Paradoxical low-flow, low-gradient severe aortic stenosis despite preserved ejection fraction is associated with higher afterload and reduced survival

Electronic Provider Notification to Facilitate the Recognition and Management of Severe Aortic Stenosis: A Randomized Clinical Trial

BACKGROUND

Symptomatic severe aortic stenosis (AS) remains undertreated with high resultant mortality despite increased growth and availability of aortic valve replacement (AVR) since the advent of transcatheter therapies. We evaluate the impact of electronic provider notifications (EPNs) on rates of AVR at 1 year.

METHODS

In a pragmatic cluster randomized clinical trial conducted within a multicenter academic health system from March 2022 through November 2023, 285 providers who had ordered a transthoracic echocardiogram (TTE) with findings potentially indicative of severe AS with an aortic valve area ≤1.0 cm2 were enrolled. Providers were randomly assigned to receive EPNs for each of their patients with severe AS on TTE or to usual care. Notifications highlighted the detection of severe AS and included patient-specific clinical guideline recommendations for its management. The primary end point was the proportion of patients with severe AS receiving AVR within 1 year of the index TTE.

RESULTS

A total of 144 providers were randomized to intervention and 141 to control, resulting in 496 and 443 patients assigned to each group, respectively. The patient cohort had mean age of 77±11 years, was 47% female, and had a mean aortic valve area of 0.8±0.1 cm2. Rates of AVR within 1 year were 48.2% with EPNs versus 37.2% with usual care (odds ratio [OR], 1.62 [95% CI, 1.13-2.32]; P=0.009]) and 60.7% and 46.5%, respectively, among symptomatic patients (OR, 1.77 [95% CI, 1.17-2.65]; P=0.006). Notification treatment effect was highest with EPNs for patients >80 years of age (OR, 2.00 [95% CI, 1.17-3.41]; P=0.01), for women (OR, 2.78, [95% CI, 1.69-4.57]; P<0.001), and when the index TTE was performed within the inpatient setting (OR, 2.49 [95% CI, 1.44-4.31]; P<0.001). Within 1 year, the restricted mean survival time was longer with EPNs in all (12 days; P=0.04) and symptomatic patients (23 days; P=0.01).

CONCLUSIONS

In this first study of EPNs for valvular heart disease, EPNs increased rates of AVR for severe AS, lessened sex and age disparities in AVR use, and improved survival time. EPNs may be a simple, scalable intervention to raise awareness of critical TTE findings and improve the quality of care for patients with severe AS.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT05230225.

Impact of Left Ventricular Mass on Mortality in Symptomatic Severe Aortic Stenosis: A Sex-Specific Analysis

Aortic stenosis (AS) is a common and serious valvular disease in older adults, often leading to increased left ventricular mass (LVM) due to pressure overload. Excessive LVM is linked to adverse outcomes, but its sex-specific prognostic significance remains unclear. Focusing on sex-based differences, this study evaluated the left ventricular mass index (LVMi) prognostic value in patients with symptomatic severe AS. We retrospectively analyzed 531 outpatients (283 men, 248 women; mean age 74.7 years) with symptomatic but stable severe AS and no prior valve procedures. Clinical and echocardiographic data were collected between April 2020 and February 2024, with a mean follow-up of 2.67 years. A total of 165 patients (31.1%) died during follow-up, 86% from cardiovascular causes. Deceased patients had lower ejection fraction and higher LVMi. Multivariate Cox analysis identified LVMi and atrial fibrillation (AF) as independent predictors of mortality, while valve intervention predicted survival. In women, both LVMi and AF predicted mortality; valve intervention was protective. In men, only the lack of valve intervention predicted death. Elevated LVMi was a strong predictor of mortality in non-operated patients, with the most pronounced impact observed in women with severe AS.

Outcomes and Predictors of Different Flow-Gradient Patterns of Aortic Stenosis After Transcatheter Aortic Valve Replacement

This study sought to explore the clinical factors associated with classical low-flow low-gradient (C-LFLG) and normal-flow low-gradient (NFLG) aortic stenosis (AS) compared with high-gradient (HG) AS. We also compared clinical and echocardiographic outcomes after transcatheter aortic valve replacement (TAVR) across flow-gradient patterns. Patients with C-LFLG AS have a higher mortality rate after TAVR than those with HG AS. However, what leads to C-LFLG AS and the predictors of mortality in this population remain unclear. In this retrospective, single-center study involving 1,415 patients with severe AS, patients were classified as having (1) HG AS (aortic valve mean gradient [MG] >40 mm Hg), (2) C-LFLG AS (MG <40 mm Hg, stroke volume index <35 ml/m2, left ventricular ejection fraction <50%), and (3) NFLG AS (MG <40 mm Hg, stroke volume index ≥35 ml/m2, left ventricular ejection fraction ≥50%). Logistic regression was used for predictors of C-LFLG AS. Cox regression was used for predictors of mortality in the C-LFLG AS population. Male gender, multiple co-morbidities, and moderate to severe mitral and tricuspid regurgitation correlated with the C-LFLG AS group. Patients with C-LFLG AS had a higher mortality risk compared with patients with HG AS at 2 years after TAVR. Patients with NFLG AS had similar mortality at 1 year, but higher mortality at 2 years after TAVR compared with patients with HG AS. End-stage renal disease, atrial fibrillation, and other co-morbidities were predictors of 2-year mortality in patients with C-LFLG AS. In conclusion, the mortality rate after TAVR was higher among patients with C-LFLG AS than those with HG AS. Male gender and multiple co-morbidities were predictors of C-LFLG AS. Multiple co-morbidities were predictors of mortality among those patients.

