Outcome of Normal-Flow Low-Gradient Severe Aortic Stenosis With Preserved Left Ventricular Ejection Fraction: A Propensity-Matched Study

Randomised study for the Optimal Treatment of symptomatic patients with low-gradient severe Aortic valve Stenosis and preserved left ventricular ejection fraction (ROTAS trial)

BACKGROUND

The best management of symptomatic patients with low-gradient (LG) severe aortic stenosis (AS) and preserved left ventricular ejection fraction (LVEF) has not been established. The Randomised study for the Optimal Treatment of symptomatic patients with low-gradient severe Aortic valve Stenosis (ROTAS) trial aimed to assess the superiority of aortic valve replacement (AVR) versus medical treatment (MT) in this specific group of AS patients.

METHODS

Patients with symptomatic LG severe AS and preserved LVEF (>50%) underwent dobutamine stress echocardiography and/or CT-aortic calcium score to confirm AS severity and were then randomised 1:1 to AVR or MT. The primary endpoint was a composite of overall death and/or cardiovascular hospitalisation.

RESULTS

The ROTAS study was stopped early because of insufficient recruitment. In the end, only 52 patients (age 79±7 years; women 54%; NYHA III-IV 27%; median STS score 3.3%) were included in the study. During follow-up (mean: 14±7 months), the primary endpoint occurred in 12 (23%) patients. Compared with MT, AVR was not associated with a significant prognostic benefit (events: 5/26 (19%) vs 7/26 (27%) (HR 0.76, 95% CI 0.24 to 2.39, p=0.63). During follow-up, 11 (42%) patients in the MT group developed class I criteria for AVR or severe symptoms justifying a cross-over to the AVR group.

CONCLUSIONS

Because of the small number of included patients and short follow-up the ROTAS trial was underpowered and unable to demonstrate a difference in the study endpoint between treatment arms. In patients in the MT arm, a regular echocardiographic and clinical assessment might be useful to disclose those developing class I indications of AVR or severe AS-related symptoms.

TRIAL REGISTRATION NUMBER

NCT01835028.

Moderate aortic stenosis: Navigating the uncharted

Aortic stenosis (AS) stands as the most common valvular heart disease in developed countries and is characterized by progressive narrowing of the aortic valve orifice resulting in elevated transvalvular flow resistance, left ventricular hypertrophy, and progressive increased risk of heart failure and sudden death. This narrative review explores clinical challenges and evolving perspectives in moderate AS, where discrepancies between aortic valve area and pressure gradient measurements may pose diagnostic and therapeutic quandaries. Transthoracic echocardiography is the first-line imaging modality for AS evaluation, yet cases of discordance may require the application of ancillary noninvasive diagnostic modalities. This review underscores the importance of accurate grading of AS severity, especially in low-gradient phenotypes, emphasizing the need for vigilant follow-up. Current clinical guidelines primarily recommend aortic valve replacement for severe AS, potentially overlooking latent risks in moderate disease stages. The noninvasive multimodality imaging approach-including echocardiography, cardiac magnetic resonance, computed tomography, and nuclear techniques-provides unique insights into adaptive and maladaptive cardiac remodeling in AS and offers a promising avenue to deliver precise indications and exact timing for intervention in moderate AS phenotypes and asymptomatic patients, potentially improving long-term outcomes. Nevertheless, what we may have gleaned from a large amount of observational data is still insufficient to build a robust framework for clinical decision-making in moderate AS. Future research will prioritize randomized clinical trials designed to weigh the benefits and risks of preemptive aortic valve replacement in the management of moderate AS, as directed by specific imaging and nonimaging biomarkers.

Energy Loss Index and Dimensionless Index Outperform Direct Valve Planimetry in Low-Gradient Aortic Stenosis

Background/Objectives: Among patients with suspected severe aortic stenosis (AS), discordance between effective orifice area (EOA) and transvalvular gradients is frequent and requires a multiparametric workup including flow assessment and calcium-scoring to confirm true severe AS. The aim of this study was to assess direct planimetry, energy loss index (Eli) and dimensionless index (DI) as stand-alone parameters to identify non-severe AS in discordant cases. Methods: In this prospective cohort study, we included consecutive AS patients > 70 years with EOA < 1.0 cm2 referred for valve replacement between 2014 and 2017. AS severity was retrospectively reassessed using the multiparametric work-up recommended in the 2021 ESC/EACTS guidelines. DI and ELi were calculated, and valve area was measured by direct planimetry on transesophageal echocardiography. Results: A total of 101 patients (mean age 82 y; 57% male) were included. Discordance between EOA and gradients was observed in 46% and non-severe AS found in 24% despite an EOA < 1 cm2. Valve planimetry performed poorly, with an area under the ROC curve (AUC) of 0.64. At a cut-off value of >0.82 cm2, sensitivity and specificity to identify non-severe AS were 67 and 66%, respectively. DI and ELi showed a higher diagnostic accuracy, with an AUC of 0.77 and 0.76, respectively. Cut-off values of >0.24 and >0.6 cm2/m2 identified non-severe AS, with a high specificity of 79% and 91%, respectively. Conclusions: Almost one in four patients with EOA < 1 cm2 had non-severe AS according to guideline-recommended multiparametric assessment. Direct valve planimetry revealed poor diagnostic accuracy and should be interpreted with caution. Usual prognostic cut-off values for DI > 0.24 and ELI > 0.6 cm2/m2 identified non-severe AS with high specificity and should therefore be included in the assessment of low-gradient AS.

