The renin-angiotensin system and right ventricular structure and function: The MESA-Right Ventricle Study

Prognostic Role of Multiparametric Cardiac Magnetic Resonance in Neo Transfusion-Dependent Thalassemia

BACKGROUND

We prospectively evaluated the predictive value of multiparametric cardiac magnetic resonance (CMR) for cardiovascular complications in non-transfusion-dependent β-thalassemia (β-NTDT) patients who started regular transfusions in late childhood/adulthood (neo β-TDT).

METHODS

We considered 180 patients (38.25 ± 11.24 years; 106 females). CMR was used to quantify cardiac iron overload, biventricular function, and atrial dimensions, and to detect left ventricular (LV) replacement fibrosis.

RESULTS

During a mean follow-up of 76.87 ± 41.60 months, 18 (10.0%) cardiovascular events were recorded: 2 heart failures, 13 arrhythmias (10 supraventricular), and 3 cases of pulmonary hypertension. Right ventricular (RV) end-diastolic volume index (EDVI), RV mass index (MI), LV replacement fibrosis, and right atrial (RA) area index emerged as significant univariate prognosticators of cardiovascular complications. The low number of events prevented us from performing a multivariable analysis including all univariable predictors simultaneously. Firstly, a multivariable analysis including the two RV size parameters (mass and volume) was carried out, and only the RV MI was proven to independently predict cardiovascular diseases. Then, a multivariable analysis, including RV MI, RA atrial area, and LV replacement fibrosis, was conducted. In this model, RV MI and LV replacement fibrosis emerged as independent predictors of cardiovascular outcomes (RV MI: hazard ratio (HR) = 1.18; LV replacement fibrosis: HR = 6.26).

CONCLUSIONS

Our results highlight the importance of CMR in cardiovascular risk stratification.

Identifying risk factors for perioperative decline in right ventricular performance in cardiac surgery patients: a prospective observational study in a tertiary care hospital

OBJECTIVES

Impaired right ventricular (RV) function after cardiac surgery is associated with morbidity and long-term mortality. The purpose of this study was to identify factors that play a role in the development of RV dysfunction in the perioperative cardiac surgery setting.

DESIGN

We performed a prospective, observational, single centre study. Over a 2-year period, baseline and perioperative characteristics were recorded. For analysis, subjects were divided into three groups: patients with a ≥3% absolute increase in postoperative RV ejection fraction (RVEF) in comparison to baseline (RVEF+), patients with a ≥3% absolute decrease in RVEF (RVEF-) and patients with a <3% absolute change in RVEF (RVEF=).

SETTING

Tertiary care hospital in the Netherlands.

PARTICIPANTS

We included all cardiac surgery patients ≥18 years of age equipped with a pulmonary artery catheter and admitted to the ICU in 2015-2016. There were no exclusion criteria. A total number of 267 patients were included (65.5% men).

OUTCOME MEASURES

Risk factors for a perioperative decline in RV function.

RESULTS

A reduction in RVEF was observed in 40% of patients. In multivariate analysis, patients with RVEF- were compared with patients with RVEF= (first-mentioned OR) and RVEF+ (second-mentioned OR). Preoperative use of calcium channel blocker (CCB) (OR 3.06, 95% CI 1.24 to 7.54/OR 2.73, 95% CI 1.21 to 6.16 (both p=0.015)), intraoperative fluid balance (FB) (OR 1.45, 95% CI 1.02 to 2.06 (p=0.039)/OR 1.09, 95% CI 0.80 to 1.49 (p=0.575)) and baseline RVEF (OR 1.22; 95% CI 1.14 to 1.30/OR 1.27, 95% CI 1.19 to 1.35 (both p<0.001)) were identified as independent risk factors for a decline in RVEF during surgery.

CONCLUSION

Apart from the impact of the perioperative FB, preoperative use of a CCB as a risk factor for perioperative reduction in RVEF is the most prominent new finding of this study.

Right Ventricle in Arterial Hypertension: Did We Forget Something?

