Chronic kidney disease is a key risk factor for aortic stenosis progression

BACKGROUND

Rapid progression of aortic stenosis (AS) has been observed in patients undergoing dialysis, but existing cross-sectional evidence is contradictory in non-dialysis-dependent chronic kidney disease (CKD). The present study sought to evaluate whether CKD is associated with the progression of AS over time in a large cohort of patients with AS.

METHODS

We retrospectively studied all consecutive patients diagnosed with AS [peak aortic jet velocity (Vmax) ≥2.5 m/s] and left ventricular ejection fraction ≥50% in the echocardiography laboratories of two tertiary centers between 2000 and 2018. The estimated glomerular filtration rate (eGFR) (mL/min/1.73 m2) was calculated from serum creatinine values. Patients were divided into five CKD stages according to the baseline eGFR. Annual rates of change in the aortic valve area (AVA) were determined by a linear mixed-effects model.

RESULTS

Among the 647 patients included, 261 (40%) had CKD. After a median follow-up of 2.9 (interquartile range 1.8-4.8) years, the mean overall rate of change in AVA was -0.077 (95% confidence interval -0.082; -0.073) cm2/year. There was an inverse relationship between the progression rate and kidney function. The more severe the CKD stage, the greater the AVA narrowing (P < .001). By multivariable linear regression analysis, the eGFR was also negatively associated (P < .001) with AS progression. An eGFR strata below 45 mL/min/1.73 m2 was associated with higher odds of rapid progression of AS than normal kidney function. During the clinical follow-up, event-free survival (patients free of aortic valve replacement or death) decreased as CKD progressed. Rapid progression of AS in patients with kidney dysfunction was associated with worse outcomes.

CONCLUSIONS

Patients with CKD exhibit more rapid progression of AS over time and require close monitoring. The link between kidney dysfunction and rapid progression of AS is still unknown and requires further research.

Impact of early versus class I-triggered surgery on postoperative survival in severe aortic regurgitation: An observational study from the Aortic Valve Insufficiency and Ascending Aorta Aneurysm International Registry

OBJECTIVES

Class I triggers for severe and chronic aortic regurgitation surgery mainly rely on symptoms or systolic dysfunction, resulting in a negative outcome despite surgical correction. Therefore, US and European guidelines now advocate for earlier surgery. We sought to determine whether earlier surgery leads to improved postoperative survival.

METHODS

We evaluated the postoperative survival of patients who underwent surgery for severe aortic regurgitation in the international multicenter registry for aortic valve surgery, Aortic Valve Insufficiency and Ascending Aorta Aneurysm International Registry, over a median follow-up of 37 months.

RESULTS

Among 1899 patients (aged 49 ± 15 years, 85% were male), 83% and 84% had class I indication according to the American Heart Association and European Society of Cardiology, respectively, and most were offered repair surgery (92%). Twelve patients (0.6%) died after surgery, and 68 patients died within 10 years after the procedure. Heart failure symptoms (hazard ratio, 2.60 [1.20-5.66], P = .016) and either left ventricular end-systolic diameter greater than 50 mm or left ventricular end-systolic diameter index greater than 25 mm/m2 (hazard ratio, 1.64 [1.05-2.55], P = .030) predicted survival independently over and above age, gender, and bicuspid phenotype. Therefore, patients who underwent surgery based on any class I trigger had worse adjusted survival. However, patients who underwent surgery while meeting early imaging triggers (left ventricular end-systolic diameter index 20-25 mm/m2 or left ventricular ejection fraction 50% to 55%) had no significant outcome penalty.

CONCLUSIONS

In this international registry of severe aortic regurgitation, surgery when meeting class I triggers led to postoperative outcome penalty compared with earlier triggers (left ventricular end-systolic diameter index 20-25 mm/m2 or ventricular ejection fraction 50%-55%). This observation, which applies to expert centers where aortic valve repair is feasible, should encourage the global use of repair techniques and the conduction of randomized trials.

Tricuspid annular dynamics, not diameter, predicts tricuspid regurgitation after mitral valve surgery: Results from a prospective randomized trial

Objective

Current guidelines advise using prophylactic tricuspid valve annuloplasty during mitral valve surgery, especially in the presence of annular diameter enlargement. However, several retrospective studies and a prospective randomized study from our department could not confirm that diameter enlargement is predictive of late regurgitation. We examined whether 2- and 3-dimensional echocardiographic and clinical characteristics could identify patients who will develop moderate or severe recurrent tricuspid regurgitation.

Methods

Patients with less than severe functional tricuspid regurgitation (FTR) were randomized not to receive tricuspid annuloplasty, and 11 of 53 of them were excluded from the study because 3-dimensional echocardiographic analysis was not possible. Cox regression was used to estimate the model-based probability of moderate or severe FTR (vena contracta ≥3 mm) or progression of TR and FTR regression using valve dimensions (annulus area, diameter perimeter, nonplanar angle, and sphericity index), dynamics (annulus contraction, annulus displacement, and displacement velocity), and clinical parameters as possible predictors.

Results

At a median follow-up of 3.8 years (range, 3-5.6 years), 17 patients had moderate or severe FTR or progression, and 13 had FTR regression. Our models identified annular displacement velocity as a significant predictor for FTR recurrence and nonplanar angle as a significant predictor for FTR regression.

Conclusions

Annular dynamics, not the dimension, predict recurrence and regression of FTR. Annular contraction should be systematically investigated as a possible surrogate of right ventricle function to prophylactically treat the tricuspid valve.

3D histopathology of stenotic aortic valve cusps using ex vivo microfocus computed tomography

Background

Calcific aortic stenosis (AS) is the most prevalent heart valve disease in developed countries. The aortic valve cusps progressively thicken and the valve does not open fully due to the presence of calcifications. In vivo imaging, usually used for diagnosis, does not allow the visualization of the microstructural changes associated with AS.

Methods

Ex vivo high-resolution microfocus computed tomography (microCT) was used to quantitatively describe the microstructure of calcified aortic valve cusps in full 3D. As case study in our work, this quantitative analysis was applied to normal-flow low-gradient severe AS (NF-LG-SAS), for which the medical prognostic is still highly debated in the current literature, and high-gradient severe AS (HG-SAS).

Results

The volume proportion of calcification, the size and number of calcified particles and their density composition was quantified. A new size-based classification considering small-sized particles that are not detected with in vivo imaging was defined for macro-, meso- and microscale calcifications. Volume and thickness of aortic valve cusps, including the complete thickness distribution, were also determined. Moreover, changes in the cusp soft tissues were also visualized with microCT and confirmed by scanning electron microscopy images of the same sample. NF-LG-SAS cusps contained lower relative amount of calcifications than HG-SAS. Moreover, the number and size of calcified objects and the volume and thickness of the cusps were also lower in NF-LG-SAS cusps than in HG-SAS.

Conclusions

The application of high-resolution ex vivo microCT to stenotic aortic valve cusps provided a quantitative description of the general structure of the cusps and of the calcifications present in the cusp soft tissues. This detailed description could help in the future to better understand the mechanisms of AS.

Prognostic implications of paradoxical low gradient severe aortic stenosis: a comprehensive analysis from a large multicentric registry

Background

Up to 40% of patients with severe aortic stenosis (SAS; indexed aortic valve area (AVAi) &lt;0.6 cm2/m2) present with low transvalvular mean gradient (MG) despite a normal left ventricular ejection fraction (EF). There is intense debate about the prognostic significance of such entity, with some referring to it as an advanced form of the disease, others as an intermediate form between a moderate and a severe form.

