Feasibility and safety of left bundle branch area pacing in patients with septal hypertrophy.

INTRODUCTION: Left bundle branch area pacing (LBBAP) aims to provide physiological ventricular activation during pacing. Left ventricular septal hypertrophy (LVSH) might be challenging for LBBAP due to the thickness of the interventricular septum and potential presence of septal scar. This study assesses the feasibility, safety, and outcome of LBBAP in patients with LVSH using primarily stylet-driven leads (SDL). METHODS: Adult patients with LVSH who underwent LBBAP between March 2019 and November 2022 were enrolled. Baseline patient characteristics, procedural data and postprocedural results were collected. The feasibility of LBBAP in LVSH patients was compared to a cohort of LBBAP patients with normal septal wall thickness (NST). RESULTS: Seventeen LVSH and 133 NST patients underwent LBBAP with successful implantation achieved in 15 LVSH patients (88%). Mean implant depth was 17.2 ± 1.9 mm, with 53% proven left bundle branch (LBB) capture. Paced QRS duration (146 ± 14 ms) and V6 R-wave peak time (V6 RWPT; 79 ± 20 ms) were comparable between patients with and without septal hypertrophy, although patients with NST had higher rates of proven LBB capture (71% vs. 53%). In LVSH pacing thresholds (0.6 ± 0.3 V at 0.4 ms) and R-wave amplitude (13.9 ± 5.6 mV) were favorable and remained stable at follow-up. At 12 months, 87% of patients had stable or improved left ventricular ejection fraction. CONCLUSION: The results of the study indicate that LBBAP in patients with LVSH is safe and feasible and no lead-related complications were observed despite a mean implant depth exceeding 15 mm. LBBAP using SDL results in favorable pacing and electrocardiographic characteristics in LVSH patients, comparable to patients with NST.

Hypertension and cardiomyopathy associated with chronic kidney disease: epidemiology, pathogenesis and treatment considerations.

Chronic kidney disease (CKD) is a complex condition with a prevalence of 10-15% worldwide. An inverse-graded relationship exists between cardiovascular events and mortality with kidney function which is independent of age, sex, and other risk factors. The proportion of deaths due to heart failure and sudden cardiac death increase with progression of chronic kidney disease with relatively fewer deaths from atheromatous, vasculo-occlusive processes. This phenomenon can largely be explained by the increased prevalence of CKD-associated cardiomyopathy with worsening kidney function. The key features of CKD-associated cardiomyopathy are increased left ventricular mass and left ventricular hypertrophy, diastolic and systolic left ventricular dysfunction, and profound cardiac fibrosis on histology. While these features have predominantly been described in patients with advanced kidney disease on dialysis treatment, patients with only mild to moderate renal impairment already exhibit structural and functional changes consistent with CKD-associated cardiomyopathy. In this review we discuss the key drivers of CKD-associated cardiomyopathy and the key role of hypertension in its pathogenesis. We also evaluate existing, as well as developing therapies in the treatment of CKD-associated cardiomyopathy.

One-Year Committed Exercise Training Reverses Abnormal Left Ventricular Myocardial Stiffness in Patients With Stage B Heart Failure With Preserved Ejection Fraction.