Right ventricular remodeling has been neglected in patients with arterial hypertension as all studies have concentrated on the left ventricle and left atrial-ventricular and ventricular-arterial coupling. The development of novel imaging techniques has revealed significant impairment in the RV structure, systolic and diastolic function, and, afterwards, RV longitudinal mechanics. However, these changes are subclinical and can be detected only after comprehensive imaging analysis. The latest findings confirm the importance of RV hypertrophy, systolic, and diastolic dysfunction in the prediction of cardiovascular adverse events in the hypertensive population, representing an important clinical implication of these parameters. In clinical practice, 2D echocardiography is widely used for the evaluation of RV remodeling. However, existing techniques are largely underused and limited to a few basic parameters (RV thickness and TAPSE), which are not nearly enough for a detailed assessment of RV remodeling. In addition, 3D echocardiography provides the possibility of accurate evaluation of RV volumes and ejection fraction, which are comparable with results obtained by cardiac magnetic resonance (CMR)-a gold standard for the evaluation of the RV. The use of 3D echocardiography is limited due to its low availability, the lack of adequate software necessary for the calculation of results, and the necessity for a higher level of expertise. CMR provides all information required for a detailed assessment of RV structural, functional, and mechanical remodeling, and it is considered the reference method for this type of evaluation. Furthermore, it is the only technique that may provide tissue characterization and evaluation of the interstitial space, which is essential for hypertensive heart disease. The aim of this review is to provide the current level of evidence regarding RV remodeling in patients with arterial hypertension evaluated with different imaging techniques and various parameters from each method.

The prognostic importance of right ventricular remodeling and the circadian blood pressure pattern on the long-term cardiovascular outcome

OBJECTIVE

We sought to investigate the predictive value of right ventricular (RV) remodeling and 24-h blood pressure (BP) patterns on long-term cardiovascular prognosis in the initially untreated hypertensive patients.

METHODS

The current study included 505 initially untreated hypertensive patients who were consequently included in this study from 2007 to 2012. All the patients underwent laboratory analysis, 24-h BP monitoring and echocardiographic examination at baseline. The patients were followed for a median period of 9 years. The adverse outcome was defined as the hospitalization due to cardiovascular events (atrial fibrillation, myocardial infarction, myocardial revascularization, heart failure, stroke, or cardiovascular death).

RESULTS

During the 9-year follow-up period adverse cardiovascular events occurred in 82 hypertensive patients. Night-time SBP, the nondipping BP pattern, left ventricle hypertrophy, RV hypertrophy, right atrial enlargement, RV diastolic dysfunction, and RV systolic dysfunction were associated with adverse cardiovascular events. Nevertheless, night-time SBP, the nondipping BP pattern, mitral E/e', left ventricle hypertrophy, and RV hypertrophy were the only independent predictors of cardiovascular events. When all four BP patterns were included in the model, only the reverse dipping BP pattern was an independent predictor of cardiovascular events.

CONCLUSION

The present investigation showed that RV hypertrophy and the reverse dipping BP pattern were independent long-term predictors of the cardiovascular outcome. Detailed echocardiographic evaluation and 24-h ambulatory blood pressure monitoring should be performed even in low-risk hypertensive patients.

The prognostic value of 2D strain in assessment of the right ventricle in patients with dilated cardiomyopathy

AIMS

Several studies have been reported using right ventricular (RV) strain as a method for evaluating RV function in patients with various cardiovascular diseases; however, the clinical relevance of RV strain in dilated cardiomyopathy (DCM) patients with sinus rhythm is unknown. The aim of this study was to investigate the relationship between RV strain and adverse events in DCM patients with sinus rhythm.

METHODS AND RESULTS

We enrolled 143 DCM patients with sinus rhythm who had been first diagnosed, evaluated, and followed at Sanggye Paik Hospital between March 2013 and August 2017. We performed echocardiography and measured RV strain values using the apical four-chamber view. The mean age was 64.6 years. During the median follow-up period of 40.0 months, adverse cardiovascular events developed in 21 patients (14.7%). By Cox proportional hazards multivariate analysis, only RV free wall longitudinal strain (RV-FWLS) independently predicted the primary outcome. Receiver-operating characteristic curve analysis showed that the optimal RV-FWLS cut-off value to identify patients with an event was -16.5% (area under the curve = 0.703, P = 0.003). When we divided the subjects into two groups based on the RV-FWLS of -16.5%, patients with RV-FWLS <-16.5% showed more favourable clinical outcomes than that in those with RV-FWLS ≥-16.5% (log-rank test, P < 0.001).

CONCLUSION

RV-FWLS was associated with a significant prognostic impact in DCM patients with sinus rhythm.

Diastolic function of the left and right ventricles of the heart in outpatients with arterial hypertension

AIM

The aim of the study is to investigate the impairment of diastolic function of the left ventricle (LV) and the right ventricle (RV) in arterial hypertension outpatients.

MATERIALS AND METHODS

Arterial hypertension patients (n = 299) and practically healthy people (n = 62) were examined on an outpatient basis. Echocardiographically, diastolic dysfunctions of both ventricles were evaluated.