Severe Mitral Regurgitation in Paradoxical Low-Flow, Low-Gradient Severe Aortic Stenosis

BACKGROUND

Patients with paradoxical low-flow, low-gradient severe aortic stenosis exhibit low transvalvular flow rate (Q), while maintaining preserved left ventricular ejection fraction. Severe mitral regurgitation (MR) also causes a low-flow state, adding complexity to diagnosis and management. This study aimed to examine the impact of severe MR on outcomes in paradoxical low-flow, low-gradient severe aortic stenosis.

METHODS

Data from an institutional echo database identified 1189 patients with adjudicated severe aortic stenosis (aortic valve area ≤1.0 cm2), low transaortic gradients (mean gradient <40 mm Hg), preserved left ventricular ejection fraction (≥50%), and low-flow rate (Q ≤210 mL/s) to confirm paradoxical low-flow, low-gradient severe aortic stenosis. Subgroups were based on MR severity (severe and non-severe). Clinical outcomes included all-cause mortality, aortic valve replacement, heart failure hospitalizations, and a composite outcome.

RESULTS

In the severe MR group (n=80), patients had lower flow rates, increased left ventricular dimensions, and a more eccentric hypertrophy pattern compared with non-severe MR (n=1109). Over a follow-up of up to 5 years, severe MR correlated with higher all-cause mortality (P=0.02) and aortic valve replacement rates (P=0.012). After multivariable adjustment, severe MR was independently associated with increased all-cause mortality risk (hazard ratio=1.43; P=0.011) and composite outcome (hazard ratio=1.64; P<0.001). Aortic valve replacement significantly reduced mortality at every MR degree, with the most substantial impact in severe MR (hazard ratio=0.18; P<0.001). Propensity-adjusted models demonstrated a stronger aortic valve replacement impact with increasing MR degree (Pinteraction=0.044).

CONCLUSIONS

Severe MR in paradoxical low-flow, low-gradient severe aortic stenosis is associated with adverse outcomes and distinctive left ventricular remodeling. Aortic valve replacement improves survival across all MR grades, with greater impact in severe MR.

Prevalence of low-flow state by automated machine-learning 3D echocardiography in patients with moderate-to-severe aortic stenosis and normal ejection-fraction

BACKGROUND

In aortic valve stenosis (AS), measurement of stroke volume index (SVi) by the 2D Doppler- technique is required to calculate the aortic valve area (AVA) and determine flow status but is prone to systematic errors.

PURPOSE

To investigate the prevalence of low-flow (LF) state (SVi ≤ 35 ml/m2) in patients with AS and concurrent SVi quantification by a validated 3D left ventricular volumetric method and standard 2D Doppler methods and its potential repercussions on flow status reclassification.

METHODS

Consecutive patients with moderate or severe AS (≤1.5 cm2 by continuity equation) and ejection fraction ≥ 50% underwent concurrent Dynamic Heart Model (DHM) evaluation with larger settings of the boundary detection sliders (end-diastolic position = 60/60; end-systolic position = 30/30).

RESULTS

We included 57 patients (median 78 years [70-85]); 40% were women. The mean AVA was 1.03 ± 0.37 cm2, median 1.00 [0.73-1.20] cm2. We found a significant but modest correlation between SVi assessed by DHM and 2D Doppler (Pearson corr.=0.48, p < 0.001). In the 25 patients with severe AS (AVA < 1 cm2) subgroup, 75% of patients categorized as LF by 2D Doppler were reclassified as normal flow by DHM. The observed proportion of overall agreement in these patients was 60% (Cohen's kappa = 0.178, p = 0.238), without significant correlation (Pearson coeff.: 0.358; p = 0.166).

CONCLUSIONS

In patients with moderate or severe AS and normal EF, the prevalence of LF state defined as SVi ≤ 35 ml/m2 may be significantly lower than previously reported when the LV volumetric metrics by DHM are employed, and the AVA is close to the replacement referral cut-off.

Do flow-gradient groups determined by MDCT predict outcomes: validating CT stroke volume

BACKGROUND

Identifying severe aortic stenosis can be difficult especially among patients with low-flow states compared to normal flow. Non-invasive modalities can aid in the diagnosis for timely treatment.

