Recommendations for the Evaluation of Left Ventricular Diastolic Function by Echocardiography : An Update from the American Society of Echocardiography and the European Association of Cardiovascular Imaging

http://www.jse.gr.jp/2016_LVDiastolicFunction.pdf

Recommendations for the Evaluation of Left Ventricular Diastolic Function by Echocardiography: An Update from the American Society of Echocardiography and the European Association of Cardiovascular Imaging

Echocardiographic assessment of left ventricular (LV) diastolic function is an integral part of the routine evaluation of patients presenting with symptoms of dyspnea or heart failure. The 2009 American Society of Echocardiography (ASE) and European Association of Echocardiography (now European Association of Cardiovascular Imaging [EACVI]) guidelines for diastolic function assessment were comprehensive, including several two-dimensional (2D) and Doppler parameters to grade diastolic dysfunction and to estimate LV filling pressures.1 Notwithstanding, the inclusion of many parameters in the guidelines was perceived to render diastolic function assessment too complex, because several readers have interpreted the guidelines as mandating all the listed parameters in the document to fall within specified values before assigning a specific grade. The primary goal of this update is to simplify the approach and thus increase the utility of the guidelines in daily clinical practice.

LV diastolic dysfunction is usually the result of impaired LV relaxation with or without …

The cohort of long-term survivors of heart transplant is expanding, and the assessment of these patients requires specific knowledge of the surgical techniques employed to implant the donor heart, the physiology of the transplanted heart, complications of invasive tests routinely performed to detect graft rejection (GR), and the specific pathologies that may affect the transplanted heart. A joint EACVI/Brazilian cardiovascular imaging writing group committee has prepared these recommendations to provide a practical guide to echocardiographers involved in the follow-up of heart transplant patients and a framework for standardized and efficient use of cardiovascular imaging after heart transplant. Since the transplanted heart is smaller than the recipient's dilated heart, the former is usually located more medially in the mediastinum and tends to be rotated clockwise. Therefore, standard views with conventional two-dimensional (2D) echocardiography are often difficult to obtain generating a large variability from patient to patient. Therefore, in echocardiography laboratories equipped with three-dimensional echocardiography (3DE) scanners and specific expertise with the technique, 3DE may be a suitable alternative to conventional 2D echocardiography to assess the size and the function of cardiac chambers. 3DE measurement of left (LV) and right ventricular (RV) size and function are more accurate and reproducible than conventional 2D calculations. However, clinicians should be aware that cardiac chamber volumes obtained with 3DE cannot be compared with those obtained with 2D echocardiography. To assess cardiac chamber morphology and function during follow-up studies, it is recommended to obtain a comprehensive echocardiographic study at 6 months from the cardiac transplantation as a baseline and make a careful quantitation of cardiac chamber size, RV systolic function, both systolic and diastolic parameters of LV function, and pulmonary artery pressure. Subsequent echocardiographic studies should be interpreted in comparison with the data obtained from the 6-month study. An echocardiographic study, which shows no change from the baseline study, has a high negative predictive value for GR. There is no single systolic or diastolic parameter that can be reliably used to diagnose GR. However, in case several parameters are abnormal, the likelihood of GR increases. When an abnormality is detected, careful revision of images of the present and baseline study (side-by-side) is highly recommended. Global longitudinal strain (GLS) is a suitable parameter to diagnose subclinical allograft dysfunction, regardless of aetiology, by comparing the changes occurring during serial evaluations. Evaluation of GLS could be used in association with endomyocardial biopsy (EMB) to characterize and monitor an acute GR or global dysfunction episode. RV size and function at baseline should be assessed using several parameters, which do not exclusively evaluate longitudinal function. At follow-up echocardiogram, all these parameters should be compared with the baseline values. 3DE may provide a more accurate and comprehensive assessment of RV size and function. Moreover, due to the unpredictable shape of the atria in transplanted patients, atrial volume should be measured using the discs' summation algorithm (biplane algorithm for the left atrium) or 3DE. Tricuspid regurgitation should be looked for and properly assessed in all echocardiographic studies. In case of significant changes in severity of tricuspid regurgitation during follow-up, a 2D/3D and colour Doppler assessment of its severity and mechanisms should be performed. Aortic and mitral valves should be evaluated according to current recommendations. Pericardial effusion should be serially evaluated regarding extent, location, and haemodynamic impact. In case of newly detected pericardial effusion, GR should be considered taking into account the overall echocardiographic assessment and patient evaluation. Dobutamine stress echocardiography might be a suitable alternative to routine coronary angiography to assess cardiac allograft vasculopathy (CAV) at centres with adequate experience with the methodology. Coronary flow reserve and/or contrast infusion to assess myocardial perfusion might be combined with stress echocardiography to improve the accuracy of the test. In addition to its role in monitoring cardiac chamber function and in diagnosis the occurrence of GR and/or CAV, in experienced centres, echocardiography might be an alternative to fluoroscopy to guide EMB, particularly in children and young women, since echocardiography avoids repeated X-ray exposure, permits visualization of soft tissues and safer performance of biopsies of different RV regions. Finally, in addition to the indications about when and how to use echocardiography, the document also addresses the role of the other cardiovascular imaging modalities during follow-up of heart transplant patients. In patients with inadequate acoustic window and contraindication to contrast agents, pharmacological SPECT is an alternative imaging modality to detect CAV in heart transplant patients. However, in centres with adequate expertise, intravascular ultrasound (IVUS) in conjunction with coronary angiography with a baseline study at 4-6 weeks and at 1 year after heart transplant should be performed to exclude donor coronary artery disease, to detect rapidly progressive CAV, and to provide prognostic information. Despite the fact that coronary angiography is the current gold-standard method for the detection of CAV, the use of IVUS should also be considered when there is a discrepancy between non-invasive imaging tests and coronary angiography concerning the presence of CAV. In experienced centres, computerized tomography coronary angiography is a good alternative to coronary angiography to detect CAV. In patients with a persistently high heart rate, scanners that provide high temporal resolution, such as dual-source systems, provide better image quality. Finally, in patients with insufficient acoustic window, cardiac magnetic resonance is an alternative to echocardiography to assess cardiac chamber volumes and function and to exclude acute GR and CAV in a surveillance protocol.

