Long-term outcome after adding an ICD to CRT in non-ischemic patients

Background

There are limited and contradictory data on the long-term mortality benefit of cardiac resyncronization therapy with implantable cardioverter defibrillator (CRT-D)as compared to Cardiac resynchonization therapy with pacemaker.

Purpose

Our aim was to evaluate the long-term all-cause mortality benefit of CRT-D compared to CRT-P by ischemic aetiology.

Methods

Between 2000 and 2018, patients, who underwent successful CRT implantation were registered. From 2524 patients, 1366 (54%) had a CRT-D implantation and 1099 (44%) had CRT-P implantation. 59 (2%) patients were excluded from the current analysis, who had an ICD upgrade with a CRT-P device during the follow-up. The primary composite endpoint was all-cause mortality, LVAD implantation or heart transplantation. Kaplan-Meier and multivariate Cox regression analyses were used to assess all-cause mortality in the total cohort and by ischemic aetiology.

Results

The median follow-up time was 3.6 years. During this time 1389 patients died from any cause, 692 patients (50%) with a CRT-D device, and 697 patients (50%) with a CRT-P. Patients in the CRT-D group were younger (67 years vs. 70 years; p<0.001), had a less advanced functional class (NYHA III/IV., 52.2% vs. 61.4%; p<0.001), wider QRS [160ms (140/180) vs. 160ms (140/170); p=0.03] and less females (18.9% vs. 33.3%; p<0.001) with an ischemic aetiology (57.7% vs. 40.2%; p<0.0001). CRT-D patients had a better renal function [eGFR, 60.5 (ml/min/1.73m2) vs. 57 (ml/min/1.73m2); p=0.02], decreased ejection fraction (28% vs. 30%; p=0.002), had more frequently ventricular arrhythmia (36% vs. 9.8%; p<0.001). CRT-D patients took more amount of beta-blockers (90.2% vs. 87.3%; p=0.03), MRA (72.2% vs. 61.6%; p<0.001) and amiodaron (32.2% vs. 20%; p<0.001). By multivariate analysis in the total cohort gender, renal function, functional class, aetiology, and the presence of ICD were independent predictors of all-cause mortality. By multivariate analysis, patients with a CRT-D device showed a 25% decreased risk of long-term mortality compared to CRT-P alone in the total cohort. (aHR 0.75; 95% CI 0.58–0.97; p=0.03). When patients were analysed by their etiology, those with non-ischemic cardiomyopathy showed a significant mortality benefit from ICD even after adjusting for relevant clinical variables (aHR 0.45; 95% CI 0.28–0.72; p<0.01). In ischemic patients despite of having a clear mid-term mortality benefit of ICD, it is decreasing after 5 years and less considerable after adjusting for clinical variables (aHR 0.92; 95% CI 0.67–1.27; p=0.60).

Conclusions

Although, CRT-D had a notable mid-term mortality benefit in ischemic patients compared to CRT-P alone, after 5 years it became less pronounced. While in non-ischemic patients, the benefit of adding an ICD to CRT lasts over 10 years.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Project no. NVKP_16-1–2016-0017 (“National Heart Program”) has been implemented with the support provided by the National Research, Development and Innovation Fund of Hungary, financed under the NVKP_16 funding scheme. The research was financed by the Thematic Excellence Programme (2020-4.1.1.-TKP2020) of the Ministry for Innovation and Technology in Hungary, within the framework of the Therapeutic Development and Bioimaging thematic programmes of the Semmelweis University. All-cause mortality

Frequent constriction-like echocardiographic findings in elite athletes following mild COVID-19: in the grasp of SARS-CoV-2?

 

The COVID-19 pandemic had a major impact on the sports community as well. Despite the vast majority of athletes experiencing mild symptoms, potential cardiac involvement and complications have to be explored to support a safe return to play. Accordingly, we were aimed at a comprehensive echocardiographic characterization of post-COVID athletes (P-CA) by comparing them to a propensity-matched healthy, non-COVID athlete (N-CA) cohort.

One hundred and seven elite athletes with COVID-19 were prospectively enrolled after an appropriate quarantine period and formed the P-CA group (23±6 years, 23% female). From our retrospective database comprising 425 elite athletes, 107 age-, gender-, body surface area-, and weekly training hours-matched subjects were selected as a reference group using propensity score matching (N-CA group). All athletes underwent a comprehensive clinical investigation protocol comprising 2D and 3D echocardiography. Left (LV) and right ventricular (RV) end-diastolic volumes (EDVi) and ejection fractions (EF) were quantified using dedicated softwares. To characterize LV longitudinal deformation, 2D global longitudinal strain (GLS) and the ratio of free wall versus septal longitudinal strain (FWLS/SLS) were also calculated. In order to describe septal flattening (SF – frequently seen in P-CA), LV eccentricity index (EI) was measured.

P-CA and N-CA athletes had comparable LV and RV EDVi (P-CA vs N-CA; 77±12 vs 78±13mL/m²; 79±16 vs 80±14mL/m², respectively). P-CA group had significantly higher LV EF (58±4 vs 56±4%, p<0.001) and GLS (−18.2±1.8 vs −17.6±2.2%, p<0.05). Eccentricity index was significantly lower in P-CA (0.89±0.10 vs 0.99±0.04, p<0.001), which was attributable to a distinct subgroup of P-CA athletes with a prominent SF (n=34, 32%), further provoked by inspiration. In this subgroup, the eccentricity index was markedly lower compared to the rest of the P-CA group (0.79±0.07 vs 0.95±0.07, p<0.001).

In the SF subgroup, LV EDVi was significantly higher (80±14 vs 75±11 mL/m², p<0.001), while RV EDVi did not differ (82±16 vs 78±15mL/m²). Moreover, the FWLS/SLS ratio was significantly lower in the SF subgroup (0.92±0.09 vs 0.97±0.08, p<0.01). Interestingly, P-CA athletes with SF experienced fatigue (17 vs 34%, p<0.05) or chest pain (0 vs 15%, p=N/A) less frequently during the course of the infection; however, the presence of a mild pericardial effusion was more common (41 vs 12%, p<0.01).

Elite athletes following COVID-19 showed distinct morphological and functional cardiac changes compared to a propensity score-matched control athlete group. These results are mainly driven by a subgroup, which presented with some echocardiographic features characteristic of constrictive pericarditis (septal flattening, lower FWLS/SLS ratio, pericardial effusion). Follow-up of athletes and further, higher case number studies are warranted to determine the clinical significance and potential effects on exercise capacity of these findings.

Funding Acknowledgement

Type of funding sources: None.

Changes of resting cardiac marker levels due to sport adaptation

Background

In acute and chronic heart diseases some cardiac necroenzymes and peptide fragments are essential during the diagnosis and following the progression of the diseases. Previous literature data are available about elevation of these cardiac markers after exhausting physical activity, but we do not have information about the resting levels in athletes.

Methods

In part of the extended cardiology screening of athletes in our institute, we analyzed the levels of hsTroponinT, CKMB, LDH and NT-proBNP from blood samples. All the samples were collected at least 12 hours after the last trainings or competitions. The results of the athletes were compared with a healthy sedentary non-athlete control group. After the blood collection all subject underwent echocardiography examinations and cardiopulmonary exercise testing. Depending on normality, groups were compared with two-tailed Student's t-test or Mann-Whitney U-test. Statistical analysis was processed in RStudio development environment.

