Left ventricular hypertrophy: pathogenesis, detection, and prognosis

Tripartite motif 10 regulates cardiac hypertrophy by targeting the PTEN/AKT pathway

The pathogenesis of cardiac hypertrophy is tightly associated with activation of intracellular hypertrophic signalling pathways, which leads to the synthesis of various proteins. Tripartite motif 10 (TRIM10) is an E3 ligase with important functions in protein quality control. However, its role in cardiac hypertrophy was unclear. In this study, neonatal rat cardiomyocytes (NRCMs) and TRIM10-knockout mice were subjected to phenylephrine (PE) stimulation or transverse aortic constriction (TAC) to induce cardiac hypertrophy in vitro and in vivo, respectively. Trim10 expression was significantly increased in hypertrophied murine hearts and PE-stimulated NRCMs. Knockdown of TRIM10 in NRCMs alleviated PE-induced changes in the size of cardiomyocytes and hypertrophy gene expression, whereas TRIM10 overexpression aggravated these changes. These results were further verified in TRIM10-knockout mice. Mechanistically, we found that TRIM10 knockout or knockdown decreased AKT phosphorylation. Furthermore, we found that TRIM10 knockout or knockdown increased ubiquitination of phosphatase and tensin homolog (PTEN), which negatively regulated AKT activation. The results of this study reveal the involvement of TRIM10 in pathological cardiac hypertrophy, which may occur by prompting of PTEN ubiquitination and subsequent activation of AKT signalling. Therefore, TRIM10 may be a promising target for treatment of cardiac hypertrophy.

Healing the Broken Heart; The Immunomodulatory Effects of Stem Cell Therapy

Cardiovascular Disease (CVD) is a leading cause of mortality within the United States. Current treatments being administered to patients who suffered a myocardial infarction (MI) have increased patient survival, but do not facilitate the replacement of damaged myocardium. Recent studies demonstrate that stem cell-based therapies promote myocardial repair; however, the poor engraftment of the transferred stem cell populations within the infarcted myocardium is a major limitation, regardless of the cell type. One explanation for poor cell retention is attributed to the harsh inflammatory response mounted following MI. The inflammatory response coupled to cardiac repair processes is divided into two distinct phases. The first phase is initiated during ischemic injury when necrosed myocardium releases Danger Associated Molecular Patterns (DAMPs) and chemokines/cytokines to induce the activation and recruitment of neutrophils and pro-inflammatory M1 macrophages (MΦs); in turn, facilitating necrotic tissue clearance. During the second phase, a shift from the M1 inflammatory functional phenotype to the M2 anti-inflammatory and pro-reparative functional phenotype, permits the resolution of inflammation and the establishment of tissue repair. T-regulatory cells (Tregs) are also influential in mediating the establishment of the pro-reparative phase by directly regulating M1 to M2 MΦ differentiation. Current studies suggest CD4+ T-lymphocyte populations become activated when presented with autoantigens released from the injured myocardium. The identity of the cardiac autoantigens or paracrine signaling molecules released from the ischemic tissue that directly mediate the phenotypic plasticity of T-lymphocyte populations in the post-MI heart are just beginning to be elucidated. Stem cells are enriched centers that contain a diverse paracrine secretome that can directly regulate responses within neighboring cell populations. Previous studies identify that stem cell mediated paracrine signaling can influence the phenotype and function of immune cell populations in vitro, but how stem cells directly mediate the inflammatory microenvironment of the ischemic heart is poorly characterized and is a topic of extensive investigation. In this review, we summarize the complex literature that details the inflammatory microenvironment of the ischemic heart and provide novel insights regarding how paracrine mediated signaling produced by stem cell-based therapies can regulate immune cell subsets to facilitate pro-reparative myocardial wound healing.

Sex-Specific Regulation of miR-29b in the Myocardium Under Pressure Overload is Associated with Differential Molecular, Structural and Functional Remodeling Patterns in Mice and Patients with Aortic Stenosis

Pressure overload in patients with aortic stenosis (AS) induces an adverse remodeling of the left ventricle (LV) in a sex-specific manner. We assessed whether a sex-specific miR-29b dysregulation underlies this sex-biased remodeling pattern, as has been described in liver fibrosis. We studied mice with transverse aortic constriction (TAC) and patients with AS. miR-29b was determined in the LV (mice, patients) and plasma (patients). Expression of remodeling-related markers and histological fibrosis were determined in mouse LV. Echocardiographic morpho-functional parameters were evaluated at baseline and post-TAC in mice, and preoperatively and 1 year after aortic valve replacement (AVR) in patients with AS. In mice, miR-29b LV regulation was opposite in TAC-males (down-regulation) and TAC-females (up-regulation). The subsequent changes in miR-29b targets (collagens and GSK-3β) revealed a remodeling pattern that was more fibrotic in males but more hypertrophic in females. Both systolic and diastolic cardiac functions deteriorated more in TAC-females, thus suggesting a detrimental role of miR-29b in females, but was protective in the LV under pressure overload in males. Clinically, miR-29b in controls and patients with AS reproduced most of the sexually dimorphic features observed in mice. In women with AS, the preoperative plasma expression of miR-29b paralleled the severity of hypertrophy and was a significant negative predictor of reverse remodeling after AVR; therefore, it may have potential value as a prognostic biomarker.

Left Ventricular Hypertrophy Does Not Affect 1-Year Clinical Outcomes in Patients Undergoing Transcatheter Aortic Valve Replacement

OBJECTIVES

The aim of this study was to evaluate the association between pre-procedural left ventricular hypertrophy (LVH) patterns and clinical outcomes after transcatheter aortic valve replacement (TAVR).

BACKGROUND

The association between pre-procedural LVH pattern and severity and clinical outcomes after TAVR is uncertain.

METHODS

Patients (n = 31,199) across 422 sites who underwent TAVR from November 2011 through June 2016 as part of the Society of Thoracic Surgeons/American College of Cardiology TVT (Transcatheter Valve Therapies) Registry linked with the Centers for Medicare and Medicaid Services database were evaluated by varying LVH patterns, according to sex-specific cutoffs for left ventricular mass index and relative wall thickness. The association between LVH pattern (concentric remodeling, concentric LVH, and eccentric LVH) and outcomes (rates of mortality, myocardial infarction [MI], stroke, new dialysis requirement) at 1-year follow-up were evaluated using multivariate hazard models.

RESULTS

There were no significant associations between concentric remodeling (death: adjusted hazard ratio [HR]: 1.03; 95% confidence interval [CI]: 0.93 to 1.15; MI: HR: 1.05; 95% CI: 0.76 to 1.46; stroke: HR: 1.11; 95% CI: 0.89 to 1.39; new dialysis: HR: 0.86; 95% CI: 0.64 to 1.15), concentric LVH (death: HR: 1.04; 95% CI: 0.95 to 1.15; MI: HR: 1.12; 95% CI: 0.82 to 1.52; stroke: HR: 1.14; 95% CI: 0.92 to 1.40; new dialysis: HR: 1.17; 95% CI: 0.90 to 1.52), or eccentric LVH (death: HR: 0.98; 95% CI: 0.87 to 1.10; MI: HR: 1.07; 95% CI: 0.71 to 1.63; stroke: HR: 1.01; 95% CI: 0.78 to 1.32; new dialysis: HR: 1.25; 95% CI: 0.92 to 1.70) and outcomes at 1 year compared with patients without LVH.

CONCLUSIONS

In a contemporary cohort of patients who underwent TAVR, pre-procedural LVH according to left ventricular mass index and relative wall thickness was not associated with adverse outcomes at 1-year follow-up. TAVR is likely to benefit patients with severe aortic stenosis regardless of the presence of LVH.

Paradoxical Higher Myocardial Wall Stress and Increased Cardiac Remodeling Despite Lower Mass in Females

Background

Increased left ventricular (LV) mass is characterized by increased myocardial wall thickness and/or ventricular dilatation that is associated with worse outcomes. We aim to comprehensively compare sex‐stratified associations between measures of LV remodeling and increasing LV mass in the general population.

