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BioRxiv : the Preprint Server For... Feb 2024Septic shock, in humans and in our well-established animal model, is associated with increases in biventricular end diastolic volume (EDV) and decreases in ejection...
BACKGROUND
Septic shock, in humans and in our well-established animal model, is associated with increases in biventricular end diastolic volume (EDV) and decreases in ejection fraction (EF). These abnormalities occur over 2 days and reverse within 10 days. Septic non-survivors do not develop an increase in EDV. The mechanism for this cardiac dysfunction and EDV differences is unknown.
METHODS
Purpose-bred beagles randomized to receive intrabronchial (n=27) or saline (n=6) were provided standard ICU care including sedation, mechanical ventilation, and fluid resuscitation to a pulmonary arterial occlusion pressure of over 10mmHg. No catecholamines were administered. Over 96h, cardiac magnetic resonance imaging, echocardiograms, and invasive hemodynamics were serially performed, and laboratory data was collected. Tissue was obtained at 66h from six septic animals.
RESULTS
From 0-96h after bacterial challenge, septic animals controls had significantly increased left ventricular wall edema (6%) and wall thinning with loss of mass (15%) which was more pronounced at 48h in non-survivors than survivors. On histology, edema was located predominantly in myocytes, the interstitium, and endothelial cells. Edema was associated with significantly worse biventricular function (lower EFs), ventricular-arterial coupling, and circumferential strain. In septic animals, from 0-24h, the EDV decreased from baseline and, despite cardiac filling pressures being similar, decreased significantly more in non-survivors. From 24-48h, all septic animals had increases in biventricular chamber sizes. Survivors biventricular EDVs were significantly greater than baseline and in non-survivors, where biventricular EDVs were not different from baseline. Preload, afterload, or HR differences did not explain these differential serial changes in chamber size.
CONCLUSION
Systolic and diastolic cardiac dysfunction during sepsis is associated with ventricular wall edema. Rather than differences in preload, afterload, or heart rate, structural alterations to the ventricular wall best account for the volume changes associated with outcome during sepsis. In non-survivors, from 0-24h, sepsis induces a more severe diastolic dysfunction, further decreasing chamber size. The loss of left ventricular mass with wall thinning in septic survivors may, in part explain, the EDV increases from 24-48h. However, these changes continued and even accelerated into the recovery phase consistent with a reparative process rather than ongoing injury.
PubMed: 38903100
DOI: 10.1101/2024.02.05.578971 -
Cardiovascular Diabetology Jun 2024Stress hyperglycemia occurs frequently in patients following acute myocardial infarction (AMI) and may aggravate myocardial stiffness, but relevant evidence is still...
BACKGROUND
Stress hyperglycemia occurs frequently in patients following acute myocardial infarction (AMI) and may aggravate myocardial stiffness, but relevant evidence is still lacking. Accordingly, this study aimed to examine the impact of admission stress hyperglycemia on left ventricular (LV) myocardial deformation in patients following AMI.
METHODS
A total of 171 patients with first AMI (96 with normoglycemia and 75 with hyperglycemia) underwent cardiac magnetic resonance (CMR) examination were included. AMI patients were classified according to admission blood glucose level (aBGL): < 7.8 mmol/L (n = 96), 7.8-11.1 mmol/L (n = 41) and ≥ 11.1 mmol/L (n = 34). LV strains, including global radial/circumferential/longitudinal peak strain (PS)/peak systolic strain rate (PSSR)/peak diastolic strain rate (PDSR), were measured and compared between groups. Further, subgroup analyses were separately conducted for AMI patients with and without diabetes. Multivariate analysis was employed to assess the independent association between aBGL and LV global PS in AMI patients.
RESULTS
LV global PS, PSSR and PDSR were decreased in radial, circumferential and longitudinal directions in hyperglycemic AMI patients compared with normoglycemic AMI patients (all P < 0.05). These differences were more obvious in patients with diabetes than those without diabetes. AMI patients with aBGL between 7.8 and 11.1 mmol/L demonstrated significant decreased radial and longitudinal PS, radial PSSR, and radial and longitudinal PDSR than those with aBGL < 7.8 mmol/L (all P < 0.05). AMI patients with aBGL ≥ 11.1 mmol/L showed significantly decreased PS, PSSR and PDSR in all three directions than those with aBGL < 7.8 mmol/L, and decreased longitudinal PSSR than those with aBGL between 7.8 and 11.1 (all P < 0.05). Further, aBGL was significantly and independently associated with radial (β = - 0.166, P = 0.003) and longitudinal (β = 0.143, P = 0.008) PS.