RESULTS

All the arterial hypertension patients had a pattern of diastolic dysfunction (DD) of the RV of different grades (grade I RVDD and grade II RVDD), regardless of the presence or absence of pulmonary arterial hypertension. Patterns of grade I LVDD and grade I RVDD were detected in 84 patients. Patterns of grade I LVDD and grade II RVDD were detected in 77 patients. Patterns of grade II LVDD and grade II RVDD were detected in 41 patients. A pattern of grade II RVDD with normal left ventricular diastolic function was detected in 97 patients with a short duration of disease (3.92 ± 0.48 years) vs the other groups with more than 15 years of hypertension. One hundred and seventy-five arterial hypertension patients had grade I or II LVDD only in 18.3% of cases according to the recommendations of the American and European societies of echocardiographers (2016).

CONCLUSION

The patients with a short period of hypertensive disease have only the pseudonormal pattern of RVDD, which can be an early diagnostic marker of heart failure. Echocardiographic diagnosis of diastolic function made according to various criteria can both increase the number of chronic heart failure patients and significantly decrease it.

Tsantan Sumtang attenuated chronic hypoxia-induced right ventricular structure remodeling and fibrosis by equilibrating local ACE-AngII-AT1R/ACE2-Ang1-7-Mas axis in rat

ETHNOPHARMACOLOGICAL RELEVANCE

Tsantan Sumtang, which consists of Choerospondias axillaris (Roxb.) Burtt et Hill, Myristica fragrans Houtt and Santalum album L, is a traditional and common prescription of Tibetan medicine. Tsantan Sumtang originates from Four Tantra with properties of nourishing heart and has been used as a folk medicine for cardiovascular diseases and heart failure in Qinghai, Tibet and Inner Mongolia. Our previous studies found that Tsantan Sumtang showed beneficial effects on right ventricular structure in hypoxia rats, while the underling mechanism remains unclear.

AIM OF THE STUDY

To elucidate the underlying mechanisms of Tsantan Sumtang attenuated right ventricular (RV) remodeling and fibrosis of chronic hypoxia-induced pulmonary arterial hypertension (HPAH) rats.

MATERIALS AND METHODS

Fifty male Sprague Dawley (SD) rats (170 ± 20 g) were randomly divided into control group, hypoxia group, and hypoxia + Tsantan Sumtang groups (1.0 g· kg^-1·day^-1, 1.25 g· kg^-1·day^-1, 1.5 g ·kg^-1·day^-1). Rats in the hypoxia group and hypoxia + Tsantan Sumtang groups were maintained in a hypobaric chamber by adjusting the inner pressure and oxygen content to simulate an altitude of 4500 m for 28 days. The mean pulmonary arterial pressure (mPAP), right ventricle hypertrophy index (RVHI), the ratio of RV weight to tibia length (TL) (RV/TL), heart rate (HR) and RV systolic pressure (RVSP) was determined. Histomorphological assay of RV structure was evaluated by hematoxylin and eosin (HE) staining. RV tissue fibrosis was assessed by collagen proportion area (CPA), collagen I, collagen III and hydroxyproline content. CPA was obtained by picro-sirius red staining (PSR). The expression of collagen I and collagen III were detected by immunohistochemistry and western blotting. The hydroxyproline content was detected by alkaline hydrolysis. In addition, the level of angiotensin II (AngII) and angiotensin 1-7 (Ang1-7) in RV tissue was tested by enzyme-linked immune sorbent assay (ELISA). Protein expression of angiotensin-converting enzyme (ACE), AngII, AngII type 1 receptor (AT1R), angiotensin-converting enzyme 2 (ACE2), Mas receptor (Mas) were determined by immunohistochemistry and western blotting. mRNA level of ACE, AT1R, ACE2, Mas were tested by qPCR. The chemical profile of Tsantan Sumtang was revealed by UHPLC-Q-Exactive hybrid quadrupole-orbitrap mass analysis.

RESULTS

Our results showed that RVHI, RV/TL and RVSP were significantly increased in HPAH rat. Furthermore, levels of collagen I, collagen III and hydroxyproline were up-regulated in RV tissue under hypoxia. We found that RV hypertrophy and fibrosis were associated with increased expression of ACE, AngII, AT1R as well as decreased expression of ACE2, Ang1-7 and Mas. RV remodeling and fibrosis were attenuated after Tsantan Sumtang administration by up-regulating ACE2 and Mas level as well as down-regulating ACE, AngII and AT1R levels in RV tissue. 35 constituents in Tsantan Sumtang were identified.