Characteristics and prognosis of isolated aortic valve infective endocarditis in patients with bicuspid aortic valves: a propensity matched study

Introduction

Bicuspid aortic valve (BAV) is the most common congenital heart disease with an increased risk of infective endocarditis (IE). Few data are available on isolated native BAV-IE. The aim of this study was to compare patients with tricuspid aortic valve (TAV) IE and BAV-IE in terms of characteristics, management and prognosis.

Material and methods

We included 728 consecutive patients with IE on isolated native aortic valve in 3 centres: Amiens and Marseille Hospitals in France and Salerno Hospital in Italy. We studied in hospital and long-term mortality before and after matching for age, sex and comorbidity index. Median follow-up was 67.2 [IQR: 19-120] months.

Results

Of the 728 patients, 123 (16.9%) had BAV. Compared with patients with TAV-IE, patients with BAV-IE were younger, had fewer co-morbidities and were more likely to be male. They presented more major neurological events and perivalvular complications (both p < 0.05). Early surgery (<30 days) was performed in 52% of BAV-IE cases vs. 42.8% for TAV-IE (p = 0.061). The 10-year survival rate was 74 ± 5% in BAV-IE patients compared with 66 ± 2% in TAV-IE patients (p = 0.047). After propensity score matching (for age, gender and comorbidities), there was no difference in mortality between the two groups, with an estimated 10-year survival of 73 ± 5% vs. 76 ± 4% respectively (p = 0.91).

Conclusion

BAV is a frequent finding in patients with isolated aortic valve IE and is associated with more perivalvular complications and neurological events. The differences in survival with TAV-IE are probably related to the age and comorbidity differences between these two populations.

Quality of Life After Transcatheter Aortic Valve Replacement in Normal-Flow, Low-Gradient Aortic Stenosis

Background

Prior studies of aortic valve replacement (AVR) in patients with normal-flow, low-gradient aortic stenosis (NF-LG AS) have demonstrated conflicting results regarding the survival benefit of AVR. Changes in quality of life (QoL) after transcatheter AVR (TAVR) have not been reported in this population.

Objectives

The purpose of this study was to compare changes in QoL after TAVR for patients with NF-LG AS to patients with high-gradient aortic stenosis (HG-AS).

Methods

Patients who underwent TAVR for severe aortic stenosis (AS) were divided into 4 hemodynamic profiles of AS, including NF-LG AS. Changes in Kansas City Cardiomyopathy Questionnaire-12 score from baseline to 1 year were compared between AS groups. The primary composite outcome indicating clinical improvement consisted of survival to 1 year and improved Kansas City Cardiomyopathy Questionnaire overall summary score of ≥5 points while adjusting for relevant baseline factors.

Results

Out of 860 patients who underwent TAVR, high gradient AS was present in 368 (42.8%) patients and NF-LG AS in 245 (28.5%). HG-AS and NF-LG AS groups had a similar proportion of patients who met the primary unadjusted outcome of clinical improvement (70.4% vs 63.9%, respectively; P = 0.189). One-year Kaplan-Meier mortality estimates were higher for NF-LG AS patients than HG-AS patients (12.9% vs 5.8%, P < 0.001). In the primary adjusted analysis, there was no significant difference in the composite outcome between HG and NF-LG AS groups (adjusted OR: 0.72, 95% CI: 0.47-1.11).

Conclusions

Selected patients with NF-LG AS experienced similar improvement in QoL after TAVR compared with HG-AS. Further investigation of patients with NF-LG AS will help to inform optimal selection for treatment with TAVR.

Quantification of physical activity with prospective activity tracking after transfemoral aortic valve replacement

BACKGROUND

Transcatheter aortic valve replacement (TAVR) is a well-established, safe and effective therapy for severe symptomatic aortic stenosis (AS). The aim of this study was to objectively quantify improvement of physical activity after TAVR, with consideration of different low-gradient AS subtypes.

METHODS AND RESULTS

All patients undergoing TAVR for severe AS were screened. Participants received a wearable activity tracker (Fitbit®) at hospital discharge following TAVR and 6 months thereafter. The difference of median daily steps was defined as surrogate outcome for physical activity. For analysis, patients were grouped into high-gradient (HG) AS (dPmean ≥40 mmHg), classical low-flow low-gradient (LFLG) AS (dPmean <40 mmHg, EF <50%), paradoxical LFLG-AS (dPmean <40 mmHg, EF ≥50%, SVi ≤35 ml/m2) and normal-flow low-gradient (NFLG) AS (dPmean <40 mmHg, EF ≥50%, SVi >35 ml/m2) according to mean transvalvular pressure gradient (dPmean), stroke volume index (SVi) and left-ventricular ejection fraction (LVEF).

