Attila Kovács

Right atrial size and function assessed with three-dimensional and speckle-tracking echocardiography in 200 healthy volunteers

AIMS Right atrial (RA) size predicts the outcome in some pathological conditions but reference values for RA volumes and myocardial function remain to be defined. Thus, we used two-dimensional speckle-tracking echocardiography (2D-STE) and three-dimensional echocardiography (3DE) to define normative reference values of RA volumes and function. METHODS AND RESULTS Two hundreds healthy volunteers (43 ± 15 years, range 18-75; 44% men) underwent two-dimensional echocardiography (2DE) to obtain RA volumes and longitudinal strain (LS) of RA wall using 2D-STE, and 3DE to measure maximal (Vmax), minimal, and preA volumes to calculate total, passive, and active emptying volumes (TotEV, PassEV, and ActEV) and emptying fractions (TotEF, PassEF, and ActEF). Three-dimensional echocardiography volumes (Vmax, 52 ± 15 mL vs. 41 ± 14 mL), EVs (TotEV, 33 ± 10 mL vs. 24 ± 9 mL), and EFs (TotEF, 63 ± 9 vs. 58 ± 9%) were larger than 2DE ones (all P < 0.0001). Indexed 3D volumes were significantly larger in men than in women. RA TotEF correlated with total LS (r = 0.24, P = 0.025) and PassEF with positive LS (LSpos; r = 0.34, P < 0.0001). Ageing was associated with a decrease in passive (LSpos, r = -041; PassEV, r = -0.26; PassEF, r = -0.38; all P < 0.0001) and an increase in active RA function (negative LS, r = 0.34; ActEV, r = 0.25; all P < 0.0001; and ActEF, r = 0.15; P = 0.035) in order to maintain TotEV (r = -0.14, P = 0.05). CONCLUSION Our study provides normative values for RA volumes and function measured by 3DE and 2D-STE in a relatively large cohort of healthy subjects with a wide age range. These data will help clinicians to identify RA remodelling and dysfunction.

MicroRNA expression profiling in benign (sporadic and hereditary) and recurring adrenal pheochromocytomas

MicroRNAs are involved in the pathogenesis of several tumors, however, there have been no data on microRNA expression in pheochromocytomas to date. The objective of our study was to perform microRNA expression profiling in sporadic and hereditary benign, and recurring adrenomedullary tumors. Furthermore, the applicability of formalin-fixed paraffin-embedded tissue samples for the analysis of microRNA expression in pheochromocytomas was examined. MicroRNA expression data of three matched frozen and formalin-fixed paraffin-embedded samples were correlated. A total of 21 formalin-fixed paraffin-embedded samples (sporadic benign, multiple endocrine neoplasia 2, von Hippel-Lindau disease, sporadic recurring) were subjected to microRNA expression profiling using microarrays. MicroRNAs with significant differences in expression were validated and sample sizes were extended including tumors from neurofibromatosis type 1 patients by real-time quantitative reverse-transcription PCR (n=33). MicroRNA target prediction was carried out by TargetScan and MicroCosm Targets. Pathway analysis of targets was performed by Ingenuity Pathway Analysis and DIANA mirPath. Furthermore, microRNA expression profiles of a malignant pheochromocytoma and a pair of primary and recurrent tumors were studied by TaqMan Human MicroRNA Cards. MicroRNA expression correlated well between frozen and formalin-fixed paraffin-embedded samples (70–92%). Microarray analysis revealed 16 significantly differentially expressed microRNAs. Five of these were validated by real-time RT-PCR. miR-139-3p, miR-541 and miR-765 were significantly differentially expressed between sporadic benign and von Hippel-Lindau-related pheochromocytomas. Significantly higher expression of miR-885-5p and miR-1225-3p was found in multiple endocrine neoplasia type 2 and sporadic recurring pheochromocytomas, respectively. Pathway analysis revealed the possible involvement of Notch- and G-protein-coupled receptor signaling in tumor recurrence. MicroRNA expression profiles in the primary recurrent and recurring malignant comparisons have been similar. In conclusion, we have proved that formalin-fixed paraffin-embedded samples can be used for the analysis of microRNA expression in pheochromocytomas. MicroRNA expression patterns differ between various sporadic, hereditary and recurring tumors and miR-1225-3p may be useful for identifying recurring pheochromocytomas.

The importance of elastin to aortic development in mice.