Objectives

To compare outcome of patients with paradoxical low gradient SAS (PLG-SAS; i.e., mean gradient &lt;40 mmHg and AVAi &lt;0.6 cm2/m2) vs. moderate aortic stenosis (MAS; i.e. mean gradient &lt;40 mmHg and AVAi &gt;0.6 cm2/m2) and high gradient SAS (HG-SAS; i.e. mean gradient &gt;40 mmHg and AVAi &lt;0.6 cm2/m2).

Methods

2582 consecutive patients with aortic stenosis (PLG-SAS, n=933; MAS, n=876 and HG-SAS, n=773) and a preserved EF (&gt;50%) from an international multicentric registry were studied. Five years mortality between groups was compared using Kaplan Meier analysis. Inverse probability weighting was used to adjust for clinical and imaging baseline characteristics. Additionally, to explore the impact of MG (&lt;40 mmHg vs. &gt;40 mmHg) in patients with AVAi &lt;0.6 cm2/m2 (PLG-SAS vs. HG-SAS) and to explore the impact of AVAi (&lt;0.6 cm2/m2 vs. &gt;0.6 cm2/m2) in patients with MG &lt;40 mmHg (PLG-SAS vs MAS) we performed 2 different propensity score analyses. Patients were censored at the time of surgery.

Results

Overall, during 23 [IQR,10–47] months of follow-up 1003 patients died and 770 patients underwent aortic valve replacement. IPW-adjusted natural history was significantly better in patients with MAS, intermediate for patients with PLG-SAS and worst in patients with HG-SAS (59 vs. 47 vs. 41%, p&lt;0.001, see Figure 1A). Furthermore, at equal MG (448 pairs), survival was significantly better in patients with MAS compared with PLG-SAS (54% vs. 39% p&lt;0.001, see Figure 1B) and at equal AVAi (377 pairs), survival was significantly better in patients with PLG-SAS compared with HG-SAS (43% vs. 32% p&lt;0.001, see Figure 1C).

Conclusions

In this large multicentric cohort, survival of PLG-SAS patients was better than that of HG-SAS patients and worse than that of MAS patients. Furthermore, with a comparable mean gradient, the smaller the calculated AVAi, the worse the prognosis whereas with a comparable AVAi, the higher the mean gradient, the worse the prognosis. Taking together, these data demonstrate that PLG-SAS is an intermediate form in the disease continuum, HG-SAS being the most malignant form of AS.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Fonds National de la Recherche Scientifique (F.R.S.–FNRS)

Impact of recent 2021 ESC guideline changes on postoperative survival of patients with severe aortic regurgitation: insights from the AVIATOR registry

Background

Until 2021, the strongest guidelines on surgical correction of severe aortic regurgitation (AR) focused on the left ventricular systolic function (LVEF) and the presence of symptoms. However, those situations lead to an outcome penalty, even after surgical correction. Left ventricle end-systolic diameter (LVESD) gained in strength in 2021 European guidelines. Moreover, more inclusive cut-off values are now recommended (class IIb) in patients at low surgical risk, reflecting the will to recommend surgery before developing heart failure and its consequences on post-operative outcome.

Purpose

We sought to evaluate the impact of guidelines triggers and their recent changes on postoperative survival of patients with severe AR from a large multicentric international registry.

Method and results

Postoperative overall survival of 1899 patients operated for severe and chronic AR (mean age 49±15 years, 85% male) in the international multicenter surgery registry for aortic valve surgery, AVIATOR, was evaluated over a median of 37 months. Twelve patients (0.6%) died postoperatively, and 68 within 10 years. By multivariable Cox analysis, presence of heart failure symptoms (HR 2.60; 95% CI [1.20–5.66]; p=0; 016), and either LVESD &gt;50 mm or &gt;25 mm/m2 (HR 1.64; 95% CI [1.05–2.55]; p=0.029) predicted survival independently over and above age (HR 2.25 per SD, 95% CI [1.67–3.03], p&lt;0.001), female gender and bicuspid phenotype. Therefore, patients operated on when meeting either old or new 2021 class I triggers had worse adjusted survival (respectively 86±2% and 87±2%) than patients operated on without meeting triggers (97±2%, p&lt;0.01). However asymptomatic patients operated on while meeting new 2021 ESC class IIb triggers (ie LVESD &gt;20 mm/m2 or LVEF between 50–55%, 10-year survival 97±3%). Moreover, the sub-group of patients having a dilated LVESD &gt;50 mm or &gt;25 mm/m2 but a preserved LVEF &gt;50% had excellent survival (10-year survival 95±3%).

Conclusions

In severe AR, patients operated on when meeting any class I trigger have postoperative survival penalty. Asymptomatic patients operated on earlier have better survival. This supports early surgery in AR as encouraged by the recent ESC/EACTS guidelines.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Fondation Nationale de la Recherche Scientifique of the Belgian Government

Heart failure with preserved ejection fraction in Belgium: characteristics and outcome of a real-life cohort

BACKGROUND

Due to aging of the population and the increase of cardiovascular risk factors, heart failure and preserved ejection fraction (HFpEF) is a rising health issue. Few data exist on the phenotype of HFpEF patients in Belgium and on their prognosis.

OBJECTIVES

We describe clinical characteristics and outcomes of Belgian HFpEF patients.

METHODS

We prospectively enrolled 183 HFpEF patients. They underwent clinical examination, comprehensive biological analysis and echocardiography, and were followed for a combined outcome of all-cause mortality and first HF hospitalisation.

RESULTS

Belgian patients with HFpEF were old (78 ± 8 years), predominantly females (62%) with multiple comorbidities. Ninety-five per cent were hypertensive, 38% diabetic and 69% overweight. History of atrial fibrillation was present in 63% of population, chronic kidney disease in 60% and anaemia in 58%. Over 30 ± 9 months, 55 (31%) patients died, 87 (49%) were hospitalised and 111 (63%) reached the combined outcome. In multivariate Cox analysis, low body mass index (BMI), NYHA class III and IV, diabetes, poor renal function and loop diuretic intake were independent predictors of the combined outcome (p < .05). BMI and renal function were also independent predictors of mortality, as were low haemoglobin, high E/e' and poor right ventricular function.

CONCLUSION

Belgian patients with HFpEF are elderly patients with a high burden of comorbidities. Their prognosis is poor with high rates of hospitalisation and mortality. Although obesity is a risk factor for developing HFpEF, low BMI is the strongest independent predictor of mortality in those patients.

Myocardial Contraction Fraction for Risk Stratification in Low-Gradient Aortic Stenosis With Preserved Ejection Fraction

BACKGROUND

Myocardial contraction fraction (MCF) is a volumetric measure of myocardial shortening independent of left ventricular size and geometry. This multicenter study investigates the usefulness of MCF for risk stratification in low-gradient severe aortic stenosis with preserved ejection fraction.

METHODS

We included 643 consecutive patients with low-gradient severe aortic stenosis with preserved ejection fraction in whom MCF was computed at baseline and analyzed mortality during follow-up.

RESULTS

Throughout follow-up with medical and surgical management (34.9 [16.1-65.3] months), lower MCF tertiles had higher mortality than the highest tertile. Eighty-month survival was 56±4% for MCF>41%, 41±4% for MCF 30% to 41%, and 40±4% for MCF<30% (P<0.001). After comprehensive adjustment, mortality risk remained high for MCF 30% to 41% (adjusted hazard ratio, 1.53 [1.08-2.18]) and for MCF<30% (adjusted hazard ratio, 1.82 [1.24-2.66]) versus MCF>41%. The optimal MCF cutoff point for mortality prediction was 41%. Age, body mass index, Charlson index, peak aortic velocity, and ejection fraction were independently associated with mortality. MCF (χ² to improve 10.39; P=0.001), provided greater additional prognostic value over the baseline parameters than stroke volume (SV) index (χ² to improve 5.41; P=0.042), left ventricular mass index (χ² to improve 2.15; P=0.137), or global longitudinal strain (χ² to improve 3.67; P=0.061). MCF outperformed ejection fraction for mortality prediction. When patients were classified by SV index and MCF, mortality risk was low when SV index was ≥30 mL/m² and MCF>41%, higher for patients with SV index ≥30 mL/m² and MCF≤41% (adjusted hazard ratio, 1.47 [1.05-2.07]) and extremely high for patients with SV index <30 mL/m² (adjusted hazard ratio, 2.29 [1.45-3.62]).