RESULTS AND CONCLUSIONS

The analysis is based on 230 patients. The median daily step count was 4409 [IQR 2581-7487] after hospital discharge and 5326 [IQR 3045-8668] 6 months thereafter. Median difference of daily steps was ∆529 [IQR -702-2152]). Patients with HG-AS and paradoxical LFLG-AS showed a significant improvement of daily steps (∆951 [IQR -378-2323], p <0.001 and (∆1392 [IQR -609-4444], p = 0.02, respectively). Patients with classical LFLG-AS showed no statistically relevant improvement of daily steps (∆192 [IQR -687-770], p = 0.79). Patients with NFLG-AS showed a numerical decline in daily steps without statistical significance (∆-300 [IQR -1334-1406], p = 0.67). This first prospective study of this sample size shows significant improvement of physical activity after TAVR with an objective and reproducible method. This was mainly driven by an improvement in patients with HG-AS and paradoxical LFLG-AS.

Low-flow, Low-gradient Severe Aortic Stenosis: A Review

Aortic stenosis (AS) is a common valve pathology experienced by patients worldwide. There are limited population-based studies assessing its prevalence; however, epidemiological studies emphasize that the burden of disease is growing. Recognizing AS relies on accurate clinical assessment and diagnostic investigations. Patients who develop severe AS are often referred to the heart team for assessment of aortic valve intervention. Although echocardiography has traditionally been used to screen and monitor the progression of AS, there can be discordance between measurements in a low-flow state. Such patients may have truly severe AS and potentially derive long-term benefit from aortic valve intervention. Accurately identifying these patients with the use of ancillary testing has been the focus of research for several years. In this article, we discuss the contemporary approaches and challenges in identifying and managing patients with low-flow, low-gradient severe AS.

TAVI for patients with normal-flow low-gradient compared to high-gradient aortic stenosis

BACKGROUND

Normal-flow (stroke volume index, SVi >35 ml/m²) low-gradient (dPmean <40 mmHg) aortic stenosis (NFLG-AS) is subject of scientific debate. Guidelines fail to give conclusive treatment recommendations. We hypothesized that NFLG patients are heterogenous, containing a subgroup similar to high-gradient aortic stenosis patients (dPmean ≥40 mmHg, HG-AS) concerning characteristics and outcomes.

METHODS

2326 patients undergoing transcatheter aortic valve replacement (TAVI) at our centre between 2013 and 2019 were analysed. 386 patients fulfilled criteria of NFLG-AS. Their median dPmean was 33 mmHg, which was used for grouping (204 patients with higher gradient NFLG-AS, 186 patients with lower gradient NFLG-AS). They were compared to 956 HG-AS patients.

RESULTS

Characteristics of lower gradient NFLG-AS patients differed from HG-AS patients in many aspects while higher gradient NFLG-AS and HG-AS patients were mostly similar, underscored by higher Society of Thoracic Surgeons scores in lower gradient NFLG-AS (lower gradient NFLG-AS, 3.9, HG-AS, 3.0, p = 0.03, higher gradient NFLG-AS, 3.0, p = 0.04). Procedural complications were comparable. Estimated 3-year all-cause mortality was higher in lower gradient NFLG-AS compared to HG-AS patients (hazard ratio 1.7, p < 0.01), whereas mortality of higher gradient NFLG-AS was similar to HG-AS patients (hazard ratio 1.2, p = 0.31). Cardiovascular mortality was highest among lower gradient NFLG-AS patients (21.6% vs. higher gradient NFLG-AS, 15.4%, vs. HG-AS, 11.1%, p < 0.01).

CONCLUSIONS

NFLG-AS patients are indeed heterogenous. NFLG-AS patients with higher gradients resemble HG-AS patients in clinical characteristics and outcomes and should not be treated differently. Lower gradient NFLG-AS patients have increased long-term mortality and the use of TAVI requires careful consideration.

Imaging Challenges in Patients with Severe Aortic Stenosis and Heart Failure: Did We Find a Way Out of the Labyrinth?

Aortic stenosis (AS) is the most frequent degenerative valvular disease in developed countries. Its incidence has been constantly rising due to population aging. The diagnosis of AS was considered straightforward for a very long time. High gradients and reduced aortic valve area were considered as "sine qua non" in diagnosis of AS until a growing body of evidence showed that patients with low gradients could also have severe AS with the same or even worse outcome. This completely changed the paradigm of AS diagnosis and involved large numbers of parameters that had never been used in the evaluation of AS severity. Low gradient AS patients may present with heart failure (HF) with preserved or reduced left ventricular ejection fraction (LVEF), associated with changes in cardiac output and flow across the aortic valve. These patients with low-flow low-gradient or paradoxical low-flow low-gradient AS are particularly challenging to diagnose, and cardiac output and flow across the aortic valve have become the most relevant parameters in evaluation of AS, besides gradients and aortic valve area. The introduction of other imaging modalities in the diagnosis of AS significantly improved our knowledge about cardiac mechanics, tissue characterization of myocardium, calcium and inflammation burden of the aortic valve, and their impact on severity, progression and prognosis of AS, not only in symptomatic but also in asymptomatic patients. However, a variety of novel parameters also brought uncertainty regarding the clinical relevance of these indices, as well as the necessity for their validation in everyday practice. The aim of this review is to summarize the prevalence of HF in patients with severe AS and elaborate on the diagnostic challenges and advantages of comprehensive multimodality cardiac imaging to identify the patients that may benefit from surgical or transcatheter aortic valve replacement, as well as parameters that may help during follow-up.