Methods and Results

Participants were prospectively recruited in the National Heart Center Singapore Biobank to examine health and cardiovascular risk factors in the general population. Cardiovascular magnetic resonance was performed in all individuals. Participants with established cardiovascular diseases and abnormal cardiovascular magnetic resonance scan results were excluded. Global and regional measures of LV remodeling (geometry, function, interstitial volumes, and wall stress) were performed using conventional image analysis and novel 3‐dimensional machine learning phenotyping. Sex‐stratified analyses were performed in 1005 participants (57% males; 53±13 years). Age and prevalence of cardiovascular risk factors were well‐matched in both sexes (P>0.05 for all). Progressive increase in LV mass was associated with increased concentricity in either sex, but to a greater extent in females. Compared with males, females had higher wall stress (mean difference: 170 mm Hg, P<0.0001) despite smaller LV mass (42.4±8.2 versus 55.6±14.2 g/m², P<0.0001), lower blood pressures (P<0.0001), and higher LV ejection fraction (61.9±5.9% versus 58.6±6.4%, P<0.0001). The regions of increased concentric remodeling corresponded to regions of increased wall stress. Compared with males, females had increased extracellular volume fraction (27.1±2.4% versus 25.1±2.9%, P<0.0001).

Conclusions

Compared with males, females have lower LV mass, increased wall stress, and concentric remodeling. These findings provide mechanistic insights that females are susceptible to particular cardiovascular complications.

Markers of Subclinical Cardiovascular Disease in Patients with Adrenal Incidentaloma

Due to the growing availability of imaging examinations the percentage of patients with incidentally diagnosed adrenal tumors has increased. The vast majority of these lesions are benign, non-functioning adenomas, although according to various estimates even up to 30%-50% of patients with adrenal incidentaloma may present biochemical hypercortisolemia, without typical clinical features of Cushing's syndrome. Adrenal adenomas secreting small amounts of glucocorticoids may cause morphological and functional changes in the myocardium and blood vessels. Early stages of cardiovascular remodeling may be observed among asymptomatic patients with adrenal adenoma. Vascular changes precede the development of cardiovascular diseases and can increase morbidity and mortality in patients with adrenal incidentaloma. This risk may result not only from the traditional risk factors. Seemingly hormonally inactive adrenal tumors can indeed produce small amounts of glucocorticoids that have metabolic implications. Therefore, evaluation of patients with incidental adrenal findings presenting with subclinical cardiovascular disease seems of particular importance.

LPS-enhanced IGF-IIR pathway to induce H9c2 cardiomyoblast cell hypertrophy was attenuated by Carthamus tinctorius extract via IGF-IR activation

The use of herbs as alternative cardiovascular disease treatment has attracted a great deal of attention owing to their lower toxicity. Whether Carthamus tinctorius extract prevent cardiomyoblast cell hypertrophy remains unclear. The present study was performed to investigate the effect of C tinctorius extract (CTF) on rat cardiomyoblast cell H9c2 and the possible molecular mechanisms. H9c2 cells were treated with lipopolysaccharide (LPS; 2 μg/mL) for 12 hours, subsequently treated with CTF (1-25 μg/mL) The incubation continued for another 24 hours, and the cells were analyzed with actin staining assay, western blot analysis, and siRNA transfection assays. In the present study, the increased cell size induced by LPS was significantly decreased by pretreating at a concentration of 1-25 μg/mL CTF. It was found that CTF could inhibit cardiac hypertrophy induced by LPS and decrease hypertrophic proteins calcineurin, p-GATA-4, GATA-4, atrial natriuretic peptide, and B-type natriuretic peptide levels in H9c2 cells. Additionally, LPS-induced insulin-like growth factor-II receptor (IGF-IIR) hypertrophy pathway was downregulated by CTF. Moreover, IGF-IR siRNA or inhibitors both reversed the CTF effects, confirming that CTF activates IGF-1R to prevent LPS-induced H9c2 cardiomyoblast cell hypertrophy. The current findings indicate that CTF activates IGF-IR to inhibit IGF-IIR signaling pathway which resulted in reducing H9c2 cardiomyoblast cell hypertrophy induced by LPS.

Impact of preprocedural left ventricle hypertrophy and geometrical patterns on mortality following TAVR

BACKGROUND

In contrast to surgical aortic valve replacement, left ventricle (LV) hypertrophy (LVH) had not been clearly associated with mortality following transcatheter aortic valve replacement (TAVR).

METHODS

We performed a retrospective analysis of patients enrolled in the Israeli multicenter TAVR registry for whom preprocedural LV mass index (LVMI) data were available. Patients were divided into categories according to LVMI: normal LVMI and mild, moderate, and severe LVH. Mild LVH was regarded as the reference group. Additionally, LV geometry patterns were examined (concentric and eccentric LVH, and concentric remodeling).

RESULTS

The cohort consisted of 1,559 patients, 46.5% male, with a mean age of 82.2 (±6.8) years and mean LVMI of 121 (±29) g/m². Rates of normal LVMI and mild, moderate, and severe LVH were 31% (n = 485), 21% (n = 322), 18% (n = 279), and 30% (n = 475), respectively. Three-year mortality rates for normal LVMI and mild, moderate, and severe LVH were 19.8%, 18.3%, 23.7%, and 24.4%, respectively. Compared to mild LVH, moderate LVH and severe LVH were independently associated with an increased risk for all-cause mortality (hazard ratio [HR] 1.58, 95% CI 1.15-2.18, P = .005; HR 1.46, 95% CI 1.1-1.95, P = .009; respectively). Concentric LVH was independently associated with a decreased risk for mortality compared to normal LV geometry (HR 0.75, 95% CI 0.63-0.89, P = .001). Compared to concentric LVH, eccentric LVH was independently associated with a 33% increased risk for mortality (HR 1.33, 95% CI 1.11-1.60, P = .002).

CONCLUSIONS

Mild concentric LVH confers a protective effect among patients with severe aortic stenosis undergoing TAVR. However, hypertrophy becomes maladaptive, and an increased baseline LVMI, eccentric pattern particularly, may be associated with all-cause mortality in this population.

Life-Course Cumulative Burden of Body Mass Index and Blood Pressure on Progression of Left Ventricular Mass and Geometry in Midlife: The Bogalusa Heart Study

RATIONALE

Data are limited regarding the influence of life-course cumulative burden of increased body mass index (BMI) and elevated blood pressure (BP) on the progression of left ventricular (LV) geometric remodeling in midlife.

OBJECTIVE

To investigate the dynamic changes in LV mass and LV geometry over 6.4 years during midlife and to examine whether the adverse progression of LV geometric remodeling is influenced by the cumulative burden of BMI and BP from childhood to adulthood.

METHODS AND RESULTS

The study consisted of 877 adults (604 whites and 273 blacks; 355 males; mean age=41.4 years at follow-up) who had 5 to 15 examinations of BMI and BP from childhood and 2 examinations of LV dimensions at baseline and follow-up 6.4 years apart during adulthood. The area under the curve (AUC) was calculated as a measure of long-term burden (total AUC) and trends (incremental AUC) of BMI and systolic BP (SBP). After adjusting for age, race, sex, smoking, alcohol drinking, and baseline LV mass index, the annual increase rate of LV mass index was associated with all BMI measures (β=0.16-0.36, P<0.05 for all), adult SBP (β=0.07, P=0.04), and total AUC of SBP (β=0.09, P=0.01) but not with childhood and incremental AUC values of SBP. All BMI and SBP measures (except childhood SBP) were significantly associated with increased risk of incident LV hypertrophy, with odds ratios of BMI (odds ratio=1.85-2.74, P<0.05 for all) being significantly greater than those of SBP (odds ratio=1.09-1.34, P<0.05 for all except childhood SBP). In addition, all BMI measures were significantly and positively associated with incident eccentric and concentric LV hypertrophy.

CONCLUSIONS

Life-course cumulative burden of BMI and BP is associated with the development of LV hypertrophy in midlife, with BMI showing stronger associations than BP. Visual Overview: An online visual overview is available for this article.

Albuminuria and other target organ damage in Chinese patients with hypertension and diabetes: A data analysis based on the ATTEND study

AIMS

The relationship between albuminuria and left ventricular hypertrophy (LVH) was well characterized in hypertension (HTN), but not in diabetes. Moreover, most studies have described the correlation between albuminuria and cardiovascular mortality, but not cardiovascular diseases (CVD) morbidity. This study aimed to explore the relationship between albuminuria and LVH, CVD morbidity in patients with HTN, diabetes mellitus (DM) or HTN + DM.

METHODS

Conducted a data analysis based on the demographic, medical history and laboratory data of 2504 patients from the ATTEND study, a national registry study on HTN and DM in Chinese outpatients.

