Prognostic value of heart failure in hemodialysis-dependent end-stage renal disease patients with myocardial fibrosis quantification by extracellular volume on cardiac magnetic resonance imaging

Inflammation Links Cardiac Injury and Renal Dysfunction: A Cardiovascular Magnetic Resonance Study

Background

Inflammation is essential in cardiorenal syndrome, however there is still a lack of evidence proving the interaction between cardiac injury, renal dysfunction and the inflammatory response. This study aimed to illustrate the association between renal dysfunction and cardiac injury with a specific focus on the role of inflammation.

Methods

A single-center, retrospective study included patients with heart failure admitted to the cardiovascular department from September 2019 to April 2022. Patients received cardiovascular magnetic resonance (CMR) imaging (T1 mapping and late gadolinium enhancement (LGE)). Demographic, creatinine and native T1 were analyzed using pearson correlation, linear regression and adjusted for confounders. Interaction and subgroup analysis were performed.

Results

Finally, 50 validated heart failure (HF) patients (age 58.5 ± 14.8 years; 78.0% men) were included. Cardiac global native T1 for the high estimated glomeruar filtration rate (eGFR) group was 1117.0 ± 56.6 ms, and for the low eGFR group was 1096.5 ± 61.8 ms. Univariate analysis identified global native T1 ( β = 0.16, 95% confidence interval (CI): 0.04-0.28, p = 0.014) and C-reactive protein (CRP) ( β = 0.30, 95% CI: 0.15-0.45, p < 0.001) as determinants of creatinine. Multivariable linear regression analysis identified global native T1 ( β = 0.12, 95% CI: 0.01-0.123, p = 0.040) as a determinant of creatinine while age and diabetes were adjusted. Significant interactions between CRP and global native T1 in relation to creatinine level (p for interaction = 0.005) were identified.

Conclusions

Kidney dysfunction was associated with cardiac injury and inflammation, respectively. The interaction between myocardial injury and kidney dysfunction is contingent on the severity of the inflammatory response. Further studies were needed to identify the mechanisms of the inflammatory response in cardiorenal syndrome.

ITRI Biofilm Prevented Thoracic Adhesion in Pigs That Received Myocardial Ischemic Induction Treated by Myocardial Implantation of EPCs and ECSW Treatment

This study tested the hypothesis that ITRI Biofilm prevents adhesion of the chest cavity. Combined extracorporeal shock wave (ECSW) + bone marrow-derived autologous endothelial progenitor cell (EPC) therapy was superior to monotherapy for improving heart function (left ventricular ejection fraction [LVEF]) in minipigs with ischemic cardiomyopathy (IC) induced by an ameroid constrictor applied to the mid-left anterior descending artery. The minipigs (n = 30) were equally designed into group 1 (sham-operated control), group 2 (IC), group 3 (IC + EPCs/by directly implanted into the left ventricular [LV] myocardium; 3 [+]/3[-] ITRI Biofilm), group 4 (IC + ECSW; 3 [+]/[3] - ITRI Biofilm), and group 5 (IC + EPCs-ECSW; 3 [+]/[3] - ITRI Biofilm). EPC/ECSW therapy was administered by day 90, and the animals were euthanized, followed by heart harvesting by day 180. In vitro studies demonstrated that cell viability/angiogenesis/cell migratory abilities/mitochondrial concentrations were upregulated in EPCs treated with ECSW compared with those in EPCs only (all Ps < 0.001). The LVEF was highest in group 1/lowest in group 2/significantly higher in group 5 than in groups 3/4 (all Ps < 0.0001) by day 180, but there was no difference in groups 3/4. The adhesion score was remarkably lower in patients who received ITRI Biofilm treatment than in those who did not (all Ps <0.01). The protein expressions of oxidative stress (NOX-1/NOX-2/oxidized protein)/apoptotic (mitochondrial-Bax/caspase3/PARP)/fibrotic (TGF-β/Smad3)/DNA/mitochondria-damaged (γ-H2AX/cytosolic-cytochrome-C/p-DRP1), and heart failure/pressure-overload (BNP [brain natriuretic peptide]/β-MHC [beta myosin heavy chain]) biomarkers displayed a contradictory manner of LVEF among the groups (all Ps < 0.0001). The protein expression of endothelial biomarkers (CD31/vWF)/small-vessel density revealed a similar LVEF within the groups (all Ps < 0.0001). ITRI Biofilm treatment prevented chest cavity adhesion and was superior in restoring IC-related LV dysfunction when combined with EPC/ECSW therapy compared with EPC/ECSW therapy alone.