Results

Results of 335 athletes from different sports (male: 162, age: 18.9±5.9 years, training: 15.8±5.9 hours/week) and 53 sedentary non-athletes (male: 23, age: 19.8±3.2 years, training: 2.7±2.3 hours/week) were compared. In athletes, increased level of hsTroponinT was found in 3.3% (n=11), of CKMB in 5.7% (n=18), of LDH in 2.7% (n=9) and of NT-proBNP in 1.2% (n=4). In the control group no elevation was found regarding the CKMB and hsTroponinT, while slightly elevated values of LDH and NT-proBNP were revealed in 1–1 cases. In athletes we measured higher CKMB (17.5±6.8 vs 12.3±3.4 U/l, p&lt;0.001) and LDH values (323.7±63.3 vs 286.0±51.1 U/l, p&lt;0.001), and lower values of NT-proBNP (27.2±29.2 vs 49 8±38.7 pg/ml, p&lt;0.001) compared to the control group, while in the hsTroponinT levels (4.3±1.4 vs 5.6±6.3 ng/l, p=0.33) no significant changes were measured. In term of the examined laboratory parameters significant correlation was found with maximal relative aerob capacity (CKMB: r=0.23, p&lt;0.001; LDH: r=0.18, p&lt;0.001; hsTroponinT: r=0.23, p&lt;0.001; NT-proBNP: r=−0.22, p&lt;0.001), but no correlation was found with age. Significant correlation was found between NT-proBNP levels and echocardiographic measurements of ventricular diameters and left ventricular wall thickness (LVEDD r=−0.15, p&lt;0.03; LVESD r=−0.18, p&lt;0.03; RVD: r=−0.15, p&lt;0.02; IVS: r=−0.22, p&lt;0.001; PWD r=−0.27, p&lt;0.001), CKMB levels correlated with left ventricular wall thickness (IVS: r=0.11, p&lt;0.05; PWD r=0.14, p&lt;0.02).

Conclusions

Based on our results, in connection with the sports adaptation of the heart, the resting levels of the cardiac markers also show significant changes, these changes are correlated with aerobic endurance and structural sport adaptation parameters as well. Our study draws attention to the importance of different assessment of cardiac markers in athletes.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): This project was supported by a grant from the National Research, Development and Innovation Office (NKFIH) of Hungary (K 135076).Supported by the ÚNKP-20-3-I-SE-41 New National Excellence Program of the Ministry for Innovation and Technology from the Source of the National Research, Development and Innovation fund.

Resident cardiac macrophages mediate adaptive myocardial remodeling

Cardiac macrophages represent a heterogeneous cell population with distinct origins, dynamics, and functions. Recent studies have revealed that C-C Chemokine Receptor 2 positive (CCR2+) macrophages derived from infiltrating monocytes regulate myocardial inflammation and heart failure pathogenesis. Comparatively little is known about the functions of tissue resident (CCR2-) macrophages. Herein, we identified an essential role for CCR2- macrophages in the chronically failing heart. Depletion of CCR2- macrophages in mice with dilated cardiomyopathy accelerated mortality and impaired ventricular remodeling and coronary angiogenesis, adaptive changes necessary to maintain cardiac output in the setting of reduced cardiac contractility. Mechanistically, CCR2- macrophages interacted with neighboring cardiomyocytes via focal adhesion complexes and were activated in response to mechanical stretch through a transient receptor potential vanilloid 4 (TRPV4)-dependent pathway that controlled growth factor expression. These findings establish a role for tissue-resident macrophages in adaptive cardiac remodeling and implicate mechanical sensing in cardiac macrophage activation.

Endothelial FGF signaling is protective in hypoxia-induced pulmonary hypertension

Hypoxia-induced pulmonary hypertension (PH) is one of the most common and deadliest forms of PH. Fibroblast growth factor receptors 1 and 2 (FGFR1/2) are elevated in patients with PH and in mice exposed to chronic hypoxia. Endothelial FGFR1/2 signaling is important for the adaptive response to several injury types and we hypothesized that endothelial FGFR1/2 signaling would protect against hypoxia-induced PH. Mice lacking endothelial FGFR1/2, mice with activated endothelial FGFR signaling, and human pulmonary artery endothelial cells (HPAECs) were challenged with hypoxia. We assessed the effect of FGFR activation and inhibition on right ventricular pressure, vascular remodeling, and endothelial-mesenchymal transition (EndMT), a known pathologic change seen in patients with PH. Hypoxia-exposed mice lacking endothelial FGFRs developed increased PH, while mice overexpressing a constitutively active FGFR in endothelial cells did not develop PH. Mechanistically, lack of endothelial FGFRs or inhibition of FGFRs in HPAECs led to increased TGF-β signaling and increased EndMT in response to hypoxia. These phenotypes were reversed in mice with activated endothelial FGFR signaling, suggesting that FGFR signaling inhibits TGF-β pathway-mediated EndMT during chronic hypoxia. Consistent with these observations, lung tissue from patients with PH showed activation of FGFR and TGF-β signaling. Collectively, these data suggest that activation of endothelial FGFR signaling could be therapeutic for hypoxia-induced PH.

Global and regional right ventricular mechanics in repaired tetralogy of Fallot with chronic severe pulmonary regurgitation: a three-dimensional echocardiography study

BACKGROUND

Data about the right ventricular (RV) mechanics adaptation to volume overload in patients with repaired tetralogy of Fallot (rToF) are limited. Accordingly, we sought to assess the mechanics of the functional remodeling occurring in the RV of rToF with severe pulmonary regurgitation.

METHODS

We used three-dimensional transthoracic echocardiography (3DTE) to obtain RV data sets from 33 rToF patients and 30 age- and sex- matched controls. A 3D mesh model of the RV was generated, and RV global and regional longitudinal (LS) and circumferential (CS) strain components, and the relative contribution of longitudinal (LEF), radial (REF) and anteroposterior (AEF) wall motion to global RV ejection fraction (RVEF) were computed using the ReVISION method.

RESULTS

Corresponding to decreased global RVEF (45 ± 6% vs 55 ± 5%, p < 0.0001), rToF patients demonstrated lower absolute values of LEF (17 ± 4 vs 28 ± 4), REF (20 ± 5 vs 25 ± 4) and AEF (17 ± 5 vs 21 ± 4) than controls (p < 0.01). However, only the relative contribution of LEF to global RVEF (0.39 ± 0.09 vs 0.52 ± 0.05, p < 0.0001) was significantly decreased in rToF, whereas the contribution of REF (0.45 ± 0.08 vs 0.46 ± 0.04, p > 0.05) and AEF (0.38 ± 0.09 vs 0.39 ± 0.04, p > 0.05) to global RVEF was similar to controls. Accordingly, rToF patients showed lower 3D RV global LS (-16.94 ± 2.9 vs -23.22 ± 2.9, p < 0.0001) and CS (-19.79 ± 3.3 vs -22.81 ± 3.5, p < 0.01) than controls. However, looking at the regional RV deformation, the 3D CS was lower in rToF than in controls only in the basal RV free-wall segment (p < 0.01). 3D RV LS was reduced in all RV free-wall segments in rToF (p < 0.0001), but similar to controls in the septum (p > 0.05).