BACKGROUND: Individuals with left ventricular (LV) hypertrophy and elevated cardiac biomarkers in middle age are at increased risk for the development of heart failure with preserved ejection fraction. Prolonged exercise training reverses the LV stiffening associated with healthy but sedentary aging; however, whether it can also normalize LV myocardial stiffness in patients at high risk for heart failure with preserved ejection fraction is unknown. In a prospective, randomized controlled trial, we hypothesized that 1-year prolonged exercise training would reduce LV myocardial stiffness in patients with LV hypertrophy. METHODS: Forty-six patients with LV hypertrophy (LV septum >11 mm) and elevated cardiac biomarkers (N-terminal pro-B-type natriuretic peptide [>40 pg/mL] or high-sensitivity troponin T [>0.6 pg/mL]) were randomly assigned to either 1 year of high-intensity exercise training (n=30) or attention control (n=16). Right-heart catheterization and 3-dimensional echocardiography were performed while preload was manipulated using both lower body negative pressure and rapid saline infusion to define the LV end-diastolic pressure-volume relationship. A constant representing LV myocardial stiffness was calculated from the following: P=S×[Exp {a (V-V0)}-1], where "P" is transmural pressure (pulmonary capillary wedge pressure - right atrial pressure), "S" is the pressure asymptote of the curve, "V" is the LV end-diastolic volume index, "V0" is equilibrium volume, and "a" is the constant that characterizes LV myocardial stiffness. RESULTS: Thirty-one participants (exercise group [n=20]: 54±6 years, 65% male; and controls (n=11): 51±6 years, 55% male) completed the study. One year of exercise training increased max by 21% (baseline 26.0±5.3 to 1 year later 31.3±5.8 mL·min-1·kg-1, P<0.0001, interaction P=0.0004), whereas there was no significant change in max in controls (baseline 24.6±3.4 to 1 year later 24.2±4.1 mL·min-1·kg-1, P=0.986). LV myocardial stiffness was reduced (right and downward shift in the end-diastolic pressure-volume relationship; LV myocardial stiffness: baseline 0.062±0.020 to 1 year later 0.031±0.009), whereas there was no significant change in controls (baseline 0.061±0.033 to 1 year later 0.066±0.031, interaction P=0.001). CONCLUSIONS: In patients with LV hypertrophy and elevated cardiac biomarkers (stage B heart failure with preserved ejection fraction), 1 year of exercise training reduced LV myocardial stiffness. Thus, exercise training may provide protection against the future risk of heart failure with preserved ejection fraction in such patients. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03476785.

An Optimized Model of Hypertrophic Preconditioning Confers Cardioprotection in the Mouse.

BACKGROUND: Conventional models of hypertrophic preconditioning (C-HP) can be established surgically through transverse aortic constriction (TAC) → deconstriction (De-TAC) → reconstriction (Re-TAC) characterized by dynamic afterload while it exerts technical difficulty on operators and poses high mortality during perioperative period in mice. We aimed to introduce an optimized method for obtaining a hypertrophic preconditioning (O-HP) model for further study on cardiac hypertrophy. METHODS: Ninety mice were divided into four groups: sham, TAC, C-HP, and O-HP. The sham group was exerted on three-time thoracotomies. The TAC group experienced twice thoracotomies and one TAC operation. C-HP and O-HP groups were given TAC, De-TAC, and Re-TAC operation at day 0, day 3, and day 7 in conventional and optimized method, respectively. We optimized the operating procedure in O-HP mice compared with the C-HP group by (1) leaving a ∼3-cm suture fixed in the subcutaneous layer after aortic constriction in TAC surgery (2) using two small forceps to untie the constriction knot instead of cutting it in the De-TAC operation. Ultrasound biomicroscopy was used for hemodynamics and cardiac function detection. Four weeks after the third surgery, all mice were sacrificed and pathology was analyzed among four groups. RESULTS: Four weeks after Re-TAC, the survival of O-HP mice was 63.3% while that of C-HP was 26.7%. Ultrasound biomicroscopy showed a successful establishment of HP models. C-HP and O-HP mice had improved cardiac structure and function indicated by left ventricular end-systolic diameter, left ventricular end-systolic posterior wall thickness, left ventricular ejection fraction, and left ventricular fractional shortening than the TAC group. Pathological analysis showed O-HP as well as C-HP had less hypertrophy than the TAC mice. CONCLUSIONS: Our results provide a rapid, safe, efficient, and reproducible method for optimized establishment of the HP model, which will facilitate studies for early intervention and prevention of left ventricular hypertrophy and heart failure.

Preclinical evidence for the therapeutic value of TBX5 normalization in arrhythmia control.