A pilot randomised controlled trial of a structured, home-based exercise programme on cardiovascular structure and function in kidney transplant recipients: the ECSERT study design and methods

BACKGROUND

Cardiovascular disease (CVD) is a major cause of morbidity and mortality in kidney transplant recipients (KTRs). CVD risk scores underestimate risk in this population as CVD is driven by clustering of traditional and non-traditional risk factors, which lead to prognostic pathological changes in cardiovascular structure and function. While exercise may mitigate CVD in this population, evidence is limited, and physical activity levels and patient activation towards exercise and self-management are low. This pilot study will assess the feasibility of delivering a structured, home-based exercise intervention in a population of KTRs at increased cardiometabolic risk and evaluate the putative effects on cardiovascular structural and functional changes, cardiorespiratory fitness, quality of life, patient activation, healthcare utilisation and engagement with the prescribed exercise programme.

METHODS AND ANALYSIS

Fifty KTRs will be randomised 1:1 to: (1) the intervention; a 12week, home-based combined resistance and aerobic exercise intervention; or (2) the control; usual care. Intervention participants will have one introductory session for instruction and practice of the recommended exercises prior to receiving an exercise diary, dumbbells, resistance bands and access to instructional videos. The study will evaluate the feasibility of recruitment, randomisation, retention, assessment procedures and the intervention implementation. Outcomes, to be assessed prior to randomisation and postintervention, include: cardiac structure and function with stress perfusion cardiac MRI, cardiorespiratory fitness, physical function, blood biomarkers of cardiometabolic health, quality of life and patient activation. These data will be used to inform the power calculations for future definitive trials.

ETHICS AND DISSEMINATION

The protocol was reviewed and given favourable opinion by the East Midlands-Nottingham 2 Research Ethics Committee (reference: 19/EM/0209; 14 October 2019). Results will be published in peer-reviewed academic journals and will be disseminated to the patient and public community via social media, newsletter articles and presentations at conferences.

TRIAL REGISTRATION NUMBER

NCT04123951.

Elevated circulating fibrocyte levels in hemodialysis-dependent end-stage renal disease patients

INTRODUCTION

Numerous studies have demonstrated that end-stage renal disease (ESRD) patients undergoing hemodialysis (HD) have high myocardial fibrosis (MF) levels. Circulating fibrocytes are bone marrow-derived circulating mesenchymal progenitors, and new evidence suggests a vital role for fibrocytes in the development of MF. This study aimed to investigate whether fibrocyte levels are elevated in patients undergoing HD and its influence factors.

METHODS

We carried out a flow cytometry analysis to measure the proportion of peripheral blood circulating fibrocytes in a cohort of 126 healthy control individuals and 161 subjects with HD. Cardiac function and morphology were assessed by electrocardiogram and transthoracic echocardiogram.

FINDINGS

Compared to healthy controls, individuals with ESRD had significantly higher levels of circulating fibrocytes. There was a strong correlation between the frequency of fragmented QRS (fQRS) and circulating fibrocytes in HD patients. Furthermore, higher fibrocytes correlated to increasing age, dialysis age, left ventricular mass index (LVMI), left ventricular ejection fraction (LVEF), and hypertension complication. On multivariate analysis, the dialysis age [odds ratio (OR) 1.011, 95% confidence interval (CI) 1.003-1.019, p = 0.006], LVMI (OR 1.012, 95% CI 1.002-1.022, p = 0.016), hypertension (OR 4.303, 95% CI 1.129-16.406, p = 0.033), and fQRS (OR 2.439, 95% CI 1.049-5.262, p = 0.038) were significant independent predictors of fibrocytes percentage.