CONCLUSIONS

3DTE allows a quantitative evaluation of the mechanics of global RVEF. In rToF with chronic volume overload, the relative contribution of the longitudinal shortening to global RVEF is affected more than either the radial or the anteroposterior components.

Long-term mortality benefit of CRT-D vs. CRT-P upgrade procedures from conventional devices without prior ventricular arrhythmias

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): This work was supported by the ÚNKP-20-3-I New National Excellence Program if the Ministry for Innovation and Technology in Hungary, the National Research, Development, and Innovation Office of Hungary (NKFIA; NVKP_16-1-2016-0017 National Heart Program), and the Higher Education Institutional Excellence Program of the Ministry for Innovation and Technology in Hungary, within the framework of the Therapeutic Development thematic program of the Semmelweis University. This work was also supported by the Artificial Intelligence Research Filed Excellence Program of the National Research, Development and Innovation Office of the Ministry of Innovation and Technology in Hungary (TKP/ITM/NKFIH). The research was also financed by the Thematic Excellence Program (Tématerületi Kiválósági Program, 2020-4.1.1-TKP2020) of the Ministry for Innovation and Technology in Hungary, within the framework of the Bioimaging thematic program of the Semmelweis University.

Background

 Cardiac Resynchronization Therapy (CRT) upgrade can reverse pacing-induced cardiomyopathy (PiCMP) and related major ventricular arrhythmias (MVA). However, there is a lack of data comparing mortality benefit of adding an ICD to CRT during upgrade procedures in those without prior malignant ventricular arrhythmias (VAs).

Purpose

 We aimed to compare the all-cause mortality, echocardiographic response, MVA occurrence and the rate of complications of patients with prior pacemakers (PM) upgraded to CRT-P or CRT-D devices. 

Methods

 Between 2000-2018 patients who underwent a successful CRT upgrade procedure from conventional pacemaker without a prior MVAs were collected. From 270 patients 83 (30.7%) upgraded to CRT-D, 187 (69.3%) to CRT-P device. The primary endpoint was all-cause mortality, secondary endpoints were echocardiographic response defined as left ventricular ejection fraction (LVEF) increase ≥5%, the occurrence of subsequent MVAs and the rate of periprocedural complications.

Results

 CRT-D upgrade patients were more likely to be males, have a favourable renal function and lower LVEF compared to CRT-P group. During the median follow-up time of 3.7 years, 25 (30%) CRT-D and 131 (70%) CRT-P upgrade patients reached the primary endpoint. By univariate analysis, CRT-D upgrade patients showed 45% (HR 0.55; 95%CI 0.38-0.78; p &lt; 0.01) lower all-cause mortality risk than CRT-P group. By multivariate analysis CRT-D (HR 0.39; 95%CI 0.23-0.66; p &lt; 0.01), male sex (HR 1.60; 95%CI 1.03-2.47; p = 0.04), LVEF (HR 0.97; 95%CI 0.94-0.99; p &lt; 0.01) have confirmed as independent predictors of all-cause mortality. Assessing secondary endpoints, LVEF response (66% vs 63%; p = 0.72), MVA occurrence (3.4% vs 0.8%; p &lt; 0.01) and the rate of periprocedural complications were comparable in the two groups (14.8% vs 7%; p = 0.87), despite the higher number of lead explantations during CRT-D procedures than CRT-P upgrade (13% vs 1%; p &lt; 0.001).

Conclusions

 Adding an ICD during CRT upgrade procedures showed 45% lower all-cause mortality risk than CRT-P alone in patients with a pacemaker and no previous ventricular arrhythmias. This beneficial effect was independent of the echocardiographic response, safety or subsequent ventricular arrhythmias. Abstract Figure.

Myocardial Lipin 1 knockout in mice approximates cardiac effects of human LPIN1 mutations

Lipin 1 is a bifunctional protein that is a transcriptional regulator and has phosphatidic acid (PA) phosphohydrolase activity, which dephosphorylates PA to generate diacylglycerol. Human lipin 1 mutations lead to episodic rhabdomyolysis, and some affected patients exhibit cardiac abnormalities, including exercise-induced cardiac dysfunction and cardiac triglyceride accumulation. Furthermore, lipin 1 expression is deactivated in failing heart, but the effects of lipin 1 deactivation in myocardium are incompletely understood. We generated mice with cardiac-specific lipin 1 KO (cs-Lpin1-/-) to examine the intrinsic effects of lipin 1 in the myocardium. Cs-Lpin1-/- mice had normal systolic cardiac function but mild cardiac hypertrophy. Compared with littermate control mice, PA content was higher in cs-Lpin1-/- hearts, which also had an unexpected increase in diacylglycerol and triglyceride content. Cs-Lpin1-/- mice exhibited diminished cardiac cardiolipin content and impaired mitochondrial respiration rates when provided with pyruvate or succinate as metabolic substrates. After transverse aortic constriction-induced pressure overload, loss of lipin 1 did not exacerbate cardiac hypertrophy or dysfunction. However, loss of lipin 1 dampened the cardiac ionotropic response to dobutamine and exercise endurance in association with reduced protein kinase A signaling. These data suggest that loss of lipin 1 impairs cardiac functional reserve, likely due to effects on glycerolipid homeostasis, mitochondrial function, and protein kinase A signaling.

Inhibition of NOX1 Mitigates Blood Pressure Increases in Elastin Insufficiency

Elastin (ELN) insufficiency leads to the cardiovascular hallmarks of the contiguous gene deletion disorder, Williams-Beuren syndrome, including hypertension and vascular stiffness. Previous studies showed that Williams-Beuren syndrome deletions, which extended to include the NCF1 gene, were associated with lower blood pressure (BP) and reduced vascular stiffness. NCF1 encodes for p47phox, the regulatory component of the NOX1 NADPH oxidase complex that generates reactive oxygen species (ROS) in the vascular wall. Dihydroethidium and 8-hydroxyguanosine staining of mouse aortas confirmed that Eln heterozygotes (Eln^+/- ) had greater ROS levels than the wild-types (Eln^+/+ ), a finding that was negated in vessels cultured without hemodynamic stressors. To analyze the Nox effect on ELN insufficiency, we used both genetic and chemical manipulations. Both Ncf1 haploinsufficiency (Ncf1^+/- ) and Nox1 insufficiency (Nox1^-/y ) decreased oxidative stress and systolic BP in Eln^+/- without modifying vascular structure. Chronic treatment with apocynin, a p47phox inhibitor, lowered systolic BP in Eln^+/- , but had no impact on Eln^+/+ controls. In vivo dosing with phenylephrine (PE) produced an augmented BP response in Eln^+/- relative to Eln^+/+ , and genetic modifications or drug-based interventions that lower Nox1 expression reduced the hypercontractile response to PE in Eln^+/- mice to Eln^+/+ levels. These results indicate that the mechanical and structural differences caused by ELN insufficiency leading to oscillatory flow can perpetuate oxidative stress conditions, which are linked to hypertension, and that by lowering the Nox1-mediated capacity for vascular ROS production, BP differences can be normalized.

