Left ventricular hypertrophy in hypertension

A meta-analysis of the diagnostic value of microRNA for hypertensive left ventricular hypertrophy

In this study, the diagnostic value of microRNAs (miRNAs) for hypertension (HTN) with left ventricular hypertrophy (LVH) were evaluated by meta-analysis. A correlation study of the diagnostic value of miRNAs in HTN with LVH was conducted using a computer search of the China Knowledge Network (CNKI), Wanfang, VIP, China Biomedical Literature Database (CBM), PubMed, Web of Science, and Embase. Studies from the time of database creation to May 2022 were evaluated. The quality assessment of diagnostic accuracy studies-2 (QUADAS-2) tool in RevMan 5.3 was used to evaluate the quality of the literature, and Meta-Disc 1.4 and Stata 16.0, were used to calculate the combined sensitivity (SEN), specificity (SPE), positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic advantage ratio (DOR), and their 95% confidence intervals. Subject working characteristic curves were plotted and the area under the curve (AUC) was calculated using Stata 16.0. Seven publications and 8 studies were included. miRNA diagnoses of HTN with LVH had SEN_combined = 0.84, SPE_combined = 0.80, PLR_combined = 4.2, NLR_combined = 0.20, DOR_combined = 21, and AUC_combined = 0.89. Subgroup analysis showed that the sensitivity of plasma miRNA for the diagnosis of HTN with LVH was 0.85, which was higher than that of serum which was 0.83. The specificity of serum miRNA for the diagnosis of HTN with LVH was 0.82, which was higher than that of plasma which was 0.78, and the diagnostic accuracy of miRNA in serum DOR was 23, which was higher than that of plasma DOR which was 20. In the diagnosis of HTN with LVH, miRNA has high sensitivity and specificity and is a better biological marker.

Estrogen regulates histone deacetylases to prevent cardiac hypertrophy

Angiotensin II stimulation of HDAC2 production, phosphorylation by CK2, and resulting modulation of target genes, which promote cardiac hypertrophy, are opposed by estrogen/ERβ. Angiotensin II also represses class II HDAC4 and 5 production and stimulates their phosphorylation, which expels them from the nucleus, and estrogen prevents this.

The development and progression of cardiac hypertrophy often leads to heart failure and death, and important modulators of hypertrophy include the histone deacetylase proteins (HDACs). Estrogen inhibits cardiac hypertrophy and progression in animal models and humans. We therefore investigated the influence of 17-β-estradiol on the production, localization, and functions of prohypertrophic (class I) and antihypertrophic (class II) HDACs in cultured neonatal rat cardiomyocytes. 17-β-Estradiol or estrogen receptor β agonists dipropylnitrile and β-LGND2 comparably suppressed angiotensin II–induced HDAC2 (class I) production, HDAC-activating phosphorylation, and the resulting prohypertrophic mRNA expression. In contrast, estrogenic compounds derepressed the opposite effects of angiotensin II on the same parameters for HDAC4 and 5 (class II), resulting in retention of these deacetylases in the nucleus to inhibit hypertrophic gene expression. Key aspects were confirmed in vivo from the hearts of wild-type but not estrogen receptor β (ERβ) gene–deleted mice administered angiotensin II and estrogenic compounds. Our results identify a novel dual regulation of cardiomyocyte HDACs, shown here for the antihypertrophic sex steroid acting at ERβ. This mechanism potentially supports using ERβ agonists as HDAC modulators to treat cardiac disease.

Echocardiographic abnormalities in familial dysautonomia

Sudden death accounts for up to 43% of all deaths in patients with familial dysautonomia (FD). The classic features of FD, namely, autonomic dysfunction, high blood pressure, and blood pressure labiality, are all risk factors for cardiac remodeling and hypertrophy. Myocardial remodeling and hypertrophy are independent risk factors for arrhythmias, cardiovascular events, and sudden death. An extensive review of the medical literature found no documentation of structural heart defects or myocardial remodeling in patients with FD. Sixteen patients with FD underwent physical examination, in-clinic blood pressure measurements, and echocardiographic study. On the basis of the findings, the patients were categorized by left ventricular geometric pattern. Twenty-four-hour ambulatory blood pressure monitoring was recommended to all participants. The majority of FD patients were found to have very high blood pressure values both during in-clinic measurements and during ambulatory blood pressure monitoring. Echocardiographic abnormalities were found in 43.75% of the study group; 18.75% of the study group had concentric hypertrophy, among which severe hypertrophy was found in 2 patients. Unknown previously, cardiac remodeling or hypertrophy is common in FD. We recommend that routine cardiac echocardiography be performed in this population, and attempts to treat high blood pressure should begin earlier in life.