Underrepresentation of women in cardiac imaging trials: A review

Inclusion and equal representation of women in cardiovascular imaging trials are essential to provide insight into the factors impacting women's heart health and outcomes. Despite heart disease being the leading cause of mortality for women in the United States, women have been underrepresented in cardiovascular clinical trials, including imaging trials. Research demonstrates that women have key sex-specific differences in the pathophysiology of cardiovascular disease, the evolution of disease state, and disease manifestation (Solimene, 2010; Nevsky et al., 2011 [1,2]). This understanding and acknowledgment come decades after clinical providers have extrapolated data from cardiovascular disease clinical trials conducted primarily on Caucasian men, assuming the data were generalizable to sex, race, and ethnicity. The current cardiology society guidelines, which recommend optimal medical therapies for various cardiovascular diseases, are based on trials predominantly focused on men rather than women. Sex-based research, governmental and institutional task forces, and policies on gender equity have made inroads into the disproportionate number of women's enrollment in clinical research. The National Institutes of Health in the 1990s set forth requirements on incorporating women and minorities in research, including clinical trials (Mastroianni et al., 1994; Mieres et al., 2014 [3,4]). Continued progress is imperative to improve the gap in the number of women enrolled in clinical research trials.

Severe aortic stenosis echocardiographic thresholds revisited

BACKGROUND

In view of inconsistencies in threshold values of severe aortic stenosis (AS) hemodynamic indices, it is unclear what is the relative contribution of each variable in a binary classification of AS based on aortic valve replacement (AVR) indication. We aimed to assess relative discriminative value and optimal threshold of each constituent hemodynamic parameter for this classification and confirm additional prognostic value.

METHODS

Echocardiography studies of 168 patients with ≥ moderate AS were included. AS types were dichotomized into Group-A, comprising moderate and Normal-Flow Low-Gradient (NFLG), and Group-B, comprising High-Gradient(HG), Low Ejection Fraction Low-Flow Low-Gradient(Low EF-LFLG), and Paradoxical Low-Flow Low-Gradient(PLFLG) AS. Aortic valve area (AVA), Doppler velocity index (DVI), peak aortic velocity, mean gradient, stroke volume index and transaortic flow rate(TFR) were assessed for A/B Group discrimination value and optimal thresholds were determined. Dichotomized values were assessed for predictive value for AVR or death.

RESULTS

C-statistic values for binary AS classification was .74-.9 for the tested variables. AVA and DVI featured the highest score, and SVI the lowest one. AVA≤.81 cm² and DVI≤.249 had 87.6% and 86% respective sensitivity for Group B patients, and a similar specificity of 80.9%. During a mean follow-up of 9.1±10.1 months, each of the tested dichotomized variables except for SVI predicted AVR or death on multivariate analysis.

CONCLUSION

An AVA value ≤.81 cm² or a DVI ≤ .249 threshold carry the highest discriminative value for severe AS in patients with aortic stenosis, translating into an independent prognostic value, and can be helpful in making clinical decisions.

Comparison of transcatheter aortic valve implantation outcomes between normal flow low gradient severe aortic stenosis and normal flow high gradient severe aortic stenosis

BACKGROUND

Normal flow low gradient severe aortic stenosis (NFLG-AS) with preserved ejection fraction is the most prevalent form of low gradient severe aortic stenosis. Despite the increased prevalence, the clinical outcomes and management strategy of NFLG-AS remain controversial. Therefore, our study aimed to evaluate transcatheter aortic valve implantation (TAVI) outcomes of patients with NFLG-AS compared with normal flow high gradient severe aortic stenosis (NFHG-AS).

METHODS

We performed a retrospective analysis of 394 patients who underwent TAVI between January 2011 to September 2020. Among 394 patients, 232 patients had NFLG-AS, and 162 patients had NFHG-AS. The primary outcomes included all-cause mortality and cardiovascular mortality. In addition, multiple secondary outcomes were evaluated, including stroke, myocardial infarction, duration of hospital stay, new-onset atrial fibrillation, temporary or permanent pacemaker requirement, major bleeding, blood transfusion, vascular complications, acute kidney injury, hemodialysis requirement, symptom improvement, and repeat hospitalizations due to any cardiac disease.

RESULTS

The cumulative six months incidence of all-cause mortality and cardiovascular mortality were similar between and NFLG-AS and NFHG-AS (4.32% vs. 5.17%, P = 0.71 and 2.47% vs. 2.59%, P = 0.94 respectively). There was no difference in the rates of stroke, myocardial infarction, duration of hospital stay, new-onset atrial fibrillation, temporary or permanent pacemaker requirement, major bleeding, blood transfusion, vascular complications, acute kidney injury, hemodialysis requirement, and symptom improvement between the two groups. However, patients with NFLG-AS compared to NFHG-AS had more frequent cardiac-related repeat hospitalizations (19.14% vs. 11.64%, P = 0.04%).