Pursuing the non-invasive assessment of cardiac contractility: the added value of pressure-area-strain loop analysis in volume overload-induced heart failure

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): This work was supported by the New National Excellence Programme (ÚNKP-19-3-I) of the Ministry for Innovation and Technology in Hungary, and the Artificial Intelligence Research Field Excellence Programme of the National Research, Development and Innovation Office of the Ministry of Innovation and Technology in Hungary.

Background

Global longitudinal strain (GLS) by speckle-tracking echocardiography (STE) is a sensitive parameter of left ventricular (LV) systolic function. Nevertheless, GLS is dependent on loading conditions. Through the analysis of pressure-strain loops, myocardial work was recently introduced and tested in different clinical scenarios. Myocardial work incorporates afterload, but still, it neglects changes in preload and LV geometry.

Purpose

Accordingly, our aim was to test our hypothesis that adding instantaneous LV size to myocardial work calculation can further mitigate the load-dependency of GLS, and therefore, a better correlation with intrinsic myocardial contractility can be achieved.

Methods

Volume overload-induced heart failure was established by an aortocaval fistula (ACF) in male Wistar rats (n = 12). Age-matched sham-operated animals served as controls (n = 12). STE was performed to assess GLS, which was immediately followed by invasive pressure-volume (P-V) analysis to assess LV pressure and to compute a gold-standard index of cardiac contractility (preload recruitable stroke work [PRSW]). Global myocardial work index (GMWI) was calculated from GLS and the invasively measured LV pressure. To compute GMWI indexed to LV area (GMWIA), the instantaneous power (calculated by multiplying the strain rate and the instantaneous LV pressure) was divided by the instantaneous LV area, and then it was integrated from mitral valve closure until mitral valve opening.

Results

LV ejection fraction did not differ significantly (ACF vs. controls: 59 ± 4 vs. 65 ± 9%, p = NS), whereas GLS (Figure 1A - representative animals) was slightly decreased in the ACF group (-13.2 ± 2.3 vs. -15.4 ± 1.9%, p &lt; 0.05). In contrast, PRSW, GMWI (Figure 1B - representative animals) and GMWIA (Figure 1C - representative animals) were considerably reduced in ACF compared to controls (57 ± 13 vs. 111 ± 38mmHg, 1383 ± 382 vs. 1928 ± 281mmHg%, 11.6 ± 3.7 vs. 47.9 ± 22.8mmHg%/mm2, all p &lt; 0.01). GLS showed moderate correlation with PRSW (r=-0.550, p &lt; 0.01), whereas GMWI correlated more significantly, but still moderately with the invasively measured LV contractility (r = 0.681, p &lt; 0.001). Correlation between the pressure-area-strain loop-derived GMWIA and P-V analysis-derived PRSW (Figure 1D) was found to be very strong (r = 0.924, p &lt; 0.001).

Conclusions

In the case of LV volume overload-induced heart failure, our pressure-area-strain loop-derived metric reflected LV contractility better than GLS and even GMWI. Therefore, the incorporation of instantaneous LV size into myocardial work calculation represents a promising clinical tool to assess and monitor intrinsic myocardial function independently of loading conditions.

Abstract Figure 1

Prognostic value of right ventricular mechanical pattern assessed with 3D echocardiography in patients with left-sided heart disease

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): This work was supported by the New National Excellence Programme (ÚNKP-19-3-I) of the Ministry for Innovation and Technology in Hungary, and the Artificial Intelligence Research Field Excellence Programme of the National Research, Development and Innovation Office of the Ministry of Innovation and Technology in Hungary.

Background

Right ventricular (RV) ejection fraction (EF) has established prognostic significance, which is independent of left ventricular (LV) EF in various cardiac diseases. However, RV EF is a cumulative result of the complex interplay between distinct mechanical components (i.e., shortening along the longitudinal, radial, and anteroposterior directions), and the prognostic value of RV motion decomposition remains to be quantified.

Objective

Our aim was to explore whether the assessment of longitudinal, radial, and anteroposterior motion components of the RV with 3D transthoracic echocardiography offers prognostic value in patients with left-sided heart disease.

Methods

Two hundred and ninety-two consecutive patients (age 59 ± 17 years, 70% male) with left-sided heart disease underwent standard clinical investigations and 3D echocardiographic examination. They were followed-up for 6.7 ± 2.2 years, and cardiac death served as the primary endpoint. LV and RV volumes and ejection fractions were quantified by the offline analysis of 3D datasets. The ReVISION method was applied to the 3D models of the RV to decompose the motion along the three orthogonal axes and to calculate longitudinal, radial, and anteroposterior EF (LEF, REF, AEF, respectively). Conventional parameters of RV systolic function (tricuspid annular plane systolic excursion [TAPSE], fractional area change [FAC]) were also assessed.

Results

Cardiac death occurred in 60 (21%) patients. Patients who died had lower LV EF (39 ± 16 vs. 52 ± 12%, p &lt; 0.001), RV EF (40 ± 11 vs. 48 ± 8%, p &lt; 0.001), and each mechanical component showed significantly lower values compared to patients alive (LEF: 13 ± 6 vs. 19 ± 6%; REF: 22 ± 7 vs. 25 ± 7%; AEF: 14 ± 6 vs. 18 ± 5%, all p &lt; 0.001). LEF was decreased to a greater degree compared to RV EF (relative %: -30 vs. -18). In univariate Cox regression models, RV EF (Hazard Ratio [HR]: 0.928, 95% Confidence Interval [CI] 0.909 – 0.948, p &lt; 0.001), LEF (0.855 [0.816 – 0.896], p &lt; 0.001), REF (0.932 [0.898 – 0.967], p &lt; 0.001), AEF (0.879 [0.841 – 0.919], p &lt; 0.001), TAPSE (0.881 [0.841-0.923], p &lt; 0.001), and FAC (0.955 [0.933-0.977], p &lt; 0.001) were all found to be significant predictors of cardiac death. From all parameters that were predictive, the optimal combination of variables was identified with an automated stepwise selection algorithm. The final multivariate model included serum creatinine (1.015 [1.010 – 1.020], p &lt; 0.001), haemoglobin concentration (0.965 [0.948 – 0.982], p &lt; 0.001), LV EF (0.977 [0.955 – 0.999], p &lt; 0.05), and LEF (0.899 [0.843 – 0.959], p &lt; 0.01) as independent predictors of cardiac death. Notably, the algorithm rather selected LEF and not RV EF.

Conclusions

3D echocardiography-derived measurements of RV systolic function are able to predict outcomes in patients with left-sided heart disease independently of LV function. The separate quantification of RV mechanical components can hold additional prognostic value compared to conventional echocardiographic parameters.

Myocardial work index better reflects contractility than longitudinal strain in rat models of pressure- and volume overload-induced heart failure

Funding Acknowledgements

Type of funding sources: None.

Speckle-tracking echocardiography (STE)-derived global longitudinal strain (GLS) is considered to be a sensitive marker of left ventricular (LV) function in a wide variety of cardiovascular diseases. Still, evidence suggests that GLS is significantly influenced by loading conditions. Myocardial work index (MWI) evaluates myocardial deformation in the context of afterload through the interpretation of strain in relation to instantaneous LV pressure. MWI may potentially overcome the limitations of mere strain calculation, and may better reflect cardiac contractility in hemodynamic overload states.