RESULTS

The prevalence of LVH and CVD was 7.7% and 21.5% in HTN + DM, 7.6% and 17.6% in HTN, 3.9% and 5.2% in DM patients. Subjects with HTN + DM implied higher risk of LVH (P = 0.023), CVD (P = 0.001) and 10-year coronary heart disease (CHD) (P < 0.001) than those with DM only. There was no significant relationship between albuminuria and LVH or CVD.

CONCLUSIONS

More than one-fifth of HTN and/or DM patients with microalbuminuria suffered from CVD. Comorbidity of DM and HTN significantly increases cardiovascular events than DM only. No statistical association between albuminuria and LVH or CVD was found.

Associations of awake and asleep blood pressure and blood pressure dipping with abnormalities of cardiac structure: the Coronary Artery Risk Development in Young Adults study

OBJECTIVES

To evaluate the associations of high awake blood pressure (BP), high asleep BP, and nondipping BP, determined by ambulatory BP monitoring (ABPM), with left ventricular hypertrophy (LVH) and geometry.

METHODS

Black and white participants (n = 687) in the Coronary Artery Risk Development in Young Adults study underwent 24-h ABPM and echocardiography at the Year 30 Exam in 2015-2016. The prevalence and prevalence ratios of LVH were calculated for high awake SBP (≥130 mmHg), high asleep SBP (≥110 mmHg), the cross-classification of high awake and asleep SBP, and nondipping SBP (percentage decline in awake-to-asleep SBP < 10%). Odds ratios for abnormal left ventricular geometry associated with these phenotypes were calculated.

RESULTS

Overall, 46.0 and 49.1% of study participants had high awake and asleep SBP, respectively, and 31.1% had nondipping SBP. After adjustment for demographics and clinical characteristics, high awake SBP was associated with a prevalence ratio for LVH of 2.79 [95% confidence interval (95% CI) 1.63-4.79]. High asleep SBP was also associated with a prevalence ratio for LVH of 2.19 (95% CI 1.25-3.83). There was no evidence of an association between nondipping SBP and LVH (prevalence ratio 0.70, 95% CI 0.44-1.12). High awake SBP with or without high asleep SBP was associated with a higher odds ratio of concentric remodeling and hypertrophy.

CONCLUSION

Awake and asleep SBP, but not the decline in awake-to-asleep SBP, were associated with increased prevalence of cardiac end-organ damage.

Association of Left Ventricular Hypertrophy with Hemoglobin Levels in Nonanemic and Anemic Populations

<b><i>Introduction:</i></b> It is established that anemia leads to adaptive changes in cardiac geometry including left ventricular hypertrophy (LVH). However, published data are still scarce regarding the association of LVH with normal-range hemoglobin levels. <b><i>Objective:</i></b> To evaluate the association between hemoglobin level and LVH in subjects with or without anemia. <b><i>Methods:</i></b> The study included 48,034 Korean men and women who received echocardiography during their medical health checkup. They were divided into 4 groups according to their hemoglobin concentration (g/dL) in men (&#x3c;14, 14–14.9, 15–15.9, and ≥16) and women (&#x3c;12, 12–12.9, 13–13.9, and ≥15). Multivariate logistic regression analysis was used to calculate adjusted ORs and 95% CI for LVH in each group compared with the group with the lowest hemoglobin. Subgroup analysis was conducted for subjects within normal hemoglobin levels. <b><i>Results:</i></b> There was an inverse relationship between hemoglobin levels and LVH, where unadjusted and adjusted ORs and 95% CI for LVH decreased with increasing hemoglobin levels in both men and women. In subgroup analysis, this inverse relationship was also observed in subjects with hemoglobin in the nonanemic range. <b><i>Conclusion:</i></b> The decrease in hemoglobin was significantly associated with the increased probability of LVH, and this association was found even in nonanemic subjects.

Increased Myocardial Stiffness in Patients With High-Risk Left Ventricular Hypertrophy: The Hallmark of Stage-B Heart Failure With Preserved Ejection Fraction

BACKGROUND

Individuals with left ventricular hypertrophy (LVH) and elevated cardiac biomarkers in middle age are at high risk for the development of heart failure with preserved ejection fraction (HFpEF). However, it is unknown what the pathophysiological underpinnings of this high-risk state may be. We tested the hypothesis that patients with LVH and elevated cardiac biomarkers would demonstrate elevated left ventricular (LV) myocardial stiffness in comparison with healthy controls as a key marker for future HFpEF.

METHODS

Forty-six patients with LVH (LV septum >11 mm) and elevated cardiac biomarkers (N-terminal pro-B-type natriuretic peptide [>40 pg/mL] or troponin T [>0.6 pg/mL]) were recruited, along with 61 age- and sex-matched (by cohort) healthy controls. To define LV pressure-volume relationships, right heart catheterization and 3-dimensional echocardiography were performed while preload was manipulated using lower body negative pressure and rapid saline infusion.

RESULTS

There were significant differences in body size, blood pressure, and baseline pulmonary capillary wedge pressure between groups (eg, pulmonary capillary wedge pressure: LVH, 13.4±2.7 versus control, 11.7±1.7 mm Hg, P<0.0001). The LV was less distensible in LVH than in controls (smaller volume for the same filling pressure). When preload was expressed as transmural filling pressure (pulmonary capillary wedge pressure - right atrial pressure), LV myocardial stiffness was nearly 30% greater in LVH than in controls (LVH stiffness constant, 0.053±0.027 versus controls, 0.042±0.020, P=0.028).

CONCLUSIONS

LV myocardial stiffness in patients with LVH and elevated biomarkers (stage-B HFpEF) is greater than in age- and sex-matched controls and thus appears to represent a transitional state from a normal healthy heart to HFpEF. Although the LV myocardial stiffness of patients with LVH is greater than that of healthy controls at this early stage, further studies are required to clarify whether interventions such as exercise training to improve LV compliance may prevent the full manifestation of the HFpEF syndrome in these high-risk individuals.

CLINICAL TRIAL REGISTRATION

URL: https://www.clinicaltrials.gov. Unique identifiers: NCT03476785 and NCT02039154.

Difference in the prevalence of subclinical left ventricular impairment among left ventricular geometric pattern in a community-based population

BACKGROUND

Left ventricular (LV) hypertrophy is reported to cause LV diastolic dysfunction. This study aimed to examine the prevalence of LV diastolic dysfunction in each group categorized by the geometric pattern of LV hypertrophy in a community-based population.

METHODS

We studied 1260 community-dwelling subjects who experienced no symptoms of obvious heart disease (461 men, 799 women) and who participated in annual health check-ups in a rural Japanese community. The subjects were divided into 4 groups according to LV mass index and relative wall thickness: normal geometry, concentric remodeling, eccentric hypertrophy, and concentric hypertrophy. We investigated the prevalence of LV diastolic dysfunction in the overall and stratified population by LV geometric pattern. LV diastolic function was determined by 3 echocardiographic parameters of LV diastolic function: early diastolic myocardial velocity, the ratio of early diastolic mitral inflow velocity and myocardial velocity, and indexed left atrial dimension. LV diastolic dysfunction was defined as the presence of abnormal values in more than 2 of 3 echocardiographic parameters.

RESULTS

The prevalence of LV diastolic dysfunction was higher in the categories with more severe LV hypertrophy. However, LV mass index, rather than relative wall thickness, was a significant determinant of LV diastolic dysfunction, after adjustment for comorbidities. In addition, 71 (10%) out of 740 subjects with normal LV geometric pattern had LV diastolic dysfunction even without obvious LV geometric change.

CONCLUSIONS

The prevalence of LV diastolic dysfunction was higher in the subjects with more severe LV hypertrophy in a community-based population. Subclinical LV diastolic dysfunction without obvious LV geometric change should be noted and its clinical impact should be elucidated.

Men are from mars, women are from venus: Factors responsible for gender differences in outcomes after surgical and trans-catheter aortic valve replacement

Females suffer higher operative (30-day) mortality than males after surgical aortic valve replacement (SAVR). In contrast, outcomes after trans-catheter aortic valve replacement (TAVR) seem to favor females, both in terms of procedural mortality, and more prominently, medium to long-term survival. With an ever-greater number of TAVR procedures being performed, an understanding of factors responsible for gender differences in outcomes after the two AVR modalities is critical for better patient selection. Current evidence suggests that this gender difference in outcomes after SAVR and TAVR stems from differences in baseline risk profiles, as well as inherent anatomic/physiological differences between genders. This review attempts to examine these clinical and physiological factors, with a goal of guiding better patient selection for each AVR modality, and to highlight areas that beg further investigation.