Estrogen inhibits cardiac hypertrophy: role of estrogen receptor-beta to inhibit calcineurin

Estrogen has been reported to prevent development of cardiac hypertrophy in female rodent models and in humans. However, the mechanisms of sex steroid action are incompletely understood. We determined the cellular effects by which 17beta-estradiol (E2) inhibits angiotensin II (AngII)-induced cardiac hypertrophy in vivo. Two weeks of angiotensin infusion in female mice resulted in marked hypertrophy of the left ventricle, exacerbated by the loss of ovarian steroid hormones from oophorectomy. Hypertrophy was 51% reversed by the administration of E2 (insertion of 0.1 mg/21-d-release tablets). The effects of E2 were mainly mediated by the estrogen receptor (ER) beta-isoform, because E2 had little effect in ERbeta-null mice but comparably inhibited AngII-induced hypertrophy in wild-type or ERalpha-null mice. AngII induced a switch of myosin heavy chain production from alpha to beta, but this was inhibited by E2 via ERbeta. AngII-induced ERK activation was also inhibited by E2 through the beta-receptor. E2 stimulated brain natriuretic peptide protein expression and substantially prevented ventricular interstitial cardiac fibrosis (collagen deposition) as induced by AngII. Importantly, E2 inhibited calcineurin activity that was stimulated by AngII, related to E2 stimulating the modulatory calcineurin-interacting protein (MCIP) 1 gene and protein expression. E2 acting mainly through ERbeta mitigates the important signaling by AngII that produces cardiac hypertrophy and fibrosis in female mice.

Impact of somatostatin analogs on the heart in acromegaly: a metaanalysis

CONTEXT

Acromegaly can be complicated by cardiomyopathy. Treatment with somatostatin analogs has been shown to improve some cardiac parameters, but most published clinical trials involved few patients and were not randomized or controlled. In addition, their results are rather variable.

OBJECTIVE

The objective of the study was to conduct a metaanalysis aimed at obtaining a more accurate picture of the effect of somatostatin analogs on the heart in patients with acromegaly.

DESIGN

We systematically reviewed all studies of somatostatin analogs in acromegaly. Eighteen studies were identified in three databases. We conducted a combined analysis of the effects of somatostatin analogs by using the overall effect size to evaluate significance and by computing the weighted mean differences with and without treatment to assess the effect size.

RESULTS

Somatostatin analog treatment was associated with significant reductions in the heart rate [-5.8 (2.1) beats/min], the left ventricular mass index [-22.3 (6.7) g/m(2)], interventricular septum thickness [-0.3 (0.2) mm], left ventricular posterior wall thickness [-0.8 (0.4) mm], and the ratio of the E-wave and A-wave peak velocities of the mitral flow profile [0.2 (0.1)]. It was also associated with improved exercise tolerance [1.6 (0.4) min]. Trends toward beneficial effects were noted for the left ventricular end-diastolic dimension [-1.5 (2.2) mm] and the left ventricular ejection fraction [3.3% (1.7%)]. Overall effect sizes were not significant for blood pressure, left ventricular end-systolic dimension, or fractional shortening. Bigger improvements were observed in studies with larger falls in IGF-I and/or GH levels and studies of younger patients.

CONCLUSION

This metaanalysis confirms that somatostatin analog therapy aimed at achieving stringent control of serum GH/IGF-I concentrations in patients with acromegaly is associated with significant positive effects on morphological and functional hemodynamic parameters.

