were found compared with the pre-operative levels at the 12-month follow-up. In the first 3 months, the reserve (Ƹ, SRs) and pump functions (SRa) in the combined treatment group decreased significantly when compared with the simple CA group, and the differences were statistically significant. Patients with paroxysmal AF may experience a short term, partial effect of LAAC on LA reserve and pump functions, which are gradually restored and the effect disappears by 12 months.

Diagnosis and treatment of feline persistent ductus arteriosus: a retrospective evaluation of 17 cats

The objective of this study was to evaluate the signalement, clinical features, and echocardiographic findings of cats diagnosed with patent ductus arteriosus (PDA) as well as short- and medium-term outcome after successful ligation of the PDA. Over a 10-year period 17 cats were diagnosed with PDA by transthoracic echocardiography. Thirteen cats were surgically treated by thoracotomy and ligation of the PDA. In all cats, a heart murmur was detected. In 88.2% of the cases, this presented as grade 4 out of 6 murmur (15/17 cats). A continuous murmur was more common (10/17 cats; 58.9%) than a systolic murmur (7/17 cats; 41.1%). Echocardiography showed that left ventricular internal diameter end diastole (LVIDd) and left ventricular internal diameter end systole (LVIDs) were significantly above reference values in the majority of cats. Mean diameter of the PDA measured at the widest point of the vessel was 3.4 mm (± 1.08 mm) and mean maximum flow velocity amounted to 5,06 m/sec (2,6m/sec-6,4m/sec). Surgery was successfully performed in all cats treated by surgical ligation and all of these patients were discharged after postoperative inpatient therapy. One cat experienced perioperative bleeding from the PDA, which was stopped efficaciously. This cat exhibited a residual shunt directly postoperatively; this could no longer be visualized in a re-check echocardiography 3 months later. Six cats were followed over a longer period of time. The surgical prognosis in this case study is very good with a postoperative survival rate of 100%. Surgical treatment of PDA is curative in animals not displaying advanced cardiac lesions. The auscultation of a heart murmur can provide initial findings indicative of PDA. Therefore, cardiac auscultation is warranted at every first presentation of a kitten. It must however be taken into consideration that not every cat with PDA necessarily has a continuous murmur but may display a systolic heart murmur. Therefore, it is important give utmost attention to the patients' clinical signs.

Sacubitril/Valsartan Alleviates Cardiac Remodeling and Dysfunction in L-NAME-Induced Hypertension and Hypertensive Heart Disease.

There is ample evidence on the benefit of angiotensin receptor-neprilysin inhibitors (ARNIs) in heart failure, yet data regarding the potential protective action of ARNIs in hypertensive heart disease are sparse. The aim of this study was to show whether an ARNI exerts a protective effect in a model of Nω-nitro-L-arginine methyl ester (L-NAME)-induced hypertension with a hypertensive heart and to compare this potential benefit with an angiotensin-converting enzyme inhibitor, captopril. Five groups of adult male Wistar rats were studied (14 per group) for four weeks: untreated controls; ARNI (68 mg/kg/day); L-NAME (40 mg/kg/day); L-NAME treated with ARNI; and L-NAME treated with captopril (100 mg/kg/day). L-NAME administration induced hypertension, accompanied by increased left ventricular (LV) weight and fibrotic rebuilding of the LV in terms of increased concentration and content of hydroxyproline in insoluble collagen and in total collagen and with a histological finding of fibrosis. These alterations were associated with a compromised systolic and diastolic LV function. Treatment with either an ARNI or captopril reduced systolic blood pressure (SBP), alleviated LV hypertrophy and fibrosis, and prevented the development of both systolic and diastolic LV dysfunction. Moreover, the serum levels of prolactin and prolactin receptor were reduced significantly by ARNI and slightly by captopril. In conclusion, in L-NAME-induced hypertension, the dual inhibition of neprilysin and AT1 receptors by ARNI reduced SBP and prevented the development of LV hypertrophy, fibrosis, and systolic and diastolic dysfunction. These data suggest that ARNI could provide protection against LV structural remodeling and functional disorders in hypertensive heart disease.

The effect of long-term soccer training on left ventricular structure and function in elite male youth soccer players.

Cardiac adaptations in elite, male adolescent youth soccer players have been demonstrated in relation to training status. The time course of these adaptations and the delineation of the influence of volatile growth phases from the training effect on these adaptations remain unclear. Consequently, the aims of the study were to evaluate the impact of 3 years of elite-level soccer training on changes in left ventricular (LV) structure and function in a group of highly trained elite youth male soccer players (SP) as they transitioned through the pre-to-adolescent phase of their growth. Twenty-two male youth SP from the highest Level of English Premier League Academy U-12 teams were evaluated once a year for three soccer seasons as the players progressed from the U-12 to U-14 teams. Fifteen recreationally active control participants (CON) were also evaluated over the same 3-year period. Two-dimensional transthoracic echocardiography was used to quantify LV structure and function. After adjusting for the influence of growth and maturation, training-induced increases in Years 2 and 3 were noted for: LV end diastolic volume (LVEDV; p = 0.02) and LV end systolic volume (LVESV; p = 0.02) in the SP compared to CON. Training-induced decrements were noted for LV ejection fraction (LVEF; p = 0.006) and TDI-S' (p < 0.001). An increase in training volume (Years 2 and 3) were aligned with LV volumetric adaptations and decrements in systolic function in the SP that were independent from the influence of rapid somatic growth. Decrements in systolic function were suggestive of a functional reserve for exercise.