METHODS

In this retrospective, single-center study of patients with aortic stenosis who underwent transcatheter aortic valve replacement (TAVR), we calculated stroke volume using CT blood pool based (CT-blp) analysis, echocardiogram and right heart catheterization (cath) performed before TAVR. We compared the performance of each modality in predicting 30-day and 1-year outcomes.

RESULTS

Three-hundred and forty-five patients were included with a median age of 84 (79-88) years and 52.8% females. CT-blp correlated more strongly (r = 0.60) with cath-derived stroke volume than echo (r = 0.37). After stratifying patients into groups based on flow and gradient using echo or CT-blp, there was no difference in mortality with either modality among the groups. However, the composite of mortality and hospital readmission was significantly higher in the low-flow low-gradient group (CT-blp 30-day OR 2.6, 95% CI 1.3-5.3, p < 0.01; 1-year OR 1.9, 95% CI 1.0-3.6; p = 0.04) compared to patients with normal flow high gradients when grouping was performed with CT-blp or echo.

CONCLUSION

Using the CT performed on patients pre-TAVR, CT-blp can provide an estimation of stroke volume that correlates well with invasive evaluation. The stroke volume may be used to stratify patient populations being evaluated for TAVR into flow gradient groups when echo is limited and avoid invasive catheterization to help identify patients with low-flow, low-gradient aortic stenosis. Further studies with larger cohorts are required to confirm our findings.

Transcatheter aortic valve replacement outcomes in patients with high gradient versus low ejection fraction low gradient severe aortic stenosis: A meta-analysis of randomized controlled trials

BACKGROUND

The outcome of Low Flow-Low Gradient (LF-LG) severe aortic stenosis (AS) patients who underwent Transcatheter Aortic Valve Replacement (TAVR) procedure is not well defined. We conducted a systematic review of the literature to compare the outcomes of TAVR in LF-LG AS patients to the more traditional high gradient (HG) aortic stenosis.

METHODS

We comprehensively searched for controlled randomized and non-randomized studies from 4 online databases. We are presenting the data using risk ratios (95 % confidence intervals) and measuring heterogeneity using Higgins' I2 index.

RESULTS

Our analysis included 4380 patients with 3425 HG patients and 955 LF-LG patients from 6 cohort (5 retrospective and 1 prospective) studies. When compared to LFLG; TAVR was associated with significantly lower 30 days mortality in HG patients (5.1 % vs 7.4 %; relative risk [RR]: 0.55; 95 % confidence interval [CI]: 0.35 to 0.86; p < 0.01). Similar findings were also observed in 12-month cardiovascular (CV) mortality (5.5 % vs. 10.4 %; RR: 0.47; 95 % CI: 0.38 to 0.60; p < 0.01 and 12-month all-cause mortality (15.9 % vs 20.9 %; RR: 0.70; 95 % CI: 0.49 to 1.00; p < 0.05). There was no significant difference in myocardial infarction (MI) after TAVR between HG and LF-LG at 30 days (0.16 % vs. 0.95 %; p < 0.09) or 12 months (0.43 % vs. 0.95 %; p = 0.20). Similarly, there was no difference in stroke rates at 30 days (2.9 % vs. 2.86 %) or at 12 months (3.6 % vs. 3.06 %).

CONCLUSIONS AND RELEVANCE

Patients with LF-LG severe AS who underwent TAVR had worse 1-year all-cause mortality, 30-day all-cause, and 1-year CV mortality when compared to TAVR in HG severe AS. There was no difference in MI or stroke rates. Therefore, with heart team discussion and informed patient decision regarding the risk and benefit, TAVR would still offer better outcomes in LFLG AS compared to conservative medical management.

Impact of valvulo-vascular haemodynamics on left ventricular remodelling and the prevalence of discordant moderate aortic stenosis

AIMS

This study aims to describe the prevalence of discordant mild/moderate aortic stenosis (AS) in a population-based study and to identify the mechanisms that lead to reduced stroke volume (SV) and discordant moderate AS.

METHODS AND RESULTS

Discordant high-gradient (HG)-mild AS, defined as AVA > 1.5 cm2 and mean pressure gradient (MG) of 20-40 mmHg, and discordant low-gradient (LG) moderate AS, defined as AVA 1.0-1.5 cm2 and MG < 20 mmHg, were assessed in 883 individuals from the DANCAVAS screening study with aortic valve calcification and 257 individuals form the PROGRESSA study excluding those with left ventricular (LV) ejection fraction < 50%. In the DANCAVAS cohort, 150 men had mild/moderate AS of which 34% had discordance between MG and AVA, representing 66% with moderate AS. Among 262 patients in the combined cohort, 39% had discordant LG-moderate AS and 6% discordant HG-mild AS. Compared with concordant mild and moderate AS, individuals with discordant LG-moderate AS were more likely to present with LV concentric remodelling geometry (26 vs. 33 vs. 45%, P < 0.001), increased valvulo-arterial impedance (3.3 ± 0.7 vs. 3.6 ± 0.5 vs. 4.1 ± 0.7 mmHg/mL/m2, P < 0.001), and reduced systemic arterial compliance (SAC) (0.74 ± 0.22 vs. 0.81 ± 0.22 vs. 0.64 ± 0.18 mL/m2/mmHg, P < 0.001). Factors associated with SV index were relative wall thickness, LV end-diastolic diameter index, SAC, and LV remodelling pattern.