Utility of Pacemaker With Sleep Apnea Monitor to Predict Left Ventricular Overload and Acute Decompensated Heart Failure

Pacemakers with sleep apnea monitor (SAM) provide an easy tool to assess obstructive sleep apnea over long periods of time. The link between respiratory disturbances at night and the incidence of acute decompensated heart failure (ADHF) is not well established. We aimed at (1) determining the ability of SAM pacemakers to evaluate the extent of left ventricular overload and (2) assess the impact of respiratory disturbances at night on the occurrence of ADHF over 1-year of follow-up. We conducted a single-center prospective study. Consecutive patients with SAM pacemakers were comprehensively assessed. SAM automatically computes a respiratory disturbance index (RDI, apneas/hypopneas per hour - AH/h) in the previous night and the percentage of nights with RDI >20 AH/h in the previous 6 months. Thirty-seven patients were included (79.3 ± 11.2 years, 46% males). A high RDI in the previous night and a higher %nights with increased RDI were associated with increased NT-proBNP values (p = 0.008 and p = 0.013, respectively) and were the sole predictors of increased noninvasive pulmonary capillary wedge pressures (PCWP) in the morning of assessment (p = 0.031 and p = 0.044, respectively). Receiver operating characteristic curve analysis revealed an area under the curve of 0.804 (95% confidence interval 0.656 to 0.953, p = 0.002) for %nights with RDI >20 AH/h in the prediction of high PCWP. Patients with >12.5% of nights with RDI >20AH/h tended to have more ADHF during follow-up (log-rank p = 0.067). In conclusion, a high burden of apneas/hypopneas at night is associated with elevated NT-proBNP and PCWP values and an increased risk of ADHF over 1 year. These patients might benefit from early tailored clinical management.

CD47 Deficiency Attenuates Isoproterenol-Induced Cardiac Remodeling in Mice

In this study, we investigated whether CD47 deficiency attenuates isoproterenol- (ISO-) induced cardiac remodeling in mice. Cardiac remodeling was induced by intraperitoneal (i.p.) injection of ISO (60 mg·kg⁻¹·d⁻¹ in 100 μl of sterile normal saline) daily for 14 days and was confirmed by increased levels of lactate dehydrogenase (LDH) and creatine kinase MB (CK-MB), increased heart weight to body weight (HW/BW) ratios, and visible cardiac fibrosis. Apoptosis was evaluated by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) staining. Levels of malondialdehyde (MDA) and reactive oxygen species (ROS) were found to be significantly higher in the ISO group than in the control group, while superoxide dismutase (SOD) levels were suppressed in the ISO group. However, CD47 knockout significantly limited ISO-induced increases in LDH, CK-MB, and HW/BW ratios, cardiac fibrosis, oxidative stress, and apoptosis in the heart. In addition, CD47 deficiency also increased p-AMPK and LAMP2 expression and decreased HDAC3, cleaved Caspase-3, cleaved Caspase-9, LC3II, and p62 expression in cardiac tissues. In conclusion, CD47 deficiency reduced i.p. ISO-induced cardiac remodeling probably by inhibiting the HDAC3 pathway, improving AMPK signaling and autophagy flux, and rescuing autophagic clearance.

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

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

Performance of a new fully automated transthoracic three-dimensional echocardiographic software for quantification of left cardiac chamber size and function: Comparison with 3 Tesla cardiac magnetic resonance

PURPOSE

To evaluate the accuracy and reproducibility of a new fully automated fast three-dimensional (3D) transthoracic echocardiography (TTE) software for the simultaneous assessment of left atrial (LA) volumes and LA ejection fraction (EF), left ventricular (LV) volumes, LV mass, and LVEF, and to compare the results obtained with a cardiac magnetic resonance (CMR) reference.

METHODS

We included retrospectively 56 patients (46 men; mean age 63 ± 13 years) in sinus rhythm who had had comprehensive 3D TTE and CMR examinations within 24 hours.

RESULTS

Despite a slight underestimation of LV and LA volumes, LVEF and LAEF were similar using CMR or 3DTTE (58% ± 16% vs 58% ± 12%; P = .65 and 45% ± 14% vs 46% ± 15%; P = .38, respectively) in the total population. Despite significant correlation between TTE and CMR measurements (r = 0.78; P < .001), 3D TTE underestimated LV mass (bias = -27 ± 35 g).

CONCLUSION

3D TTE using a new-generation fully automated software is a fast and reproducible imaging modality for simultaneous extensive quantification of left heart chambers size and function in routine practice. Potential underestimation of LA volume and LV mass, and of LVEF in patients with LVEF <50%, should be taken into consideration.

Mildly Decreased Renal Function and Its Relation to Left Ventricular Geometry Change

BACKGROUND

It is believed that left ventricular (LV) geometry change contributes to the elevated cardiovascular risk in patients with chronic kidney disease. However, data are less available on the association between LV geometry change and mildly decreased renal function within estimated glomerular filtration rate (eGFR) from 60 to 89 (mL/min/1.73 m²).Methods and Results:In a cohort of 47,730 Koreans undergoing echocardiography as part of a health check-up, we evaluated the association of LV hypertrophy (LVH) and abnormal relative wall thickness (RWT) with 4 levels and 3 levels of eGFR in men (≥90, 89.99-80, 79.99-70, 69.99-60) and women (≥90, 89.99-80, 79.99-60), respectively. Multivariate logistic regression analysis was used to calculate the odds ratios (OR) and 95% confidence intervals (CI) for LVH and abnormal RWT, adjusting for conventional cardiovascular risk factors (adjusted OR [95% CI]). In the fully adjustment model, men did not show a significant association between LVH and levels of eGFR between 60 and 89. However, abnormal RWT was significantly associated with the levels of eGFR between 60 and 89. Women did not show a significant association of LVH and abnormal RWT with levels of eGFR between 60 and 89.

CONCLUSIONS

Men with mildly decreased renal function (eGFR between 60 and 89 mL/min/1.73 m²) had increased probability of LV geometry change represented by abnormal RWT.

Prenatal Alcohol Exposure Causes Adverse Cardiac Extracellular Matrix Changes and Dysfunction in Neonatal Mice

Fetal alcohol syndrome (FAS) is the most severe condition of fetal alcohol spectrum disorders (FASD) and is associated with congenital heart defects. However, more subtle defects such as ventricular wall thinning and cardiac compliance may be overlooked in FASD. Our studies focus on the role of cardiac fibroblasts in the neonatal heart, and how they are affected by prenatal alcohol exposure (PAE). We hypothesize that PAE affects fibroblast function contributing to dysregulated collagen synthesis, which leads to cardiac dysfunction. To investigate these effects, pregnant C57/BL6 mice were intraperitoneally injected with 2.9 g EtOH/kg dose to achieve a blood alcohol content of approximately 0.35 on gestation days 6.75 and 7.25. Pups were sacrificed on neonatal day 5 following echocardiography measurements of left ventricular (LV) chamber dimension and function. Hearts were used for primary cardiac fibroblast isolation or protein expression analysis. PAE animals had thinner ventricular walls than saline exposed animals, which was associated with increased LV wall stress and decreased ejection fraction. In isolated fibroblasts, PAE decreased collagen I/III ratio and increased gene expression of profibrotic markers, including α-smooth muscle actin and lysyl oxidase. Notch1 signaling was assessed as a possible mechanism for fibroblast activation, and indicated that gene expression of Notch1 receptor and downstream Hey1 transcription factor were increased. Cardiac tissue analysis revealed decreased collagen I/III ratio and increased protein expression of α-smooth muscle actin and lysyl oxidase. However, Notch1 signaling components decreased in whole heart tissue. Our study demonstrates that PAE caused adverse changes in the cardiac collagen profile and a decline in cardiac function in the neonatal heart.

Ultrasound and Microbubble-targeted Delivery of a microRNA Inhibitor to the Heart Suppresses Cardiac Hypertrophy and Preserves Cardiac Function

MicroRNAs (miRs) are dysregulated in pathological left ventricular hypertrophy. AntimiR inhibition of miR-23a suppressed hypertension-induced cardiac hypertrophy in preclinical models, but clinical translation is limited by a lack of cardiac-targeted delivery systems. Ultrasound-targeted microbubble cavitation (UTMC) utilizes microbubbles as nucleic acid carriers to target delivery of molecular therapeutics to the heart. The objective of this study was to evaluate the efficacy of UTMC targeted delivery of antimiR-23a to the hearts of mice for suppression of hypertension-induced cardiac hypertrophy.