CONCLUSIONS

MCF is a valuable marker of risk in low-gradient severe aortic stenosis with preserved ejection fraction and could improve decision-making, especially in normal-flow low-gradient severe aortic stenosis with preserved ejection fraction.

Inhibition of aquaporin-1 prevents myocardial remodeling by blocking the transmembrane transport of hydrogen peroxide

Pathological remodeling of the myocardium has long been known to involve oxidant signaling, but strategies using systemic antioxidants have generally failed to prevent it. We sought to identify key regulators of oxidant-mediated cardiac hypertrophy amenable to targeted pharmacological therapy. Specific isoforms of the aquaporin water channels have been implicated in oxidant sensing, but their role in heart muscle is unknown. RNA sequencing from human cardiac myocytes revealed that the archetypal AQP1 is a major isoform. AQP1 expression correlates with the severity of hypertrophic remodeling in patients with aortic stenosis. The AQP1 channel was detected at the plasma membrane of human and mouse cardiac myocytes from hypertrophic hearts, where it colocalized with NADPH oxidase-2 and caveolin-3. We show that hydrogen peroxide (H₂O₂), produced extracellularly, is necessary for the hypertrophic response of isolated cardiac myocytes and that AQP1 facilitates the transmembrane transport of H₂O₂ through its water pore, resulting in activation of oxidant-sensitive kinases in cardiac myocytes. Structural analysis of the amino acid residues lining the water pore of AQP1 supports its permeation by H₂O₂ Deletion of Aqp1 or selective blockade of the AQP1 intrasubunit pore inhibited H₂O₂ transport in mouse and human cells and rescued the myocyte hypertrophy in human induced pluripotent stem cell-derived engineered heart muscle. Treatment of mice with a clinically approved AQP1 inhibitor, Bacopaside, attenuated cardiac hypertrophy. We conclude that cardiac hypertrophy is mediated by the transmembrane transport of H₂O₂ by the water channel AQP1 and that inhibitors of AQP1 represent new possibilities for treating hypertrophic cardiomyopathies.

Diagnostic and Prognostic Accuracy of Aortic Valve Calcium Scoring in Patients With Moderate-to-Severe Aortic Stenosis

Background: Assessing the true severity of aortic stenosis (AS) remains a challenge, particularly when echocardiography yields discordant results. Recent European and American guidelines recommend measuring aortic valve calcium (AVC) by multidetector row computed tomography (MDCT) to improve this assessment. Aim: To define, using a standardized MDCT scanning protocol, the optimal AVC load criteria for truly severe AS in patients with concordant echocardiographic findings, to establish the ability of these criteria to predict clinical outcomes, and to investigate their ability to delineate truly severe AS in patients with discordant echocardiographic AS grading. Methods and Results: Two hundred and sixty-six patients with moderate-to-severe AS and normal LVEF prospectively underwent MDCT and Doppler-echocardiography to assess AS severity. In patients with concordant AS grading, ROC analysis identified optimal cut-off values for diagnosing severe AS using different AVC load criteria. In these patients, 4-year event-free survival was better with low AVC load (60-63%) by these criteria than with high AVC load (23-26%, log rank p < 0.001). Patients with discordant AS grading had higher AVC load than those with moderate AS but lower AVC load than those with severe high-gradient AS. Between 36 and 55% of patients with severe LG-AS met AVC load criteria for severe AS. Although AVC load predicted outcome in these patients as well, its prognostic impact was less than in patients with concordant AS grading. Conclusions: Assessment of AVC load accurately identifies truly severe AS and provides powerful prognostic information. Our data further indicate that patients with discordant AS grading consist in a heterogenous group, as evidenced by their large range of AVC load. MDCT allows to differentiate between truly severe and pseudo-severe AS in this population as well, although the prognostic implications thereof are less pronounced than in patients with concordant AS grading.

Diabetic phenotype and prognosis of patients with heart failure and preserved ejection fraction in a real life cohort

Background

Heart failure with preserved ejection fraction (HFpEF) is a heterogeneous syndrome, with several underlying etiologic and pathophysiologic factors. The presence of diabetes might identify an important phenotype, with implications for therapeutic strategies. While diabetes is associated with worse prognosis in HFpEF, the prognostic impact of glycemic control is yet unknown. Hence, we investigated phenotypic differences between diabetic and non-diabetic HFpEF patients (pts), and the prognostic impact of glycated hemoglobin (HbA1C).

Methods

We prospectively enrolled 183 pts with HFpEF (78 ± 9 years, 38% men), including 70 (38%) diabetics (type 2 diabetes only). They underwent 2D echocardiography (n = 183), cardiac magnetic resonance (CMR) (n = 150), and were followed for a combined outcome of all-cause mortality and first HF hospitalization. The prognostic impact of diabetes and glycemic control were determined with Cox proportional hazard models, and illustrated by adjusted Kaplan Meier curves.

Results

Diabetic HFpEF pts were younger (76 ± 9 vs 80 ± 8 years, p = 0.002), more obese (BMI 31 ± 6 vs 27 ± 6 kg/m², p = 0.001) and suffered more frequently from sleep apnea (18% vs 7%, p = 0.032). Atrial fibrillation, however, was more frequent in non-diabetic pts (69% vs 53%, p = 0.028). Although no echocardiographic difference could be detected, CMR analysis revealed a trend towards higher LV mass (66 ± 18 vs 71 ± 14 g/m², p = 0.07) and higher levels of fibrosis (53% vs 36% of patients had ECV by T1 mapping > 33%, p = 0.05) in diabetic patients.

Over 25 ± 12 months, 111 HFpEF pts (63%) reached the combined outcome (24 deaths and 87 HF hospitalizations). Diabetes was a significant predictor of mortality and hospitalization for heart failure (HR: 1.72 [1.1–2.6], p = 0.011, adjusted for age, BMI, NYHA class and renal function). In diabetic patients, lower levels of glycated hemoglobin (HbA1C < 7%) were associated with worse prognosis (HR: 2.07 [1.1–4.0], p = 0.028 adjusted for age, BMI, hemoglobin and NT-proBNP levels).

Conclusion

Our study highlights phenotypic features characterizing diabetic patients with HFpEF. Notably, they are younger and more obese than their non-diabetic counterpart, but suffer less from atrial fibrillation. Although diabetes is a predictor of poor outcome in HFpEF, intensive glycemic control (HbA1C < 7%) in diabetic patients is associated with worse prognosis.

Myocardial strain imaging: review of general principles, validation, and sources of discrepancies

Myocardial tissue tracking imaging techniques have been developed for a more accurate evaluation of myocardial deformation (i.e. strain), with the potential to overcome the limitations of ejection fraction (EF) and to contribute, incremental to EF, to the diagnosis and prognosis in cardiac diseases. While most of the deformation imaging techniques are based on the similar principles of detecting and tracking specific patterns within an image, there are intra- and inter-imaging modality inconsistencies limiting the wide clinical applicability of strain. In this review, we aimed to describe the particularities of the echocardiographic and cardiac magnetic resonance deformation techniques, in order to understand the discrepancies in strain measurement, focusing on the potential sources of variation: related to the software used to analyse the data, to the different physics of image acquisition and the different principles of 2D vs. 3D approaches. As strain measurements are not interchangeable, it is highly desirable to work with validated strain assessment tools, in order to derive information from evidence-based data. There is, however, a lack of solid validation of the current tissue tracking techniques, as only a few of the commercial deformation imaging softwares have been properly investigated. We have, therefore, addressed in this review the neglected issue of suboptimal validation of tissue tracking techniques, in order to advocate for this matter.