Accordingly, our aim was to examine the relationship of GLS and MWI with load-independent markers of LV contractility in rat models of pressure- and volume overload-induced heart failure.

Male Wistar rats underwent transverse aortic constriction (TAC; n = 12) to generate LV pressure overload, or aortocaval fistula (ACF; n = 12) was established to induce severe LV volume overload. In case of the control groups, sham procedures were performed (n = 12/12). Echocardiography loops were obtained to determine STE-derived GLS and global MWI. Pressure-volume analysis with transient occlusion of the inferior vena cava was carried out to calculate preload recruitable stroke work (PRSW), as a load-independent „gold-standard" parameter of LV contractility.

GLS was mildly reduced in the ACF group (-13.2 ± 2.4 vs. -15.4 ± 2.0%, p &lt; 0.05), while it was significantly lower in TAC group compared to controls (-7.0 ± 2.8 vs. -14.5 ± 2.5%; p &lt; 0.001). In contrast with these findings, PRSW and also MWI were significantly reduced in ACF (58 ± 14 vs. 111 ± 40 mmHg; 1328 ± 411 vs. 1934 ± 308 mmHg%, both p &lt; 0.01), however, they were comparable between TAC and the corresponding sham group (110 ± 26 vs. 116 ± 68 mmHg; 1687 ± 275 Hgmm% vs. 1537 ± 662 Hgmm%; both p = NS). In the pooled population, GLS did not show relationship with PRSW (r=-0.23; p = 0.12), while MWI showed significant correlation with it (r = 0.70; p &lt; 0.001).

GLS is significantly influenced by loading conditions, therefore, in case of severe pressure- or volume overload it may not be a reliable marker of LV contractility. In our rat model of pressure overload induced heart failure, contractility was maintained despite decreased GLS, while in the model of volume overload induced heart failure, GLS was maintained despite decreased contractility. MWI reflects contractility in hemodynamic overload states, therefore, it may be a more suitable marker of systolic function.

Abstract Figure. Pressure-strain loops of the groups

Mechanical contraction patterns of the systemic right ventricle: a 3D echocardiography study

Funding Acknowledgements

Type of funding sources: None.

Background. In patients with transposition of great arteries (TGA) post atrial switch operation or with congenitally corrected TGA (ccTGA), the morphologically right ventricle (RV) has to adapt to the chronically increased systemic pressure.

Purpose. To investigate the functional adaptation of the systemic RV in patients with TGA post Mustard repair or ccTGA. 

Methods. RV volumes and EF were measured by 3D echocardiography in 33 patients with the systemic RV (21 TGA and 12 ccTGA; 45 ± 13y, 61% male), and in 33 healthy volunteers (44 ± 13y, 61% male). 

The 3D RV model was postprocessed by the ReVISION software and its contraction was decomposed along the longitudinal, radial and anteroposterior directions (Fig.A, Systemic RV in TGA) providing longitudinal, radial and anteroposterior EF (LEF, REF and AEF). Relative contribution of each component was measured as the ratio between LEF, REF and AEF to the global RVEF (LEFi, REFi and AEFi).

Results. Systemic RV was significantly larger with reduced function compared to controls (Tab). 3D RVEF demonstrated stronger correlation with BNP (Rho -0.76, p &lt; 0.0001) compared to other parameters of RV function (free wall strain 0.55, p = 0.0083; FAC -0.47, p = 0.024; S’ -0.39 and TAPSE 0.06, p &gt; 0.05).

While in healthy volunteers, all 3 components of RV systolic function contributed equally to the global RV EF, in patients with TGA the relative contribution of the anteroposterior component was dominant and differed significantly from longitudinal and radial components (AEFi 0.48 ± 0.06 vs LEFi 0.31 ± 0.07 vs REFi 0.36 ± 0.09, p &lt; 0.0001)(Fig. B,C). In patients with ccTGA the longitudinal component was dominant and provided a relative compensation for the reduced anteroposterior and radial components (LEFi 0.47 ± 0.07 vs AEFi 0.34 ± 0.07, p = 0.0002 and vs REFi 0.36 ± 0.09, p = 0.0023)(Fig. B,C). Relative contribution of the radial contraction was significantly reduced in all systemic RV patients.

Conclusions. Systemic RV contraction patterns change significantly with anteroposterior contraction being dominant in patients with TGA post Mustard repair and longitudinal component being dominant in ccTGA.

3DE should be a part of routine assessment of the systemic RV, especially in TGA since no conventional echo parameters take into account anteroposterior RV contraction.

Parameters of RV systolic function Parameter Control group (N = 33) All SRV patients (N = 33) TGA (N = 21) ccTGA (N = 12) 3D EF, % 60 ± 3.8 36 ± 8.6* 34 ± 7.3* 38 ± 10* FAC, % 41.4 ± 3.7 25.9 ± 9.3* 25.1 ± 9.2* 27.1 ± 9.9* TAPSE, mm 24.6 ± 4.2 11.9 ± 3.9* 11.1 ± 2.9* 13.2 ± 5.1* RV free wall strain, % -32.5 ± 4.2 -14.5 ± 3.5* -14.5 ± 2.9* -15.5 ± 3.5* * p &lt; 0.0001 Abstract Figure.

Functional adaptation of the right ventricle to different degrees of the left ventricular systolic dysfunction in patients with left-sided heart disease: a three-dimensional echocardiography study

Funding Acknowledgements

Type of funding sources: None.

Background. Right ventricular (RV) systolic dysfunction in patients with left-sided heart disease is known adverse factor. However, the RV adaptation at the different degrees of left ventricular (LV) dysfunction remains to be clarified.

Purpose

 to assess the change in RV contraction pattern in relation to LV ejection fraction (EF) in patients with left-sided heart disease.

Methods. LV and RV volumes and EF were measured by 3D-echocardiography in 295 patients with left-sided heart disease (59 ± 17years, 69% male). The 3D meshmodel of the RV was postprocessed by the ReVISION software and its contraction pattern was decomposed along the longitudinal, radial and anteroposterior directions (Fig. A) providing longitudinal, radial and anteroposterior EF (LEF, REF, AEF). Relative contribution of each component to the RV systolic function was measured as the ratio between LEF, REF and AEF and global RVEF (LEFi, REFi, AEFi).

Results. Patients with LV systolic dysfunction also had reduced RVEF. Relative contribution of the longitudinal and anteroposterior components decreased, while radial component increased in patients with reduced LVEF (Table).

RV LEF and AEF significantly correlated with the LVEF (Rho 0.50 and 0.51, p &lt; 0.0001), while the correlation between REF and LVEF was weak (Rho 0.22, p = 0.0002).

There was a significant drop in LEF and AEF (Fig. B) and their relative contribution to the total RVEF (Fig. C) starting from the earlier stages of LV dysfunction. However, it was effectively compensated by significant increase in the radial RV component resulting in preservation of total RVEF in those with normal, mildly and moderately reduced LVEF (50 [46;54] vs 47 [44;52] vs 46 [42;49]%), whereas total RVEF dropped significantly only in severe LV dysfunction (30 [25;39]%; p &lt; 0.0001) (Fig. D).