http://www.alexandresiciliano.com.br/guideline-transplante.pdf

European Association of Cardiovascular Imaging/Cardiovascular Imaging Department of the Brazilian Society of Cardiology recommendations for the use of cardiac imaging to assess and follow patients after heart transplantation.

Adult cardiac Sca-1-positive cells differentiate into beating cardiomyocytes

A large number of clinical trials have shown stem cell therapy to be a promising therapeutic approach for the treatment of cardiovascular diseases. Since the first transplantation into human patients, several stem cell types have been applied in this field, including bone marrow derived stem cells, cardiac progenitors as well as embryonic stem cells and their derivatives. However, results obtained from clinical studies are inconsistent and stem cell-based improvement of heart performance and cardiac remodeling was found to be quite limited. In order to optimize stem cell efficiency, it is crucial to elucidate the underlying mechanisms mediating the beneficial effects of stem cell transplantation. Based on these mechanisms, researchers have developed different improvement strategies to boost the potency of stem cell repair and to generate the "next generation" of stem cell therapeutics. Moreover, since cardiovascular diseases are complex disorders including several disease patterns and pathologic mechanisms it may be difficult to provide a uniform therapeutic intervention for all subgroups of patients. Therefore, future strategies should aim at more personalized SC therapies in which individual disease parameters influence the selection of optimal cell type, dosage and delivery approach.

/pdf/stem-cell-therapy-in-heart-diseases-cell-types-mechanisms-vnecljcdj7.pdf

Stem Cell Therapy in Heart Diseases – Cell Types, Mechanisms and Improvement Strategies

Aims Cardiosphere-derived cells (CDCs) are in clinical development as a regenerative cell product which can be expanded ex vivo from patient cardiac biopsies. Cardiosphere-derived cells are clonogenic, exhibit multilineage differentiation, and exert functional benefits in preclinical models of heart failure. The origin of CDCs remains unclear: are these cells endogenous to the heart, or do they arise from cells that populate the heart via blood-borne seeding?

Methods and results Right ventricular endomyocardial biopsies were obtained from cardiac transplant recipients ( n = 10, age 57 ± 15 years), and CDCs expanded from each biopsy. Donor-recipient mismatches were used to probe the origin of CDCs in three complementary ways. First, DNA analysis of short-tandem nucleotide repeats (STRs) was performed on genomic DNA from donor and recipient, then compared with the STR pattern of CDCs. Second, in two cases where the donor was male and the recipient female, CDCs were examined for the presence of X and Y chromosomes by fluorescence in situ hybridization. Finally, in two cases, quantitative PCR (qPCR) was performed for individual-specific polymorphisms of a major histocompatability locus to quantify the contribution of recipient cells to CDCs.

In no case was recipient DNA detectable in the CDCs by STR analysis. In the two cases in which a female patient had received a male heart, all CDCs examined had an X and Y chromosome, similarly indicating exclusively donor origin. Likewise, qPCR on CDCs did not detect any recipient DNA.