CONCLUSION

Discordant moderate AS is common, accounting for two-thirds of patients with moderate AS in the general male population. Patients with discordant LG-moderate AS have predominantly a concentric remodelling pattern with reduced SV. Reduced SV index was associated with signs of reduced vascular compliance, suggesting that altered vascular properties drive differences in remodelling patterns and discordant moderate AS.

Transcatheter Aortic Valve Replacement Beyond Severe Aortic Stenosis: JACC State-of-the-Art Review

Transcatheter aortic valve replacement (TAVR) has become the preferred treatment option in appropriate patients with symptomatic severe aortic stenosis (AS). A number of advancements have since expanded the eligible population to bicuspid aortic valve with feasible anatomy; small aortic annuli; low-flow, low-gradient AS; and younger patients. Focus has also shifted beyond the symptomatic severe patients to asymptomatic severe and moderate AS, as early valve replacement may prevent irreversible cardiac remodeling. Dedicated devices to treat native aortic regurgitation have shown encouraging short-term outcomes. While the expansion of TAVR to younger patients has raised questions about valve durability and feasibility of reintervention, valve-in-valve TAVR has thus far shown encouraging midterm results. In this review, we summarize the evidence in these contemporary TAVR populations, exploring both the promise and challenge of broadening the patient pool for this minimally invasive procedure.

Stroke volume index (SVI) predicts all-cause mortality following transcatheter aortic valve replacement (TAVR)

BACKGROUND

Left ventricular systolic dysfunction in patients with severe aortic stenosis (AS) may result in low transvalvular gradients and underestimation of AS severity. A low-flow state may occur with reduced LVEF. Little is known about the implications of low compared to normal flow in patients with reduced LVEF undergoing transcatheter aortic valve replacement (TAVR).

OBJECTIVES

We compared survival rates with degree of flow across stenosed aortic valves and left ventricular dysfunction. We hypothesized that the stroke volume index (SVI) offers essential information regarding survival following TAVR.

METHODS

We retrospectively reviewed patients with LVEF <50 % undergoing TAVR at the Gates Vascular Institute in Buffalo, New York, from 2012 to 2017. We performed Receiver Operator Characteristics to examine the value of SVI in predicting the postoperative outcome of patients. Kaplan-Meier and Cox regression analyses were used to investigate the effect of a low-flow state on five-year survival in patients with systolic dysfunction undergoing TAVR.

RESULTS

Five-year survival following TAVR was decreased in patients with low-flow AS (SVI <35 mL/m2) compared to patients with normal flow. Seventy-four percent (n = 50) of patients with low-flow compared to 43 % (n = 22) of patients with normal flow were deceased five years post-TAVR (p ≤0.001). ROC curve indicated SVI to be a clinical predictor of five year survival (AUC 0.732, 95 % CI: 0.641-0.823, p < 0.001).

CONCLUSION

Patients with systolic dysfunction and low transvalvular flow AS had increased mortality five years following TAVR. These findings highlight a better prognosis in patients with normal flow and LV systolic dysfunction.

CONDENSED ABSTRACT

Low-flow aortic stenosis can occur with reduced left ventricular function. We compared survival rates of patients with known reduced left ventricular function in low-flow and normal flow aortic stenosis. This retrospective single-center study examined mortality rates following transcatheter aortic valve replacement. The mean gradient was not a predictor of mortality. This study shows patients with low-flow aortic stenosis have decreased five-year survival following valve replacement.

Valvular Heart Disease-A New Evolving Paradigm

Valvular heart disease is one of the most common cardiovascular diseases today and may result in severe limiting symptoms, a shortened lifespan, and, in some cases, sudden death. It is important to identify significant valve disease because intervention can restore quality of life and in many instances increase longevity. In most patients, the diagnosis of significant valvular heart disease can be made on the basis of a physical examination, yet nearly half of the patients who could benefit from interventions are not being recognized or referred. There have been major improvements in both the diagnosis and treatment of patients with valvular heart disease, with noninvasive echocardiography available to confirm the presence and severity of valve disease, better and more durable surgical procedures, and the advent of catheter-based therapies. There are now national guidelines to aid clinicians in the optimal timing of the intervention, which are presented. However, it is now recognized that the long-standing volume or pressure overload from valve disease can result in incipient ventricular dysfunction even before the onset of symptoms or a drop in ejection fraction; therefore, there is an impetus to recognize and to treat these patients earlier and earlier in the disease natural history. A shared decision-making process should play a key role in the final decision for therapy, outlining the goals and risks of possible intervention coupled with the patient's own needs and expectations.