CONCLUSION

There was no significant difference in all-cause mortality and cardiovascular mortality between NFLG-AS and NGHG-AS six months post-TAVI. However, patients undergoing TAVI with NFLG-AS had significantly higher rates of cardiac-related repeat hospitalizations.

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.

Rational and design of the ROTAS study: a randomized study for the optimal treatment of symptomatic patients with low-gradient severe aortic valve stenosis and preserved left ventricular ejection fraction

AIMS

Fifteen to thirty percentage of patients with severe aortic stenosis (AS) have preserved left ventricular ejection fraction (LVEF) and a discordant AS pattern at Doppler echocardiography, which is characterized by a small (<1 cm2) aortic area and low mean aortic gradient (<40 mmHg). The 'Randomized study for the Optimal Treatment of symptomatic patients with low-gradient severe Aortic Stenosis and preserved left ventricular ejection fraction' (ROTAS trial) aims at demonstrating the superiority of aortic valve replacement vs. a 'watchful waiting strategy' in symptomatic patients with low-gradient (LS), severe AS, and preserved LVEF, stratified according to indexed stroke volume, in terms of all-cause mortality or cardiovascular-related hospitalization during follow-up (FU).

METHODS AND RESULTS

The ROTAS trial will be a multicentre randomized non-blinded study involving 16 reference centres. AS severity will be confirmed by a multimodality approach (rest and stress echocardiography, calcium scoring, and cardiac magnetic resonance imaging for optimally characterize the population), which could provide important inputs to improve the pathophysiological understanding of this complex disease. Well-characterized patients will be randomized according to the management strategy. The primary endpoint will be the occurrence of all-cause mortality or cardiac related-hospitalizations during 2-year FU. One hundred and eighty subjects per group will be included.

CONCLUSION

The management of patients with LS severe AS and preserved LVEF is largely debated. ROTAS trial will allow a comprehensive evaluation of this particular pattern of AS and will establish which is the most appropriate management of these patients.

Left Ventricular Hypertrophic Change Indicating Poor Prognosis in Patients With Normal-Flow, Low-Gradient Severe Aortic Stenosis With Preserved Left Ventricular Ejection Fraction

Background: Risk stratification of normal-flow, low-gradient (NFLG) severe aortic stenosis (SAS) with preserved left ventricular (LV) ejection fraction (EF) remains unclear.

Methods and Results: Of 289 consecutive patients diagnosed with SAS by aortic valve area <1.0 cm², 66 with NFLG-SAS (stroke volume index >35 mL/m², mean pressure gradient <40 mmHg, LVEF ≥50%) were enrolled in this study; patients with bicuspid aortic valve, acute coronary syndrome, hemodialysis, or a history of aortic valve replacement (AVR) were excluded. Adverse events (AEs) were defined as cardiovascular death, hospitalization for heart failure, and deteriorating condition requiring AVR. Factors associated with AEs were investigated using a Cox proportional hazards model. Over a median of 675 days of follow-up, 25 AEs were recorded: 4 cardiovascular deaths, 12 hospitalizations for heart failure, and 9 patients requiring AVR. In addition, there were 14 events of progression to high-gradient SAS. Multivariable analysis showed significant associations between AEs and the presence of symptoms (hazard ratio [HR] 10.276; 95% confidence interval [CI] 3.724–28.357; P<0.001), LV hypertrophy (LV mass index >115 and >95 mg/m² for males and females, respectively; HR 3.257; 95% CI 1.172–9.050; P=0.024), and tricuspid regurgitation (TR) velocity (HR 2.761; 95% CI 1.246–6.118; P=0.012).

Conclusions: The presence of symptoms, LV hypertrophy, and high TR velocity could be reliable prognostic indicators and may require watchful waiting for timely AVR in patients with NFLG-SAS.

Echocardiographic assessment of aortic stenosis: a practical guideline from the British Society of Echocardiography

The guideline provides a practical step-by-step guide in order to facilitate high-quality echocardiographic studies of patients with aortic stenosis. In addition, it addresses commonly encountered yet challenging clinical scenarios and covers the use of advanced echocardiographic techniques, including TOE and Dobutamine stress echocardiography in the assessment of aortic stenosis.

Non-contrast myocardial T1 global and regional reference values at 3 Tesla cardiac magnetic resonance in aortic stenosis

BACKGROUND

T1 mapping using cardiac magnetic resonance (CMR) was recently proposed as a promising non-contrast imaging technique for the assessment of diffuse myocardial fibrosis (MF) in aortic stenosis (AS).

AIMS

To provide reference values for native T1 mapping at 3 Tesla magnetic field strength in subjects with moderate or severe AS and in control subjects; to identify factors associated with the presence of diffuse MF in severe AS; to assess the regional distribution of diffuse MF; and to compare the level of diffuse MF in the different types of AS, stratified by flow and gradient patterns.

METHODS

Retrospective study based on 160 consecutive patients with moderate (n=11) to severe (n=149) AS and 47 control subjects referred for CMR.