CONCLUSION

Tsantan Sumtang attenuated RV remodeling and fibrosis in rat exposed to chronic hypoxia. The pharmacological effect of Tsantan Sumtang was based on equilibrating ACE-AngII-AT1R and ACE2-Ang1-7-Mas axis of RV tissue in HPAH rat.

Treatment of Pulmonary Hypertension With Angiotensin II Receptor Blocker and Neprilysin Inhibitor Sacubitril/Valsartan

BACKGROUND

Angiotensin II has been implicated in maladaptive right ventricular (RV) hypertrophy and fibrosis associated with pulmonary hypertension (PH). Natriuretic peptides decrease RV afterload by promoting pulmonary vasodilation and inhibiting vascular remodeling but are degraded by neprilysin. We hypothesized that angiotensin receptor blocker and neprilysin inhibitor, sacubitril/valsartan (Sac/Val, LCZ696), will attenuate PH and improve RV function by targeting both pulmonary vascular and RV remodeling.

METHODS

PH was induced in rats using the SU5416/hypoxia model (Su/Hx), followed by 6-week treatment with placebo, Sac/Val, or Val alone. There were 4 groups: CON-normoxic animals with placebo (n=18); PH-Su/Hx rats+placebo (n=34); PH+Sac/Val (N=24); and PH+Val (n=16).

RESULTS

In animals with PH, treatment with Sac/Val but not Val resulted in significant reduction in RV pressure (mm Hg: PH: 62±4, PH+Sac/Val: 46±5), hypertrophy (RV/LV+S: PH: 0.74±0.06, PH+Sac/Val: 0.46±0.06), collagen content (µg/50 µg protein: PH: 8.2±0.3, PH+Sac/Val: 6.4±0.4), pressures and improvement in RVs (mm/s: PH: 31.2±1.8, PH+Sac/Val: 43.1±3.6) compared with placebo. This was associated with reduced pulmonary vascular wall thickness, increased lung levels of ANP (atrial natriuretic peptide), BNP (brain-type natriuretic peptide), and cGMP, and decreased plasma endothelin-1 compared with PH alone. Also, PH+Sac/Val animals had altered expression of PKC isozymes in RV tissue compared with PH alone.

CONCLUSIONS

Sac/Val reduces pulmonary pressures, vascular remodeling, as well as RV hypertrophy in a rat model of PH and may be appropriate for treatment of pulmonary hypertension and RV dysfunction.

Right Ventricular Structure and Function Are Associated With Incident Atrial Fibrillation: MESA-RV Study (Multi-Ethnic Study of Atherosclerosis-Right Ventricle)

BACKGROUND

Right ventricular (RV) morphology has been associated with drivers of atrial fibrillation (AF) risk, including left ventricular and pulmonary pathology, systemic inflammation, and neurohormonal activation. The aim of this study was to investigate the association between RV morphology and risk of incident AF.

METHODS AND RESULTS

We interpreted cardiac magnetic resonance imaging in 4204 participants free of clinical cardiovascular disease in the MESA (Multi-Ethnic Study of Atherosclerosis). Incident AF was determined using hospital discharge records, study electrocardiograms, and Medicare claims data. The study sample (n=3819) was 61±10 years old and 47% male with 47.2% current/former smokers. After adjustment for demographics and clinical factors, including incident heart failure, higher RV ejection fraction (hazard ratio, 1.16 per SD; 95% confidence interval, 1.03-1.32; P=0.02) and greater RV mass (hazard ratio, 1.25 per SD; 95% confidence interval, 1.08-1.44; P=0.002) were significantly associated with incident AF. After additional adjustment for the respective left ventricular parameter, higher RV ejection fraction remained significantly associated with incident AF (hazard ratio, 1.15 per SD; 95% confidence interval, 1.01-1.32; P=0.04), whereas the association was attenuated for RV mass (hazard ratio, 1.16 per SD; 95% confidence interval, 0.99-1.35; P=0.07). In a subset of patients with available spirometry (n=2540), higher RV ejection fraction and mass remained significantly associated with incident AF after additional adjustment for lung function (P=0.02 for both).

CONCLUSIONS

Higher RV ejection fraction and greater RV mass were associated with an increased risk of AF in a multiethnic population free of clinical cardiovascular disease at baseline.