AIMS: Arrhythmias and sudden cardiac death (SCD) occur commonly in patients with heart failure. We found T-box 5 (TBX5) dysregulated in ventricular myocardium from heart failure patients and thus we hypothesized that TBX5 reduction contributes to arrhythmia development in these patients. To understand the underlying mechanisms, we aimed to reveal the ventricular TBX5-dependent transcriptional network and further test the therapeutic potential of TBX5 level normalization in mice with documented arrhythmias. METHODS AND RESULTS: We used a mouse model of TBX5 conditional deletion in ventricular cardiomyocytes. Ventricular (v) TBX5 loss in mice resulted in mild cardiac dysfunction and arrhythmias and was associated with a high mortality rate (60%) due to SCD. Upon angiotensin stimulation, vTbx5KO mice showed exacerbated cardiac remodelling and dysfunction suggesting a cardioprotective role of TBX5. RNA-sequencing of a ventricular-specific TBX5KO mouse and TBX5 chromatin immunoprecipitation was used to dissect TBX5 transcriptional network in cardiac ventricular tissue. Overall, we identified 47 transcripts expressed under the control of TBX5, which may have contributed to the fatal arrhythmias in vTbx5KO mice. These included transcripts encoding for proteins implicated in cardiac conduction and contraction (Gja1, Kcnj5, Kcng2, Cacna1g, Chrm2), in cytoskeleton organization (Fstl4, Pdlim4, Emilin2, Cmya5), and cardiac protection upon stress (Fhl2, Gpr22, Fgf16). Interestingly, after TBX5 loss and arrhythmia development in vTbx5KO mice, TBX5 protein-level normalization by systemic adeno-associated-virus (AAV) 9 application, re-established TBX5-dependent transcriptome. Consequently, cardiac dysfunction was ameliorated and the propensity of arrhythmia occurrence was reduced. CONCLUSIONS: This study uncovers a novel cardioprotective role of TBX5 in the adult heart and provides preclinical evidence for the therapeutic value of TBX5 protein normalization in the control of arrhythmia.

Prevention of heart failure with preserved ejection fraction (HFpEF): reexamining microRNA-21 inhibition in the era of oligonucleotide-based therapeutics.

Heart failure with preserved ejection fraction (HFpEF) accounts for 50% of cases of heart failure, which is the most common cause of hospitalization in US patients over the age of 65. HFpEF pathogenesis is increasingly believed to be due to pathological hypertrophy and fibrosis of the myocardium that may be a result of systemic inflammation from comorbid conditions such as hypertension, diabetes mellitus, chronic obstructive pulmonary disease, anemia, chronic kidney disease and others. It is believed that oxidative stress triggers a process of pathological hypertrophy and fibrosis in cardiac endothelial cells, which leads to increased left ventricle filling pressures and, eventually, symptoms of heart failure. Numerous recent major clinical trials that have examined various therapies aimed at improving mortality in HFpEF have emerged empty-handed and thus the search for effective management strategies continues. Over the last several years, there have been many new developments in the field of antisense oligonucleotide-based therapeutics, which involves using noncoding nucleic acid particles such as microRNA and small interfering RNA to repress the expression of specific messenger RNA. In this article, we review the concept of using oligonucleotide-based therapeutics to prevent or treat HFpEF by targeting a specific microRNA that has been implicated in the pathogenesis of myocardial fibrosis and hypertrophy, microRNA-21 (miR-21). We review the various evidence that implicates miR-21 in the process of myocardial fibrosis and discuss recent attempts to use antimiR-21 compounds to prevent fibrosis. We also discuss proposed methods for screening patients at high risk for HFpEF for diastolic dysfunction in order to determine which patients.

Mutation-specific pathology and treatment of hypertrophic cardiomyopathy in patients, mouse models and human engineered heart tissue.

Hypertrophic cardiomyopathy (HCM) is the most common inherited cardiomyopathy and is characterized by asymmetric left ventricular hypertrophy and diastolic dysfunction, and a frequent cause of sudden cardiac death at young age. Pharmacological treatment to prevent or reverse HCM is lacking. This may be partly explained by the variety of underlying disease causes. Over 1500 mutations have been associated with HCM, of which the majority reside in genes encoding sarcomere proteins, the cardiac contractile building blocks. Several mutation-mediated disease mechanisms have been identified, with proof for gene- and mutation-specific cellular perturbations. In line with mutation-specific changes in cellular pathology, the response to treatment may depend on the underlying sarcomere gene mutation. In this review, we will discuss evidence for mutation-specific pathology and treatment responses in HCM patients, mouse models and engineered heart tissue. The pros and cons of these experimental models for studying mutation-specific HCM pathology and therapies will be outlined.

rAAV9-Mediated MEK1 Gene Expression Restores Post-conditioning Protection Against Ischemia Injury in Hypertrophic Myocardium.