Methods: Cationic lipid microbubbles were loaded with 300 pmol negative control antimiR (NC) or antimiR-23a. Mice received continuous phenylephrine infusion via implanted osmotic minipumps, then UTMC treatments with intravenously injected antimiR-loaded microbubbles 0, 3, and 7 days later. At 2 weeks, hearts were harvested and miR-23a levels were measured. Left ventricular (LV) mass and function were assessed with echocardiography.

Results: UTMC treatment with antimiR-23a decreased cardiac miR-23a levels by 41 ± 8% compared to UTMC + antimiR-NC controls (p < 0.01). Furthermore, LV mass after 1 week of phenylephrine treatment was 17 ± 10% lower following UTMC + antimiR-23a treatment compared to UTMC + antimiR-NC controls (p = 0.02). At 2 weeks, fractional shortening was 23% higher in the UTMC + antimiR-23a mice compared to UTMC + antimiR-NC controls (p < 0.01).

Conclusions: UTMC is an effective technique for targeted functional delivery of antimiRs to the heart causing suppression of cardiac hypertrophy and preservation of systolic function. This approach could represent a revolutionary therapy for patients suffering from pathological cardiac hypertrophy and other cardiovascular conditions.

MicroRNA-122 promotes cardiomyocyte hypertrophy via targeting FoxO3

OBJECTIVE

-microRNAs (miRNAs) have emerged as novel regulators for cardiac hypertrophy. MiR-122 is well recognized as a promising therapeutic target in liver disease, whereas recently plays important roles in cardiovascular diseases. The current study aimed to explore the effect of miR-122 on the pathogenesis of cardiomyocyte hypertrophy.

METHODS AND RESULTS

-The cardiomyocytes isolated from the neonatal rat ventricular cardiomyocytes (NRVMs) were collected and performed to Angiotensin II (Ang II) administration. We observed a dramatically increased miR-122 expression in hypertrophic cardiomyocytes. The NRVMs transfected with miR-122 mimic or negative control were utilized for the functional analysis. Overexpression of miR-122 increased the morphology size of cardiomyocytes and promoted the pro-hypertrophic genes expression, whereas downregulated the anti-hypertrophic genes upon Ang II stimulation. The bioinformatics analysis and luciferase reporter assays exhibited that miR-122 directly targeted FoxO3 and attenuated its gene level in hypertrophic cardiomyocytes. Moreover, miR-122 negatively regulated FoxO3 but promoted calcineurin signaling pathway activation. Importantly, FoxO3 overexpression significantly reversed the effect of miR-122 on cardiomyocyte hypertrophy.

CONCLUSION

-Collected, our finding demonstrated that miR-122 accelerated the development of cardiomyocytes hypertrophy partially via directly regulation of FoxO3-calcineurin pathway.

Aldehyde Dehydrogenase 2 and Heart Failure

Heart failure (HF) is a structural or functional cardiac abnormal syndrome characterized with series of symptoms and signs such as breathlessness, fatigue, pulmonary crackles, and peripheral edema. Being a terminal phase of most myocardial lesions, HF has become a leading cause of mobility and mortality worldwide, associated with heavy clinical burden and economic costs affecting over 23 million people [14]. There is an increase to 5.5% with systolic dysfunction and an increase to 36.0% with diastolic dysfunction in people 60 years or older [85]. The costs accompanied with heart failure stand 2-3% of the total healthcare system expenditure in high-income countries and are expected to increase >2-fold in the next 2 decades [34].

Interplay of cardiac remodelling and myocardial stiffness in hypertensive heart disease: a shear wave imaging study using high-frame rate echocardiography

Aims

To determine myocardial stiffness by means of measuring the velocity of naturally occurring myocardial shear waves (SWs) at mitral valve closure (MVC) and investigate their changes with myocardial remodelling in patients with hypertensive heart disease.

Methods and results

Thirty-three treated arterial hypertension (HT) patients with hypertrophic left ventricular (LV) remodelling (59 ± 14 years, 55% male) and 26 aged matched healthy controls (55±15 years, 77% male) were included. HT patients were further divided into a concentric remodelling (HT1) group (13 patients) and a concentric hypertrophy (HT2) group (20 patients). LV parasternal long-axis views were acquired with an experimental ultrasound scanner at 1266 ± 317 frames per seconds. The SW velocity induced by MVC was measured from myocardial acceleration maps. SW velocities differed significantly between HT patients and controls (5.83 ± 1.20 m/s vs. 4.04 ± 0.96 m/s; P &lt; 0.001). In addition, the HT2 group had the highest SW velocities (P &lt; 0.001), whereas values between controls and the HT1 group were comparable (P = 0.075). Significant positive correlations were found between SW velocity and LV remodelling (interventricular septum thickness: r = 0.786, P &lt; 0.001; LV mass index: r = 0.761, P &lt; 0.001). SW velocity normalized for wall stress indicated that myocardial stiffness in the HT2 group was twice as high as in controls (P &lt; 0.001), whereas values of the HT1 group overlapped with the controls (P = 1.00).

Conclusions

SW velocity as measure of myocardial stiffness is higher in HT patients compared with healthy controls, particularly in advanced hypertensive heart disease. Patients with concentric remodelling have still normal myocardial properties whereas patients with concentric hypertrophy show significant stiffening.

Coronary Microcirculation in Aortic Stenosis

Aortic stenosis is a heterogeneous disorder. Variations in the pathological and physiological responses to pressure overload are incompletely understood and generate a range of flow and pressure gradient patterns, which ultimately cause varying microvascular effects. The impact of cardiac-coronary coupling depends on these pressure and flow effects. In this article, we explore important concepts concerning cardiac physiology and the coronary microcirculation in aortic stenosis and their impact on myocardial remodeling, aortic valve flow patterns, and clinical progression.

Aortic stenosis and diabetes mellitus: An ominous combination

Aortic stenosis and diabetes mellitus are both progressive diseases which, if left untreated, result in significant morbidity and mortality. There is evidence that the prevalence of diabetes is substantially increased in patients with aortic stenosis and those with diabetes have increased rates of progression from mild to severe aortic stenosis. There are good data supporting the hypothesis that aortic stenosis and diabetes mellitus are associated with diabetes mellitus being detrimental towards the quality of life and survival of patients. Thus, a thorough understanding of the pathogenesis of both of these disease processes and the relationship between them aids in designing appropriate preventive and therapeutic approaches. This review aims to give a comprehensive and up-to-date insight into the influence of diabetes mellitus on patients with degenerative aortic stenosis, as well as the prognosis and therapeutic approach to these patients.

Protective role of wild garlic on isoproterenol-induced myocardial necrosis in wistar rats

ETHNOPHARMACOLOGICAL RELEVANCE

Tulbaghia violacea Harv. (TVL) is a folk medicine, native to South Africa which has previously shown antioxidant, anti-hypertensive and anti-diabetic effects.

THE AIM OF THE STUDY

The aim of the current study was to investigate the protective role of wild garlic or TVL on isoproterenol (ISO)-induced myocardial necrosis in rats.

MATERIALS AND METHODS

Animal (n = 6 each group) were pre and co-treated with TVL (60 mg/kg body weight) daily for 30 days. Myocardial necrosis was administrated by subcutaneous injection of ISO (85 mg/kg body weight) into rats on 29th and 30th day. On the 31st day, rats were anaesthetized and blood, heart samples were obtained for the biochemical, histopathological and molecular study. The specific protein target analysis from TVL was done by reverse docking study (reverse pharmacophore mapping) using PharmMapper.

RESULTS

The levels of cardiac markers, lipid peroxidation products, and heart rate were considerably increased in ISO-induced myocardial necrosis in rats whilst plasma enzymatic antioxidants were significantly decreased. Myocardial necrotic mRNA genes were increased in ISO-induced myocardial necrosis in rats compared to controls. Pre and co-treatment with TVL and ramipril of myocardial necrosis in rats showed significant effects on all the biochemical and molecular studies evaluated. TVL reduced heart rate, prevented oxidative stress and downregulated the Fas-receptor and caspase-mediated apoptosis-signaling pathway, and heart muscle damage in myocardial necrosis in rats. The specific target protein [disulfide, bis (2-sulfhydrylethyl] from TVL mediates the protective effects.