CONCLUSIONS
Hyperglycemia may exacerbate LV myocardial stiffness in patients experienced first AMI, leading to reduction in LV strains. aBGL was an independent indicator of impaired LV global PS in AMI patients. Blood glucose monitoring is more valuable for AMI patients with diabetes.
Topics: Humans; Male; Female; Middle Aged; Hyperglycemia; Aged; Ventricular Function, Left; Blood Glucose; Predictive Value of Tests; Magnetic Resonance Imaging, Cine; Biomarkers; Patient Admission; Ventricular Dysfunction, Left; Myocardial Infarction; Risk Factors; Retrospective Studies; Biomechanical Phenomena
PubMed: 38902730
DOI: 10.1186/s12933-024-02295-y -
Arteriosclerosis, Thrombosis, and... Jun 2024Vascular calcification is associated with increased mortality in patients with cardiovascular disease. Secondary calciprotein particles are believed to play a causal...
BACKGROUND
Vascular calcification is associated with increased mortality in patients with cardiovascular disease. Secondary calciprotein particles are believed to play a causal role in the pathophysiology of vascular calcification. The maturation time (T) of calciprotein particles provides a measure of serum calcification propensity. We compared T between patients with ST-segment-elevated myocardial infarction and control subjects and studied the association of T with cardiovascular risk factors and outcome.
METHODS
T was measured by nephelometry in 347 patients from the GIPS-III trial and in 254 matched general population controls from PREVEND (Prevention of Renal and Vascular End-Stage Disease). We also assessed the association between T and left ventricular ejection fraction, as well as infarct size, the incidence of ischemia-driven reintervention during 5 years of follow-up, and serum nitrite as a marker of endothelial dysfunction.
RESULTS
Patients with ST-segment-elevated myocardial infarction had a significantly lower T (ie, higher serum calcification propensity) compared with controls (T: 289±63 versus 338±56 minutes; <0.001). In patients with ST-segment-elevated myocardial infarction, lower T was associated with female sex, lower systolic blood pressure, lower total cholesterol, lower LDL (low-density lipoprotein) cholesterol, lower triglycerides, and higher HDL (high-density lipoprotein) cholesterol but not with circulating nitrite or nitrate. Ischemia-driven reintervention was associated with higher LDL (=0.03) and had a significant interaction term for T and sex (=0.005), indicating a correlation between ischemia-driven reintervention and T above the median in men and below the median in women, between 150 days and 5 years of follow-up.
CONCLUSIONS
Serum calcification propensity is increased in patients with ST-segment-elevated myocardial infarction compared with the general population, and its contribution is more pronounced in women than in men. Its lack of/inverse association with nitrite and blood pressure confirms T to be orthogonal to traditional cardiovascular disease risk factors. Lower T was associated with a more favorable serum lipid profile, suggesting the involvement of divergent pathways of calcification stress and lipid stress in the pathophysiology of myocardial infarction.
PubMed: 38899469
DOI: 10.1161/ATVBAHA.124.320974 -
Scientific Reports Jun 2024The aim of this study was to develop a simple but effective nomogram to predict risk of septic cardiomyopathy (SCM) in the intensive care unit (ICU). We analyzed data...