Impact of sex-specific thresholds for low flow in assessment of prognosis in concordantly and discordantly graded aortic valve stenosis

AIMS

Sex-specific low flow was recently defined as stroke volume index (SVi) ≤ 40 mL/m² in men and ≤32 mL/m² in women. We tested the prognostic association of these cut-offs in patients with aortic stenosis (AS) with concordantly and discordantly graded AS [concordantly graded AS by energy loss (CGASEL) and discordantly graded AS by energy loss (DGASEL)] based on pressure recovery adjusted aortic valve area [energy loss (EL)].

METHODS AND RESULTS

Data from 1351 patients with asymptomatic AS, peak jet velocity <4 m/s, and preserved left ventricular ejection fraction enrolled in the Simvastatin and Ezetimibe in Aortic Stenosis study were used. DGASEL was defined as EL <1.0 cm² with mean aortic gradient <40 mmHg and CGASEL as EL ≥1.0 cm² with mean aortic gradient <40 mmHg. Patients were further grouped into normal and low flow. The outcome was combined all-cause death and hospitalization for heart failure (HF). CGASEL with normal/low flow was present in 915/253 patients, and DGASEL with normal/low flow was present in 57/126 patients. During a median follow-up of 4.3 years, event-free survival was lower in patients with DGASEL irrespective of flow compared to CGASEL with normal flow (P < 0.05). In Cox regression analysis, DGASEL with normal or low flow were both associated with increased risk of all-cause death and hospitalization for HF after adjustment for age, sex, heart rate, randomized study treatment, hypertension, aortic valve replacement, and aortic valve calcification (P < 0.05). No survival difference was found between patients with normal vs. low flow within groups of DGASEL or CGASEL.

CONCLUSION

Identification of low flow by the proposed sex-specific thresholds of SVi needs more prognostic validation before application in clinical practice.

CLINICALTRIALS.GOV IDENTIFIER

NCT00092677.

[Sex and age distribution of global disease burden of calcific aortic valve disease]

OBJECTIVES

To analyze sex and age distribution of global disease burden of calcific aortic valve disease (CAVD) from 1990 to 2021.

METHODS

CAVD data during 1990-2021 were obtained from the IHME website for Global Burden of Disease (GBD). The prevalence, mortality, years lived with disability (YLDs), and disability-adjusted life years (DALYs) were analyzed by gender and age groups. Joinpoint regression was used to calculate annual percentage change (APC) and average annual percentage change (AAPC).

RESULTS

In 2021, there were 13.32 million CAVD patients and 142 000 deaths caused by CAVD globally. Age-standardized prevalence was higher in males (193.2/105) than that in females (128.9/105). Patients in 65-<85 age group accounted for 64.0% of total cases, while those ≥85 years old accounted for 16.1%. From 1990 to 2021, prevalence increased in both sexes with an AAPC of 0.72% for males and 0.57% for females, respectively. Prevalence grew fastest from 2000 to 2010, slowed thereafter, and declined from 2015 to 2021. In <65 years old, the mortality of males was 2.4 times higher than that of females, while in ≥85 years old, mortality of females (117.3/105) exceeded that of males (99.1/105). YLD rates increased with age, and were higher in males for all age groups. DALY rates decreased overall but increased in ≥85 years old, with a greater increase in females.

CONCLUSIONS

There are significant gender and age disparities in global disease burden of CAVD, with the elderly, especially super-elderly females deserving particular attention. It is recommended to develop personalized intervention strategies for these populations.

Outcome Factors for Women Undergoing Transcatheter Aortic Valve Replacement

Women with severe aortic stenosis undergoing transcatheter aortic valve replacement (TAVR) have a higher burden of symptoms, are older at the time of the TAVR procedure, and have unique anatomic features that increase the periprocedural risk. However, long-term outcomes including mortality are favorable for women compared with men. Careful attention is needed in considering the vascular access route and choice of valve platform to mitigate complications. Large prospective trials dedicated to women undergoing TAVR are needed to investigate individual female-specific factors determining outcomes.

A proposal of a simplified grading and echo-based staging of aortic valve stenosis to streamline management

In this paper we discuss the relevance of continuity equation based aortic valve area (AVA) calculation as a robust parameter suitable for accurate grading of aortic stenosis (AS) irrespective of flow conditions. Combining the AVA-based grading and echocardiography-based staging, can provide with the most comprehensive clinical assessment of patients with AS and preserved left ventricular systolic function to streamline management decisions.

Prognostication and Interventional Guidance Using Acceleration-Ejection Time Ratio in Undifferentiated Paradoxical Low-Flow Low-Gradient Aortic Stenosis

BACKGROUND

Studies in paradoxical low-flow low-gradient aortic stenosis (PLFAS) have demonstrated conflicting outcomes with variable survival advantage from aortic valve replacement (AVR). PLFAS is a heterogeneous composition of patients with uncertainty regarding true stenosis severity that continues to confound decision-making for AVR.