Update on novel targets and potential treatment avenues in pulmonary hypertension

Pulmonary hypertension (PH) is a condition marked by a combination of constriction and remodeling within the pulmonary vasculature. It remains a disease without a cure, as current treatments were developed with a focus on vasodilatory properties but do not reverse the remodeling component. Numerous recent advances have been made in the understanding of cellular processes that drive pathologic remodeling in each layer of the vessel wall as well as the accompanying maladaptive changes in the right ventricle. In particular, the past few years have yielded much improved insight into the pathways that contribute to altered metabolism, mitochondrial function, and reactive oxygen species signaling and how these pathways promote the proproliferative, promigratory, and antiapoptotic phenotype of the vasculature during PH. Additionally, there have been significant advances in numerous other pathways linked to PH pathogenesis, such as sex hormones and perivascular inflammation. Novel insights into cellular pathology have suggested new avenues for the development of both biomarkers and therapies that will hopefully bring us closer to the elusive goal: a therapy leading to reversal of disease.

The influence of type 2 diabetes and arterial hypertension on right ventricular layer-specific mechanics

AIMS

The aim of the investigation was to evaluate layer-specific right ventricular (RV) deformation in normotensive and hypertensive subjects with type 2 diabetes mellitus (DM).

METHODS

This cross-sectional study included 129 subjects (40 controls, 42 normotensive DM and 47 hypertensive DM patients) who underwent complete two-dimensional echocardiographic examination (2DE) including multilayer strain analysis.

RESULTS

2DE RV global and free wall longitudinal strains were reduced in normotensive and hypertensive DM subjects than in controls. RV global longitudinal layer-specific strains (endo-, mid- and epicardial) were lower in normotensive and hypertensive DM patients than in controls. On the other side, layer-specific strains of RV free wall were lower in hypertensive DM patients than in controls, without significant difference between controls and normotensive DM subjects. Parameters of DM control (fasting glucose and glycosylated hemoglobin) were associated with 2DE RV global longitudinal endo- and mid-myocardial layer strain.

CONCLUSIONS

Diabetes and hypertension significantly influence RV mechanics assessed by 2DE conventional and 2DE multilayer strain. Hypertension has an additive unfavorable influence on RV deformation in diabetic patients. Laboratory parameters of diabetic control were associated with RV structure, diastolic function and mechanics assessed with complex 2DE strain analysis.

Relationship between right ventricular remodeling and heart rate variability in arterial hypertension

OBJECTIVE

We aimed at evaluating right ventricular remodeling (structure, function, and mechanics) and heart rate variability (HRV), as well as their interaction, in untreated hypertensive patients.

METHOD

This cross-sectional study involved 55 untreated hypertensive patients and 40 patients with no risk factors, similar by sex and age. All the patients underwent a 24-h Holter monitoring and comprehensive two-dimensional and three-dimensional echocardiography assessment (2DE and 3DE).

RESULTS

All time and frequency domain HRV variables were reduced in the hypertensive patients. Right ventricular systolic and diastolic function, as well as right ventricular longitudinal strain, was significantly impaired in the hypertensive patients. Parameters that indicate comprehensive right ventricular remodeling (right ventricular wall thickness, tricuspid E/e' ratio, 2DE right ventricular longitudinal strain, and 3D right ventricular ejection fraction) correlated with the parameters of cardiac sympathovagal balance (SD of all normal RR intervals, root mean square of the difference between the coupling intervals of adjacent RR intervals, 24-h low-frequency domain, 24-h high-frequency domain, and 24-h total power). Of note, right ventricular diastolic function, right ventricular longitudinal function, and 3DE right ventricular ejection fraction were associated with cardiac autonomic nervous function, independently of age, BMI, blood pressure, and left ventricular hypertrophy.

CONCLUSIONS

Right ventricular structure, systolic and diastolic function, as well as right ventricular longitudinal deformation, are significantly impaired in untreated hypertensive patients. HRV variables are also decreased in hypertensive population. 2DE and 3DE parameters resembling right ventricular remodeling are independently associated with cardiac autonomic nervous system markers in the whole study population.

The renin-angiotensin-aldosterone-system and right heart failure in congenital heart disease

Adults with congenital heart disease represent a rapidly growing patient group. Dysfunction of the right ventricle is often present, and right heart failure constitutes the main cause of death. Heart failure therapies used in acquired left heart failure are often initiated in adults with right heart failure due to congenital heart disease, but the right ventricle differs substantially from the left ventricle, and the clinical evidence for this treatment strategy is lacking.