CONCLUSION

Wild garlic or TVL extract has shown a protective effect on ISO-induced myocardial necrosis in rats by increasing antioxidant production confirmed with docking studies.

Evaluation of left ventricular mass on cadmium-zinc-telluride imaging: Validation against cardiac magnetic resonance

BACKGROUND

Single-photon emission computed tomography has shown relevant limitations in the quantification of left ventricular (LV) mass. We sought to compare the estimates of LV mass on Cadmium-Zinc-Telluride (CZT) myocardial perfusion imaging (MPI) as compared to cardiac magnetic resonance (CMR).

METHODS AND RESULTS

Twenty-five patients underwent MPI on a CZT camera and CMR on a 1.5 T scanner within 12 ± 3 weeks. LV mass was quantified on CZT images using two softwares: 4D-MSPECT (4DM) and Emory Cardiac Toolbox (ECTb). LV mass by CMR was quantified using MASS software (Medis, Leiden, The Netherlands). LV mass values obtained with 4DM and ECTb were highly reproducible [intraclass correlation coefficients .98 (95% CI .97-.99), and .98 (95% CI 0.97-.99), respectively]. The mean LVM mass values were 151 ± 44 g on CMR, 151 ± 43 g with 4DM (P = NS vs CMR), and 157 ± 42 g with ECTb (P < .001 vs CMR; P = .007 vs 4DM) CZT images. There was an excellent correlation between LV mass values between CMR and both 4DM (R2 = .95; P < .001) and ECTb (R2 = .98; P < .001) with narrow limits of agreement (- 13.6% to + 13.4% for 4DM, and - 5.6% to + 14.1% for ECTb).

CONCLUSIONS

The evaluation of LV mass is feasible on CZT images, showing excellent agreement with CMR.

Ventricular remodeling in preterm infants: computational cardiac magnetic resonance atlasing shows significant early remodeling of the left ventricle

BACKGROUND

Premature birth is associated with ventricular remodeling, early heart failure, and altered left ventricular (LV) response to physiological stress. Using computational cardiac magnetic resonance (CMR) imaging, we aimed to quantify preterm ventricular remodeling in the neonatal period, and explore contributory clinical factors.

METHODS

Seventy-three CMR scans (34 preterm infants, 10 term controls) were performed to assess in-utero development and preterm ex-utero growth. End-diastolic computational atlases were created for both cardiac ventricles; t statistics, linear regression modeling, and principal component analysis (PCA) were used to describe the impact of prematurity and perinatal factors on ventricular volumetrics, ventricular geometry, myocardial mass, and wall thickness.

RESULTS

All preterm neonates demonstrated greater weight-indexed LV mass and higher weight-indexed end-diastolic volume at term-corrected age (P < 0.05 for all preterm gestations). Independent associations of increased term-corrected age LV myocardial wall thickness were (false discovery rate <0.05): degree of prematurity, antenatal glucocorticoid administration, and requirement for >48 h postnatal respiratory support. PCA of LV geometry showed statistical differences between all preterm infants at term-corrected age and term controls.

CONCLUSIONS

Computational CMR demonstrates that significant LV remodeling occurs soon after preterm delivery and is associated with definable clinical situations. This suggests that neonatal interventions could reduce long-term cardiac dysfunction.

A high-throughput ratiometric method for imaging hypertrophic growth in cultured primary cardiac myocytes

Maladaptive hypertrophy of cardiac myocytes increases the risk of heart failure. The underlying signaling can be triggered and interrogated in cultured neonatal ventricular myocytes (NRVMs) using sophisticated pharmacological and genetic techniques. However, the methods for quantifying cell growth are, by comparison, inadequate. The lack of quantitative, calibratable and computationally-inexpensive high-throughput technology has limited the scope for using cultured myocytes in large-scale analyses. We present a ratiometric method for quantifying the hypertrophic growth of cultured myocytes, compatible with high-throughput imaging platforms. Protein biomass was assayed from sulforhodamine B (SRB) fluorescence, and image analysis calculated the quotient of signal from extra-nuclear and nuclear regions. The former readout relates to hypertrophic growth, whereas the latter is a reference for correcting protein-independent (e.g. equipment-related) variables. This ratiometric measure, when normalized to the number of cells, provides a robust quantification of cellular hypertrophy. The method was tested by comparing the efficacy of various chemical agonists to evoke hypertrophy, and verified using independent assays (myocyte area, transcripts of markers). The method's high resolving power and wide dynamic range were confirmed by the ability to generate concentration-response curves, track the time-course of hypertrophic responses with fine temporal resolution, describe drug/agonist interactions, and screen for novel anti-hypertrophic agents. The method can be implemented as an end-point in protocols investigating hypertrophy, and is compatible with automated plate-reader platforms for generating high-throughput data, thereby reducing investigator-bias. Finally, the computationally-minimal workflow required for obtaining measurements makes the method simple to implement in most laboratories.

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Maladaptive hypertrophy of myocytes can lead to heart failure.

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Common methods for tracking growth in cultured myocytes are inadequate.

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We design and test a method for tracking myocyte hypertrophy in vitro.

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The method provides a ratiometric index of growth for high throughput analyses.

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Using the method, we characterize further details of (anti)hypertrophic responses.

Histone deacetylases in cardiovascular and metabolic diseases

Histone deacetylases (HDACs) regulate gene transcription by catalyzing the removal of acetyl groups from key lysine residues in nucleosomal histones and via the recruitment of other epigenetic regulators to DNA promoter/enhancer regions. Over the past two decades, HDACs have been implicated in multiple processes pertinent to cardiovascular and metabolic diseases, including cardiac hypertrophy and remodeling, fibrosis, calcium handling, inflammation and energy metabolism. The development of small molecule HDAC inhibitors and genetically modified loss- and gain-of-function mouse models has allowed interrogation of the roles of specific HDAC isoforms in these processes. Isoform-selective HDAC inhibitors may prove to be powerful therapeutic agents for the treatment of cardiovascular diseases, obesity and diabetes.

Optimal Duration for Clopidogrel Suspension Prior to Coronary Artery Bypass Grafting

BACKGROUND

American College of Cardiology (ACC) guidelines suggest clopidogrel (Plavix) suspension for 5 days before non-emergent cardiac surgery (class IIa, level B). It puts the patients with recent angioplasty and ongoing ischemia at a higher risk of stent thrombosis. We sought to determine the bleeding risk in patients who stopped clopidogrel at 3 and less than 3 days before coronary artery bypass grafting (CABG) as compared to the usual 5 days prior to CABG.

METHODS

A retrospective single center study was performed; and a total of 90 patients were included. Forty patients were not on clopidogrel but underwent CABG and hence were used as a control group (group 3). Fifty remaining patients were divided into three groups. Patients in whom clopidogrel was stopped 3 days or less before CABG were included in group 1 (n = 25); group 2 included patients who followed the standard ACC guidelines and clopidogrel was suspended 5 days before the CABG (n = 17); and finally patients who had stopped clopidogrel 4 days prior to surgery were included in group 4 (n = 8). This was compared to controls. Postoperative hemoglobin drop was analyzed between subgroups using IBM SPSS version 25.

RESULTS

The mean age of the included population was 69.9 years (46 - 88) with 65% of them being male and 35% female patients. The difference in the hemoglobin fall was compared amongst these groups using the one-way ANOVA. There were no outliers, as assessed by boxplot, the data were normally distributed for each group, as assessed by Shapiro-Wilk test (P > 0.05), and there was homogeneity of variances, as assessed by Levene's test of homogeneity of variances (P > 0.05). The fall in hemoglobin for the four different groups was analyzed. The fall in hemoglobin in group 1 (stopped clopidogrel 3 days or less before CABG) was (n = 25, 2.36 ± 1.24), the fall in group 2 (stopped clopidogrel 5 days prior to CABG) was (n = 17, 2.89 ± 1.22), the fall in hemoglobin in group 3 (patients not on clopidogrel) was (n = 40, 2.54 ± 1.35), and the fall in hemoglobin in group 4 (patients stopped clopidogrel 4 days prior to CABG) was (n = 8, 2.02 ± 1.31). ANOVA was subsequently performed on the patient data, which showed no statistical difference between all the four groups regarding the fall in hemoglobin during surgery (P = 0.41).

CONCLUSIONS

Our study concludes that there was no significant difference in the hemoglobin drop of the patients who had clopidogrel stopped 3 days prior to the major procedure like CABG in comparison to the patients who stopped clopidogrel 5 days before surgery. We advocate, that early cessation of clopidogrel is posing a threat of thrombosis in high risk patients with no additional benefit of decreased bleeding risks. However, large population studies are needed to validate the results.