PURPOSE: We investigated whether increased expression of activated mitogen-activated protein kinase (MAPK) kinases 1 (MEK1) restores ischemic post-conditioning (IPostC) protection in hypertrophic myocardium following ischemia/reperfusion (I/R) injury. METHODS: C57Bl/6 mice received recombinant adeno-associated virus type 9 (rAAV9)-mediated activated MEK1 gene delivery systemically, then following the induction of cardiac hypertrophy via transverse aortic constriction for 4 weeks. In a Langendorff model, hypertrophic hearts were subjected to 40 min/60 min I/R or with IPostC intervention consisting of 6 cycles of 10 s reperfusion and 10 s no-flow before a 60-min reperfusion. Hemodynamics, infarct size (IS), myocyte apoptosis and changes in expression of reperfusion injury salvage kinase (RISK) pathway were examined. RESULTS: rAAV9-MEK1 gene delivery led to a 4.3-fold and 2.7-fold increase in MEK1 mRNA and protein expression in the heart versus their control values. I/R resulted in a larger IS in hypertrophic than in non-hypertrophic hearts (52.3 ± 4.7% vs. 40.0 ± 2.5%, P < 0.05). IPostC mediated IS reduction in non-hypertrophic hearts (27.6 ± 2.6%, P < 0.05), while it had no significant effect in hypertrophic hearts (46.5 ± 3.1%, P=NS) compared with the IS in non-hypertrophic or hypertrophic hearts subjected to I/R injury only, respectively. Hemodynamic decline induced by I/R was preserved by IPostC in non-hypertrophic hearts but not in hypertrophic hearts. rAAV9-MEK1 gene delivery restored IPostC protection in hypertrophic hearts evidenced by reduced IS (32.0 ± 2.8% vs. 46.5 ± 3.1%) and cardiac cell apoptosis and largely preserved hemodynamic parameters. These protective effects were associated with significantly increased phosphorylation of ERK1/2 and ribosomal protein S6 kinases (p70S6K), but it had no influence on Akt and glycogen synthase kinase-3ß. CONCLUSION: These results demonstrated that rAAV9-mediated activated MEK1 expression restores IPostC protection in the hypertrophic heart against I/R injury through the activation of ERK pathway.

iTRAQ­based quantitative proteomics analysis of the potential application of secretoneurin gene therapy for cardiac hypertrophy induced by DL­isoproterenol hydrochloride in mice.

A previous study by our group demonstrated a protective role of the neuropeptide secretoneurin (SN) in DL­isoproterenol hydrochloride (ISO)­induced cardiac hypertrophy in mice. To further characterize the molecular mechanism of SN treatment, an isobaric tags for relative and absolute quantification (iTRAQ)­based quantitative proteomic analysis was applied to identify putative target proteins and molecular pathways. An SN expression vector was injected into the myocardial tissues of mice, and the animals were then subcutaneously injected with ISO (5 mg/kg/day) for 7 days to induce cardiac hypertrophy. The results of echocardiography and hemodynamic measurements indicated that the function of the heart impaired by ISO treatment was significantly ameliorated via SN gene injection. The investigation of heart proteomics was performed by iTRAQ­based liquid chromatography­tandem mass spectrometry analysis. A total of 2,044 quantified proteins and 15 differentially expressed proteins were associated with SN overexpression in mice with cardiac hypertrophy. Functional enrichment analysis demonstrated that these effects were possibly associated with metabolic processes. A protein­protein interaction network analysis was constructed and the data indicated that apolipoprotein C­III (Apoc3) was associated with the positive effect of SN on the induction of cardiac hypertrophy in mice. The present study proposed a potential mechanism of SN action on Apoc3 upregulation that may contribute to the amelioration of cardiac hypertrophy. These findings can aid the clinical application of SN in patients with cardiac hypertrophy.

Alcohol septal ablation in patients with severe septal hypertrophy.