The aim of this study was to develop a simple but effective nomogram to predict risk of septic cardiomyopathy (SCM) in the intensive care unit (ICU). We analyzed data from patients who were first admitted to the ICU for sepsis between 2008 and 2019 in the MIMIC-IV database, with no history of heart disease, and divided them into a training cohort and an internal validation cohort at a 7:3 ratio. SCM is defined as sepsis diagnosed in the absence of other cardiac diseases, with echocardiographic evidence of left (or right) ventricular systolic or diastolic dysfunction and a left ventricular ejection fraction (LVEF) of less than 50%. Variables were selected from the training cohort using the Least Absolute Shrinkage and Selection Operator (LASSO) regression to develop an early predictive model for septic cardiomyopathy. A nomogram was constructed using logistic regression analysis and its receiver operating characteristic (ROC) and calibration were evaluated in two cohorts. A total of 1562 patients participated in this study, with 1094 in the training cohort and 468 in the internal validation cohort. SCM occurred in 13.4% (147 individuals) in the training cohort, 16.0% (75 individuals) in the internal validation cohort. After adjusting for various confounding factors, we constructed a nomogram that includes SAPS II, Troponin T, CK-MB index, white blood cell count, and presence of atrial fibrillation. The area under the curve (AUC) for the training cohort was 0.804 (95% CI 0.764-0.844), and the Hosmer-Lemeshow test showed good calibration of the nomogram (P = 0.288). Our nomogram also exhibited good discriminative ability and calibration in the internal validation cohort. Our nomogram demonstrated good potential in identifying patients at increased risk of SCM in the ICU.
Topics: Humans; Nomograms; Intensive Care Units; Male; Female; Cardiomyopathies; Middle Aged; Sepsis; Aged; ROC Curve; Risk Factors; Risk Assessment
PubMed: 38898142
DOI: 10.1038/s41598-024-64965-x -
Indian Heart Journal Jun 2024The study was carried out to evaluate the role of the AST (Aspartate transaminase)/ALT (Alanine transaminase) ratio as an indicator of the functional severity in people...
OBJECTIVE
The study was carried out to evaluate the role of the AST (Aspartate transaminase)/ALT (Alanine transaminase) ratio as an indicator of the functional severity in people with chronic heart failure (CHF) with reduced left ventricular ejection fraction.
METHODS
A prospective cross-sectional study was conducted in a tertiary care centre in South India among the individuals who had left ventricular ejection fraction (LVEF) of ≤40 %. The study period was between January 2021 and December 2021. Consecutive patients with the criteria were enrolled in the study. Study participants were grouped based on their AST/ALT ratio value (ratio<1 and ratio≥1).
RESULTS
In present study of 100 participants, there was a statistically significant difference between two groups with respect to ALT, AST/ALT ratio, and ALP (Alkaline phosphatase). There was a significant correlation between the APRI (AST to platelet ratio index) and FIB-4 (Fibrosis-4) with AST/ALT ratio. Diagnostic analysis of AST/ALT ratio to predict the severity of CHF with reduced EF, the area under the curve (AUC) was 0.547 (p-value = 0.5654) with a 95 % confidence interval of 0.299-0.795 with an optimal cut-off value of 0.6, sensitivity of 96.70 %, and specificity of 33.33 %.
CONCLUSION
The AST/ALT ratio is increased in patients with CHF patients with reduced left ventricular ejection fraction. It is a simple predictor of left ventricular dysfunction in patients with heart failure with reduced ejection fraction.
PubMed: 38897408
DOI: 10.1016/j.ihj.2024.06.004 -
Journal of Cellular and Molecular... Jun 2024Takotsubo syndrome (TTS) is a particular form of acute heart failure that can be challenging to distinguish from acute coronary syndrome at presentation. TTS was... (Review)
Review
Takotsubo syndrome (TTS) is a particular form of acute heart failure that can be challenging to distinguish from acute coronary syndrome at presentation. TTS was previously considered a benign self-limiting condition, but it is now known to be associated with substantial short- and long-term morbidity and mortality. Because of the poor understanding of its underlying pathophysiology, there are few evidence-based interventions to treat TTS. The hypotheses formulated so far can be grouped into endogenous adrenergic surge, psychological stress or preexisting psychiatric illness, coronary vasospasm with microvascular dysfunction, metabolic and energetic alterations, and inflammatory mechanisms. Current evidence demonstrates that the infiltration of immune cells such as macrophages and neutrophils play a pivotal role in TTS. At baseline, resident macrophages were the dominant subset in cardiac macrophages, however, it underwent a shift from resident macrophages to monocyte-derived infiltrating macrophages in TTS. Depletion of macrophages and monocytes in mice strongly protected them from isoprenaline-induced cardiac dysfunction. It is probable that immune cells, especially macrophages, may be new targets for the treatment of TTS.