Left ventricular geometric patterns in patients with type A aortic dissection

BACKGROUND

Aortic dilatation is a major risk factor for aortic dissection. The aim of the present study was to assess the relationship between left ventricular (LV) geometry and maximal ascending aorta (MAA).

METHODS

We reviewed data from patients who were diagnosed with acute type A aortic dissection and who underwent surgical management from December 2002 to March 2016 at Dong-A University Hospital. Among 151 patients with non-Marfan aortic dissection in the study, 50 who had echocardiography preoperatively were investigated and MAA diameter was analyzed by LV geometric patterns.

RESULTS

Patients' mean age was 59.6 ± 13.5 years and 38.0% were male. The mean MAA diameter was 52.9 ± 8.5 mm. MAA diameter was significantly correlated with LV mass index (r = 0.62, P < 0.001). On analysis by LV geometry, MAA diameter showed a significant difference between the 4 groups (P = 0.02), and the eccentric and concentric hypertrophy groups showed significantly larger MAA diameter than the other two groups.

CONCLUSION

MAA diameter was associated with LV mass index and was significantly different between LV geometry types. In this study, not only concentric hypertrophy but also eccentric LV hypertrophy was related to larger MAA in type A aortic dissection patients.

Left Ventricular Mass and Thickness: Why Does It Matter?

Several left ventricular geometric patterns have been described both in healthy and pathologic hearts. Left ventricular mass, wall thickness, and the ratio of wall thickness to radius are important measures to characterize the spectrum of left ventricular geometry. For clinicians, an increase in left ventricular mass is the hallmark of left ventricular hypertrophy. Although pathologic hypertrophy initially can be compensatory, eventually it may become maladaptive and evolve toward progressive left ventricular dysfunction and heart failure. In particular, patients who show left ventricular dilation and hypertrophy in association with a low relative wall thickness are likely to carry the highest risk.

Cardiac Disorders and Pathophysiology of Sarcomeric Proteins

The sarcomeric proteins represent the structural building blocks of heart muscle, which are essential for contraction and relaxation. During recent years, it has become evident that posttranslational modifications of sarcomeric proteins, in particular phosphorylation, tune cardiac pump function at rest and during exercise. This delicate, orchestrated interaction is also influenced by mutations, predominantly in sarcomeric proteins, which cause hypertrophic or dilated cardiomyopathy. In this review, we follow a bottom-up approach starting from a description of the basic components of cardiac muscle at the molecular level up to the various forms of cardiac disorders at the organ level. An overview is given of sarcomere changes in acquired and inherited forms of cardiac disease and the underlying disease mechanisms with particular reference to human tissue. A distinction will be made between the primary defect and maladaptive/adaptive secondary changes. Techniques used to unravel functional consequences of disease-induced protein changes are described, and an overview of current and future treatments targeted at sarcomeric proteins is given. The current evidence presented suggests that sarcomeres not only form the basis of cardiac muscle function but also represent a therapeutic target to combat cardiac disease.

Cardiovascular magnetic resonance T2* mapping for structural alterations in hypertrophic cardiomyopathy

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HCM patients exhibited significantly decreased T2* values compared to controls.

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Within HCM patients, those with myocardial fibrosis presented with decreased T2* values.

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T2* provided good diagnostic accuracy to diagnose HCM with fibrosis.

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T2* may add information for identifying a higher risk sub-group of HCM patients.

Purpose

Hypertrophic cardiomyopathy (HCM) is characterized by a heterogeneous morphology and variable prognosis. A mismatch between left ventricular mass (LVM) and microvascular circulation with corresponding relative ischemia has been implicated to cause myocardial replacement fibrosis that deteriorates prognosis. Besides parametric T1 mapping, Cardiovascular Magnetic Resonance (CMR) T2* mapping is able to identify ischemia as well as fibrosis in cardiac and extracardiac diseases. Therefore, we aimed to investigate the value of T2* mapping to characterize structural alterations in patients with HCM.

Methods

CMR was performed on a 1.5 T MR imaging system (Achieva, Philips, Best, Netherlands) using a 5-channel coil in patients with HCM (n = 103, 50.6 ± 16.4 years) and in age- and gender-matched controls (n = 20, 44.8 ± 16.9 years). T2* mapping (1 midventricular short axis slice) was acquired in addition to late gadolinium enhancement (LGE). T2* values were compared between patients with HCM and controls as well as between HCM patients with- and without fibrosis.

Results

HCM patients showed significantly decreased T2* values compared to controls (26.2 ± 4.6 vs. 31.3 ± 4.3 ms, p < 0.001). Especially patients with myocardial fibrosis presented with decreased T2* values in comparison to those without fibrosis (25.2 ± 4.0 vs. 28.7 ± 5.3 ms, p = 0.003). A regression model including maximum wall thickness, LVM and T2* values provided good overall diagnostic accuracy of 80% to diagnose HCM with and without fibrosis.

Conclusion

In this study, parametric mapping identified lower T2* values in HCM patients compared to controls, especially in a sub-group of patients with myocardial fibrosis. As myocardial fibrosis has been suggested to influence prognosis of patients with HCM, T2* mapping may add information for identifying a higher risk sub-group of HCM patients.

Left Ventricular Mass Quantification by Two-Dimensional Echocardiography in a Pediatric Population: Correlation with Cardiac Magnetic Resonance Imaging

Quantification of left ventricular (LV) mass by echocardiography has not been validated against the gold standard of cardiac magnetic resonance imaging (CMR) in the pediatric population. The purpose of this study was to compare LV mass by two-dimensional and conventional M-mode echocardiography versus CMR in children. Consecutive CMR studies were paired with echocardiograms and retrospectively analyzed in children age ≤ 16 years (3 days old to 16 years old). Studies performed > 3 months between modalities and single ventricle anatomy were excluded. Unindexed LV mass was calculated using M-mode, area-length (AL), and truncated ellipsoid (TE) methods via echocardiography, and compared to cine stack CMR images. There were 46 patients included in the study (both MRI and echocardiography). Good correlations were observed for LV mass measured by CMR and all echocardiographic methods: M-mode (R = 0.965), AL (R = 0.975), and TE (R = 0.975). There was a significant overestimation using TE echocardiography, by a mean of 10.5 g (95% confidence interval 5.7-15.2 g, p < 0.05). There was no significant over- or underestimation of LV mass observed by M-mode or AL echocardiographic measurements, with tight limits of agreement when compared to CMR (95% confidence interval - 5.2 to 4.4 g and - 1.5 to 6.7 g, respectively). Interobserver agreement was good for each of the echocardiographic measurements, but inferior with M-mode (ICC, 0.89) compared to two-dimensional methods (ICC, 0.97). Echocardiographic estimates of LV mass have good correlation with CMR in children. Performance comparison showed AL echocardiographic method provides the most accurate measurement of LV mass with the best reproducibility compared to other methods.

Down-regulation of miR-200c attenuates AngII-induced cardiac hypertrophy via targeting the MLCK-mediated pathway

Background

MicroRNAs (miRNAs) have been shown to commonly contribute to cardiac hypertrophy (CH). The aim of this study was to test the hypothesis that miR‐200c plays an important role in the progression of CH by targeting myosin light chain kinase (MLCK/MYLK).

Methods and results

Cardiac hypertrophy was induced by aortic banding (AB) in rats. Cellular hypertrophy in neonatal rat cardiomyocytes (NCMs) was induced by AngII treatment. Echocardiography, histology and molecular measurements were used to assess the results of the experiments. The levels of apoptosis and reactive oxygen species (ROS) were also measured. Quantitative real‐time PCR (qRT‐PCR) and Western blotting were used to measure mRNA and protein levels respectively. The present results showed that miR‐200c expression was increased in response to CH both in vivo and in vitro. The down‐regulation of miRNA‐200c by a specific inhibitor markedly ameliorated CH resulting from AngII treatment, and the mRNA levels of atrial natriuretic peptide, brain natriuretic peptide and β‐myosin heavy chain were simultaneously decreased. Notably, minimal apoptosis and ROS accumulation were identified in AngII‐induced hypertrophic cardiomyocytes. Conversely, the up‐regulation of miR‐200c using specific mimics reversed these effects. Mechanistic investigations demonstrated that the MLCK gene is a direct target of miR‐200c; an increase in miR‐200c levels led to a decrease in the expression of MLCK and its downstream effector, p‐MLC2, while miR‐200c inhibition increased the expression of these proteins. Furthermore, inhibiting MLCK impaired the anti‐hypertrophic effects contributions produced by the knockdown of miR‐200c.

