Assessment of left ventricular diastolic function after Transcatheter aortic valve implantation in aortic stenosis patients by echocardiographic according to different guidelines

Myocardial transcriptomic analysis of diabetic patients with aortic stenosis: key role for mitochondrial calcium signaling

BACKGROUND

Type 2 diabetes (T2D) is a frequent comorbidity encountered in patients with severe aortic stenosis (AS), leading to an adverse left ventricular (LV) remodeling and dysfunction. Metabolic alterations have been suggested as contributors of the deleterious effect of T2D on LV remodeling and function in patients with severe AS, but so far, the underlying mechanisms remain unclear. Mitochondria play a central role in the regulation of cardiac energy metabolism.

OBJECTIVES

We aimed to explore the mitochondrial alterations associated with the deleterious effect of T2D on LV remodeling and function in patients with AS, preserved ejection fraction, and no additional heart disease.

METHODS

We combined an in-depth clinical, biological and echocardiography phenotype of patients with severe AS, with (n = 34) or without (n = 50) T2D, referred for a valve replacement, with transcriptomic and histological analyses of an intra-operative myocardial LV biopsy.

RESULTS

T2D patients had similar AS severity but displayed worse cardiac remodeling, systolic and diastolic function than non-diabetics. RNAseq analysis identified 1029 significantly differentially expressed genes. Functional enrichment analysis revealed several T2D-specific upregulated pathways despite comorbidity adjustment, gathering regulation of inflammation, extracellular matrix organization, endothelial function/angiogenesis, and adaptation to cardiac hypertrophy. Downregulated gene sets independently associated with T2D were related to mitochondrial respiratory chain organization/function and mitochondrial organization. Generation of causal networks suggested a reduced Ca2+ signaling up to the mitochondria, with the measured gene remodeling of the mitochondrial Ca2+ uniporter in favor of enhanced uptake. Histological analyses supported a greater cardiomyocyte hypertrophy and a decreased proximity between the mitochondrial VDAC porin and the reticular IP3-receptor in T2D.

CONCLUSIONS

Our data support a crucial role for mitochondrial Ca2+ signaling in T2D-induced cardiac dysfunction in severe AS patients, from a structural reticulum-mitochondria Ca2+ uncoupling to a mitochondrial gene remodeling. Thus, our findings open a new therapeutic avenue to be tested in animal models and further human cardiac biopsies in order to propose new treatments for T2D patients suffering from AS.

TRIAL REGISTRATION

URL: https://www.

CLINICALTRIALS

gov ; Unique Identifier: NCT01862237.

Transcatheter aortic valve implantation in severe aortic stenosis does not necessarily reverse left ventricular myocardial damage: data of long-term follow-up

AIMS

Aortic stenosis (AS) is causing myocardial damage and replacement is mainly indicated based on symptoms. Non-invasive estimation of myocardial work (MW) provides a less afterload-dependent too for assessing myocardial function. We sought to look at the impact of transcatheter aortic valve implantation (TAVI) on the myocardium at long-term follow-up and according to current indications.

METHODS AND RESULTS

We conducted an observational, cross-sectional, single-centre study. Patients were selected based on the validated indication for a TAVI. Standardized echocardiographies were repeated. A total of 102 patients were included. The mean age was 85 years, 45% were female, 68% had high blood pressure, and 52% had a coronary disease. One-fifth was suffering from low-flow-low-gradient AS. A follow-up was performed at 22 ± 9.5 months after the TAVI. No TAVI dysfunction was observed. Left ventricular (LV) ejection fraction was stable (62 ± 8%), and global longitudinal strain had improved (-14.0 ± 3.7 vs. -16.0 ± 3.6%, P < 0.0001). No improvement of the MW parameters was noticed (LV global work index 2099 ± 692 vs. 2066 ± 706 mmHg%, P = 0.8, LV global constructive 2463 ± 736 vs. 2463 ± 676 mmHg%, P = 0.8). Global wasted work increased [214 (149; 357) vs. 247 (177; 394) mmHg%, P = 0.0008].

CONCLUSION

In a population of severe symptomatic AS patients who had undergone a TAVI, the non-invasive myocardial indices that assess the LV performance at long-term follow-up did not improve. These results are questioning the timing of the intervention and the need for more attention in the pharmacological management of these AS patients.

Evaluation of Left Ventricle Systolic Functions with 2D Strain Echocardiography After Transcatheter Aortic Valve Replacement in Patients with Severe Aortic Stenosis

BACKGROUND

It has been suggested that there is deterioration in global left ventricular (LV) longitudinal function in patients with severe aortic valve stenosis and the decrease in LV global longitudinal strain (LV-GLS) is associated with worsening prognosis. The aim of the study is to examine left ventricular mechanical changes with LV strain imaging in addition to routine examination in patients who underwent transcatheter aortic valve replacement (TAVR).

MATERIAL AND METHODS

Fifty patients who had been scheduled for the TAVR procedure between 2016 to 2018 were enrolled. The patients were evaluated before TAVR, 1 and 6 months after the procedure. The patients' LV ejection fraction (LVEF), LV-GLS, LV mass (LVM), and LV mass index (LVMI), relative wall thickness (RWT) and left atrial volume index (LAVI) were calculated with transthoracic echocardiography. The patients' performance scores were evaluated with Kansas City Cardiomyopathy Questionnaire (KCCQ-12).