OBJECTIVES

The purpose of this study was to investigate the utility of the Doppler acceleration (AT) to ejection (ET) time ratio (AT:ET) for prediction of prognosis and benefit from AVR in undifferentiated PLFAS.

METHODS

Patients with echocardiographic findings of PLFAS (aortic valve area <1.0 cm2 or indexed aortic valve area <0.6 cm2/m2, mean gradient <40 mm Hg, indexed stroke volume <35 mL/m2, and left ventricular ejection fraction ≥50%) were identified and grouped according to an AT:ET cutoff of 0.35. The primary outcome was a 5-year composite of cardiac mortality or AVR. Secondary outcomes included the individual components of the primary endpoint and all-cause mortality at 5 years. Effect of AVR was analyzed in the AT:ET <0.35 and ≥0.35 groups.

RESULTS

A total of 171 PLFAS patients (median age 77.0 years, 57% women) were followed for a median of 8.9 years. AT:ET ≥0.35 was an independent predictor of the primary outcome (HR: 4.77 [95% CI: 2.94-7.75]; P < 0.001) with incremental value over standard indices of stenosis severity (net reclassification improvement: 0.57 [95% CI: 0.14-0.84]). AT:ET ≥0.35 also remained predictive of increased cardiac death (HR: 2.91 [95% CI: 1.47-5.76]; P = 0.002) and AVR (HR: 8.45 [95% CI: 4.16-17.1]; P < 0.001), respectively, following competing risk analysis. No difference in all-cause mortality was observed. AVR in the AT:ET ≥0.35 group was associated with significant reductions in 5-year cardiac (HR: 0.09 [95% CI: 0.02-0.36]; P < 0.001) and all-cause mortality (HR: 0.16 [95% CI: 0.07-0.38]; P < 0.001). No improvement in survival from AVR was demonstrated in AT:ET <0.35 patients.

CONCLUSIONS

AT:ET ≥0.35 in PLFAS predicts poorer outcomes and/or need for AVR. In undifferentiated PLFAS patients, AT:ET may have a potential role in improving patient selection for prognostic AVR.

Right ventricular dysfunction and impaired right ventricular-pulmonary arterial coupling in paradoxical low-flow, low-gradient aortic stenosis

AIMS

Paradoxical low-flow, low-gradient aortic stenosis (pLFLG AS) may represent a diagnostic challenge, and its pathophysiology is complex. While left ventricular (LV) systolic function is preserved, right ventricular dysfunction (RVD) and consecutive LV underfilling may contribute to low-flow and reduced stroke volume index, and to adverse outcomes following transcatheter aortic valve implantation (TAVI). The aim of this study was to evaluate the potential role of RVD in pLFLG AS, and to assess the impact of pre-procedural RVD on clinical outcomes after TAVI in patients with pLFLG AS.

METHODS AND RESULTS

Out of 2739 native AS patients, who received TAVI at the University of Cologne Heart Center between March 2013 and June 2021, 114 patients displayed pLFLG AS and were included in this study. Right ventricular (RV) function was assessed by transthoracic echocardiography, and a fractional area change (FAC) ≤35% and/or a tricuspid annular plane systolic excursion (TAPSE) <18 mm determined RVD. In addition, the TAPSE/systolic pulmonary artery pressure ratio (TAPSE/sPAP) was monitored as a measure of RV-pulmonary arterial (PA) coupling. An impaired FAC and TAPSE was present in 21.9% and 45.6% of patients, respectively, identifying RVD in 50.0%. RVD (p = 0.016), reduced FAC (p = 0.049), reduced TAPSE (p = 0.035) and impaired RV-PA coupling (TAPSE/sPAP ratio <0.31 mm/mmHg; p = 0.009) were associated with significantly higher all-cause mortality compared to patients with normal RV function. After adjustment for sex, age, body mass index, EuroSCORE II, previous myocardial infarction and mitral regurgitation, independent predictors for all-cause mortality were FAC, sPAP, TAPSE/sPAP ratio, right atrial area, RV diameter and tricuspid regurgitation.

CONCLUSIONS

Adverse RV remodelling, RVD and impaired RV-PA coupling provide an explanation for low-flow and reduced stroke volume index in a subset of patients with pLFLG AS, and are associated with excess mortality after TAVI.

Paradoxical prognostic impact of severe aortic stenosis following trans-catheter aortic valve implantation

BACKGROUND

Aortic valve replacement is recommended for patients with "very severe" aortic stenosis (AS), irrespective of symptomatic manifestation. Nonetheless, the prognostic ramifications of "very severe" AS, as opposed to "severe" AS, subsequent to trans-catheter aortic valve implantation (TAVI) remain enigmatic.

METHODS

We enrolled consecutive patients who received TAVI at our institute between May 2015 and April 2021. We scrutinized the impact of baseline "very severe" AS upon 3-year all-cause death or heart failure hospitalization following TAVI, in comparison to "severe" AS.