RESULTS

Mean native T1 increased progressively across controls (1221±23ms), moderate AS (1249±26ms) and severe AS (1273±43ms). T1 times correlated significantly with left ventricular (LV) remodelling (indexed LV mass and LV diastolic volume) and functional LV alterations (global longitudinal strain and LV ejection fraction). Native T1 appears to be elevated in the basal segments of the septum in moderate AS, and to extend to midventricular and apical segments in severe AS. Mean T1 time was higher in classical low-flow/low-gradient AS (1295±62ms) than in the other types of AS (P=0.006). The level of diffuse MF in paradoxical low-flow/low-gradient AS (1280±42ms) was higher than in moderate AS, but similar to that in high-gradient AS (1271±42ms) (P=0.07).

CONCLUSIONS

Assessment of diffuse MF in AS using T1 mapping is feasible and reproducible in clinical practice. T1 value increases with AS severity, along with morphological and functional LV alterations, particularly in the basal segments of the septum.

Impact of surgical aortic valve replacement on global and regional longitudinal strain across four flow gradient patterns of severe aortic stenosis

To evaluate the impact of surgical aortic valve replacement (SAVR) on global (GLS) and regional longitudinal strain (RLS) across four flow-gradient patterns of severe aortic stenosis (AS) 3 months after surgery. A total of 103 patients with severe AS (aortic valve area < 1.0 cm²) were examined by speckle tracking echocardiography the day before SAVR and at 3-months follow-up. Patients were stratified into four flow-gradient patterns by stroke volume index (>35 mL/m² vs. ≤35 mL/m²) and mean transaortic gradients (>40 mmhg vs. ≤40 mmhg): normal-flow, high gradient (NF/HG); low-flow, high gradient (LF/HG); normal-flow, low gradient (NF/LG); low-flow, low gradient (LF/LG). Strain analysis comprised GLS and RLS at a basal (BLS), mid-ventricular (MLS) and apical level (ALS). Patients with high gradients improved GLS (NF/HG: 16.1 ± 3.5 % vs. 17.3 ± 3.4 %, p = 0.03 and LF/HG: 15.4 ± 3.6 % vs. 16.9 ± 3.1 %, p = 0.03), BLS (NF/HG: 12.7 ± 3.1 % vs. 14.2 ± 3.1 %, p = 0.003 and LF/HG: 11.4 ± 3.2 % vs. 13.8 ± 2.7 %, p = 0.005) and MLS (NF/HG: 15.4 ± 3.3 % vs. 16.5 ± 3.3 %, p = 0.04 and LF/HG: 14.5 ± 3.1 % vs. 16.2 ± 2.7 %, p = 0.01) whereas patients with low gradients showed no improvements three months after SAVR. ALS did not change significantly in any group. Patients with high gradients demonstrated a reduction in left ventricular (LV) mass index (p < 0.001) and N-terminal pro-Brain Natriuretic Peptide levels (p < 0.001) following SAVR in contrast to patients with low gradients. Patients with high gradient severe AS improve GLS and RLS three months after SAVR with concomitant reduction of LV mass and neurohormonal activation whereas patients with low gradients do not improve longitudinal strain, LV mass or neurohormonal activation.

National trends and 30-day readmission rates for next-day-discharge transcatheter aortic valve replacement: An analysis from the Nationwide Readmissions Database, 2012-2016

Transcatheter aortic valve replacement (TAVR) has evolved toward a minimalist approach, resulting in shorter hospital stays. Real-world trends of next-day discharge (NDD) TAVR are unknown. This study aimed to evaluate underlying trends and readmissions of NDD TAVR.

METHODS

This study was derived from the Nationwide Readmissions Database from 2012 to 2016. International Classification of Diseases, Ninth and Tenth Revisions, codes were used to identify patients. Any discharge within 1 day of admission was identified as NDD. NDD TAVR trends over the years were analyzed, and any admissions within 30 days were considered readmissions. A hierarchical logistic regression model was used to identify predictors of readmission.

RESULTS

Of 49,742 TAVR procedures, 3,104 were NDD. The percentage of NDD TAVR increased from 1.5% (46/3,051) in 2012 to 12.2% (2,393/19,613) in 2016. However, the 30-day readmission rate remained the same over the years (8.6%). The patients' mean age was 80.3 ± 8.4 years. Major readmission causes were heart-failure exacerbation (16%), infections (9%), and procedural complications (8%). In 2016, there were significantly higher late conduction disorder and gastrointestinal bleeding readmission rates than in 2012-2015. Significant predictors of readmission were anemia, baseline conduction disease, cardiac arrhythmias, heart failure, chronic kidney disease, chronic obstructive pulmonary disease, neoplastic disorders, and discharge to facility.

CONCLUSIONS

The percentage of NDD TAVR increased over the years; however, readmission rates remained the same, with a higher rate of conduction abnormality-related hospitalizations in 2016. Careful discharge planning that includes identification of baseline factors that predict readmission and knowledge of etiologies may further prevent 30-day readmissions.