Estrogen inhibits cardiomyocyte hypertrophy in vitro. Antagonism of calcineurin-related hypertrophy through induction of MCIP1

Evidence from in vivo studies suggests that some inputs to cardiac hypertrophy are opposed by the actions of estrogen. However, the mechanisms of E2 action in this respect are mainly unknown. An important pathway that is utilized by multiple hypertrophic stimuli involves the activation of the tyrosine phosphatase, calcineurin (PP2B). Here we show that 17beta-estradiol (E2) significantly prevents angiotensin II (AngII)- or endothelin-1 (ET-1)-induced new protein synthesis, skeletal muscle actin expression, and increased surface area in cultured rat cardiomyocytes. ET-1 stimulated calcineurin phosphatase activity, resulting in new protein synthesis, and both were prevented by E2. E2 induced the MCIP1 gene, an inhibitor of calcineurin activity, via phosphatidylinositol 3-kinase, transcriptional, and mRNA stability mechanisms. Small interfering RNA for MCIP1 significantly reversed both the E2 restraint of protein synthesis and the inhibition of AngII-induced calcineurin activity. AngII-induced the translocation of the hypertrophic transcription factor, NF-AT, to the nucleus of the cardiomyocyte and stimulated NF-AT transcriptional activity. Both were prevented by E2. AngII also stimulated the activation of ERK and protein kinase C, contributing to cardiac hypertrophy. E2 inhibited these pathways, related to the stimulation of atrial natriuretic peptide production and secretion. Thus, restraint of calcineurin and kinase signaling to the hypertrophic program underlie these important effects of E2.

Left ventricular hypertrophy and endothelial functions in patients with essential hypertension

OBJECTIVE

In this study, we used a non-invasive method in patients with essential hypertension and without any overt clinical evidence of atherosclerosis to investigate the role of left ventricular hypertrophy (LVH) in endothelial functions.

METHODS

We assessed endothelial function in 32 hypertensive patients with LVH (group 1), 28 hypertensive patients without LVH (group 2) and 29 normotensive subjects (control group). Flow-mediated (endothelium-dependent) and nitrate induced (endothelium-independent) dilatation of the brachial artery was evaluated in all groups.

RESULTS

Flow-mediated dilatation was considerably higher in the control group than in group 1 and 2 (13.98 +/- 2.92%, 4.67 +/- 1.09% and 7.02 +/- 1.79% respectively, p < 0.001). In addition, endothelium-dependent dilatation was significantly lower in group 1 than in group 2 (p < 0.001), whereas nitrate induced changes were similar in all groups.

CONCLUSION

Vascular endothelial functions are impaired in hypertensive patients. There may be heterogeneity of endothelial dysfunction among patients with hypertension. Presence of LVH has an additional negative effect on endothelial function in hypertensive patients.

Comparative Effects of Irbesartan Versus Amlodipine on Left Ventricular Mass Index in Hypertensive Patients with Left Ventricular Hypertrophy

The aim of this study was to comparatively assess the effects of irbesartan and amlodipine monotherapies on left ventricular mass index (LVMI) in patients with mild to moderate untreated hypertension and echocardiographically determined left ventricular hypertrophy (LVH). Sixty hypertensive patients (35 men, 25 women; mean age, 52.8 years +/- 12.6) with diastolic blood pressure (BP) > or = 100 mm Hg were randomized to irbesartan 150 mg once daily or amlodipine 5 mg once daily for a 4-week titration period. Dosage of both drugs was increased to irbesartan 300 mg once daily or amlodipine 10 mg once daily in case of sitting diastolic BP still >90 mm Hg after the first 2 weeks of treatment. Dosage doubling was necessary in more than 50% of patients in both treatment groups. After the titration period, only the responders (sitting diastolic BP < or = 90 mm Hg) entered a 5-month maintenance period. After 3 months, echocardiographically estimated LVMI decreased by 23.2% in the irbesartan-treated patients and 11.4% in the amlodipine-treated patients, with an adjusted mean difference of 11.8% in favor of irbesartan (P < 0.0001). After 6 months, it decreased by 24.7% in the irbesartan-treated patients and 13.0% in the amlodipine-treated patients, with an adjusted mean difference of 11.6% in favor of irbesartan (P < 0.0001).

Survival and trends of occurrence of left ventricular hypertrophy, gender differences, 1967-92: The Reykjavik Study

OBJECTIVE

We estimated the prevalence, incidence and risk factors of left ventricular hypertrophy (LVH) in a prospective cohort study of 26 489 participants.