Natural History of Asymptomatic Severe Aortic Stenosis and the Association of Early Intervention With Outcomes: A Systematic Review and Meta-analysis

Importance

Whether intervention should be performed in patients with asymptomatic severe aortic stenosis (AS) remains debated.

Objective

To meta-analyze the natural history of asymptomatic severe AS and examine the association of early intervention with survival.

Data Sources

PubMed, Embase, and Cochrane databases were searched from inception to February 1, 2020.

Study Selection

Observational studies of adult patients with asymptomatic severe AS.

Data Extraction and Synthesis

Two investigators independently extracted study and patient characteristics, follow-up time, events, and prognostic indicators of events. Random-effects models were used to derive pooled estimates.

Main Outcomes and Measures

The meta-analysis on natural history was performed on the primary end point of all-cause death occurring during a conservative treatment period, with secondary end points consisting of cardiac death, death due to heart failure, sudden death, development of symptoms, development of an indication for aortic valve intervention, and aortic valve intervention. The primary end point for the meta-analysis of early intervention vs a conservative strategy was all-cause death during long-term follow-up. Finally, meta-analysis was performed on the association of prognostic indicators with the composite of death or aortic valve intervention found in multivariable models.

Results

A total of 29 studies with 4075 patients with 11 901 years of follow-up were included. Pooled rates per 100 patients per year were 4.8 (95% CI, 3.6-6.4) for all-cause death, 3.0 (95% CI, 2.2-4.1) for cardiac death, 2.0 (95% CI, 1.3-3.1) for death due to heart failure, 1.1 (95% CI, 0.6-2.1) for sudden death, 18.1 (95% CI, 12.8-25.4) for an indication for aortic valve intervention, 18.5 (95% CI, 13.4-25.5) for development of symptoms, and 19.2 (95% CI, 15.5-23.8) for aortic valve intervention. Early intervention was associated with a significant reduction in long-term mortality (hazard ratio, 0.38; 95% CI, 0.25-0.58). Factors associated with worse prognosis were severity of AS, low-flow AS, left ventricular damage, and atherosclerotic risk factors.

Conclusions and Relevance

Data from observational studies and a recent randomized clinical trial suggest that many patients with asymptomatic severe AS develop an indication for aortic valve intervention, and their deaths are mostly cardiac but not only sudden. Other end points besides sudden death should be considered during the decision to perform early intervention that are associated with improved survival.

Severe Aortic Stenosis and Chronic Kidney Disease: Outcomes and Impact of Aortic Valve Replacement

Background

The prognostic significance of chronic kidney disease (CKD) in severe aortic stenosis is poorly understood and no studies have yet evaluated the effect of aortic‐valve replacement (AVR) versus conservative management on long‐term mortality by stage of CKD.

Methods and Results

We included 4119 patients with severe aortic stenosis. The population was divided into 4 groups according to the baseline estimated glomerular filtration rate: no CKD, mild CKD, moderate CKD, and severe CKD. The 5‐year survival rate was 71±1% for patients without CKD, 62±2% for those with mild CKD, 54±3% for those with moderate CKD, and 34±4% for those with severe CKD (P<0.001). By multivariable analysis, patients with moderate or severe CKD had a significantly higher risk of all‐cause (hazard ratio [HR] [95% CI]=1.36 [1.08–1.71]; P=0.009 and HR [95% CI]=2.16 [1.67–2.79]; P<0.001, respectively) and cardiovascular mortality (HR [95% CI]=1.39 [1.03–1.88]; P=0.031 and HR [95% CI]=1.69 [1.18–2.41]; P=0.004, respectively) than patients without CKD. Despite more symptoms, AVR was less frequent in moderate (P=0.002) and severe CKD (P<0.001). AVR was associated with a marked reduction in all‐cause and cardiovascular mortality versus conservative management for each CKD group (all P<0.001). The joint‐test showed no interaction between AVR and CKD stages (P=0.676) indicating a nondifferentialeffect of AVR across stages of CKD. After propensity matching, AVR was still associated with substantially better survival for each CKD stage relative to conservative management (all P<0.0017).

Conclusions

In severe aortic stenosis, moderate and severe CKD are associated with increased mortality and decreased referral to AVR. AVR markedly reduces all‐cause and cardiovascular mortality, regardless of the CKD stage. Therefore, CKD should not discourage physicians from considering AVR.

Test–retest reliability of left and right ventricular systolic function by new and conventional echocardiographic and cardiac magnetic resonance parameters

Aims 

Reproducible evaluation of left (LV) and right ventricular (RV) function is crucial for clinical decision-making and risk stratification. We evaluated whether speckle-tracking echocardiography (STE) and cardiac magnetic resonance feature-tracking (cMR-FT) global longitudinal (GLS) and circumferential strains allow better test–retest reproducibility of LV and RV systolic function than conventional cMR and echocardiographic parameters.

Methods and results 

Thirty healthy volunteers and 20 chronic heart failure patients underwent cMR and STE twice on separate days to evaluate test–retest coefficient of variation (CV), intraclass correlation coefficient (ICC) and estimated sample sizes for significant changes in LV and RV function. Among LV parameters, cMR-left ventricular ejection fraction (LVEF) had the highest reproducibility (CV = 6.7%, ICC = 0.98), significantly better than cMR-FT-GLS (CV = 15.1%, ICC = 0.84), global circumferential strains (CV = 11.5%, ICC = 0.94) and echocardiographic LVEF (CV = 11.3%, ICC = 0.93). STE-LV-GLS (CV = 8.9%, ICC = 0.94) had significantly better reproducibility than cMR-FT-LV-GLS. Among RV parameters, STE-RV-GLS (CV = 7.3%, ICC = 0.93) had significantly better CV than cMR-right ventricular ejection fraction (RVEF) (CV = 13%, ICC = 0.82). cMR-FT-RV-GLS (CV = 43%, ICC = 0.39) performed poorly with significantly lower reproducibility than all other RV parameters. Owing to their superior interstudy reproducibility, cMR-LVEF (n = 12), cMR-RVEF (n = 41), STE-LV-GLS and STE-RV-GLS (both n = 14) were the parameters allowing the lowest calculated sample sizes to detect 10% change in LV or RV systolic function.

Conclusion 

STE-LV-GLS and STE-RV-GLS showed higher test–retest reliability than other echocardiographic measurements of LV and RV function. They also allowed smaller calculated sample sizes, supporting the use of STE-LV and RV-GLS for longitudinal follow-up of LV and RV function.

Progression of Normal Flow Low Gradient "Severe" Aortic Stenosis With Preserved Left Ventricular Ejection Fraction

Normal-flow low-gradient severe aortic stenosis (NF-LG-SAS), defined by an aortic valve area (AVA) <1 cm², mean pressure gradient (MPG) <40 mm Hg and indexed stroke volume ≥35 ml/m², is the most prevalent form of low-gradient aortic stenosis (AS) with preserved ejection fraction (PEF). However, the true severity of AS in these patients is controversial. The aim of this Doppler echocardiographic study was to investigate changes over time in the hemodynamic severity of patients with NF-LG-SAS with PEF. We retrospectively identified 96 patients who had 2 Doppler echocardiographic examinations without an intervening event. After a median follow-up of 25 (interquartile range 15 to 52) months, progression was observed, with increased transaortic MPG (from 28 [25 to 33] to 39 [34 to 50] mm Hg; p<0.001), peak aortic jet velocity (from 3.46 [3.20 to 3.64] to 4.01 [3.70 to 4.39] m/s; p<0.001), and decreased AVA (from 0.87 [0.82 to 0.94] to 0.72 [0.62 to 0.81] cm²; p<0.001). Median annual rates of progression were 4.3 (1.7 to 8.1) mm Hg/year, 0.25 (0.08 to 0.44) m/s/year, and -0.05 (-0.10 to -0.02) cm²/year, respectively. There was no significant change in left ventricular ejection fraction over time (p = 0.74). At follow-up, 46 patients (48%) acquired the features of classical high-gradient severe AS (MPG ≥40 mm Hg). This study shows that most patients with NF-LG-SAS with PEF exhibit significant hemodynamic progression of AS severity without EF impairment. These findings suggest that NF-LG-SAS with PEF is an "intermediate" stage between moderate AS and classical high-gradient severe AS requiring close monitoring.