Effect of the 2017 European Guidelines on Reclassification of Severe Aortic Stenosis and Its Influence on Management Decisions for Initially Asymptomatic Aortic Stenosis

BACKGROUND

The 2017 European Society of Cardiology guidelines for valvular heart disease included changes in the definition of severe aortic stenosis (AS). We wanted to evaluate its influence on management decisions in asymptomatic patients with moderate-severe AS.

METHODS

We reclassified the AS severity of the participants of the PRIMID-AS study (Prognostic Importance of Microvascular Dysfunction in Asymptomatic Patients With AS), using the 2017 guidelines, determined their risk of reaching a clinical end point (valve replacement for symptoms, hospitalization, or cardiovascular death) and evaluated the prognostic value of aortic valve calcium score and biomarkers. Patients underwent echocardiography, cardiac magnetic resonance imaging, exercise tolerance testing, and biomarker assessment.

RESULTS

Of the 174 participants, 45% (56/124) classified as severe AS were reclassified as moderate AS. This reclassified group was similar to the original moderate group in clinical characteristics, gradients, calcium scores, and remodeling parameters. There were 47 primary end points (41 valve replacement, 1 death, and 5 hospitalizations-1 chest pain, 2 dyspnea, 1 heart failure, and 1 syncope) over 368±156 days follow-up. The severe and reclassified groups had a higher risk compared with moderate group (adjusted hazard ratio 4.95 [2.02-12.13] and 2.78 [1.07-7.22], respectively), with the reclassified group demonstrating an intermediate risk. A mean pressure gradient ≥31 mm Hg had a 7× higher risk of the primary end point in the reclassified group. Aortic valve calcium score was more prognostic in females and low valve area but not after adjusting for gradients. NT-proBNP (N-terminal pro-brain-type natriuretic peptide) and myocardial perfusion reserve were associated with the primary end point but not after adjusting for positive exercise tolerance testing. Troponin was associated with cardiovascular death or unplanned hospitalizations.

CONCLUSIONS

Reclassification of asymptomatic severe AS into moderate AS was common using the European Society of Cardiology 2017 guidelines. This group had an intermediate risk of reaching the primary end point. Exercise testing, multimodality imaging, and lower mean pressure gradient threshold of 31 mm Hg may improve risk stratification. Registration: URL: https://www.clinicaltrials.gov. Unique identifier: NCT01658345.

Dimensionless Index in Patients With Low-Gradient Severe Aortic Stenosis and Preserved Ejection Fraction

Background

Risk stratification of patients with low-gradient (LG) severe aortic stenosis (AS) despite preserved left ventricular ejection fraction remains challenging. We sought to evaluate the relationship between the dimensionless index (DI)—the ratio of the left ventricular outflow tract time-velocity integral to that of the aortic valve jet—and mortality in these patients.

Methods

Seven hundred fifty-five patients with LG severe AS (defined by aortic valve area ≤1 cm 2 or aortic valve area indexed to body surface area ≤0.6 cm 2 /m 2 and mean aortic pressure gradient <40 mm Hg) and preserved left ventricular ejection fraction ≥50% were studied. Flow status was defined according to stroke volume index <35 mL/m 2 (low flow, LF) or ≥35 mL/m 2 (normal flow, NF).

Results

After adjustment for age, sex, body mass index, Charlson comorbidity index, history of hypertension, history of atrial fibrillation, AS-related symptoms, left ventricular ejection fraction, indexed left ventricular ventricular mass, aortic valve area, and aortic valve replacement as a time-dependent covariate, patients with LG-LF and DI<0.25 exhibited a considerable increased risk of death compared with patients with LG-NF and DI≥0.25 (adjusted hazard ratio, 2.41 [95% CI, 1.61–3.62]; P <0.001), LG-NF and DI<0.25 (adjusted hazard ratio, 1.84 [95% CI, 1.24–2.73]; P =0.003), and LG-LF and D≥0.25 (adjusted hazard ratio, 2.27 [95% CI, 1.42–3.63]; P <0.001). In contrast, patients with LG-LF and DI≥0.25, LG-NF and DI<0.25, and LG-NF and DI≥0.25 had similar outcome. DI<0.25 showed incremental prognostic value in patients with LG-LF severe AS but not in patients with LG-NF severe AS.

Conclusions

Among patients with LG severe AS and preserved left ventricular ejection fraction, decreased DI<0.25 is a reliable parameter in patients with LF to identify a subgroup of patients at higher risk of death who may derive benefit from aortic valve replacement.