DISCUSSION

We concluded that bone marrow-derived circulating fibrocytes were significantly increased in ESRD patients with HD compared with controls. Our data suggested that these cells might play essential roles during MF in HD patients.

A Personalized Approach to Chronic Kidney Disease and Cardiovascular Disease: JACC Review Topic of the Week

Cardiovascular disease is the most common cause of death in patients with end-stage renal disease (ESRD). The initiation of dialysis for treatment of ESRD exacerbates chronic electrolyte and hemodynamic perturbations. Rapid large shifts in effective intravascular volume and electrolyte concentrations ultimately lead to subendocardial ischemia, increased left ventricular wall mass, and diastolic dysfunction, and can precipitate serious arrhythmias through a complex pathophysiological process. These factors, unique to advanced kidney disease and its treatment, increase the overall incidence of acute coronary syndrome and sudden cardiac death. To date, risk prediction models largely fail to incorporate the observed cardiovascular mortality in the CKD population; however, multimodality imaging may provide an additional prognostication and risk stratification. This comprehensive review discusses the cardiovascular risks associated with hemodialysis, and explores the pathophysiology and the novel utilization of multimodality imaging in CKD to promote a personalized approach for these patients with implications for future research.

Heart failure in chronic kidney disease: the emerging role of myocardial fibrosis

Heart failure (HF) is one of the main causes of morbidity and mortality in patients with chronic kidney disease (CKD). Decreased glomerular filtration rate is associated with diffuse deposition of fibrotic tissue in the myocardial interstitium [i.e. myocardial interstitial fibrosis (MIF)] and loss of cardiac function. MIF results from cardiac fibroblast-mediated alterations in the turnover of fibrillary collagen that lead to the excessive synthesis and deposition of collagen fibres. The accumulation of stiff fibrotic tissue alters the mechanical properties of the myocardium, thus contributing to the development of HF. Accumulating evidence suggests that several mechanisms are operative along the different stages of CKD that may converge to alter fibroblasts and collagen turnover in the heart. Therefore, focusing on MIF might enable the identification of fibrosis-related biomarkers and targets that could potentially lead to a new strategy for the prevention and treatment of HF in patients with CKD. This article summarizes current knowledge on the mechanisms and detrimental consequences of MIF in CKD and discusses the validity and usefulness of available biomarkers to recognize the clinical-pathological variability of MIF and track its clinical evolution in CKD patients. Finally, the currently available and potential future therapeutic strategies aimed at personalizing prevention and reversal of MIF in CKD patients, especially those with HF, will be also discussed.

Imaging tools for assessment of myocardial fibrosis in humans: the need for greater detail

Myocardial fibrosis is recognized as a key pathological process in the development of cardiac disease and a target for future therapeutics. Despite this recognition, the assessment of fibrosis is not a part of routine clinical practice. This is primarily due to the difficulties in obtaining an accurate assessment of fibrosis non-invasively. Moreover, there is a clear discrepancy between the understandings of myocardial fibrosis clinically where fibrosis is predominately studied with comparatively low-resolution medical imaging technologies like MRI compared with the basic science laboratories where fibrosis can be visualized invasively with high resolution using molecularly specific fluorescence microscopes at the microscopic and nanoscopic scales. In this article, we will first review current medical imaging technologies for assessing fibrosis including echo and MRI. We will then highlight the need for greater microscopic and nanoscopic analysis of human tissue and how this can be addressed through greater utilization of human tissue available through endomyocardial biopsies and cardiac surgeries. We will then describe the relatively new field of molecular imaging that promises to translate research findings to the clinical practice by non-invasively monitoring the molecular signature of fibrosis in patients.