Significant Change In Left Ventricular Mass Research Articles

Porcine Model of Hypertrophy-Independent Left Ventricular Stiffening via Repetitive Pressure Overload.

Diastolic dysfunction arising from alterations in myocardial structure and/or function is a central component of several cardiovascular disorders, including heart failure with preserved ejection fraction (HFpEF). Basic research aimed at understanding underlying mechanisms contributing to the development of diastolic dysfunction has generally centered upon models of left ventricular (LV) hypertrophy arising from persistent and severe elevations in myocardial afterload (e.g., aortic banding). Mechanisms of hypertrophy-independent diastolic dysfunction, on the other hand, have received less attention, even though overt anatomic LV hypertrophy is absent in many HFpEF patients. Here, we describe the development of a novel porcine model of repetitive pressure overload (RPO) in which chronic, intermittent exposure to transient episodes of hypertension produces an increase in LV stiffness, interstitial fibrosis, cardiomyocyte hypertrophy, and capillary rarefaction without significant changes in LV mass. This model offers important insight into how diastolic dysfunction and HFpEF may develop in the absence of comorbidities, sustained hypertension, or LV hypertrophy, while also providing a useful translational research tool for investigation of novel therapeutic approaches to restore myocardial compliance and improve diastolic function.

Tafamidis decreased cardiac amyloidosis deposition in patients with Ala97Ser hereditary transthyretin cardiomyopathy: a 12-month follow-up cohort study

BackgroundTransthyretin cardiac cardiomyopathy (ATTR-CM) is a rare but life-threatening disease. Tafamidis is an effective treatment for patients with ATTR-CM, however its long-term effects on cardiac remodeling and cardiac amyloid deposition are unknown. This study aimed to used cardiac magnetic resonance (CMR) to investigate the effects of tafamidis on patients with hereditary A97S ATTR-CM.MethodsWe retrospectively analyzed a prospective cohort of ATTR-CM patients, including 14 with hereditary A97S ATTR-CM and 17 healthy controls with baseline CMR data. All ATTR-CM patients received tafamidis treatment and received CMR with extracellular volume (ECV) at baseline and after 1 year of follow-up.ResultsBaseline N-terminal pro-B-type natriuretic peptide, left ventricular (LV) mass, LV ejection fraction, global radial, circumferential and longitudinal strain, T1 mapping and ECV were significantly worse in the patients with ATTR-CM compared with the healthy controls. After 1 year of tafamidis treatment, ECV decreased from 51.5 ± 8.9% to 49.0 ± 9.4% (P = 0.041), however there were no significant changes in LV mass, LV ejection fraction, global radial strain, global circumferential strain, global longitudinal strain and T1 mapping.ConclusionsAfter a one-year treatment period, tafamidis exhibited subtle but statistically significant reductions in ECV, potentially indicating a decrease in amyloid deposition among patients diagnosed with hereditary A97S ATTR-CM.

Abstract P758: Ischemic Stroke Induced Cardiac Dysfunction in Aged Mice

Introduction: Acute ischemic stroke patients with cardiac complications have increased in-hospital mortality. Most of these cardiac complications have been attributed to pre-existing cardiac comorbidities. Aging is a known risk factor for both stroke and myocardial injury. It is being increasingly recognized that ischemic injury to the brain in itself may lead to cardiac injury. However, the post stroke brain- heart interaction is not well defined in the aged. This study was designed to fill this gap in our knowledge. Methods: C57BL6/J young (3 months) and aged (18 months) male mice were subjected to 60 minutes of middle cerebral artery occlusion (MCAO). Mice had electrocardiogram (EKG, using rodent surgical monitor) and Echocardiogram (using vevo 3100 imaging system) pre-stroke, post stroke day 3, 7, and 14. All mice were sacrificed at day 14. EKG and ECHO results were analyzed using generalized estimated equation method with post hoc group comparison test at each time point, Bonferroni correction. Results: There was a significant decrease in cardiac output after stroke in aged but not young mice at three days post stroke, as compared to baseline (young, baseline:18.5±1.6ml/min vs day 3:16.6±5.16 ml/min, n=8; aged, baseline 25.4±6.8 6 ml/min vs. day 3, 16.8±6.8 n=6, p=0.0038). The cardiac output normalized to baseline in young but remained significantly low in aged mice even at day 14. Interestingly, the Left ventricular (LV) mass decreased significantly after stroke in aged mice at day 3, 118.4±23.2 mg as compared to baseline, 160.7±22.9 mg. This remained significantly lower than baseline at post stroke day seven, 124.6±32.9 mg and fourteen, 129.5±37.2 mg, p<0.05. A similar trend was seen in left ventricular anterior and posterior wall thickness. There was no significant change in LV mass in young mice, p>0.05. Conclusion: Our data indicates that cardiac output decreases after stroke in aged mice. Interestingly, there is a significant decrease in left ventricular mass and ventricular wall thickness in aged mice after MCAO, indicating cardiac atrophy. We speculate this may be secondary to cardiac ischemia caused by stroke. Ongoing work in our laboratory is aimed at examining the histological changes in cardiomyocytes after MCAO.