In this review, we identified existing clinical studies evaluating the effects of ACE inhibitors, angiotensin II receptor blockers and aldosterone antagonists in adults with congenital heart disease by a systematic literature search. From 13 identified studies no clear evidence of beneficial effects was found, but the design of the studies limits the validity of the results. The studies in general include low numbers of patients, have short follow-up periods and evaluate surrogate endpoints instead of hard clinical endpoints. Specific evaluation of symptomatic patients with a systemic right ventricle indicates that these patients may benefit from RAAS inhibitory treatments, but this requires further investigation.

To conclude, existing studies do not support the use of RAAS inhibitory treatments in right heart failure due to congenital heart disease but contain important limitations. Hence, there is a need for new well-designed trials including higher numbers of patients and validated endpoints to optimize and guide future treatment of this patient group.

Higher Plasma Myostatin Levels in Cor Pulmonale Secondary to Chronic Obstructive Pulmonary Disease

Objective

To analyze plasma myostatin levels and investigate their relationship with right ventricular (RV) function in patients with cor pulmonale secondary to chronic obstructive pulmonary disease (COPD).

Methods

The study recruited 81 patients with advanced COPD and 40 age-matched controls. The patients were divided into two groups: those with cor pulmonale and those without. Echocardiography was used to evaluate RV function and morphology, and the value of tricuspid annular plane systolic excursion (TAPSE) less than 16 mm was considered RV dysfunction. Plasma myostatin levels were analyzed by enzyme-linked immunosorbent assay, and B-type natriuretic peptide (BNP) levels were analyzed as a comparison of myostatin.

Results

The data detected cor pulmonale in 39/81 patients, with the mean value of TAPSE of 14.3 mm. Plasma myostatin levels (ng/mL) were significantly higher in patients with cor pulmonale (16.68 ± 2.95) than in those without (13.56 ± 3.09), and much higher than in controls (8.79±2.79), with each p<0.01. Significant differences were also found in plasma BNP levels among the three groups (p<0.05). Multivariate regression analysis suggested that myostatin levels were significantly correlated with the values of TAPSE and RV myocardium performance index among the COPD patients, and that BNP levels were significantly correlated only with systolic pulmonary arterial pressure, with each p<0.05.

Conclusions

Plasma myostatin levels are increased in COPD patients who have cor pulmonale. Stronger correlations of plasma myostatin levels with echocardiographic indexes of the right heart suggest that myostatin might be superior to BNP in the early diagnosis of cor pulmonale in COPD.

PKC δ and βII regulate angiotensin II-mediated fibrosis through p38: a mechanism of RV fibrosis in pulmonary hypertension

Pulmonary hypertension (PH) eventually leads to right ventricular (RV) fibrosis and dysfunction that is associated with increased morbidity and mortality. Although angiotensin II plays an important role in RV remodeling associated with hypoxic PH, the molecular mechanisms underlying RV fibrosis in PH largely remain unresolved. We hypothesized that PKC-p38 signaling is involved in RV collagen accumulation in PH and in response to angiotensin II stimulation. Adult male Sprague-Dawley rats were exposed to 3 wk of normoxia or hypoxia (10% FiO2 ) as a model of PH. Hypoxic rats developed RV hypertrophy and fibrosis associated with an increase in PKC βII and δ protein expression and p38 dephosphorylation in freshly isolated RV cardiac fibroblasts. Further mechanistic studies were performed in cultured primary cardiac fibroblasts stimulated with angiotensin II, a key activator of ventricular fibrosis in PH. Angiotensin II induced a reduction in p38 phosphorylation that was attenuated following chemical inhibition of PKC βII and δ. Molecular and chemical inhibition of PKC βII and δ abrogated angiotensin II-induced cardiac fibroblast proliferation and collagen deposition in vitro. The effects of PKC inhibition on proliferation and fibrosis were reversed by chemical inhibition of p38. Conversely, constitutive activation of p38 attenuated angiotensin II-induced increase of cardiac fibroblast proliferation and collagen accumulation. PKC βII- and δ-dependent inactivation of p38 regulates cardiac fibroblast proliferation and collagen deposition in response to angiotensin II, which suggests that the PKC-p38 signaling in cardiac fibroblasts may be involved and important in the pathophysiology of RV fibrosis in PH.

Right ventricle free wall mechanics in metabolic syndrome without type-2 diabetes: effects of a 3-month lifestyle intervention program

Background

Growing evidence demonstrates subtle left ventricular myocardial dysfunction in patients with metabolic syndrome (MetS), with central obesity, glucose intolerance and inflammation emerging as important contributors. Whether these results can be translated to the right ventricle (RV) is not yet fully elucidated. Furthermore, although lifestyle intervention favorably impacts MetS components and inflammatory biomarkers, its effect on RV myocardial function remains unknown today.