Conclusions. The longitudinal and anteroposterior RV contraction was related to the LVEF and decreased from early stages of the LV systolic dysfunction. Increase in the radial component compensated for the loss of longitudinal and anteroposterior RV components in mild and moderate LV dysfunction to maintain total RVEF. Drop in all three components resulted in significant reduction of total RVEF in severe LV dysfunction.

Characteristics of study population Overall (N = 295) LVEF≥50% (N = 166) LVEF &lt; 50% (N = 129) LV EF, % 49.6 ± 14.3 59.9 ± 5.6 36.4 ± 10.9* RV EF, % 46.5 ± 9.2 49.8 ± 6.9 42.3 ± 10.0* RV LEFi 0.42 ± 0.09 0.45 ± 0.09 0.38 ± 0.09* RV REFi 0.47 ± 0.1 0.45 ± 0.1 0.50 ± 0.09* RV AEFi 0.39 ± 0.08 0.41 ± 0.08 0.37 ± 0.07* *p &lt; 0.0001 Abstract Figure.

Assessment of right ventricular segmental volumes and ejection fractions using a 15-segment model: three-dimensional echocardiographic study in healthy volunteers

Funding Acknowledgements

Type of funding sources: None.

On top of global ventricular function, segmental metrics may bear clinically relevant information. Concerning the left ventricle (LV), standardized segmentation is widely performed in different cardiovascular imaging modalities mainly to correlate regional dysfunction with coronary perfusion territories, or to appreciate and quantify distinct patterns in LV myocardial function. The same applies to the right ventricle (RV); as pulmonary hypertension, or arrhythmogenic cardiomyopathy are just two clinical examples among several others, where established regional dysfunction exists. Nevertheless, only a few options are available for the comprehensive and quantitative assessment of the segmental RV function due to its complex three-dimensional (3D) shape.

Therefore, our aim was to develop a 3D echocardiographic software solution for volumetric partitioning of the RV using a 15-segment model and to investigate a large number of healthy volunteers to describe the normal segmental pattern.

One hundred and fifty healthy adults with a balanced age range and an equal sex distribution were investigated (15-15 women and men in each age groups: 20-29, 30-39, 40-49, 50-59, 60+). Beyond standard two-dimensional echocardiographic protocol, full volume 3D datasets were acquired. Using commercially available software, we reconstructed the 3D mesh model of the RV and measured end-diastolic (EDV), end-systolic volumes and ejection fraction (EF). The 3D model was post-processed using the ReVISION method to calculate regional and segmental volumes and EFs. Fifteen standard segments were separated and quantified (Figure).

Increasing age resulted in significantly lower RV stroke volume (r=-0.17; p &lt; 0.05) and tended towards lower RV EDV (r=-0.15, p = 0.06). EDVs of inflow tract and outflow tract segments decreased during aging (r=-0.21, p &lt; 0.05 and r=-0.26, p &lt; 0.01, respectively). Between the pre-specified age groups, there was no difference concerning global RVEF (ANOVA p = NS). In the 50-59 age group, regional EF of septal segments and also free wall segments were significantly lower compared to subjects in the 30-39 and 40-49 age categories (both p &lt; 0.05). Global RV EDV was significantly lower in women (women vs. men: 95 ± 20 vs. 125 ± 28 ml; p &lt; 0.05) along with a higher RV EF compared to men (62 ± 4 vs. 59 ± 4; p &lt; 0.05). However, segmental EFs of apical, septal mid anterior, free wall mid posterior, free wall mid lateral, septal basal anterior and inflow tract segments were comparable between genders.

The ReVISION method allows a volumetric partitioning of the RV 3D models to investigate segmental geometry and function in a 15-segment model. We have explored segmental differences between different ages and genders. Further studies are warranted to justify the importance of segmental assessment of the RV in different cardiac diseases.

Abstract Figure. Separation of 15 standard RV segments

Efficacy and tolerability of bevacizumab in patients with severe Covid-19

On the basis of Covid-19-induced pulmonary pathological and vascular changes, we hypothesize that the anti-vascular endothelial growth factor (VEGF) drug bevacizumab might be beneficial for treating Covid-19 patients. From Feb 15 to April 5, 2020, we conducted a single-arm trial (NCT04275414) and recruited 26 patients from 2-centers (China and Italy) with severe Covid-19, with respiratory rate ≥30 times/min, oxygen saturation ≤93% with ambient air, or partial arterial oxygen pressure to fraction of inspiration O₂ ratio (PaO₂/FiO₂) >100 mmHg and ≤300 mmHg, and diffuse pneumonia confirmed by chest imaging. Followed up for 28 days. Among these, bevacizumab plus standard care markedly improves the PaO₂/FiO₂ ratios at days 1 and 7. By day 28, 24 (92%) patients show improvement in oxygen-support status, 17 (65%) patients are discharged, and none show worsen oxygen-support status nor die. Significant reduction of lesion areas/ratios are shown in chest computed tomography (CT) or X-ray within 7 days. Of 14 patients with fever, body temperature normalizes within 72 h in 13 (93%) patients. Relative to comparable controls, bevacizumab shows clinical efficacy by improving oxygenation and shortening oxygen-support duration. Our findings suggest bevacizumab plus standard care is highly beneficial for patients with severe Covid-19. Randomized controlled trial is warranted.

In this single-arm clinical trial, the authors show that treatment of COVID-19 patients with bevacizumab, an anti-vascular endothelial growth factor drug, can improve PaO₂/FiO₂ ratios and oxygen-support status. Relative to an external control group, bevacizumab shows clinical efficacy by improving oxygenation.

Glibenclamide reverses cardiovascular abnormalities of Cantu syndrome driven by KATP channel overactivity

Cantu syndrome (CS) is a complex disorder caused by gain-of-function (GoF) mutations in ABCC9 and KCNJ8, which encode the SUR2 and Kir6.1 subunits, respectively, of vascular smooth muscle (VSM) KATP channels. CS includes dilated vasculature, marked cardiac hypertrophy, and other cardiovascular abnormalities. There is currently no targeted therapy, and it is unknown whether cardiovascular features can be reversed once manifest. Using combined transgenic and pharmacological approaches in a knockin mouse model of CS, we have shown that reversal of vascular and cardiac phenotypes can be achieved by genetic downregulation of KATP channel activity specifically in VSM, and by chronic administration of the clinically used KATP channel inhibitor, glibenclamide. These findings demonstrate that VSM KATP channel GoF underlies CS cardiac enlargement and that CS-associated abnormalities are reversible, and provide evidence of in vivo efficacy of glibenclamide as a therapeutic agent in CS.

Lateral left ventricular lead position is superior to posterior position in long-term outcome of patients underwent cardiac resynchronization therapy

Background

Preferring side branch of coronary sinus during cardiac resynchronization therapy (CRT) implantation is empirical due to the limited data on the association of left ventricular (LV) lead position and long-term clinical outcome.

Purpose

We evaluated the long-term all-cause mortality by LV lead non-apical positions and further characterized them by interlead electrical delay (IED).