Elastin is an essential component of vertebrate arteries that provides elasticity and stores energy during the cardiac cycle. Elastin production in the arterial wall begins midgestation but increases rapidly during the last third of human and mouse development, just as blood pressure and cardiac output increase sharply. The aim of this study is to characterize the structure, hemodynamics, and mechanics of developing arteries with reduced elastin levels and determine the critical time period where elastin is required in the vertebrate cardiovascular system. Mice that lack elastin (Eln(-/-)) or have approximately one-half the normal level (Eln(+/-)) show relatively normal cardiovascular development up to embryonic day (E) 18 as assessed by arterial morphology, left ventricular blood pressure, and cardiac function. Previous work showed that just a few days later, at birth, Eln(-/-) mice die with high blood pressure and tortuous, stenotic arteries. During this period from E18 to birth, Eln(+/-) mice add extra layers of smooth muscle cells to the vessel wall and have a mean blood pressure 25% higher than wild-type animals. These findings demonstrate that elastin is only necessary for normal cardiovascular structure and function in mice starting in the last few days of fetal development. The large increases in blood pressure during this period may push hemodynamic forces over a critical threshold where elastin becomes required for cardiovascular function. Understanding the interplay between elastin amounts and hemodynamic forces in developing vessels will help design treatments for human elastinopathies and optimize protocols for tissue engineering.

Reduced expression of Cx43 attenuates ventricular remodeling after myocardial infarction via impaired TGF-β signaling

In addition to mediating cell-to-cell electrical coupling, gap junctions are important in tissue repair, wound healing, and scar formation. The expression and distribution of connexin43 (Cx43), the major gap junction protein expressed in the heart, are altered substantially after myocardial infarction (MI); however, the effects of Cx43 remodeling on wound healing and the attendant ventricular dysfunction are incompletely understood. Cx43-deficient and wild-type mice were subjected to proximal ligation of the anterior descending coronary artery and followed for 6 days or 4 wk to test the hypothesis that reduced expression of Cx43 influences wound healing, fibrosis, and ventricular remodeling after MI. We quantified the progression of infarct healing by measuring neutrophil expression, collagen content, and myofibroblast expression. We found significantly reduced transformation of fibroblasts to myofibroblasts at 6 days and significantly reduced collagen deposition both in the infarct at 6 days and at 4 wk in the noninfarcted region of Cx43-deficient mice. As expected, transforming growth factor (TGF)-beta, a profibrotic cytokine, was dramatically upregulated in MI hearts, but its phosphorylated comediator (pSmad) was significantly downregulated in the nuclei of Cx43-deficient hearts post-MI, suggesting that downstream signaling of TGF-beta is diminished substantially in Cx43-deficient hearts. This diminution in profibrotic TGF-beta signaling resulted in the attenuation of adverse structural remodeling as assessed by echocardiography. These findings suggest that efforts to enhance the expression of Cx43 to maintain intercellular coupling or reduce susceptibility to arrhythmias should be met with caution until the role of Cx43 in infarct healing is fully understood.

Strain and strain rate by speckle-tracking echocardiography correlate with pressure-volume loop-derived contractility indices in a rat model of athlete's heart

Contractile function is considered to be precisely measurable only by invasive hemodynamics. We aimed to correlate strain values measured by speckle-tracking echocardiography (STE) with sensitive contractility parameters of pressure-volume (P-V) analysis in a rat model of exercise-induced left ventricular (LV) hypertrophy. LV hypertrophy was induced in rats by swim training and was compared with untrained controls. Echocardiography was performed using a 13-MHz linear transducer to obtain LV long- and short-axis recordings for STE analysis (GE EchoPAC). Global longitudinal (GLS) and circumferential strain (GCS) and longitudinal (LSr) and circumferential systolic strain rate (CSr) were measured. LV P-V analysis was performed using a pressure-conductance microcatheter, and load-independent contractility indices [slope of the end-systolic P-V relationship (ESPVR), preload recruitable stroke work (PRSW), and maximal dP/dt-end-diastolic volume relationship (dP/dtmax-EDV)] were calculated. Trained rats had increased LV mass index (trained vs. control; 2.76 ± 0.07 vs. 2.14 ± 0.05 g/kg, P < 0.001). P-V loop-derived contractility parameters were significantly improved in the trained group (ESPVR: 3.58 ± 0.22 vs. 2.51 ± 0.11 mmHg/μl; PRSW: 131 ± 4 vs. 104 ± 2 mmHg, P < 0.01). Strain and strain rate parameters were also supernormal in trained rats (GLS: -18.8 ± 0.3 vs. -15.8 ± 0.4%; LSr: -5.0 ± 0.2 vs. -4.1 ± 0.1 Hz; GCS: -18.9 ± 0.8 vs. -14.9 ± 0.6%; CSr: -4.9 ± 0.2 vs. -3.8 ± 0.2 Hz, P < 0.01). ESPVR correlated with GLS (r = -0.71) and LSr (r = -0.53) and robustly with GCS (r = -0.83) and CSr (r = -0.75, all P < 0.05). PRSW was strongly related to GLS (r = -0.64) and LSr (r = -0.71, both P < 0.01). STE can be a feasible and useful method for animal experiments. In our rat model, strain and strain rate parameters closely reflected the improvement in intrinsic contractile function induced by exercise training.