OBJECTIVE: The current guidelines suggest alcohol septal ablation (ASA) is less effective in hypertrophic obstructive cardiomyopathy (HOCM) patients with severe left ventricular hypertrophy, despite acknowledging that systematic data are lacking. Therefore, we analysed patients in the Euro-ASA registry to test this statement. METHODS: We compared the short-term and long-term outcomes of patients with basal interventricular septum (IVS) thickness <30 mm Hg to those with ≥30 mm Hg treated using ASA in nine European centres. RESULTS: A total of 1519 patients (57±14 years, 49% women) with symptomatic HOCM were treated, including 67 (4.4%) patients with IVS thickness ≥30 mm. The occurrence of short-term major adverse events were similar in both groups. The mean follow-up was 5.4±4.3 years and 5.1±4.1 years, and the all-cause mortality rate was 2.57 and 2.94 deaths per 100 person-years of follow-up in the IVS <30 mm group and the IVS ≥30 mm group (p=0.047), respectively. There were no differences in dyspnoea (New York Heart Association class III/IV 12% vs 16%), residual left ventricular outflow tract gradient (16±20 vs 16±16 mm Hg) and repeated septal reduction procedures (12% vs 18%) in the IVS <30 mm group and IVS ≥30 mm group, respectively (p=NS for all). CONCLUSIONS: The short-term results and the long-term relief of dyspnoea, residual left ventricular outflow obstruction and occurrence of repeated septal reduction procedures in patients with basal IVS ≥30 mm is similar to those with IVS <30mm. However, long-term all-cause and cardiac mortality rates are worse in the ≥30 mm group.

Cardio- Renal Outcomes With Long- Term Agalsidase Alfa Enzyme Replacement Therapy: A 10- Year Fabry Outcome Survey (FOS) Analysis.

PURPOSE: Following the publication of 5-year agalsidase alfa enzyme replacement therapy (ERT) outcomes data from the Fabry Outcome Survey (FOS), 10-year data were analyzed. PATIENTS AND METHODS: FOS (ClinicalTrials.gov identifier: NCT03289065) data (April 2001 to August 2018) were retrospectively analyzed. Estimated glomerular filtration rate (eGFR) and left ventricular mass indexed to height (LVMI) were analyzed after treatment start (baseline) for patients with ≥3 measurements, including baseline and year 10. RESULTS: Median (range) age (years) of the evaluable treated renal cohort at treatment start was 48.8 (17.9-67.3) for females (n=62), 34.4 (18.0-66.8) for males (n=90). With eGFR ≥60 mL/min/1.73 m2 at baseline, mean (95% CI) rate of eGFR change (eGFR/year) over 10 years was relatively stable in females (n=52; -0.55 [-1.12, +0.01]) and slightly declined in males (n=79; -1.99 [-2.45, -1.54]). With impaired kidney function (eGFR <60 mL/min/1.73 m2) at baseline, mean (95% CI) eGFR/year was stable in females (n=10; -0.14 [-1.43, +1.15]) and slightly declined in males (n=11; -2.79 [-4.01, -1.56]) over 10 years. Median (range) age (years) of the evaluable treated cardiac cohort at treatment start was 46.7 (3.7-67.3) for females (n=34), 28.2 (4.0-54.2) for males (n=35). With left ventricular hypertrophy (LVH; LVMI >48 g/m2.7 in females, >50 g/m2.7 in males) at baseline, mean (95% CI) LVMI/year slightly increased over 10 years in females (n=18; +1.51 [+0.91, +2.12]) and males (n=14; +0.87 (+0.19, +1.55). Without LVH at baseline, mean (95% CI) LVMI/year was stable in females (n=16; +0.52 [-0.13, +1.17]) and males (n=21; +0.57 [+0.02, +1.13]) over 10 years. CONCLUSION: Agalsidase alfa-treated patients with 10-year FOS data and preserved kidney function and/or normal LVMI at baseline remained largely stable; those with decreased kidney function or LVH at baseline experienced modest declines in renal function and/or increases in LVMI.

Effect of renal denervation procedure on left ventricular mass, myocardial strain and diastolic function by CMR on a 12-month follow-up.