Topics: Takotsubo Cardiomyopathy; Humans; Inflammation; Animals; Macrophages
PubMed: 38896112
DOI: 10.1111/jcmm.18503 -
BioRxiv : the Preprint Server For... Jun 2024Heart failure with preserved ejection fraction (HFpEF) is increasingly common but its pathogenesis is poorly understood. The ability to assess genetic and pharmacologic...
UNLABELLED
Heart failure with preserved ejection fraction (HFpEF) is increasingly common but its pathogenesis is poorly understood. The ability to assess genetic and pharmacologic interventions is hampered by the lack of robust preclinical mouse models of HFpEF. We have developed a novel "2-hit" model, which combines obesity and insulin resistance with chronic pressure overload to recapitulate clinical features of HFpEF. C57BL6/NJ mice fed a high fat diet for >10 weeks were administered an AAV8-driven vector resulting in constitutive overexpression of mouse . Control mice, HFD only, Renin only and HFD-Renin (aka "HFpEF") littermates underwent a battery of cardiac and extracardiac phenotyping. HFD-Renin mice demonstrated obesity and insulin resistance, a 2-3-fold increase in circulating renin levels that resulted in 30-40% increase in left ventricular hypertrophy, preserved systolic function, and diastolic dysfunction indicated by altered E/e', IVRT, and strain measurements; increased left atrial mass; elevated natriuretic peptides; and exercise intolerance. Transcriptomic and metabolomic profiling of HFD-Renin myocardium demonstrated upregulation of pro-fibrotic pathways and downregulation of metabolic pathways, in particular branched chain amino acid catabolism, similar to findings in human HFpEF. Treatment of these mice with the sodium-glucose cotransporter 2 inhibitor empagliflozin, an effective but incompletely understood HFpEF therapy, improved exercise tolerance, left heart enlargement, and insulin homeostasis. The HFD-Renin mouse model recapitulates key features of human HFpEF and will enable studies dissecting the contribution of individual pathogenic drivers to this complex syndrome. Addition of HFD-Renin mice to the preclinical HFpEF model platform allows for orthogonal studies to increase validity in assessment of interventions.
NEW & NOTEWORTHY
Heart failure with preserved ejection fraction (HFpEF) is a complex disease to study due to limited preclinical models. We rigorously characterize a new two-hit HFpEF mouse model, which allows for dissecting individual contributions and synergy of major pathogenic drivers, hypertension and diet-induced obesity. The results are consistent and reproducible in two independent laboratories. This high-fidelity pre-clinical model increases the available, orthogonal models needed to improve our understanding of the causes and assessment treatments for HFpEF.
PubMed: 38895483
DOI: 10.1101/2024.06.06.597821 -
Journal of Cellular and Molecular... Jun 2024Chronic intermittent hypoxia (CIH) is associated with an increased risk of cardiovascular diseases. Previously, we have shown that berberine (BBR) is a potential...
Chronic intermittent hypoxia (CIH) is associated with an increased risk of cardiovascular diseases. Previously, we have shown that berberine (BBR) is a potential cardioprotective agent. However, its effect and mechanism on CIH-induced cardiomyopathy remain uncovered. This study was designed to determine the effects of BBR against CIH-induced cardiac damage and to explore the molecular mechanisms. Mice were exposed to 5 weeks of CIH with or without the treatment of BBR and adeno-associated virus 9 (AAV9) carrying SIRT6 or SIRT6-specific short hairpin RNA. The effect of BBR was evaluated by echocardiography, histological analysis and western blot analysis. CIH caused the inactivation of myocardial SIRT6 and AMPK-FOXO3a signalling. BBR dose-dependently ameliorated cardiac injury in CIH-induced mice, as evidenced by increased cardiac function and decreased fibrosis. Notably, SIRT6 overexpression mimicked these beneficial effects, whereas infection with recombinant AAV9 carrying SIRT6-specific short hairpin RNA abrogated them. Mechanistically, BBR reduced oxidative stress damage and preserved mitochondrial function via activating SIRT6-AMPK-FOXO3a signalling, enhancing mitochondrial biogenesis as well as PINK1-Parkin-mediated mitophagy. Taken together, these data demonstrate that SIRT6 activation protects against the pathogenesis of CIH-induced cardiac dysfunction. BBR attenuates CIH-induced myocardial injury by improving mitochondrial biogenesis and PINK1-Parkin-dependent mitophagy via the SIRT6-AMPK-FOXO3a signalling pathway.