RESULTS

A total of 239 patients (84.8 ± 5.4 years old, 58 men) were included. Baseline "very severe" AS was observed in 65 (27 %) patients, who exhibited more advanced hypertrophy and higher B-type natriuretic peptide levels compared to those with "severe" AS (p < 0.05 for both). Baseline "very severe" AS was paradoxically associated with higher freedom from the primary endpoint following TAVI compared to those with "severe" AS (p = 0.01).

CONCLUSIONS

The presence of baseline "very severe" AS was paradoxically associated with improved clinical outcomes subsequent to TAVI, in contrast to the cases of "severe" AS.

Sex-Related Differences in the Pathophysiology, Cardiac Imaging, and Clinical Outcomes of Aortic Stenosis: A Narrative Review

Aortic stenosis (AS) is the most common valvular heart disease in developed countries, and its prevalence is higher in older patients. Clinical studies have shown gender disparity in the pathogenesis and the progression of aortic stenosis. This disparity has led to several overwhelming questions regarding its impact on the clinical outcomes and treatment of the disease and the requirement of personalized sex-specific approaches for its management. Indeed, aortic stenosis differs in the pathophysiological response to pressure overload created by the stenosis in women compared to men, which would translate into differences in cardiac remodeling and clinical outcomes. Several studies have focused on understanding the differences regarding disease progression according to biological gender and have found that sex hormones play a crucial role. Sex hormones affect many metabolic processes, thus activating crucial cell signaling and energy metabolism through mitochondrial activity. Yet, there is still a significant gap in knowledge on how biological sex influences the pathophysiology of AS. In this review, we have discussed studies that point to the role of sex-related physiological differences in the molecular pathways and the clinical presentation of the disease and outcome in women and men. We used the format of narrative review to review and summarize the body of literature without being systematic but with taking great care of considering the most impactful data available to date on the topic, especially randomized trials, metanalyses, and prospective studies and registries when available, as well as experimental studies with rigorous methodological approaches regarding the basic mechanisms and pathophysiology of the disease in women compared to men. The opinion of the authors on a particular issue or finding was expressed when appropriate for clarification.

Prognostic Relevance of Gradient and Flow Status in Severe Aortic Stenosis

Background: Severe aortic stenosis (AS) may present with different flow, gradient and left ventricular ejection fraction (LVEF) patterns. Paradoxical low-flow low-gradient (PLF-LG) severe AS has a specific clinical profile, but its prognosis and management remain controversial. Our aim is to evaluate the impact of different AS patterns in the incidence of major clinical events. Methods: A retrospective observational study was carried out on all the consecutive patients diagnosed with severe AS at our tertiary hospital centre in 2021. Echocardiographic measurements were carefully reviewed, and patients were classified following current guidelines into four categories: high gradient (HG), concordant low-flow low-gradient (CLF-LG), paradoxical low-flow low-gradient (PLF-LG) and normal-flow low-gradient (NF-LG). The baseline characteristics and clinical events (heart failure admission, intervention and death) at 1-year follow-up were collected from medical records. The association between categories and events was established using Student's t test or ANOVA as required. Results: 205 patients with severe AS were included in the study (81 ± 10 years old, 52.7% female). Category distribution was as follows: HG (138, 67.3%), PLF-LG (34, 19.8%), CLF-LG (21, 10.2%) and NF-LG (12, 5.9%). During the follow-up, 24.8% were admitted due to heart failure, 68.3% received valve replacement (51.7% TAVR) and 22% died. Severe tricuspid regurgitation was more frequent in patients with PLF-LG than in HG AS (14.7% vs. 2.2%; p < 0.01). Despite no differences in intervention rate, more patients with PLF-LG (32.4% vs. 15.9%; p = 0.049) died during the evolution. Conclusions: The PLF-LG pattern was the second most common pattern of severe AS in our cohort, and it was related to a higher mortality with no differences in intervention rate. Thus, this controversial category, rather than being underestimated, should be followed closely and considered for early intervention.

Echocardiography-Derived Forward Left Ventricular Output Improves Risk Prediction in Systolic Heart Failure

BACKGROUND

Although it is widely used to classify patients with heart failure (HF), the prognostic role of left ventricular ejection fraction (LVEF) is debated. The aim of this study was to test the hypothesis that echocardiographic measures of forward left ventricular (LV) output, being more representative of cardiac hemodynamics, might improve risk prediction in a large cohort of patients with HF with systolic dysfunction.

METHODS

Consecutive stable patients with HF with LVEF <50% on guideline-recommended therapies undergoing echocardiography including the evaluation of forward LV output (i.e., LV outflow tract [LVOT] velocity-time integral [VTI], stroke volume index [SVi], and cardiac index) over a 6-year period were selected and followed for the end point of cardiac and all-cause death.