PURPOSE: To investigate the effects of renal denervation (RDN) on left ventricular (LV) mass, myocardial strain and diastolic function in patients with treatment-resistant arterial hypertension by cardiac magnet resonance imaging on a 12-month follow-up. MATERIALS AND METHODS: Sixteen patients (38% female) were examined before and 12 months after RDN. LV morphology and strain were analyzed. Diastolic function was determined by early (EPFR) and atrial peak filling rates (APFR) derived from differential volume-time-curve analysis. Clinical visits included 24-h ambulant blood pressure monitoring (ABPM). RESULTS: Twelve months after RDN LV mass decreased from 80 ± 21 g/m2 to 74 ± 20 g/m2 (P < 0.05). Global radial (35 ± 12% vs. 41 ± 10%, P < 0.05) and longitudinal strain improved (- 15 ± 4% vs. - 17 ± 3%, P < 0.05). Global circumferential strain (- 16 ± 5% vs. - 18 ± 4%, P = 0.12) remained unchanged. The parameter of diastolic LV function PFRR (EPFR/APFR) improved following RDN (0.9 ± 0.4 vs. 1.1 ± 0.5, P < 0.05). Individual changes of LV mass were associated with an increase of EPFR (r = - 0.54, P < 0.05) and a reduction of APFR by trend (r = 0.45, P = 0.08). Systolic ABPM showed a decrease by trend (152 mmHg vs. 148 mmHg, P = 0.08). CONCLUSIONS: After RDN we observed a reduction of LV mass, improvement of global strain and diastolic function.

Left Atrium Dilatation and Left Ventricular Hypertrophy Predispose to Atrial Fibrillation in Patients With Community-Acquired Pneumonia.

Atrial fibrillation (AF) is one of the most common cardiovascular complications in patients hospitalized with community-acquired pneumonia (CAP). However, predisposing clinical factors associated with AF in CAP patients have not been fully elucidated. We enrolled 545 patients consecutively hospitalized for CAP. Data on demographic characteristics and co-morbidities were collected and all patients underwent ECG, echocardiography, and laboratory measurements. During the in-hospital stay, 9.5% of patients experienced a new episode of AF within 24 to 72 hours from admission. CAP patients who experienced AF had a higher indexed left atrial area (LAAi) and a higher proportion of concentric left ventricular hypertrophy than those not presenting AF. Univariate logistic regression analysis showed that hypertension, history of coronary heart disease, high Pneumonia Severity Index classes, history of paroxysmal AF, systolic heart failure, concentric left ventricular hypertrophy, and an enlarged LAAi were associated with a new episode of AF. A multivariable logistic analysis showed that history of paroxysmal AF (odds ratio [OR] 11.7; 95% confidence interval [CI] 5.8 to 23.7; p <0.001), enlarged LAAi (OR 5.4; 95% CI 2.5 to 11.9; p <0.001), and concentric left ventricular hypertrophy (OR 2.2; 95 CI 1.1 to 4.6; p = 0.034) remained independently associated with AF occurrence. In conclusion, in this large cohort of CAP patients, history of paroxysmal AF, enlarged LAAi, and concentric left ventricular hypertrophy are independent predictors of AF occurrence during the early stages of pneumonia.

Echocardiographic Abnormalities and Determinants of 1-Month Outcome of Stroke Among West Africans in the SIREN Study.

Background Little is known about the relationship between echocardiographic abnormalities and outcome among patients with acute stroke. We investigated the pattern and association of baseline echocardiographic variables with 1-month disability and mortality among patients with stroke in the SIREN (Stroke Investigative Research and Education Network) study. Methods and Results We enrolled and followed up consecutive 1020 adult patients with acute stroke with baseline transthoracic echocardiography from west Africa. To explore the relationship between echocardiographic variables and 1-month disability (using modified Rankin scale >3) and fatality, regression models were fitted. Relative risks were computed with 95% CIs. The participants comprised 60% men with a mean age of 59.2±14.6 years. Ischemic stroke was associated with smaller aortic root diameter (30.2 versus 32.5, P=0.018) and septal (16.8 versus 19.1, P<0.001) and posterior wall thickness at systole (18.9 versus 21.5, P=0.004). Over 90% of patients with stroke had abnormal left ventricular (LV) geometry with eccentric hypertrophy predominating (56.1%). Of 13 candidate variables investigated, only baseline abnormal LV geometry (concentric hypertrophy) was weakly associated with 1-month disability (unadjusted relative risk, 1.80; 95% CI , 0.97-5.73). Severe LV systolic dysfunction was significantly associated with increased 1-month mortality (unadjusted relative risk, 3.05; 95% CI , 1.36-6.83). Conclusions Nine of 10 patients with acute stroke had abnormal LV geometry and a third had systolic dysfunction. Severe LV systolic dysfunction was significantly associated with 1 month mortality. Larger studies are required to establish the independent effect and unravel predictive accuracy of this association.