Role of Right Ventricular Global Longitudinal Strain in Predicting Early and Long-Term Mortality in Cardiac Resynchronization Therapy Patients

Background Right ventricular (RV) dysfunction has been associated with poor prognosis in chronic heart failure (HF). However, less data is available about the role of RV dysfunction in patients with cardiac resynchronization therapy (CRT). We aimed to investigate if RV dysfunction would predict outcome in CRT. Design We enrolled prospectively ninety-three consecutive HF patients in this single center observational study. All patients underwent clinical evaluation and echocardiography before CRT and 6 months after implantation. We assessed RV geometry and function by using speckle tracking imaging and calculated strain parameters. We performed multivariable Cox regression models to test mortality at 6 months and at 24 months. Results RV dysfunction, characterized by decreased RVGLS (RV global longitudinal strain) [10.2 (7.0–12.8) vs. 19.5 (15.0–23.9) %, p<0.0001] and RVFWS (RV free wall strain) [15.6 (10.0–19.3) vs. 17.4 (10.5–22.2) %, p = 0.04], improved 6 months after CRT implantation. Increasing baseline RVGLS and RVFWS predicted survival independent of other parameters at 6 months [hazard ratio (HR) = 0.37 (0.15–0.90), p = 0.02 and HR = 0.42 (0.19–0.89), p = 0.02; per 1 standard deviation increase, respectively]. RVGLS proved to be a significant independent predictor of mortality at 24 months [HR = 0.53 (0.32–0.86), p = 0.01], and RVFWS showed a strong tendency [HR = 0.64 (0.40–1.00), p = 0.05]. The 24-month survival was significantly impaired in patients with RVGLS below 10.04% before CRT implantation [area under the curve = 0.72 (0.60–0.84), p = 0.002, log-rank p = 0.0008; HR = 5.23 (1.76–15.48), p = 0.003]. Conclusions Our findings indicate that baseline RV dysfunction is associated with poor short-term and long-term prognosis after CRT implantation.

Measuring Left Ventricular Pressure in Late Embryonic and Neonatal Mice

Blood pressure increases significantly during embryonic and postnatal development in vertebrate animals. In the mouse, blood flow is first detectable around embryonic day (E) 8.5(1). Systolic left ventricular (LV) pressure is 2 mmHg at E9.5 and 11 mmHg at E14.5(2). At these mid-embryonic stages, the LV is clearly visible through the chest wall for invasive pressure measurements because the ribs and skin are not fully developed. Between E14.5 and birth (approximately E21) imaging methods must be used to view the LV. After birth, mean arterial pressure increases from 30 - 70 mmHg from postnatal day (P) 2 - 35(3). Beyond P20, arterial pressure can be measured with solid-state catheters (i.e. Millar or Scisense). Before P20, these catheters are too big for developing mouse arteries and arterial pressure must be measured with custom pulled plastic catheters attached to fluid-filled pressure transducers(3) or glass micropipettes attached to servo null pressure transducers(4). Our recent work has shown that the greatest increase in blood pressure occurs during the late embryonic to early postnatal period in mice(5-7). This large increase in blood pressure may influence smooth muscle cell (SMC) phenotype in developing arteries and trigger important mechanotransduction events. In human disease, where the mechanical properties of developing arteries are compromised by defects in extracellular matrix proteins (i.e. Marfans Syndrome(8) and Supravalvular Aortic Stenosis(9)) the rapid changes in blood pressure during this period may contribute to disease phenotype and severity through alterations in mechanotransduction signals. Therefore, it is important to be able to measure blood pressure changes during late embryonic and neonatal periods in mouse models of human disease. We describe a method for measuring LV pressure in late embryonic (E18) and early postnatal (P1 - 20) mice. A needle attached to a fluid-filled pressure transducer is inserted into the LV under ultrasound guidance. Care is taken to maintain normal cardiac function during the experimental protocol, especially for the embryonic mice. Representative data are presented and limitations of the protocol are discussed.