Gender differences in left ventricular hypertrophy regression after renal denervation in patients with resistant hypertension

Purpose . To study the regression of left ventricular hypertrophy (LVH) in men and women with resistant hypertension (RH) after renal denervation (RDN). Material and Methods . A total of 84 patients (50% men) with RH were enrolled in the study after signing informed consent. Renal denervation was performed in all patients. Initially and at 6 and 12 months after treatment, patients underwent careful examination. These analyses included office blood pressure (BP) measurement, transthoracic echocardiography (TTE) study with assessments of the left ventricular (LV) wall thickness and LV mass (LVM), and cardiac magnetic resonance (CMR) imaging. Results. Groups of men and women were comparable in regard to office BP, age, number of administered antihypertensive drugs, and the number of radiofrequency energy applications for RDN. The LVM in the male group was significantly higher than in women due to anatomy differences. According to echocardiography data, the rate of LVH was insignificantly higher in women: 90% in women versus 76% in men, χ 2 = 0.079. In the presence of a significant and comparable BP reduction, significant regression in the values interventricular wall thickness (by 4.4%, р =0.039) and LVM (by 9.5%, р =0.044) was found in men one year after RND according to data of echocardiography. According to CMR according to CMR, LVM decreased by 11.9% at six months ( р =0.039) and by 22.9% at 12 months ( р =0.026) after RND. However, no significant changes in LVM were found in women. The extent of LVM regression did not depend on the antihypertensive effect of RDN in either group. Conclusion. The frequency of LVH was insignificantly higher in women than in men: 90% in women versus 76% in men. One year after RDN, LVH significantly regressed in men, but not in women, and did not depend on degree of BP reduction.

Impact of asymptomatic hypertension on left and right ventricular functions by echocardiography

Background: Hypertension generally has no symptoms and is called the silent killer as the first warning presentation may itself be a cardiac failure or myocardial infarction, which is often massive and fatal. Hypertension many times remains asymptomatic for several years and is detected on regular health check-ups. Aims and Objective: The objective of this study is to study the cardiac changes in both right and left ventricles by echocardiography in asymptomatic hypertensive participants. Materials and Methods: Twenty-five asymptomatic cases and 29 normotensive controls (total 54 participants) were studied. All the participants were male aged between 20 years and 60 years and above. Clinical evaluation was done by determining their age, systolic and diastolic blood pressures, heart rate, and symptoms. Cardiac structural and functional changes were studied by echocardiogram. Cardiac output, stroke volume, left ventricular (LV) mass, right ventricular thickness, LV systolic and diastolic dimensions and functions, fractional fiber shortening, and ejection fraction were studied in both cases and controls. Results: There was a change in LV mass in asymptomatic hypertensive participants when compared with control participants. There was a statistically significant change in LV mass measured in grams (weight) showing P < 0.001 (0.00 vs. 0.00) in asymptomatic cases and healthy normotensive controls, and the LV posterior wall also showed a statistically significant change with P < 0.001 (0.008 vs. 0.009) in asymptomatic cases and normotensive controls. Conclusions: There is increased cardiac mortality and morbidity in asymptomatic hypertensive participants in whom the cardiac damage is concealed, compared with symptomatic hypertensives who consult a physician as soon as symptoms are felt.

Serum Bicarbonate and Structural and Functional Cardiac Abnormalities in Chronic Kidney Disease - A Report from the Chronic Renal Insufficiency Cohort Study

Background: Heart failure (HF) is a frequent occurrence in chronic kidney disease (CKD) patients and predicts poor survival. Serum bicarbonate is associated with increased rates of HF in CKD; however, the mechanisms leading to this association are incompletely understood. This study aims to assess whether serum bicarbonate is independently associated with structural and functional cardiac abnormalities in CKD. Methods: The association between serum bicarbonate and left ventricular (LV) hypertrophy (LVH), LV mass indexed to height^2.7, LV geometry, ejection fraction (EF) and diastolic dysfunction was assessed in 3,483 participants without NYHA class III/IV HF, enrolled in the Chronic Renal Insufficiency Cohort study. Results: The mean estimated glomerular filtration rate was 42.5 ± 17 ml/min/1.73 m². The overall prevalence of LVH was 51.2%, with 57.8, 50.9 and 47.7% for bicarbonate categories <22, 22-26 and >26 mmol/l, respectively. Participants with low bicarbonate were more likely to have LVH and abnormal LV geometry (OR 1.32; 95% CI 1.07-1.64, and OR 1.57; 95% CI 1.14-2.16, respectively). However, the association was not statistically significant after adjustment for demographics, traditional cardiovascular risk factors, medications and kidney function (OR 1.07; 95% CI 0.66-1.72, and OR 1.27; 95% CI 0.64-2.51, respectively). No association was found between bicarbonate and systolic or diastolic dysfunction. During follow-up, no significant changes in LV mass or EF were observed in any bicarbonate strata. Conclusions: In a large CKD study, serum bicarbonate was associated with LV mass and concentric LVH; however, this association was attenuated after adjustment for clinical factors suggesting that the observed cardiac effects are mediated through yet unknown mechanisms.