Topics: Berberine; Animals; Sirtuins; Signal Transduction; Hypoxia; Mice; Male; Forkhead Box Protein O3; Oxidative Stress; Mice, Inbred C57BL; AMP-Activated Protein Kinases; Mitochondria; Mitophagy; Ventricular Remodeling; Disease Models, Animal
PubMed: 38894630
DOI: 10.1111/jcmm.18407 -
Diagnostics (Basel, Switzerland) Jun 2024Non-ischemic dilated cardiomyopathy (DCM) represents a significant cause of heart failure, defined as the presence of left ventricular (LV) dilatation and systolic... (Review)
Review
Non-ischemic dilated cardiomyopathy (DCM) represents a significant cause of heart failure, defined as the presence of left ventricular (LV) dilatation and systolic dysfunction unexplained solely by abnormal loading conditions or coronary artery disease. Cardiac resynchronization therapy (CRT) has emerged as a cornerstone in the management of heart failure, particularly in patients with DCM. However, identifying patients who will benefit the most from CRT remains challenging. Speckle tracking echocardiography (STE) has garnered attention as a non-invasive imaging modality that allows for the quantitative assessment of myocardial mechanics, offering insights into LV function beyond traditional echocardiographic parameters. This comprehensive review explores the role of STE in guiding patient selection and optimizing outcomes in CRT for DCM. By assessing parameters such as LV strain, strain rate, and dyssynchrony, STE enables a more precise evaluation of myocardial function and mechanical dyssynchrony, aiding in the identification of patients who are most likely to benefit from CRT. Furthermore, STE provides valuable prognostic information and facilitates post-CRT optimization by guiding lead placement and assessing response to therapy. Through an integration of STE with CRT, clinicians can enhance patient selection, improve procedural success rates, and ultimately, optimize clinical outcomes in patients with DCM. This review underscores the pivotal role of STE in advancing personalized management strategies for DCM patients undergoing CRT.
PubMed: 38893704
DOI: 10.3390/diagnostics14111178 -
Diagnostics (Basel, Switzerland) Jun 2024The benefit of prophylactic implantable cardioverter defibrillators (ICDs) in patients with severe systolic dysfunction of non-ischemic origin is still unclear, and the...
Right Bundle Branch Block Predicts Appropriate Implantable Cardioverter Defibrillator Therapies in Patients with Non-Ischemic Dilated Cardiomyopathy and a Prophylactic Implantable Cardioverter Defibrillator.
The benefit of prophylactic implantable cardioverter defibrillators (ICDs) in patients with severe systolic dysfunction of non-ischemic origin is still unclear, and the identification of patients at risk for sudden cardiac death remains a major challenge. We retrospectively reviewed all consecutive patients with non-ischemic dilated cardiomyopathy (NICM) who underwent prophylactic ICD implantation between 2008 and 2020 in two tertiary centers. Our main goal was to identify the predictors of appropriate ICD therapies (anti-tachycardia pacing [ATP] and/or shocks) in this cohort of patients. A total of 224 patients were included. After a median follow-up of 51 months, 61 patients (27.2%) required appropriate ICD therapies. Patients with appropriate ICD therapies were more frequently men (87% vs. 69%, = 0.006), of younger age (59 years, (53-65) vs. 64 years, (57-70); = 0.02), showed more right bundle branch blocks (RBBBs) (15% vs. 4%, = 0.007) and less left bundle branch blocks (LBBBs) (26% vs. 47%, = 0.005) in the ECG, and had higher left ventricular end-diastolic (100 mL/m, (90-117) vs. 86, (71-110); = 0.011) and systolic volumes (72 mL/m, (59-87) vs. 61, (47-81), = 0.05). In a multivariate competing-risks regression analysis, RBBB (HR 2.26, CI 95% 1.02-4.98, = 0.043) was identified as an independent predictor of appropriate ICD therapies. RBBBs may help to identify patients with NICM at high risk of ventricular arrhythmias and requiring ICD intervention.
PubMed: 38893699
DOI: 10.3390/diagnostics14111173