[The state of the colorectal screening in Hungary: lessons of the pilot programs].

In Hungary, colorectal cancer is the second most common malignant disease. Due to its natural history, colorectal cancer is particularly suitable for screening. At present, epidemiological evidences of the effectiveness of detection of the symptomless colorectal cancer and its precursors are only available for the demonstration of fecal occult blood, endoscopic methods are also in use. For mass screening, fecal occult blood tests are recommended. Guaiac-type chemical methods are widely criticized because of the lack of specificity. Out of the emerging technologies, immunochemical methods based on the antigenicity of blood proteins (hemoglobin) seem to be the most suitable. In the model programmes organized in the frame of the National Public Health Programme, an immunochemical method using two blood proteins (hemoglobin and albumin) have been used. The compliance was not more than 30-45%. About one-third of those with positive blood test refused colonoscopy. The programmes revealed a great number of adenomatous polyps and early cancers, and in the way, the effectiveness of the method has been proved. The model programmes are still continued. Before the continuous and gradual extension of colorectal screening, the validity of the specific method needs to be tested and proved in order to be recognized as a routine procedure for screening. There is a need to test the feasibility of total colonoscopy, however, to this effect the colonoscopic capacity in the country has to be further developed.

Rationale and design of the BUDAPEST-CRT Upgrade Study: A prospective, randomized, multicentre clinical trial

Abstract Aims There is lack of conclusive evidence from randomized clinical trials on the efficacy and safety of upgrade to cardiac resynchronization therapy (CRT) in patients with implanted pacemakers (PM) or defibrillators (ICD) with reduced left ventricular ejection fraction (LVEF) and chronic heart failure (HF). The BUDAPEST-CRT Upgrade Study was designed to compare the efficacy and safety of CRT upgrade from conventional PM or ICD therapy in patients with intermittent or permanent right ventricular (RV) septal/apical pacing, reduced LVEF, and symptomatic HF. Methods and results The BUDAPEST-CRT study is a prospective, randomized, multicentre, investigator-sponsored clinical trial. A total of 360 subjects will be enrolled with LVEF ≤ 35%, NYHA functional classes II–IVa, paced QRS ≥ 150 ms, and a RV pacing ≥ 20%. Patients will be followed for 12 months. Randomization is performed in a 3:2 ratio (CRT-D vs. ICD). The primary composite endpoint is all-cause mortality, a first HF event, or less than 15% reduction in left ventricular (LV) end-systolic volume at 12 months. Secondary endpoints are all-cause mortality, all-cause mortality or HF event, and LV volume reduction at 12 months. Tertiary endpoints include changes in quality of life, NYHA functional class, 6 min walk test, natriuretic peptides, and safety outcomes. Conclusion The results of our prospective, randomized, multicentre clinical trial will provide important information on the role of cardiac resynchronization therapy with defibrillator (CRT-D) upgrade in patients with symptomatic HF, reduced LVEF, and wide-paced QRS with intermittent or permanent RV pacing. Clinical trials.gov identifier NCT02270840.

Differences in the expression of histamine-related genes and proteins in normal human adrenal cortex and adrenocortical tumors

Histamine is involved in the pathogenesis of several tumors; however, there are no data on its possible involvement in human adrenocortical tumorigenesis. The expression of genes and proteins involved in the biosynthesis (histidine decarboxylase, HDC), action (histamine receptors: HRH1–HRH4), and metabolism of histamine is largely unknown both in the normal human adrenal cortex and in adrenocortical tumors. In this study, we examined the expression of histamine-related genes and proteins and histamine content in normal adrenal cortex, benign adrenocortical adenomas, and malignant adrenocortical cancer (ACC). Fifteen normal adrenals and 43 tumors were studied. mRNA expression was examined by real time RT-PCR. Western-blotting and immunohistochemistry were used for the study of proteins. Tissue histamine content was determined by enzyme-linked immunosorbent assay. We found that all proteins involved in histamine biosynthesis and action are present both in the normal adrenal cortex and in the tumors studied. HDC expression and histamine content was highest in the normal tissues and lower in benign tumors, whereas it was significantly less in ACCs. HRH3 expression was significantly higher in ACC samples than in the other groups. Adrenocortical tumorigenesis might, thus, be characterized by reduced histamine biosynthesis; furthermore, different adrenocortical tumor subtypes may show unique histamine receptor expression profiles.