Methods

In our retrospective database 2087 patients were registered between 2000 and 2018. Those with non-apical LV lead locations were classified into anterior (n=108), posterior (n=643), and lateral (n=1336) groups. All-cause mortality was assessed by Kaplan-Meier and Cox analyses. Echocardiographic response was measured 6 months after CRT implantation.

Results

During the median follow-up time of 3.7 years, 1150 (55.1%) patients died, 710 (53.1%) with lateral, 78 (72.2%) with anterior and 362 (56.3%) with posterior positions. Patients with lateral position had significantly better outcome in all-cause mortality compared to others (HR 0.80; 95% CI: 0.71–0.90; p&lt;0.0001), which was also confirmed by multivariate analysis after adjusting for relevant clinical covariates (HR 0.81; 95% CI: 0.72–0.91; p&lt;0.0001). When echocardiographic response was evaluated in the lateral group, patients with an IED longer than 110 ms (ROC AUC 0.63; 95% CI: 0.53–0.73; p=0.012) showed 2.1 times higher odds of improvement in echocardiographic response 6 months after the implantation.

Conclusions

In this study we proved that after CRT implantation only the lateral LV lead location was associated with long-term mortality benefit. Moreover, patients with this position showed the greatest echocardiographic response over 110 ms IED.

Survival of total patient cohort

Funding Acknowledgement

Type of funding source: None

Exploring sex-specific patterns of mortality predictors among patients undergoing cardiac resynchronization therapy: a machine learning approach

Background

The relative importance of variables explaining sex differences in outcomes is scarcely explored in patients undergoing cardiac resynchronization therapy (CRT).

Purpose

We sought to implement and evaluate machine learning (ML) algorithms for the prediction of 1- and 3-year all-cause mortality in patients undergoing CRT implantation. We also aimed to assess the sex-specific differences and similarities in the predictors of mortality using ML approaches.

Methods

A retrospective registry of 2191 CRT patients (75% males) was used in the current analysis. ML models were implemented in 6 partially overlapping patient subsets (all patients, females or males with 1- or 3-year follow-up data available). Each cohort was randomly split into a training (80%) and a test set (20%). After hyperparameter tuning with 10-fold cross-validation in the training set, the best performing algorithm was also evaluated in the test set. Model discrimination was quantified using the area under the receiver-operating characteristic curves (AUC) and the associated 95% confidence intervals. The most important predictors were identified using the permutation feature importances method.

Results

Conditional inference random forest exhibited the best performance with AUCs of 0.728 [0.645–0.802] and 0.732 [0.681–0.784] for the prediction of 1- and 3-year mortality, respectively. Etiology of heart failure, NYHA class, left ventricular ejection fraction and QRS morphology had higher predictive power in females, whereas hemoglobin was less important than in males. The importance of atrial fibrillation and age increased, whereas the relevance of serum creatinine decreased from 1- to 3-year follow-up in both sexes.

Conclusions

Using advanced ML techniques in combination with easily obtainable clinical features, our models effectively predicted 1- and 3-year all-cause mortality in patients undergoing CRT implantation. The in-depth analysis of features has revealed marked sex differences in mortality predictors. These results support the use of ML-based approaches for the risk stratification of patients undergoing CRT implantation.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): National Research, Development and Innovation Office of Hungary

Mechanical diversity in the adaptation of left and right ventricular function to long-term exercise: 3D echocardiographic study in a large cohort of competitive athletes

 

Regular physical exercise results in complex remodelling of the left- (LV) and right ventricle (RV), commonly referred as the athlete's heart. Despite the well-known changes in ventricular volumes and mass, data are scarce regarding ventricular mechanics and its connection to exercise performance.

Accordingly, our aim was to characterize biventricular morphological and functional changes and their association with peak exercise capacity in a large cohort of athletes using three-dimensional (3D) echocardiography.

Competitive athletes of various training regimes (n=525, age: 20±6 years, training: 15±7 hours/week, 30% female) were enrolled, while 73 age- and gender-matched sedentary volunteers served as the control group. Full volume 3D echocardiographic datasets focused on the LV or the RV were acquired for further analysis: LV and RV end-diastolic volume (EDVi), LV mass (Mi) indices and ejection fraction (EF) were quantified. To characterize biventricular mechanics, LV and RV global longitudinal strain (GLS) and global circumferential strain (GCS) were also measured using dedicated software. Athletes also underwent cardiopulmonary exercise testing to determine peak oxygen uptake (VO2/kg).

Athletes had significantly higher LV and RV EDVi (81±13 vs. 64±11 mL/m2; 83±14 vs. 63±11 mL/m2; both p&lt;0.001) and also LVMi (87±15 vs. 65±12 g/m2; p&lt;0.001) compared to controls. LV and RV EF were significantly lower in athletes (57±5 vs. 60±6%; 55±5 vs. 58±5%; both p&lt;0.001). LV GLS (−19.5±2.1 vs. −20.6±2.6%; p&lt;0.001) and also LV GCS (−27.9±3.2 vs. −29.8±4.4%; p&lt;0.001) was lower in athletes compared to controls. In opposed to the LV, RV GLS did not differ between the two groups (−29.3±5.8 vs. −29.5±5.3%; p=NS), however, RVGCS was decreased in athletes compared to controls (−24.4±6.1 vs. −28.6±7.3%; p&lt;0.001). In athletes, ventricular morphology measured by LV and RV EDVi correlated with VO2/kg (both r=0.37; p&lt;0.001), while functional measures, such as lower resting LV GLS (r=0.22; p&lt;0.001) and RV GCS (r=0.14; p&lt;0.01) also showed relationship with better exercise performance.

According to our results, regular physical exercise is associated with significant changes of LV and RV geometry and mechanics. Resting biventricular systolic function of the athlete's heart is characterized by a mild reduction, which is attributable to a lower longitudinal and circumferential shortening on the left side of the heart, while on the right side lower circumferential shortening can be seen along with a maintained longitudinal shortening. Moreover, this mechanical pattern also correlates with exercise performance.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): “National Heart Program” NVKP_16-1-2016-0017; NKFIH K_16 K120277 to BM

Longitudinal strain reflects the interaction of myocardial contractility to afterload in rat models of hemodynamic overload-induced heart failure

Background

Two-dimensional (2D) speckle tracking echocardiography (STE)-derived myocardial strain parameters are sensitive markers of left ventricular (LV) systolic function. Novel findings suggest that the contractile state of the myocardium, afterload and preload are major determinants of STE measurements. However, the hypothesis that longitudinal strain expresses the interaction between contractility and loading conditions rather than contractility alone in hemodynamic overload-induced heart failure (HF) has not been tested.

Purpose

This study aimed to explore the connection between longitudinal strain and contractility, afterload and preload in rat models of pressure overload (PO)- and volume overload (VO)-induced heart failure (HF).

Methods

Pressure overload (PO)-induced HF was evoked by transverse aortic constriction ([TAC], n=14). Volume overload (VO)-induced HF was established by an aortocaval fistula ([ACF], n=12). Age-matched sham operated animals served as controls. Pressure-volume analysis was carried out to compute cardiac contractility (slope of end-systolic pressure-volume relationship [ESPVR]), afterload (arterial elastance [Ea]) and ventriculo-arterial coupling ([VAC] = Ea/ESPVR). Preload was evaluated by meridional end-diastolic wall stress (σend-diastolic). STE was performed to assess global longitudinal strain (GLS).