Impact of Aortic Stenosis on Myofiber Stress: Translational Application of Left Ventricle-Aortic Coupling Simulation

The severity of aortic stenosis (AS) has traditionally been graded by measuring hemodynamic parameters of transvalvular pressure gradient, ejection jet velocity, or estimating valve orifice area. Recent research has highlighted limitations of these criteria at effectively grading AS in presence of left ventricle (LV) dysfunction. We hypothesized that simulations coupling the aorta and LV could provide meaningful insight into myocardial biomechanical derangements that accompany AS. A realistic finite element model of the human heart with a coupled lumped-parameter circulatory system was used to simulate AS. Finite element analysis was performed with Abaqus FEA. An anisotropic hyperelastic model was assigned to LV passive properties, and a time-varying elastance function governed the LV active response. Global LV myofiber peak systolic stress (mean ± standard deviation) was 9.31 ± 10.33 kPa at baseline, 13.13 ± 10.29 kPa for moderate AS, and 16.18 ± 10.59 kPa for severe AS. Mean LV myofiber peak systolic strains were −22.40 ± 8.73%, −22.24 ± 8.91%, and −21.97 ± 9.18%, respectively. Stress was significantly elevated compared to baseline for moderate (p < 0.01) and severe AS (p < 0.001), and when compared to each other (p < 0.01). Ventricular regions that experienced the greatest systolic stress were (severe AS vs. baseline) basal inferior (39.87 vs. 30.02 kPa; p < 0.01), mid-anteroseptal (32.29 vs. 24.79 kPa; p < 0.001), and apex (27.99 vs. 23.52 kPa; p < 0.001). This data serves as a reference for future studies that will incorporate patient-specific ventricular geometries and material parameters, aiming to correlate LV biomechanics to AS severity.

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.

Impact of anatomical variations of the left ventricular outflow tract on stroke volume calculation by Doppler echocardiography in aortic stenosis

BACKGROUND

Accurate calculation of stroke volume (SV) by Doppler echocardiography is important for the assessment of aortic stenosis (AS), which may be impacted by anatomical variations of left ventricular outflow tract (LVOT).

METHODS

Patients with AS (n = 64) were studied using computed tomography (CT) and transthoracic echocardiography (TTE). Anatomical variations of LVOT areas were measured at (a) the aortic annulus (A_a ); (b) 5 mm (A₅ ); and (c) 10 mm below the annulus (A₁₀ ) by CT. LVOT diameters were also measured by 2D TTE at these three levels for calculation of LVOT areas. Stroke volumes (SV) were calculated using continuity equation. The impacts of anatomical variations of LVOT on SV calculation were evaluated.

RESULTS

Anatomical LVOT area increased from A_a to A₁₀ (5.0 ± 0.9 cm² vs 5.8 ± 1.9 cm² , P < .01). Differences between TTE-calculated LVOT areas and anatomical areas were most significant at A₁₀ due to elongation of mediolateral diameters with variable changes in anteroposterior diameters (5.8 ± 1.9 cm² vs 3.4 ± 1.1 cm² , P < .001). Although mean calculated SV by TTE was not significant at different LVOT levels (A_a 69 ± 22 mL, vs A₅ 66 ± 21 mL, vs A₁₀ 66 ± 28 ± 22 mL, P > .05), the most significant variations in individuals were at A₁₀ levels (ΔSV: 8.2 ± 6.4 mL, 12 ± 9%).

CONCLUSION

Variations of LVOT anatomy in individuals with AS significantly impact the SV calculated by Doppler echocardiography. These features should be taken into account for AS diagnosis and a clinical decision-making for intervention.

Outcome of Normal-Flow Low-Gradient Severe Aortic Stenosis With Preserved Left Ventricular Ejection Fraction: A Propensity-Matched Study

Background

Normal‐flow, low‐gradient severe aortic stenosis (NF‐LG‐SAS), defined by aortic valve area <1 cm², mean gradient <40 mm Hg, and indexed stroke volume >35 mL/m², is the most prevalent form of low‐gradient aortic stenosis (AS). However, the true severity of AS and the management of NF‐LG‐SAS are controversial. The aim of this study was to evaluate the outcome of patients with NF‐LG‐SAS compared with moderate AS (MAS) and with high‐gradient severe‐AS (HG‐SAS).

Methods and Results

A total of 154 patients with NF‐LG‐SAS, 366 with MAS (aortic valve area between 1.0 and 1.3 cm²), and 1055 with HG‐SAS were included. On multivariate analysis, after adjustment for covariates of prognostic importance, NF‐LG‐SAS patients did not exhibit an excess risk of mortality compared with MAS patients under medical management (hazard ratio=1.13 [95% CI, 0.82‐1.56]; P=0.45) and under medical and surgical management (hazard ratio 1.06 [95% CI, 0.79‐1.43]; P=0.70), even after further adjustment for aortic valve replacement (hazard ratio=1.09 [95% CI, 0.81‐1.48]; P=0.56). The 6‐year cumulative incidence of aortic valve replacement (performed in accordance with guidelines) was comparable between the 2 groups (39±4% for NF‐LG‐SAS and 35±3% for MAS, P=0.10). After propensity score matching (n=226), NF‐LG‐SAS and MAS patients also had comparable outcomes under medical (P=0.41) and under medical and surgical management (P=0.52). NF‐LG‐SAS had better outcomes than HG‐SAS patients (adjusted hazard ratio 1.84 [95% CI, 1.18‐2.88]; P<0.001).

Conclusions

This study shows that patients with NF‐LG‐SAS have a comparable outcome to those with MAS when aortic valve replacement is performed during follow‐up according to guidelines, mostly at the stage of HG‐SAS. Rigorous echocardiographic assessment to rule out measurement errors and close follow‐up are essential to detect progression to true severe AS in NF‐LG‐SAS.