Fibroblast growth factor 23: a biomarker of fibrosis and prognosis in heart failure with preserved ejection fraction

AIMS

Besides regulating calcium-phosphate metabolism, fibroblast growth factor 23 (FGF-23) has been associated with incident heart failure (HF) and left ventricular hypertrophy. However, data about FGF-23 in HF and preserved ejection fraction (HFpEF) remain limited. The aim of this study was to assess the association between FGF-23 levels, clinical and imaging characteristics, particularly diffuse myocardial fibrosis, and prognosis in HFpEF patients.

METHODS AND RESULTS

We prospectively included 143 consecutive HFpEF patients (78 ± 8 years, 61% female patients) and 31 controls of similar age and gender (75 ± 6 years, 61% female patients). All subjects underwent a complete two-dimensional echocardiography and cardiac magnetic resonance with extracellular volume (ECV) assessment by T1 mapping. FGF-23 was measured at baseline. Among the patients, differences in clinical and imaging characteristics across tertiles of FGF-23 levels were analysed with a trend test across the ordered groups. Patients were followed over time for a primary endpoint of all-cause mortality and first HF hospitalization and a secondary endpoint of all-cause mortality. Median FGF-23 was significantly higher in HFpEF patients compared with controls of similar age and gender (247 [115; 548] RU/mL vs. 61 [51; 68] RU/mL, P < 0.001). Among HFpEF patients, higher FGF-23 levels were associated with female sex, higher incidence of atrial fibrillation, lower haemoglobin, worse renal function, and higher N terminal pro brain natriuretic peptide levels (P for trend < 0.05 for all). Regarding imaging characteristics, patients with higher FGF-23 levels had greater left atrial volumes, worse right ventricular systolic function, and more fibrosis estimated by ECV (P for trend < 0.05 for all). FGF-23 was moderately correlated with ECV (r = 0.46, P < 0.001). Over a mean follow-up of 30 ± 8 months, 43 patients (31%) died and 69 patients (49%) were hospitalized for HF. A total of 87 patients (62%) reached the primary composite endpoint of all-cause mortality and/or first HF hospitalization. In multivariate Cox regression analysis for the primary endpoint, FGF-23 (HR: 3.44 [2.01; 5.90], P < 0.001) and E wave velocities (HR: 1.01 [1.00; 1.02], P = 0.034) were independent predictors of the primary composite endpoint. In multivariate Cox regression analysis for the secondary endpoint, ferritin (HR: 1.02 [1.01; 1.03], P < 0.001), FGF-23 (HR: 2.85 [1.26; 6.44], P = 0.012), and ECV (HR: 1.26 [1.03; 1.23], P = 0.008) were independent predictors of all-cause mortality.

CONCLUSIONS

Fibroblast growth factor 23 (FGF-23) levels were significantly higher in HFpEF patients compared with controls of similar age and gender. FGF-23 was correlated with fibrosis evaluated by ECV. High levels of FGF-23 were significantly associated with signs of disease severity such as worse renal function, larger left atrial volumes, and right ventricular dysfunction. Moreover, FGF-23 was a strong predictor of poor outcome (mortality and first HF hospitalization).

Right Ventricular Global Longitudinal Strain and Outcomes in Heart Failure with Preserved Ejection Fraction

BACKGROUND

Right ventricular (RV) strain has emerged as an accurate tool for RV function assessment and is a powerful predictor of survival in patients with heart failure with reduced ejection fraction. However, its prognostic impact in patients with heart failure with preserved ejection fraction (HFpEF) remains unclear. The aim of this study was to compare the prognostic value of RV global longitudinal strain (RVGLS) by two-dimensional speckle-tracking echocardiographic (STE) imaging in patients with HFpEF against conventional RV function parameters.

METHODS

Patients with HFpEF were prospectively recruited, and 149 of 183 (81%) with analyzable STE RVGLS images constituted the final study population (mean age, 78 ± 9 years; 61% women), compared with 28 control subjects of similar age and sex. All control subjects and 120 patients also underwent cardiac magnetic resonance imaging. Patients were followed up for a primary end point of all-cause mortality and first heart failure hospitalization, and Cox regression analysis was performed.

RESULTS

Mean STE RVGLS was significantly altered in patients with HFpEF compared with control subjects (-21.7 ± 4.9% vs -25.9 ± 4.2%, P < .001). STE RVGLS correlated well with RV ejection fraction by cardiac magnetic resonance (r = -0.617, P < .001). Twenty-eight patients with HFpEF (19%) had impaired STE RVGLS (>-17.5%). During a mean follow-up period of 30 ± 9 months, 91 patients with HFpEF (62%) reached the primary end point. A baseline model was created using independent predictors of the primary end point: New York Heart Association functional class III or IV, hemoglobin level, estimated glomerular filtration rate, and the presence of moderate or severe tricuspid regurgitation. Impaired STE RVGLS provided significant additional prognostic value over this model (χ² to enter = 7.85, P = .005). Impaired tricuspid annular plane systolic excursion and fractional area change, however, did not.

CONCLUSIONS

In patients with HFpEF, impaired RVGLS has strong prognostic value. STE RVGLS should be considered for systematic evaluation of RV function to identify patients at high risk for adverse events.

P787 Interstudy reproducibility in the real world of speckle tracking echocardiography in direct comparison with cardiac magnetic resonance

Funding Acknowledgements

Fond national de la recherche scientifique (FNRS)

Background

New research methods to assess cardiac function such as 2D speckle tracking echocardiography (STE) are emerging in clinical practice after showing incremental prognostic information beyond ejection fraction in a variety of settings. However, comprehensive data regarding the day to day reproducibility is still lacking.

Aim

To assess the inter and especially the day to day intravariability of RV and LV GLS STE in direct comparison with cMR in asymptomatic volunteers and in patients with heart failure.

Methods for the volunteers:30 asymptomatic volunteers ( 34 ± 9years, 33% were women) underwent 2 cMR and 2 echocardiography studies with a maximal interval between each study of 6 days and 20 minutes between each technique. RV strain was performed on a RV focus view and LV strain on 4, 3 and 2 chamber views using the segment software. cMR- RVEF and cMR-LVEF was performed in short axis view.

Preliminary Results: Volunteers

Average values for the the STE measurements was -24.2%±2.3 and -27.4%±2.1 for LV and RV GLS respectively. Average values for the 2 cMR measurements was 61.9% ±4.5 and 56.3%± 6.2% for cMR-LVEF and RVEF respectively. The interstudy varability coefficient of variability was lower in GLS-STE parameters (RV-GLS = 7.7% and LV-GLS = 6.3%) than for the cMR parameters (cMR-LVEF= 8.2% and cMR-RVEF= 12.9%). The superior interstudy reproducibility resulted in lower calculated sample sizes require by GLS compared with cMR to show clinically relevant changes in LV and RV function. (Figure 1)

Conclusion

LV and RV -GLS- STE has excellent interstudy reproducibility in normal hearts and is as good as cMR- LVEF and RVEF.