Incomplete structural reverse remodeling from late-stage left ventricular hypertrophy impedes the recovery of diastolic but not systolic dysfunction in rats.

OBJECTIVE: Pressure overload-induced left ventricular myocardial hypertrophy (LVH) regresses after pressure unloading. However, distinct structural alterations become less reversible during the progression of LVH, which might influence the restoration of cardiac function. Here, we investigated how a reverse remodeling process from early versus late-stage LVH affects different aspects of left ventricular function. METHODS: Pressure overload was induced in rats for 6, 12 and 18 weeks. Sham-operated animals were used as controls. Pressure unloading was evoked by removing the aortic constriction at week 6 (early-debanded) and week 12 (late-debanded). Echocardiography and histological analyses were carried out to detect structural alterations. Pressure-volume analysis was performed to assess left ventricular function. Molecular alterations were analyzed by quantitative real-time-PCR, and western blot. RESULTS: Myocardial hypertrophy regressed to a similar degree in early and late-debanded groups. Accordingly, no differences were detected in the extent of regression regarding left ventricular mass, cardiomyocyte diameter, heart weight-to-tibial length ratio and beta-to-alpha myosin heavy chain expression. In contrast, resorption of interstitial and perivascular myocardial fibrosis was only detected in the early-debanded group, whereas it persisted in the late-debanded group. Removing the aortic constriction normalized ventriculo-arterial coupling and increased systolic performance in both debanded groups. However, the residual dysfunction in active relaxation and passive stiffness was more severe in the late-debanded compared to the early-debanded group. CONCLUSION: Early debanding led to complete structural reverse remodeling (reduced hypertrophy and fibrosis) and full restoration of left ventricular function. In contrast, myocardial fibrosis persisted after late debanding, which impeded the normalization of diastolic but not systolic function.

Fabry disease in cardiology practice: Literature review and expert point of view.

Fabry disease is an X-linked progressive multisystemic genetic sphingolipidosis caused by deficient activity of lysosomal α-galactosidase A. Men aged>30 years and women aged>40 years most often present with unexplained left ventricular hypertrophy, usually concentric and non-obstructive, but sometimes mimicking sarcomeric hypertrophic cardiomyopathy, particularly when isolated, as in the cardiac or late-onset variant of the disease. In hypertrophic cardiomyopathy cohorts, up to 1% of patients have been diagnosed with Fabry disease. Frequent cardiac symptoms include chronotropic incompetence, severe conduction disturbances and arrhythmias, heart failure and sudden death, and cardiovascular complications are currently the leading cause of death at a mean age of 55 years in men and 66 years in women. Complementary to screening for extracardiac manifestations, the initial cardiac evaluation should include long-duration electrocardiogram recordings, echocardiography and late gadolinium and T1 mapping magnetic resonance imaging. Abnormalities of a non-hypertrophied inferolateral wall at the base of the left ventricle (thinning, decreased strain, midwall fibrosis) and low native T1 signal on magnetic resonance imaging are evocative. Aggressive cardiac management may include the control of cardiovascular risk factors, anticoagulation, permanent cardiac pacing and/or an implantable cardioverter defibrillator device, while antiarrhythmics and beta-blockers should be used with caution. Specific therapy should be initiated at the earliest stage, when the first structural or functional cardiac abnormalities are detected, and should include enzyme replacement therapy (available since 2001) or chaperone therapy (available since 2016) (the use of which is limited to patients with Fabry disease and an amenable α-galactosidase A [GLA] gene mutation).

A gene therapeutic approach to inhibit calcium and integrin binding protein 1 ameliorates maladaptive remodelling in pressure overload.