RESULTS

Twenty-six patients were female (52%), and the mean ages of patients were 75.30±12.26 years. The mean LVEF of the patients was measured at 54.04±13.48% and 58.10±11.49% and 59.36±11.85 pre-procedure, at first and 6 months, respectively. This increase in LVEF was statistically significant (p<0.001). The mean LV-GLS was measured -15.83±2.78 pre-procedure. The mean of LV-GLS were -18.73±3.49 and -19.87±4.05 at first and 6 months, respectively. Performance scores of patients significantly improved after the procedure (p<0.001). The significant decreases in LVM, LVMI, RWT, and LAVI at 6 month compared to the pre-procedural evaluation (p<0.001).

CONCLUSION

In severe aortic stenosis with deformation of left ventricular myocardial mechanics, including global longitudinal strain, a successful TAVR procedure provides a significant improvement in myocardial mechanics in early and mid-term follow-up with.

Echocardiographic assessment of diastolic dysfunction in elderly patients with severe aortic stenosis before and after aortic valve replacement

Background

The 2016 guidelines of the American Society of Echocardiography (ASE) and European Association of Cardiovascular Imaging (EACVI) for evaluation of left ventricular (LV) diastolic dysfunction by Doppler flow and tissue Doppler- echocardiography do not adjust assessment of high filling pressures for patients with aortic stenosis (AS). However, most of the studies on this patient group indicate age independent specific diastolic features in AS. The aim of this study is to identify disease-specific range and distribution of diastolic functional parameters and their ability to identify high N-terminal prohormone of brain natriuretic peptide (NT-proBNP) levels as a marker for high filling pressures.

Methods

In this study, 169 patients who underwent surgical aortic valve replacement (SAVR) or transcatheter aortic valve replacement (TAVR) were prospectively enrolled. Resting echocardiography was performed including Doppler of the mitral inflow, pulmonary venous flow, tricuspid regurgitant flow and tissue Doppler in the mitral ring and indexed volume-estimates of the left atrium (LAVI). Echocardiography, and NT-proBNP levels were assessed before TAVR/SAVR and at two postoperative visits at 6 and 12 months.

Results

Pre- and postoperative values were septal e′; 5.1 ± 3.9, 5.2 ± 1.6 cm/s; lateral e′ 6.3 ± 2.1; 7.7 ± 2.7 cm/s; E/e′19 ± 8; 16 ± 7 cm/s; E velocity 96 ± 32; 95 ± 32 cm/s; LAVI 39 ± 8; 36 ± 8 ml/m², pulmonary artery pressure (PAP) 39 ± 8; 36 ± 8 mmHg, respectively. The scoring recommended by ASE/EACVI detected elevated NT pro-BNP with a specificity of 25%. Adjusting thresholds towards PAP ≥ 40 mmHg, E velocity ≥ 100 cm/s, E deceleration time < 220 ms, and E/septal e′ ≥ 20 or septal e′ < 5.0 cm/s increased prediction of NT-proBNP levels ≥500 ng/L with substantially improved specificity (> 85%).

Conclusion

Diastolic echocardiographic parameters in AS indicate persistent impaired relaxation and NT-proBNP indicate elevated filling pressures in most of the patients, improving only modestly 6–12 months after TAVR and SAVR. Applying the 2016 ASE/EACVI recommendations for detection of elevated filling pressures to patients with AS, elevated NT pro-BNP levels could not be reliably detected. However, adjusting thresholds of the echocardiographic parameters increased specificities to useful diagnostic levels.

Trial registration

The study was prospectively approved by the regional ethical committee, REK North with the registration number: REK 2010/397-10.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12947-021-00262-1.

The Degree of Cardiac Remodelling before Overload Relief Triggers Different Transcriptome and miRome Signatures during Reverse Remodelling (RR)-Molecular Signature Differ with the Extent of RR

This study aims to provide new insights into transcriptome and miRome modifications occurring in cardiac reverse remodelling (RR) upon left ventricle pressure-overload relief in mice. Pressure-overload was established in seven-week-old C57BL/6J-mice by ascending aortic constriction. A debanding (DEB) surgery was performed seven weeks later in half of the banding group (BA). Two weeks later, cardiac function was evaluated through hemodynamics and echocardiography, and the hearts were collected for histology and small/bulk-RNA-sequencing. Pressure-overload relief was confirmed by the normalization of left-ventricle-end-systolic-pressure. DEB animals were separated into two subgroups according to the extent of cardiac remodelling at seven weeks and RR: DEB1 showed an incomplete RR phenotype confirmed by diastolic dysfunction persistence (E/e' ≥ 16 ms) and increased myocardial fibrosis. At the same time, DEB2 exhibited normal diastolic function and fibrosis, presenting a phenotype closer to myocardial recovery. Nevertheless, both subgroups showed the persistence of cardiomyocytes hypertrophy. Notably, the DEB1 subgroup presented a more severe diastolic dysfunction at the moment of debanding than the DEB2, suggesting a different degree of cardiac remodelling. Transcriptomic and miRomic data, as well as their integrated analysis, revealed significant downregulation in metabolic and hypertrophic related pathways in DEB1 when compared to DEB2 group, including fatty acid β-oxidation, mitochondria L-carnitine shuttle, and nuclear factor of activated T-cells pathways. Moreover, extracellular matrix remodelling, glycan metabolism and inflammation-related pathways were up-regulated in DEB1. The presence of a more severe diastolic dysfunction at the moment of pressure overload-relief on top of cardiac hypertrophy was associated with an incomplete RR. Our transcriptomic approach suggests that a cardiac inflammation, fibrosis, and metabolic-related gene expression dysregulation underlies diastolic dysfunction persistence after pressure-overload relief, despite left ventricular mass regression, as echocardiographically confirmed.