Methods

Thirty-nine MetS adults free of diabetes were enrolled in a three month lifestyle intervention program including diet and physical exercise, and compared with forty healthy controls. Blood biochemistry, echocardiography including tissue Doppler imaging (TDI), and vector velocity imaging of the RV free wall to assess global longitudinal strain (GLS) and strain rates (SR) were obtained at baseline and after the intervention.

Results

Compared with controls, MetS patients presented similar right atrial and RV morphology but reduced systolic (P = 0.04) and early diastolic (P = 0.02) velocities of the tricuspid annulus. They showed attenuated RV GLS (−21.4 ± 4.5vs-25.7 ± 4.9%, P < 0.001) as well as early diastolic (P = 0.003) and systolic (P < 0.001) SR. Multiple regression analyses revealed log PAI-1 active, (P < 0.001), log adiponectin, (P = 0.01), LV mass indexed (P = 0.004) and central fat (P = 0.03) as independent predictors of RV GLS (R² = 0.46, P < 0.001). Biological markers of MetS and inflammation as well as RV GLS (−21.8 ± 3.8vs-24.3 ± 3.0%, P = 0.009) and systolic (P = 0.003) and early diastolic (P = 0.01) SR, but not TDI indexes, significantly improved after diet and exercise training, and vector velocity imaging data in MetS following the lifestyle intervention no longer differed from controls.

Conclusions

MetS is associated with subtle impairments in both RV free wall diastolic and systolic myocardial function which could be partly related to central-obesity induced changes in pro- and anti-inflammatory cytokines and left ventricular remodeling. The favorable impact of healthy dieting and physical activity on RV free wall mechanics indicates that cellular and sub-cellular alterations responsible for the RV myocardial abnormalities are probably not permanent and modifiable throughout adequate interventional strategies.

Trial registration

American National Institutes of Health database NCT00917917.

Effects of the metabolic syndrome on right heart mechanics and function

BACKGROUND

We sought to investigate right ventricular (RV) and right atrial (RA) deformation obtained using 3-dimensional echocardiography (3DE) and 2-dimensional (2DE) strain in subjects with the metabolic syndrome (MS).

METHODS

This cross-sectional study included 108 untreated subjects with the MS and 75 control subjects similar according to sex and age. The MS was defined by the presence ≥ 3 American Heart Association/National Heart, Lung, and Blood Institute criteria. All the subjects underwent adequate laboratory analyses and complete 2DE and 3DE examination.

RESULTS

2DE global longitudinal strain of the RV was significantly decreased in the MS group compared with the control subjects (-24 ± 5 vs -27 ± 5%; P < 0.001). Similar results were obtained for the RA longitudinal strain (40 ± 5 vs 44 ± 7%; P < 0.001). Systolic and early diastolic RV and RA strain rates were decreased, whereas late diastolic strain rates were increased among the MS participants compared with the control subjects. 3DE RV ejection fraction was significantly decreased in the MS subjects (55 ± 4 vs 58 ± 4%; P < 0.001). The multivariate analysis of MS criteria showed that systolic blood pressure, waist circumference, and fasting glucose were independently associated with RV and/or RA myocardial function and deformation.

CONCLUSIONS

RV mechanics and RA mechanics, assessed using 3DE and 2DE strain, were significantly deteriorated in the MS subjects. Among all MS risk factors, systolic blood pressure, abdominal circumference, and fasting glucose were the most responsible for the right heart remodelling.

Right ventricular hypertrophy in systemic hypertension: an updated review of clinical studies

AIM

Experimental and clinical evidence supports the view that right ventricular hypertrophy (RVH) may parallel left ventricular hypertrophy in systemic hypertension; a comprehensive analysis of this issue, however, is lacking. Thus, we analyzed the literature in order to provide an updated information on the right ventricular structural changes associated to systemic hypertension.

DESIGN

A literature search using the key words 'right ventricle' 'right ventricular hypertrophy', 'biventricular hypertrophy' 'right and left ventricular hypertrophy'. 'hypertension', 'echocardiography' was performed in order to identify relevant articles. Full articles published in English language in the last three decades reporting studies in adult hypertensive individuals were considered.