Echocardiography cMR LV-GLS-STE RV-GLS-STE LVEF RVEF Mean difference ±SD 0.6 ± 1.88 0.5± 1.73 1.14 ± 5.22 0.98 ± 7.23 Coefficient of variation 7.7% 6.3% 8.2% 12.9% Sample Size for 2% absolute change in GLS or 5% absolute change in cMR- EF 18 16 22 44 Sample size required to detect a clinically significant change in global longidutdinal strain speckle tracking (GLS-STE) echocardiographie and cMR - ejection fraction (EF). RV and LV indicate Right ventricular and left ventricular respectively.

P1393 Intervendor difference in global and regional 2D speckle tracking strain. comparison against cMR tagging

Funding Acknowledgements

Fondation de Recherche Scientifique Belge FRSM PDR 19488731

BACKGROUND

2D-speckle-tracking (ST) echocardiography is currently widely used for estimation of global (G) and regional myocardial deformation. In previous works, we showed good correlation between global longitudinal (LS) and circumferential strain (CS) from one 2DST vendor with cMR-Tagging, however with significant bias between both methods. Also, we found poorer agreement between 2DST and cMR-Tagging on regional basis. However it is unknown how 2DST from other vendors would comparte to cMR tagging.

PURPOSE

To asssess vendor differences in global and regional strain assessment and compare 1) the agreement of 2 different 2DST softwares for global and regional LS and CS among each other and against cMR-Tagging as reference; and 2) the accuracy of both softwares to detect infarcted segments.

METHODS

100 subjects with different cardiac disease (among which 31 with chronic infarct) underwent 2DST and tagging and LGE cMR on the same day. Global and regional CS (16 AHA segments) and LS (18 AHA segments) was computed using 2 different ST vendor softwares and compared to cMR-Tagging with HARP. Accuracy of regional 2D-ST by both vendors to detect infarcted segments (ie &gt;75% transmurality of late gadolinium) was compared using ROC analysis.

RESULTS

Global LS (ICC = 0.87) and CS 2DST (ICC = 0.83, p &lt; 0.001) agreed well between both vendors, but GCS values of vendor2 were significantly greater than that of vendor 1. Also we fond good correlation between ST of both vendors and cMR-Tagging for GLS (ICC = 0.80 and ICC = 0.69 for vendor 1 and 2 respectively) and GCS (ICC = 0.64 and ICC = 0.50 for vendor 1 and 2 respectively). Bias for GLS (-4.6 ± 2.9% and -6.1 ± 3.8% for vendor 1 and 2 respectively) vs cMR-Tagging was similar, however GCS of vendor 2 had higher bias vs cMR-Tagging (-16.0 ± 8.5%) than vendor 1 (-5.1 ± 5.8%).

Agreement for regional strains is shown in the figure below. Overall, regional LS and CS agreed adequately among both vendors. Agreement of regional LS and CS vs cMR-tagging was slightly better for vendor 1, with less bias than for vendor 2, and disagreement was similarly located (ie agreement with cMR-Tagging for LS in inferolateral inferior and inferoseptal basal segments). The predictive accuracy of regional CS and LS for detecting segments with infarct was higher for vendor 2 (AUC 0.76 and 0.68) than for vendor 1 (AUC 0.70 and 0.63) .

CONCLUSION

GLS agreed well among both vendors and with cMR-Tagging, confirming the universal validity of this measurement. However vendor 2 provided significantly greater GCS values and had higher bias against cMR-Tagging than vendor 1. On regional basis CS and LS agreed moderately well among both vendors, however vendor 2 agreed less with cMR-Tagging than vendor 1, but astoundingly had higher diagnostic accuracy for detecting infarct. Overall this findings call for further efforts in standardization of 2DST CS and regional strain.

Abstract P1393 Figure.

The MIDA Mortality Risk Score: development and external validation of a prognostic model for early and late death in degenerative mitral regurgitation

Aims

In degenerative mitral regurgitation (DMR), lack of mortality scores predicting death favours misperception of individual patients' risk and inappropriate decision-making.

Methods and results

The Mitral Regurgitation International Database (MIDA) registries include 3666 patients (age 66 ± 14 years; 70% males; follow-up 7.8 ± 5.0 years) with pure, isolated, DMR consecutively diagnosed by echocardiography at tertiary (European/North/South-American) centres. The MIDA Score was derived from the MIDA-Flail-Registry (2472 patients with DMR and flail leaflet-Derivation Cohort) by weighting all guideline-provided prognostic markers, and externally validated in the MIDA-BNP-Registry (1194 patients with DMR and flail leaflet/prolapse-Validation Cohort). The MIDA Score ranged from 0 to 12 depending on accumulating risk factors. In predicting total mortality post-diagnosis, the MIDA Score showed excellent concordance both in Derivation Cohort (c = 0.78) and Validation Cohort (c = 0.81). In the whole MIDA population (n = 3666 patients), 1-year mortality with Scores 0, 7-8, and 11-12 was 0.4, 17, and 48% under medical management and 1, 7, and 14% after surgery, respectively (P < 0.001). Five-year survival with Scores 0, 7-8, and 11-12 was 98 ± 1, 57 ± 4, and 21 ± 10% under medical management and 99 ± 1, 82 ± 2, and 57 ± 9% after surgery (P < 0.001). In models including all guideline-provided prognostic markers and the EuroScoreII, the MIDA Score provided incremental prognostic information (P ≤ 0.002).

Conclusion

The MIDA Score may represent an innovative tool for DMR management, being able to position a given patient within a continuous spectrum of short- and long-term mortality risk, either under medical or surgical management. This innovative prognostic indicator may provide a specific framework for future clinical trials aiming to compare new technologies for DMR treatment in homogeneous risk categories of patients.

How Should Very Severe Aortic Stenosis Be Defined in Asymptomatic Individuals?

See Article by Kanamori et al.

P324Impact of impaired right ventricular strain on the prognosis of HFpEF

Background

Right ventricle (RV) strain has emerged as an accurate and sensitive tool for RV function assessment and is a powerful predictor of survival in heart failure with reduced ejection fraction. The impact of impaired RV strain on prognosis of HFpEF patients however, remains unclear.

Purpose

We sought to analyze RV global longitudinal strain (RV-GLS) by 2D speckle tracking echocardiography (STE) in controls and HFpEF patients and determine its prognostic value.

Methods

Between January 2015 and June 2017, we prospectively enrolled 163 consecutive patients with HFpEF (78±9 years, 62% women) and 27 age and sex matched controls (76±5 years, 67% women). All patients underwent complete 2D echography. Myocardial deformation was assessed on a dedicated four chambers view, with a speckle tracking software. Due to poor tracking quality, RV-GLS could not be analyzed in 14 patients (7.4%). Impaired RV-GLS was defined as a GLS above −17.5% corresponding to the mean + 2 SD of age and sex matched controls. HFpEF patients were followed up for a combined outcome of all-cause mortality and first HF hospitalization.

Results

Mean RV-GLS was significantly altered in HFpEF patients compared to controls (−21.7±4.9% vs −25.9±4.2%; p<0.001). 28 HFpEF patients (19%) had an impaired RV-GLS.

During a mean follow-up of 19±9months, 73 HFpEF patients (49%) reached the combined outcome (15 all cause deaths and 58 first HF hospitalization). In univariate Cox regression analysis, loop diuretic medication (HR 1.92 [1.10–3.32], p=0.021), low hemoglobin (HR 0.85 [0.75–0.97], p=0.013), low eGFR (HR 0.97 [0.96–0.99], p<0.001), E wave velocity (HR 1.01 [1.00–1.02], p<0.001), septal E/e' (HR 1.03 [1.00–1.05], p=0.011) and impaired RV-GLS (HR 2.01 [1.19–3.40], p=0.009) were significantly associated with worse prognosis.