Aims: Chronic heart failure is becoming increasingly prevalent and is still associated with a high mortality rate. Myocardial hypertrophy and fibrosis drive cardiac remodelling and heart failure, but they are not sufficiently inhibited by current treatment strategies. Furthermore, despite increasing knowledge on cardiomyocyte intracellular signalling proteins inducing pathological hypertrophy, therapeutic approaches to target these molecules are currently unavailable. In this study, we aimed to establish and test a therapeutic tool to counteract the 22 kDa calcium and integrin binding protein (CIB) 1, which we have previously identified as nodal regulator of pathological cardiac hypertrophy and as activator of the maladaptive calcineurin/NFAT axis. Methods and results: Among three different sequences, we selected a shRNA construct (shCIB1) to specifically down-regulate CIB1 by 50% upon adenoviral overexpression in neonatal rat cardiomyocytes (NRCM), and upon overexpression by an adeno-associated-virus (AAV) 9 vector in mouse hearts. Overexpression of shCIB1 in NRCM markedly reduced cellular growth, improved contractility of bioartificial cardiac tissue and reduced calcineurin/NFAT activation in response to hypertrophic stimulation. In mice, administration of AAV-shCIB1 strongly ameliorated eccentric cardiac hypertrophy and cardiac dysfunction during 2 weeks of pressure overload by transverse aortic constriction (TAC). Ultrastructural and molecular analyses revealed markedly reduced myocardial fibrosis, inhibition of hypertrophy associated gene expression and calcineurin/NFAT as well as ERK MAP kinase activation after TAC in AAV-shCIB1 vs. AAV-shControl treated mice. During long-term exposure to pressure overload for 10 weeks, AAV-shCIB1 treatment maintained its anti-hypertrophic and anti-fibrotic effects, but cardiac function was no longer improved vs. AAV-shControl treatment, most likely resulting from a reduction in myocardial angiogenesis upon downregulation of CIB1. Conclusions: Inhibition of CIB1 by a shRNA-mediated gene therapy potently inhibits pathological cardiac hypertrophy and fibrosis during pressure overload. While cardiac function is initially improved by shCIB1, this cannot be kept up during persisting overload.

Prophylactic Effect of Amiodarone Infusion on Reperfusion Ventricular Fibrillation After Release of Aortic Cross-Clamp in Patients with Left Ventricular Hypertrophy Undergoing Aortic Valve Replacement: ARandomized Controlled Trial.

OBJECTIVE: To investigate whether prophylactic amiodarone infusion prevents ventricular fibrillation after aortic cross-clamp release and attenuates cytokine production in patients with left ventricular hypertrophy undergoing cardiac surgery. DESIGN: Prospective, randomized controlled trial. SETTING: A public hospital. PARTICIPANTS: The study comprised 68 patients undergoing aortic valve replacement for severe aortic stenosis. INTERVENTIONS: Patients were randomly assigned to receive a 150mg bolus then 30mg/h continuous infusion of amiodarone (amiodarone group) or a 1 mg/kg bolus then 1 mg/kg/h continuous infusion of lidocaine (lidocaine group). The primary outcome was the ventricular fibrillation incidence rate after aortic cross-clamp release. Secondary outcomes included perioperative serum interleukin-6 and tumor necrosis factor-alpha levels. MEASUREMENTS AND MAIN RESULTS: The ventricular fibrillation incidence rate was significantly lower in the amiodarone than in the lidocaine group (20.6% v 50%, relative risk 0.41; 95% confidence interval [CI] 0.20-0.86; p = 0.021). Interleukin-6 levels 1hour after aortic cross-clamp release and at intensive care unit admission were significantly lower in the amiodarone than in the lidocaine group (geometric mean [95% CI] 117.4pg/mL [87.1-158.4] v 339.5pg/mL [210.6-547.2]; p < 0.01 and 211.1pg/mL [162.8-73.6] v 434.1pg/mL [293.7-641.5]; p < 0.01, respectively). Tumor necrosis factor-alpha levels 1hour after aortic cross-clamp release were significantly lower in the amiodarone than in the lidocaine group (geometric mean [95% CI] 1.624pg/mL [1.359-1.940] v 2.283pg/mL [1.910-2.731]; p = 0.02). CONCLUSIONS: Amiodarone prevented reperfusion ventricular fibrillation in patients with left ventricular hypertrophy undergoing aortic valve replacement to a greater extent than did lidocaine. Furthermore, amiodarone inhibited postoperative interleukin-6 and tumor necrosis factor-alpha production.