Left ventricular structure and remodeling in patients with COPD

BackgroundData on cardiac alterations such as left ventricular (LV) hypertrophy, diastolic dysfunction, and lower stroke volume in patients with COPD are discordant. In this study, we investigated whether early structural and functional cardiac changes occur in patients with COPD devoid of manifest cardiovascular disease, and we assessed their associations with clinical and functional features.MethodsForty-nine patients with COPD belonging to all Global Initiative for Chronic Obstructive Lung Disease (GOLD) classes were enrolled and compared with 36 controls. All subjects underwent clinical history assessment, lung function testing, blood pressure measurement, electrocardiography, and conventional and Doppler tissue echocardiography. Patients were also subjected to computed tomography to quantify emphysema score.ResultsPatients with COPD had lower LV cavity associated with a marked increase in relative wall thickness (RWT), suggesting concentric remodeling without significant changes in LV mass. RWT was significantly associated with ratio of the forced expiratory volume in 1 second to the forced vital capacity and emphysema score and was the only cardiac parameter that – after multivariate analysis – significantly correlated with COPD conditions in all individuals. Receiver operating characteristic curve analysis showed that RWT (with a cutoff point of 0.42) predicted the severity of COPD with 83% specificity and 56% sensitivity (area under the curve =0.69, 95% confidence interval =0.59–0.81). Patients with COPD showed right ventricular to be functional but no structural changes.ConclusionPatients with COPD without evident cardiovascular disease exhibit significant changes in LV geometry, resulting in concentric remodeling. In all individuals, RWT was significantly and independently related to COPD. However, its prognostic role should be determined in future studies.

Effects of a Low-Volume Aerobic-Type Interval Exercise on V˙O2max and Cardiac Mass

The aim of this study was to compare the effects of time-efficient, low-volume interval exercises on cardiorespiratory capacity and left ventricular (LV) mass with traditional continuous exercise in sedentary adults. Forty-two healthy but sedentary male subjects (age 26.5 ± 6.2 yr) participated in an 8-wk, five times per week, supervised exercise intervention. They were randomly assigned to one of three exercise protocols: sprint interval training (SIT, 5 min, 100 kcal), high-intensity interval aerobic training (HIAT, 13 min, 180 kcal), and continuous aerobic training (CAT, 40 min, 360 kcal). Cardiorespiratory capacity (V˙O2max) and LV mass (3T-MRI) were measured preintervention and postintervention. We observed significant (P < 0.01) increases in V˙O2max in all three groups, and the effect of the HIAT was the greatest of the three (SIT, 16.7% ± 11.6%; HIAT, 22.5% ± 12.2%; CAT, 10.0% ± 8.9%; P = 0.01). There were significant changes in LV mass, stroke volume (SV), and resting HR in both the SIT (LV mass, 6.5% ± 8.3%; SV, 5.3% ± 8.3%; HR, -7.3% ± 11.1%; all P < 0.05) and HIAT (LV mass, 8.0% ± 8.3%; SV, 12.1% ± 9.8%; HR, -12.7% ± 12.2%; all P < 0.01) but not in the CAT (LV mass, 2.5% ± 10.1%; SV, 3.6% ± 6.6%; HR, -2.2% ± 13.3%; all P > 0.05). Our study revealed that V˙O2max improvement with the HIAT was greater than with the CAT despite the HIAT being performed with a far lower volume and in far less time than the CAT. This suggests that the HIAT has potential as a time-efficient training mode to improve V˙O2max in sedentary adults.