Conclusion Cardiosphere-derived cells are of endogenous cardiac origin, with no detectable contribution from extra-cardiac seeding.

https://capricor.com/wp-content/uploads/2014/04/Intrinsic-cardiac-origin-Whie-2013.pdf

Intrinsic cardiac origin of human cardiosphere-derived cells.

Objective Expected values of tissue Doppler imaging (TDI) velocities and myocardial performance index (MPI) after heart transplantation (HTx) have not been evaluated. This study assessed left and right ventricular (LV and RV) structure and function during the first year after HTx using these indexes. Methods and results Echocardiography including MPI and TDI systolic (S′), early (E′) and late (A′) diastolic velocities of RV and LV were performed in 20 donors (mean age 35±13 years) and serially in 20 recipients (mean age 59±9 years) during the first year after HTx. Increase in LV mass occurred at 7 days, with normalisation at 3 months (p Conclusions This study is the first to identify the normal changes of TDI and MPI of both ventricles during the first year after HTx. An increase in LV mass and impairment of bi-ventricular systolic and diastolic function occur early after HTx with gradual improvement during the first year. No significant changes in myocyte size were observed, but there was a substantial increase in fibrosis.

https://heart.bmj.com/content/heartjnl/early/2011/05/16/hrt.2010.220871.full.pdf

Changes in left and right ventricular function of donor hearts during the first year after heart transplantation

BACKGROUND AND AIM OF THE STUDY Cholesterol is a known risk factor in aortic stenosis and valve degeneration, and the liver X receptor (LXR) is a regulator of cholesterol and phospholipid metabolism. It was hypothesized that an LXR agonist would reduce calcium and lipid deposition in aortic valves. METHODS Apolipoprotein E-/- (ApoE-/-) mice fed a high-fat diet were implanted with glutaraldehyde-fixed porcine valve fragments. The animals were treated with either the LXR agonist T1317 or vehicle for eight weeks. RESULTS The LXR agonist reduced lipid deposition in native aortic roots and sinuses about two-fold (p < 0.05), and echocardiography revealed lower transvalvular velocities in vivo (p < 0.05). Similarly, treatment with the LXR agonist significantly reduced the calcium content (by ca. 50%, p < 0.05) and lipid content (by ca. 20%, p < 0.01) of explanted porcine valve tissue. Serum low-density lipoprotein (LDL) and total cholesterol levels were also lower in treated mice (p < 0.01). Serum levels of the inflammatory chemokine platelet factor 4 were reduced by 30% compared to controls. Cultured valvular cells treated with oxidized LDL (ox-LDL) developed greater numbers of calcific nodules. The ox-LDL treatment of valvular endothelial cells increased adhesion to mononuclear cells, while the LXR agonist reversed both the increase in adhesion and vascular cell adhesion protein-1 expression mediated by ox-LDL. CONCLUSION The data acquired suggested that calcium and lipid deposition in heart valves can be altered by inhibiting lipid metabolism via LXR, and that the mechanism may involve inflammatory cell signaling. These results indicate that enhancement of cholesterol efflux activity may have the potential to reduce bioprosthetic and native valve degeneration.

An agonist of liver X receptor slows valvular disease in a hypercholesterolemia mouse model.

The recent emergence of bright, inexpensive colored LEDs offers several advantages over traditional light sources,
including reduced size and increased portability, low power consumption and heat production, increased durability and
longer life, and high temporal resolution. We assembled a modular array of different Phillips LUMILED LUXEON
LEDs, white and seven colors with peak wavelengths between 450 and 640 nm and bandwidths of 20-30 nm. LED
illumination was fiber-optically coupled to the transmitted light path of an inverted microscope, and digital images of
sectioned human tissue stained with absorbing dyes were acquired using combinations of the white and color LEDs. The
LED array was also coupled to an endoscope and used to image human and mouse tissue in situ . Image contrast was
assessed (1) qualitatively by looking down the microscope and by viewing the digital images, and (2) quantitatively by
using entropy analysis in the real and frequency domains to assess the dependence of contrast enhancement on spatial
frequency. Contrast in image features of a given color range was enhanced by LEDs conjugate to that color, whereas
LED colors spanning a wider range enhanced contrast in the entire image, with white LEDs often maximizing contrast of
tissue. This analysis demonstrates the utility of LED illumination in modulating contrast in light microscopy and
endoscopy, which may facilitate spectral segmentation and classification of image features.

Kevin Burton

Papers

Intrinsic cardiac origin of human cardiosphere-derived cells.

Changes in left and right ventricular function of donor hearts during the first year after heart transplantation

An agonist of liver X receptor slows valvular disease in a hypercholesterolemia mouse model.

Contrast enhancement in biomedical optical imaging using ultrabright color LEDs