Conclusion

Our studies suggest that miR‐200c may serve as a potential therapeutic target that could delay hypertrophy. We have also uncovered a relationship between miR‐200c and MLCK, identifying MLCK as a direct mediator of miR‐200c.

Cortical Bone Derived Stem Cells for Cardiac Wound Healing

Ischemic heart disease can lead to myocardial infarction (MI), a major cause of morbidity and mortality worldwide. Adoptive transfer of multiple stem cell types into failing human hearts has demonstrated safety however the beneficial effects in patients with cardiovascular disorders have been modest. Modest improvement in patients with cardiac complications warrants identification of a novel stem cell population that possesses effective reparative properties and improves cardiac function after injury. Recently we have shown in a mouse model and a porcine pre-clinical animal model, that cortical bone derived stem cells (CBSCs) enhance cardiac function after MI and/or ischemia-reperfusion injury. These beneficial effects of allogeneic cell delivery appear to be mediated by paracrine mechanisms rather than by transdifferentiation of injected cells into vessels and/or immature myocytes. This review will discuss role of CBSCs in cardiac wound healing. After having modest beneficial improvement in most of the clinical trials, a critical need is to understand the interaction of the transplanted stem cells with the ischemic cardiac environment. Transplanted stem cells are exposed to pro-inflammatory factors and activated immune cells and fibroblasts, but their interactions remain unknown. We have shown that CBSCs modulate different processes including modulation of the immune response, angiogenesis, and restriction of infarct sizes after cardiac injury. This review will provide information on unique protective signature of CBSCs in rodent/swine animal models for heart repair that should provide basis for developing novel therapies for treating heart failure patients.

Yes-associated protein (YAP) mediates adaptive cardiac hypertrophy in response to pressure overload

Cardiovascular disease (CVD) remains the leading cause of death globally, and heart failure is a major component of CVD-related morbidity and mortality. The development of cardiac hypertrophy in response to hemodynamic overload is initially considered to be beneficial; however, this adaptive response is limited and, in the presence of prolonged stress, will transition to heart failure. Yes-associated protein (YAP), the central downstream effector of the Hippo signaling pathway, regulates proliferation and survival in mammalian cells. Our previous work demonstrated that cardiac-specific loss of YAP leads to increased cardiomyocyte (CM) apoptosis and impaired CM hypertrophy during chronic myocardial infarction (MI) in the mouse heart. Because of its documented cardioprotective effects, we sought to determine the importance of YAP in response to acute pressure overload (PO). Our results indicate that endogenous YAP is activated in the heart during acute PO. YAP activation that depended upon RhoA was also observed in CMs subjected to cyclic stretch. To examine the function of endogenous YAP during acute PO, Yap ^{+/ flox};Cre ^α-MHC (YAP-CHKO) and Yap ^{+/ flox} mice were subjected to transverse aortic constriction (TAC). We found that YAP-CHKO mice had attenuated cardiac hypertrophy and significant increases in CM apoptosis and fibrosis that correlated with worsened cardiac function after 1 week of TAC. Loss of CM YAP also impaired activation of the cardioprotective kinase Akt, which may underlie the YAP-CHKO phenotype. Together, these data indicate a prohypertrophic, prosurvival function of endogenous YAP and suggest a critical role for CM YAP in the adaptive response to acute PO.

Computational analysis of the electromechanical performance of mitral valve cerclage annuloplasty using a patient-specific ventricular model

We aimed to propose a novel computational approach to predict the electromechanical performance of pre- and post-mitral valve cerclage annuloplasty (MVCA). Furthermore, we tested a virtual estimation method to optimize the left ventricular basement tightening scheme using a pre-MVCA computer model. The present model combines the three-dimensional (3D) electromechanics of the ventricles with the vascular hemodynamics implemented in a lumped parameter model. 3D models of pre- and post-MVCA were reconstructed from the computed tomography (CT) images of two patients and simulated by solving the electromechanical-governing equations with the finite element method. Computed results indicate that reduction of the dilated heart chambers volume (reverse remodeling) appears to be dependent on ventricular stress distribution. Reduced ventricular stresses in the basement after MVCA treatment were observed in the patients who showed reverse remodeling of heart during follow up over 6 months. In the case who failed to show reverse remodeling after MVCA, more virtual tightening of the ventricular basement diameter than the actual model can induce stress unloading, aiding in heart recovery. The simulation result that virtual tightening of the ventricular basement resulted in a marked increase of myocardial stress unloading provides in silico evidence for a functional impact of MVCA treatment on cardiac mechanics and post-operative heart recovery. This technique contributes to establishing a pre-operative virtual rehearsal procedure before MVCA treatment by using patient-specific cardiac electromechanical modeling of pre-MVCA.

Target organ damage in newly detected hypertensive patients

Background:

Hypertension (HTN) is difficult to diagnose since it is asymptomatic. Most of the patients with HTN are unaware of their disease, and hence a large number of these subjects have target organ damage (TOD) on their first arrival at hospital or clinic. Hence, early detection and treatment of TOD determines the cardiovascular prognosis in hypertensive patient and can retard or prevent further damage.

Methods:

An observational and cross-sectional study was carried out in a tertiary care hospital and clinical profile was collected. Newly detected hypertensive men and women were recruited from outpatient and inpatient departments of medicine based on a set of inclusion and exclusion criteria. The study was carried out over a duration of 18 months from March 2014 to August 2015.

Results:

A total of 150 participants were included in the study with a mean age of 51.64 ± 11.64 years. A total of 91 participants had presence of at least one TOD. In our study, retinopathy (20.67%), macroalbuminuria (MA) (44.67%), electrocardiographic left ventricular hypertrophy (LVH) (20.67%), echocardiographic LVH (29.33%), diastolic dysfunction (21.33%), and systolic dysfunction (3.33%) were particularly notable. Grade 3 retinopathy, microalbuminria, and diastolic dysfunction were associated with severity of HTN.

Conclusion:

We conclude that a strong relationship exists between HTN and TOD. The evidence for TOD was found to be greater than that expected in newly detected hypertensive patients. Hence, a tight control of blood pressure represents the first step in treating essential HTN, which not only keep the blood pressure under control and further steps to be taken to prevent or retard the onset/progression of TOD.

A Fortified Method to Screen and Detect Left Ventricular Hypertrophy in Asymptomatic Hypertensive Adults: A Korean Retrospective, Cross-Sectional Study

Purpose

Left ventricular (LV) mass is determined by the wall thickness and diameter. LV hypertrophy (LVH), the increase in LV mass, is usually screened with electrocardiography but is often insensitive. We tried to fortify the rule to detect LVH using cardiothoracic ratio (CTR) in chest X-ray and well-known risk factors besides electrocardiography.

Materials and Methods

This retrospective cross-sectional study included asymptomatic hypertensive individuals aged ≥40 y who underwent voluntary checkups including echocardiography. Independent variables to explain LVH (LV mass index>115 g/m² for men and >95 g/m² for women calculated on echocardiography) were chosen among Sokolow-Lyon voltage amplitude (SLVA), CTR and cardiovascular risk factors by multiple logistic regression analysis. The diagnostic rule to detect LVH was made by summing up the rounded-off odds ratio of each independent variable and was validated using bootstrapping method.

Results

Among the 789 cases enrolled (202 females (25.6%), mean age 59.6±8.8 y), 168 (21.3%) had LVH. The diagnostic rule summed female, age≥65 y, BMI≥25 kg/m², SLVA≥35 mm, and CTR≥0.50 (scoring 1 per each). Its c-statistics was 0.700 (95% CI: 0.653, 0.747), significantly higher (p<0.001) than that of SLVA≥35 mm, 0.522 (95% CI: 0.472, 0.572). The sensitivity and specificity of the model were 61.9% and 72.1% for score≥2 and 30.4% and 92.9% for score≥3. The SLVA≥35 mm criteria showed sensitivity of 12.5% and specificity of 91.9%.

Conclusions

The rule to sum up the number of the risk factors of female, age≥65 y, BMI≥25 kg/m², SLVA≥35 mm, and CTR≥0.50 may be a better diagnostic tool for screening LVH, than the electrocardiography-only criteria, at the score≥2.