Results

GLS was impaired in both PO-induced HF (−5.9±0.6 vs. −12.9±0.5%, TAC vs Sham, P&lt;0.001) and VO-evoked HF (−11.7±0.7 vs. −13.5±0.4%, ACF vs Sham, P=0.048). Hemodynamic measurements indicated that the TAC group presented with maintained ESPVR, increased Ea and enhanced σend-diastolic. In contrast, the ACF group was characterized by reduced ESPVR, decreased Ea and enhanced σend-diastolic. Ordinary least squares non-linear regression revealed that GLS was predominantly determined by afterload (Ea) in the TAC model and by contractility (ESPVR) in the ACF model. In accordance, GLS showed a strong correlation with Ea in case of PO-induced HF (R= 0.848, P&lt;0.001) and with ESPVR in case of VO-evoked HF (R=−0.526; P=0.008), respectively. Furthermore, GLS also demonstrated strong correlation with VAC in both the TAC and the ACF models. Of particular interest, a robust correlation between VAC and GLS could also be detected in the entire study population (R= 0.654, P&lt;0.001).

Conclusion

Both afterload and contractility define GLS. Hence, under conditions when both factors become altered, GLS reflects VAC.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): NVKP_16-1-2016-0017

Nutritional modulation of heart failure in mitochondrial pyruvate carrier-deficient mice

The myocardium is metabolically flexible; however, impaired flexibility is associated with cardiac dysfunction in conditions including diabetes and heart failure. The mitochondrial pyruvate carrier (MPC) complex, composed of MPC1 and MPC2, is required for pyruvate import into the mitochondria. Here we show that MPC1 and MPC2 expression is downregulated in failing human and mouse hearts. Mice with cardiac-specific deletion of Mpc2 (CS-MPC2-/-) exhibited normal cardiac size and function at 6 weeks old, but progressively developed cardiac dilation and contractile dysfunction, which was completely reversed by a high-fat, low-carbohydrate ketogenic diet. Diets with higher fat content, but enough carbohydrate to limit ketosis, also improved heart failure, while direct ketone body provisioning provided only minor improvements in cardiac remodelling in CS-MPC2-/- mice. An acute fast also improved cardiac remodelling. Together, our results reveal a critical role for mitochondrial pyruvate use in cardiac function, and highlight the potential of dietary interventions to enhance cardiac fat metabolism to prevent or reverse cardiac dysfunction and remodelling in the setting of MPC deficiency.

Cardiac functional consequences of stroke induced by transient middle cerebral artery occlusion in a rodent model

Background

The cardiac functional consequences of ischaemic stroke are still need to be elucidated, while according to ethical issues only non-inasive measurents were carried out in patients underwent transient cerebral ischaemia.

Purpose

We aimed at investigating left ventricular function using non-invasive and invasive modalities in a rat model of transient focal ischaemia.

Methods

Age-matched, young adult rats were used for this study. Serial left ventricular echocardiographic measurements and speckle-tracking analysis were performed in rats (n=9) underwent transient middle cerebral artery occlusion (MCAO) before, during and immediately after the induction of stroke, with a follow-up at 24, 48, 72 hours; 7, 11 and 14 days. In another experimental setting, 48 hours after stroke induction (MCAO group, n=9) we characterized left ventricular function by pressure-volume analysis, that was compared to sham-operated controls (Co group, n=9).

Results

Serial echocardiographic measurements showed impaired systolic function, that was most severe 48 hours after MCAO (global circumferential strain, GCS: −14.8±2.6% 48 hours after MCAO vs. −19.3±2.4% baseline, p&lt;0.05). A complete recovery of systolic functional deterioration was observed after 14 days (GCS: −19.2±2.5% 14 days after MCAO vs. −19.3±2.4% baseline, n.s.). Heart weight (normalized to tibial weight) did not differ between MCAO and Co animals. Pressure-volume analysis revealed unaltered diastolic function and showed unchanged load-independent contractility index values (slope of end-systolic pressure-volume relationship, ESPVR: 2.56±0.29mmHg/μl MCAO vs. 2.55±0.59 mmHg/μl Co, n.s.) after MCAO. There was a tendency towards increased systolic pressure and deteriorated ventriculo-arterial coupling in animals underwent stroke.

Conclusions

Our data suggests that MCAO is associated with reversible impairment of systolic function during echocardiographic measurements, however without alteration of intrinsic myocardial contractility. The tendency towards increased afterload might explain the observed alterations in rats underwent stroke.

Funding Acknowledgement

Type of funding source: None

Resting levels of cardiac markers in athletes

Introduction

Examination of specific cardiac enzymes and peptide fragments is essential in cases of acute myocardial ischemia and heart failure. According to previous data, exhausting physical effort may cause temporary increase of cardiac necroenzyme levels, while no information is available on their resting values in athletes.

Methods

Resting serum levels of hsTroponinT, CKMB, LDH and NT-proBNP were measured as part of extended sports cardiology screening in healthy athletes and a healthy sedentary non-athlete control group. Depending on normality, groups were compared with two-tailed Student's t-test or Mann-Whitney U-test. Statistical analysis was processed in RStudio integrated development environment.

Results

Results of 237 healthy athletes from different sports (male: 144, age: 19.1±5.9 years, training: 16.0±6.7 hours/week) and 53 sedentary non-athletes (male: 23, age: 19.8±3.2 years, training: 2.6±2.3 hours/week) were analysed. In athletes, increased resting cardiac marker levels were measured as follows: CKMB: 6.3% (n=15), LDH: 3.4% (n=8), hsTroponinT: 4.2% (n=10), NT-proBNP: 0.8% (n=2) of the cases. No elevation of CKMB and hsTroponin T levels were measured in the control group, while only single cases of increased LDH and NT-proBNP were detected. We measured higher levels of CKMB (17.6±7.3 vs. 12.3±3.4 U/l, p&lt;0.001), LDH (322.4±60.8 vs. 286.0±51.1 U/l, p&lt;0.001) and hsTroponinT (6.2±4.7 vs. 4.3±1.4 ng/l, p&lt;0.05), while lower levels of NT-proBNP (23.9±27.2 vs. 49.8±38.7 pg/ml, p&lt;0.001) in athletes compared to the control group. In male athletes, higher levels of CKMB (18.5±6.6 vs. 16.0±8.2 U/l, p&lt;0.001), LDH (337.0±62.2 vs. 300.7±51.9 U/l, p&lt;0.001) and hsTroponinT (7.0±5.3 vs. 4.3±1.9 ng/l, p&lt;0.001), and lower levels of NT-proBNP (19.8±23.1 vs. 35.0±34.1 pg/ml, p&lt;0.001) were measured compared to female athletes. Levels of hsTroponinT decreased in athletes due to increasing age (r=−0.20, p&lt;0.05).

Discussion

According to our results, resting levels of cardiac markers show significant alterations due to sport adaptation of the heart. These changes depend on age and sex as well.

Conclusions

Our research attract attention to different assessment of cardiac markers in athletes in respect of recognition of cardiovascular pathologies.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): This project was supported by a grant from the National Research, Development and Innovation Office (NKFIH) of Hungary.