In multivariate Cox analysis, hemoglobin levels (HR 0.83 [0.72–0.96], p=0.01), eGFR (HR 0.98 [0.97–0.99]; p=0.009) and impaired RV-GLS (HR 2.48 [1.38–4.44], p=0.002), were independent predictors of the combined outcome. Kaplan-Meier event free survival curves show that HFpEF patients with RV-GLS above −17.5% had worse prognosis than those with better myocardial deformation (p=0.009, Figure).

Conclusions

RV-GLS is significantly different between controls and HFpEF patients. In HFpEF, impaired RV-GLS is associated with worse prognosis.

Aortic Valve Surgery in Nonelderly Patients: Insights Gained From AVIATOR

Aortic valve surgery in non-elderly patients represents a very challenging patient population. The younger the patient is at the point of aortic valve intervention, the longer their anticipated life expectancy will be, with longer exposure to valve-related complications and risk for re-operation. Although the latest international guidelines recommend aortic valve repair in patients with aortic valve insufficiency, what we see in the real world is that the vast majority of these aortic valves are replaced. However, current prosthetic valves has now been shown to lead to significant loss of life expectancy for non-elderly patients up to 50% for patients in their 40s undergoing mechanical aortic valve replacement. Bioprostheses carry an even worse long-term survival, with higher rates of re-intervention. The promise of trans-catheter valve-in-valve technology is accentuating the trend of bioprosthetic implantation in younger patients, without yet the appropriate evidence. In contrast, aortic valve repair has shown excellent outcomes in terms of quality of life, freedom from re-operation and freedom from major adverse valve-related events with similar life expectancy to general population as it is also found for the Ross procedure, the only available living valve substitute. We are at a time when the paradigm of aortic valve surgery needs to change for the better. To better serve our patients, we must acquire high quality real-world evidence from multiple centers globally - this is the vision of the AVIATOR registry and our common responsibility.

Associations and prognostic significance of diffuse myocardial fibrosis by cardiovascular magnetic resonance in heart failure with preserved ejection fraction

BACKGROUND

Increased myocardial fibrosis may play a key role in heart failure with preserved ejection fraction (HFpEF) pathophysiology. The study aim was to evaluate the presence, associations, and prognostic significance of diffuse fibrosis in HFpEF patients compared to age- and sex-matched controls.

METHODS

We prospectively included 118 consecutive HFpEF patients. Diffuse myocardial fibrosis was estimated by extracellular volume (ECV) quantified by cardiovascular magnetic resonance with the modified Look-Locker inversion recovery sequence. We determined an ECV age- and sex-adjusted cutoff value (33%) in 26 controls.

RESULTS

Mean ECV was significantly higher in HFpEF patients versus healthy controls (32.9 ± 4.8% vs 28.2 ± 2.4%, P <  0.001). Multivariate logistic regression showed that body mass index (BMI) (odds ratio (OR) =0.92 [0.86-0.98], P = 0.011), diabetes (OR = 2.62 [1.11-6.18], P = 0.028), and transmitral peak E wave velocity (OR = 1.02 [1.00-1.03], P = 0.022) were significantly associated with abnormal ECV value. During a median follow-up of 11 ± 6 months, the primary outcome (all-cause mortality or first heart failure hospitalization) occurred in 38 patients. In multivariate Cox regression analysis, diabetes (hazard ratio (HR) =1.98 [1.04; 3.76], P = 0.038) and hemoglobin level (HR = 0.81 [0.67; 0.98], P = 0.028) were significant predictors of composite outcome. The ECV ability to improve this model added significant prognostic information. We then developed a risk score including diabetes, hemoglobin and ECV > 33% demonstrating significant prediction of risk and validated this score in a validation cohort of 53 patients. Kaplan-Meier curves showed a significant difference according to tertiles of the probability score (P <  0.001).

CONCLUSION

Among HFpEF patients, high ECV, likely reflecting abnormal diffuse myocardial fibrosis, was associated with a higher rate of all-cause death and first HF hospitalization in short term follow up.

TRIAL REGISTRATION

Characterization of Heart Failure With Preserved Ejection Fraction.

TRIAL REGISTRATION NUMBER

NCT03197350 . Date of registration: 20/06/2017. This trial was retrospectively registered.

AMPK activation counteracts cardiac hypertrophy by reducing O-GlcNAcylation

AMP-activated protein kinase (AMPK) has been shown to inhibit cardiac hypertrophy. Here, we show that submaximal AMPK activation blocks cardiomyocyte hypertrophy without affecting downstream targets previously suggested to be involved, such as p70 ribosomal S6 protein kinase, calcineurin/nuclear factor of activated T cells (NFAT) and extracellular signal-regulated kinases. Instead, cardiomyocyte hypertrophy is accompanied by increased protein O-GlcNAcylation, which is reversed by AMPK activation. Decreasing O-GlcNAcylation by inhibitors of the glutamine:fructose-6-phosphate aminotransferase (GFAT), blocks cardiomyocyte hypertrophy, mimicking AMPK activation. Conversely, O-GlcNAcylation-inducing agents counteract the anti-hypertrophic effect of AMPK. In vivo, AMPK activation prevents myocardial hypertrophy and the concomitant rise of O-GlcNAcylation in wild-type but not in AMPKα2-deficient mice. Treatment of wild-type mice with O-GlcNAcylation-inducing agents reverses AMPK action. Finally, we demonstrate that AMPK inhibits O-GlcNAcylation by mainly controlling GFAT phosphorylation, thereby reducing O-GlcNAcylation of proteins such as troponin T. We conclude that AMPK activation prevents cardiac hypertrophy predominantly by inhibiting O-GlcNAcylation.

Three-dimensional echocardiographic quantification of the left-heart chambers using an automated adaptive analytics algorithm: multicentre validation study

Aims

Although recommended by current guidelines, adoption of three-dimensional echocardiographic (3DE) chamber quantification in clinical practice has lagged because of time-consuming analysis. We recently validated an automated algorithm that measures left atrial (LA) and left ventricular (LV) volumes and ejection fraction (EF). This study aimed to determine the accuracy and reproducibility of these measurements in a multicentre setting.

Methods and results

180 patients underwent 3DE imaging (Philips) at six sites. Images were analysed using automated HeartModel (HM) software with endocardial border correction when necessary and by manual tracing. Measurements were performed by each site and by the Core Laboratory (CL) as the reference. Inter-technique comparisons included HM measurements by the sites against manual tracing by CL, and showed strong correlations (r-values: LVEDV: 0.97, LVESV: 0.97, LVEF: 0.88, LAV: 0.96), with the automated technique slightly underestimating LV volumes (biases: LVEDV: -14 ± 20 ml, LVESV: -6 ± 20 ml), LVEF (-2 ± 7%) and LAV (-9 ± 10 ml). Intra-technique comparisons included HM measurements by the sites against CL, with and without corrections. Corrections were unnecessary or minimal in most patients, and improved the measurements only modestly. Comparisons without corrections showed perfect agreement for all parameters. With corrections, correlations were better (r-values: LVEDV: 0.99, LVESV: 0.99, LVEF: 0.94, LAV: 0.99) and biases (LVEDV: -8 ± 12 ml, LVESV: -6 ± 12 ml, LVEF: 1 ± 5%, LAV: -10 ± 6 ml) smaller than in inter-technique comparison. All automated measurements with corrections were more reproducible than manual measurements.

Conclusion

Automated 3DE analysis of left-heart chambers is an accurate alternative to conventional manual methodology, which yields almost the same values across laboratories and is more reproducible. This technique may contribute towards full integration of 3DE quantification into clinical routine.