Abstract 9529: Effects of Sevelamer Carbonate on Arterial Stiffness and Left Ventricular Mass in Patients with Stage 3 Chronic Kidney Disease: Results of a Randomized Controlled Trial

Introduction: Serum phosphate independently predicts cardiovascular mortality in the general population and in chronic kidney disease (CKD), even when levels are in the normal range. Phosphate has been implicated in the development and progression of vascular calcification and increased arterial stiffness, which is a driver of structural heart disease. We hypothesised that the non-calcium-based phosphate binder sevelamer carbonate would reduce left ventricular (LV) mass, reduce arterial stiffness and improve LV systolic and diastolic function in patients with stage 3 non-diabetic CKD. Methods: This was a single-centre, randomised, double-blind, placebo-controlled trial (figure). All patients received sevelamer carbonate for four weeks before randomisation to sevelamer or placebo for a further 36 weeks. Cardiovascular magnetic resonance imaging and echocardiography were used to assess LV mass and systolic and diastolic function. Arterial stiffness was determined by carotid-femoral pulse wave velocity (PWV). Results: A total of 120 patients were recruited. Mean age was 55 ± 14 years with 55% male and mean glomerular filtration rate 50 ± 13ml/min/1.73m 2 . Mean baseline LV mass, function and volumes were normal. After 40 weeks there were no significant changes in LV mass (-1.0 ± 7.2 vs. -0.2 ± 6.6 grams, P =0.6), LV systolic and diastolic function or PWV between sevelamer and placebo groups (table). Despite regular monitoring only 56% of subjects took ≥80% of prescribed therapy. Conclusion: In patients with stage 3 non-diabetic CKD, 40 weeks of treatment with sevelamer carbonate did not improve LV mass, LV systolic and diastolic function, or arterial stiffness.

Changes in components of left ventricular mechanics under selective beta-1 blockade: insight from traditional and new technologies in echocardiography

Myocardial inotropism is considered to be reduced under beta-1 adrenoreceptor blockage (beta1-block). However, relationships between components of left ventricular (LV) systolic mechanics under beta1-block accounting for physiological correlates are only partially explored. Hypertensive outpatient without previous cardiovascular events and with normal LV ejection fraction (EF) at rest underwent echocardiographic evaluations of LV size and systolic function by standard, tissue-Doppler, and speckle-tracking methods before and after 2 weeks of treatment with bisoprolol to obtain change in LV systolic mechanics at a stable heart rate reduction (-20 +/- 10% from baseline) without significant change in LV mass. In the study sample (n = 26, 62% women, mean age 52 +/- 10 years), under bisoprolol, afterload [i.e. circumferential (CESS) and meridional (MESS) end-systolic stress], LV mass, left atrial volume, and EF did not change significantly; LV chamber contractility [i.e. CESS/LV end-systolic volume index (CESS/ESVi) as well as MESS/ESVi] and relative wall thickness (RWT) decreased; stroke volume increased (all P < 0.05). Circumferential LV contractility (i.e. stress-corrected midwall shortening) increased, whereas regional longitudinal strain and strain rate, and global longitudinal strain decreased (all P < 0.05). Peak velocities of the systolic displacement of the lateral and medial mitral anulus did not change under bisoprolol. Parameters of longitudinal LV systolic function did not correlate with preload, afterload, RWT, or with stoke volume. In hypertensive subjects with preserved LV EF, parameters of longitudinal LV systolic mechanics may not reflect the LV myocardial contractility status in steady-state conditions under short-term treatment with beta1-block.

Advantages of blood pressure optimization

Lowering blood pressure (BP) reduces cardiovascular events, but aggressive BP management may not be advantageous. Optimal BP control (target: <120/80 mm Hg) and conventional BP control (target: <140/90 mm Hg) were compared in patients with hypertension in terms of target-organ damage and tolerability. A total of 23 patients with hypertension were randomly assigned to optimal versus conventional therapy for 6 months. Therapy was initiated with lercanidipine 10 mg/day. For BP control, the dose could be doubled or other drugs added. Three indices of target-organ damage were studied: left ventricular mass (LVM) index, flow-mediated dilatation (FMD) of the brachial artery, and 24-hour urinary albumin excretion. The BP decreased markedly by 21.3+/-3.4/13.2+/-1.7 mm Hg in the conventional therapy group and by 26.6+/-3.6/17.9+/-1.5 mm Hg in the optimal therapy group. Diastolic BP was significantly lower, by 4.7+/-2.3 mm Hg, in the optimal therapy group (P<.05). Ambulatory BP was also decreased in both groups. There was no significant change in LVM or FMD in either group. Baseline LVM index and FMD values were correlated with systolic BP (r=0.51, P=.02; r=0.54, P=.009). In the optimal therapy group, urinary albumin excretion increased significantly (P=.04). Plasma levels of B-type natriuretic peptide (BNP) decreased with antihypertensive therapy (P=.03). Treatment was well tolerated, and none of the patients withdrew from the study. There was no significant difference in adverse events between the 2 groups. Optimization of BP is feasible, safe, and well tolerated; however, a larger study of longer duration may be needed to demonstrate improvements in LVM and endothelial function with conventional versus optimal therapy.