RESULTS

A total of 13 studies, including 1290 untreated (45%) and treated hypertensive patients and 259 normotensive controls, were considered. Overall, in hypertensive individuals right ventricular wall was thicker than in normotensive counterparts (standardized difference 1.3 mm, P < 0.001). RVH prevalence consistently varied among studies (17.0-80.0%) with an average of 28.6% in the pooled population. This was also the case for LVH prevalence rates (9.0-100%) with an average value of 30.6%.

CONCLUSION

Clinical studies consistently indicate that RVH is a common cardiac phenotype in systemic hypertension. As this finding is based on a limited number of cross-sectional studies including small population samples, further investigations are needed to determine the clinical utility and prognostic value of this phenotype in clinical practice.

Metabolic syndrome and right ventricle: an updated review

The cluster of metabolic and hemodynamic abnormalities which characterize the metabolic syndrome (MS) is responsible for subclinical cardiac and extra-cardiac damage such as left ventricular hypertrophy, diastolic dysfunction, carotid atherosclerosis and microalbuminuria. The development of different non-invasive imaging methods enabled a detail investigation of right ventricular structure and function, and revealed that right ventricular remodeling followed changes in the left ventricular structure and function in patients with arterial hypertension, diabetes or obesity. Previous investigations also reported that the coexistence of two components of the MS induced more significant cardiac remodeling than the presence of only one MS risk-factor. The relationship between different components of the MS (increased blood pressure, abdominal obesity, increased fasting glucose level and dyslipidemia) and right ventricular remodeling could be explained by several hemodynamic and non-hemodynamic mechanisms. However, the association between right ventricular remodeling and the MS has not been sufficiently investigated so far. The aim of this article was to review recent articles focusing on the association between metabolic syndrome components and the metabolic syndrome itself with impairments in right ventricular structure and function assessed by different imaging techniques.

Left atrial enlargement and right ventricular hypertrophy in essential hypertension

AIM

Diastolic dysfunction related to hypertensive left ventricular hypertrophy (LVH) has been shown to affect right-sided cardiac morphology and haemodynamics. As left atrial enlargement (LAE) is a marker of chronically elevated left ventricular (LV) filling pressure and diastolic dysfunction, we investigated the relationship between LAE and right ventricular hypertrophy (RVH) in systemic hypertension.

METHODS

A total of 330 essential hypertensives, categorized according to tertiles of left atrial (LA) diameter indexed to body surface area were considered for the analysis. All subjects underwent a quantitative echocardiographic examination as well as extensive clinical and laboratory investigations. RVH was defined as anterior right ventricular (RV) wall thickness ≥ 6.0/5.5 mm in men and women, respectively, and LVH as LV mass index ≥ 51/47 g/m(2.7) in men and women, respectively.

RESULTS

The prevalence of LVH increased across LA diameter tertiles from 21.0% to 50% and that of RVH from 26.3% to 41.8% (p < 0.01for both). This was also the case for biventricular hypertrophy (from 10.0% to 26.0%, p < 0.01). Differences in both LV and RV structure across LA diameter tertiles remained significant after adjusting for age, office systolic/diastolic blood pressure and duration of hypertension. Similar results were obtained when study population was divided according to absolute LA diameter tertiles.

CONCLUSIONS

Our findings provide further evidence of an interaction between left and right chambers in systemic hypertension by showing that LAE is associated with RVH. The clinical and prognostic implications of such observation remain be evaluated in future prospective studies.

Angiotensin-converting enzyme I/D gene polymorphism affects early cardiac response to professional training in young footballers

BACKGROUND

The renin-angiotensin-aldosterone system plays a role in physiological and pathological responses of the heart to both static and dynamic exercise. Previous studies showed that the level of angiotensin II is determined by the angiotensin-converting enzyme insertion/deletion (ACE I/D) polymorphism.

AIM

We aimed in this study to determine the effect of ACE I/D gene polymorphism on the extent of functional and structural cardiac changes in response to one year of professional football training in young footballers.

METHODS AND RESULTS

We studied 68 young male football players and a comparable control group. Besides medical history and clinical examination, 12 lead ECG and transthoracic 2D echocardiography examination were performed. Genotyping of ACE was analyzed using PCR-based technique. There was no statistically significant difference in distribution of genotypes among athletes compared with control subjects. D allele showed a graded effect on both EF (73.55, 67.5 and 60.2%, p=0.03) and PASP (37.6, 26.1 and 21.39 mmHg, p=0.02) in DD, ID and II subjects, respectively.

CONCLUSION

Early cardiac changes in young footballers can be affected by ACE I/D polymorphism. There is a summative effect of the D allele in increasing EF and PASP in response to professional football training.