MATERIAL AND METHODS

The LVH was defined as Minnesota Code 310 on electrocardiogram (ECG). Everyone with this code at first visit was defined as a prevalence case and those who developed it between subsequent visits were incidence cases. The comparison cohort were all other participants in the Reykjavik Study stages I-V.

RESULTS

A total of 297 men and 49 women were found to have LVH of 3.2% and 0.5%, respectively. The incidence was 25 per 1000 per year amongst men and six per 1000 per year amongst women. Prevalence in both genders increased with increasing age. Risk factors at the time of diagnosis were systolic blood pressure [odds ratio (OR) per mmHg 1.02; 95% confidence interval (CI): 1.01-1.03], age (OR per year 1.04; 95% CI: 1.02-1.05), silent myocardial infarction (MI) (OR 3.18; 95% CI: 1.39-7.27) and ST-T changes (OR 3.06; 95% CI: 2.14-4.38) amongst men and systolic blood pressure and age for women with similar odds ratio. Predictive factors for acquiring LVH were systolic blood pressure [incidence ratio (IR) 1.01; 95% CI: 1.01-1.02] and angina with ECG changes (IR 2.33; 95% CI: 1.08-5.02) amongst men and systolic blood pressure amongst women (IR 1.03; 95% CI: 1.01-1.04). The risk for coronary mortality was significantly increased amongst women with hypertrophy [hazard ratio (HR) 3.07; 95% CI: 1.5-6.31] and their total survival was poorer with increasing time from diagnosis of LVH (HR 2.17; 95% CI: 1.36-3.48).

CONCLUSIONS

We conclude that the presence of LVH and its appearance is associated with age and increased blood pressure amongst both genders. Women with LVH have poorer survival than other women and they are at threefold risk of dying of ischaemic heart disease.

Left ventricular midwall function improves with antihypertensive therapy and regression of left ventricular hypertrophy in patients with asymptomatic hypertension

Recent evidence suggests that regression of left ventricular hypertrophy (LVH) with antihypertensive therapy improves prognosis. The mechanism for this benefit is unknown but may be related to effects on myocardial performance. Midwall fractional shortening (mFS) is often depressed in patients with asymptomatic hypertension, is associated with LVH, and is a potent, independent predictor of outcome. We therefore examined whether antihypertensive therapy may improve midwall performance. mFS as well as conventional echocardiographic parameters were measured serially among 29 hypertensive persons during 6 months of drug therapy. Stress-adjusted and absolute midwall function improved by 10% and 11%, respectively (p <0.05), whereas no significant changes were detected in other measures of chamber function. Improvement in function was more pronounced in patients with concentrically remodeled ventricular geometry and in those who achieved greater reductions in left ventricular (LV) mass. Antihypertensive therapy and LV mass regression is associated with demonstrable improvements in cardiac performance when assessed using mFS. Determinations of mFS may have a promising role in identifying patients with early hypertensive heart disease, tracking responses to therapy, and in elucidating the potential beneficial effects associated with LV mass regression.

Differential effects of 17beta-estradiol on mitogen-activated protein kinase pathways in rat cardiomyocytes

Cardiac myocytes contain functional estrogen receptors, however, the effect of estrogen on growth-related signaling pathways such as mitogen-activated protein kinases (MAPK) in the pathogenesis of cardiac disease is unclear. MAPKs are critically involved in regulatory signaling pathways which ultimately lead to cardiac hypertrophy. Here we show that 17beta-estradiol (E2) activates extracellular signal-regulated kinase (ERK1/2), c-Jun-NH2-terminal protein kinase (JNK) and p38 in rat cardiomyocytes in a distinctive pattern. As shown by immunoblot analysis and phosphorylation assays, E2 (10(-9) M) induced a rapid and transient activation of ERK1/2 and a rapid but sustained increase of JNK phosphorylation. In contrast, E2 had only a marginal effect on p38 activation. Furthermore, MAPK phosphatase expression was induced by E2 and E2-stimulated expression of endothelial and inducible NO synthase was inhibited by PD 98059, an inhibitor of the ERK pathway. These novel observations may help to explain the role of estrogen in gender-based differences found in cardiac disease.