Age and sex corrected normal reference values of T1, T2 T2* and ECV in healthy subjects at 3T CMR

BACKGROUND

Myocardial T1, T2 and T2* imaging techniques become increasingly used in clinical practice. While normal values for T1, T2 and T2* times are well established for 1.5 Tesla (T) cardiovascular magnetic resonance (CMR), data for 3T remain scarce. Therefore we sought to determine normal reference values relative to gender and age and day to day reproducibility for native T1, T2, T2* mapping and extracellular volume (ECV) at 3T in healthy subjects.

METHODS

After careful exclusion of cardiovascular abnormality, 75 healthy subjects aged 20 to 90 years old (mean 56 ± 19 years, 47% women) underwent left-ventricular T1 (3-(3)-3-(3)-5 MOLLI)), T2 (8 echo- spin echo-imaging) and T2 * (8 echo gradient echo imaging) mapping at 3T CMR (Philips Ingenia 3T and computation of extracellular volume after administration of 0.2 mmol/kg Gadovist). Inter- and intra-observer reproducibility was estimated by intraclass correlation coefficient (ICC). Day to day reproducibility was assessed in 10 other volunteers.

RESULTS

Mean myocardial T1 at 3T was 1122 ± 57 ms, T2 52 ± 6 ms, T2* 24 ± 5 ms and ECV 26.6 ± 3.2%. T1 (1139 ± 37 vs 1109 ± 73 ms, p < 0.05) and ECV (28 ± 3 vs 25 ± 2%, p < 0.001), but not T2 (53 ± 8 vs 51 ± 4, p = NS) were significantly greater in age matched women than in men. T1 (r = 0.40, p < 0.001) and ECV (r = 0.37, p = 0.001) increased, while T2 decreased significantly (r = -0.25, p < 0.05) with increasing age. T2* was not influenced by either gender or age. Intra and inter-observer reproducibility was high (ICC ranging between 0.81-0.99), and day to day coefficient of variation was low (6.2% for T1, 7% for T2, 11% for T2* and 11.5% for ECV).

CONCLUSIONS

We provide normal myocardial T2, T2*,T1 and ECV reference values for 3T CMR which are significantly different from those reported at 1.5 Tesla CMR. Myocardial T1 and ECV values are gender and age dependent. Measurement had high inter and intra-observer reproducibility and good day-to-day reproducibility.

Assessment of aortic valve calcium load by multidetector computed tomography. Anatomical validation, impact of scanner settings and incremental diagnostic value

OBJECTIVES

To validate aortic valve calcium (AVC) load measurements by multidetector row computed tomography (MDCT), to evaluate the impact of tube potential and slice thickness on AVC scores, to examine the accuracy of AVC load in distinguishing severe from nonsevere aortic stenosis (AS) and to investigate its effectiveness as an alternative diagnosis method when echocardiography remains inconclusive.

METHODS

We prospectively studied 266 consecutive patients with moderate to severe AS who underwent MDCT to measure AVC load and a comprehensive echocardiographic examination to assess AS severity. AVC load was validated against valve weight in 57 patients undergoing aortic valve replacement. The dependence of AVC scores on tube potential and slice thickness was also tested, as well as the relationship between AVC load and echocardiographic criteria of AS severity.

RESULTS

MDCT Agatston score correlated well with valve weight (r = 0.82, p < 0.001) and hemodynamic indices of AS severity (all p < 0.001). Ex-vivo Agatston scores decreased significantly with increasing tube potential and slice thickness (repeated measures ANOVA p < 0.001). Multivariate analysis identified mean gradient, the indexed effective orifice area, male gender and left ventricular outflow tract cross-sectional area as independent correlates of the in-vivo AVC load.

CONCLUSIONS

MDCT-derived AVC load correlated well with valve weight and hemodynamic indices of AS severity. It also depends on tube potential and slice thickness, thus suggesting that these parameters should be standardized to optimize reproducibility and accuracy.

Metabolism and acetylation contribute to leucine-mediated inhibition of cardiac glucose uptake

High plasma leucine levels strongly correlate with type 2 diabetes. Studies of muscle cells have suggested that leucine alters the insulin response for glucose transport by activating an insulin-negative feedback loop driven by the mammalian target of rapamycin/p70 ribosomal S6 kinase (mTOR/p70S6K) pathway. Here, we examined the molecular mechanism involved in leucine's action on cardiac glucose uptake. Leucine was indeed able to curb glucose uptake after insulin stimulation in both cultured cardiomyocytes and perfused hearts. Although leucine activated mTOR/p70S6K, the mTOR inhibitor rapamycin did not prevent leucine's inhibitory action on glucose uptake, ruling out the contribution of the insulin-negative feedback loop. α-Ketoisocaproate, the first metabolite of leucine catabolism, mimicked leucine's effect on glucose uptake. Incubation of cardiomyocytes with [¹³C]leucine ascertained its metabolism to ketone bodies (KBs), which had a similar negative impact on insulin-stimulated glucose transport. Both leucine and KBs reduced glucose uptake by affecting translocation of glucose transporter 4 (GLUT4) to the plasma membrane. Finally, we found that leucine elevated the global protein acetylation level. Pharmacological inhibition of lysine acetyltransferases counteracted this increase in protein acetylation and prevented leucine's inhibitory action on both glucose uptake and GLUT4 translocation. Taken together, these results indicate that leucine metabolism into KBs contributes to inhibition of cardiac glucose uptake by hampering the translocation of GLUT4-containing vesicles via acetylation. They offer new insights into the establishment of insulin resistance in the heart.NEW & NOTEWORTHY Catabolism of the branched-chain amino acid leucine into ketone bodies efficiently inhibits cardiac glucose uptake through decreased translocation of glucose transporter 4 to the plasma membrane. Leucine increases protein acetylation. Pharmacological inhibition of acetylation reverses leucine's action, suggesting acetylation involvement in this phenomenon.Listen to this article's corresponding podcast at http://ajpheart.podbean.com/e/leucine-metabolism-inhibits-cardiac-glucose-uptake/.

Impact of left ventricular outflow tract ellipticity on the grading of aortic stenosis in patients with normal ejection fraction

BACKGROUND

The pathophysiology of paradoxical low-gradient (LG) severe aortic stenosis (SAS) remains controversial. As low transvalvular flow has been implicated, we sought to investigate the impact of left ventricular outflow tract (LVOT) ellipticity on the estimation of the LV stroke volume, the calculation of the aortic valve area (AVA) by use of the continuity equation and on AS severity grading.

METHODS

We studied 190 consecutive patients (mean age: 72 ± 13 years; male: 57%) with SAS (indexed AVA < 0.6 cm2/m2) and preserved LV ejection fraction, including 120 patients with severe high gradient (HG) AS and 70 with severe paradoxical LG-AS. AS severity, LV volumes and LVOT ellipticity were assessed by 2D-Doppler echocardiography and cardiac magnetic resonance (CMR).

RESULTS

The LVOT exhibited an elliptical shape on CMR images, with a shorter anterior-posterior than median-lateral diameter (2.2 ± 0.2 vs 2.8 ± 0.3 cm, p < 0.01). Accordingly, the LVOT area measured by planimetry was larger than by 2D-echocardiography, assuming a circular orifice (4.9 ± 0.9 cm2 vs 3.7 ± 0.8 cm2, p < 0.01). Inputting the elliptical LVOT area into the continuity equation resulted in a 29% increase in the indexed AVA (from 0.41 ± 0.09 cm2 to 0.54 ± 0.10 cm2). Accordingly, 30 (43%) patients with severe paradoxical LG-SAS were reclassified as having moderate AS. Similar results were obtained when considering 3D-echo for direct planimetry of the LVOT in a subset of 75 patients.

CONCLUSIONS

Our results confirm that the LVOT is elliptical in shape and that taking this parameter into account in the calculation of the AVA results in reclassification of 43% of patients with severe paradoxical LG-AS into moderate AS.