RESULTS

Among the 1,509 patients analyzed (mean age, 71 ± 12 years; 75% men; mean LVEF, 35 ± 9%), 328 (22%) died during a median follow-up period of 28 months (interquartile range, 14-40 months), 165 (11%) of cardiac causes. On multivariable regression analysis, LVOT VTI (P < .001), SVi (P < .001), and cardiac index (P < .001), but not LVEF (P > .05), predicted cardiac and all-cause death. The optimal prognostic cutoffs for LVOT VTI, SVi, and cardiac index were 15 cm, 38 mL/m2, and 2 L/min/m2, respectively. Adding each of these measures to a multivariable risk model (including clinical, biohumoral, and echocardiographic markers) improved risk prediction (P < .001). Among the different measures of forward LV output, cardiac index was less accurate than LVOT VTI and SVi.

CONCLUSIONS

The echocardiographic evaluation of forward LV output improves risk prediction in patients with HF across a wide LVEF spectrum over other well-established clinical, biohumoral, and echocardiographic prognostic markers.

[Prognosis of patients with supranormal ejection fraction undergoing percutaneous aortic valve replacement]

Introduction and objectives

Several studies have shown that reduced (< 50%) left ventricular ejection fraction (LVEF) is an independent risk factor for cardiovascular events and mortality in patients with severe aortic stenosis (AS) undergoing valve replacement. Although patients with preserved LVEF (> 50%) have a better prognosis, there is a group with supranormal LVEF (≥ 70%) whose prognosis seems to differ due to their characteristics. The aim of this study was to evaluate outcomes after transcatheter aortic valve implantation (TAVI) in patients with severe AS and supranormal LVEF.

Methods

We performed a retrospective cohort study that included 1160 patients undergoing TAVI between 2007 and 2021 at Hospital Clínico San Carlos (Madrid, Spain). The patients were classified according to preoperative LVEF into reduced (< 50%), normal (50% to 69%), and supranormal (≥ 70%). Clinical, echocardiographic variables, and the following outcomes were compared: death from any cause at 30 days and at 1 year, death from cardiovascular causes at 1 year, and rehospitalization due to cardiovascular causes at 1 year.

Results

Of the 1160 patients with severe AS who underwent TAVI during the study period, 276 (23.8%) had reduced LVEF, 702 (60.5%) had normal LVEF, and 182 (15.7%) had supranormal LVEF. Patients with supranormal LVEF were predominantly men (82.9 ± 5.3 years) and had lower ventricular volumes, higher relative wall thickness, and concentric geometry. There were no differences in 30-day or 1-year mortality. However, rehospitalization for cardiovascular causes at 1 year was significantly higher in the supranormal LVEF group (LVEF < 50%: 29.2%; LVEF 50% to 69%: 27.4%; LVEF ≥ 70%: 34.4%; P < .043).

Conclusions

Patients with severe AS and supranormal preprocedural LVEF (≥ 70%) who underwent TAVI had a higher rate of cardiovascular rehospitalization at 1 year, with no differences in mortality.

Severe Mitral Regurgitation in Paradoxical Low-Flow Low-Gradient Severe Aortic Stenosis

Background

Patients with paradoxical low-flow, low-gradient severe aortic stenosis (LFLGAS) exhibit low transvalvular flow rate (Q), while maintaining preserved left ventricular ejection fraction (LVEF). Concomitant severe mitral regurgitation (MR) contributes to the low flow state, adding complexity to diagnosis and management. This study aimed to examine the impact of severe MR on outcomes in paradoxical LFLGAS.

Methods

Data from an institutional echo database identified 1,189 patients with adjudicated severe aortic stenosis (AVA≤1.0 cm 2 ), low transaortic gradients (mean gradient<40 mmHg), preserved LVEF (≥50%), and low flow rate (Q≤210 ml/sec), to confirm paradoxical LFLGAS. Subgroups were based on MR severity (severe and non-severe). Clinical outcomes included all-cause mortality, aortic valve replacement (AVR), heart failure hospitalizations, and a composite outcome.

Results

In the severe MR group (n=80), patients had lower flow rates, increased LV dimensions and a more eccentric hypertrophy pattern compared to non-severe MR (n=1,109). Over a median 5-year follow-up, severe MR correlated with higher all-cause mortality (p=0.02) and AVR rates (p=0.012). After adjustment, severe MR was independently associated with increased all-cause mortality risk (HR=1.43, p=0.011) and composite outcome (HR=1.64, p<0.001). AVR significantly reduced mortality at every MR degree, with the most substantial impact in severe MR (HR=0.18, p<0.001). Propensity-adjusted models demonstrated a stronger AVR impact with increasing MR degree (p-for-interaction=0.044).

Conclusions

Severe MR in paradoxical LFLGAS is associated with adverse outcomes and distinctive LV remodeling. Aortic valve replacement improves survival across all MR grades, with greater impact in severe MR.

Cellular and extracellular proteomic profiling of paradoxical low-flow low-gradient aortic stenosis myocardium

Aims

Patients with severe aortic stenosis (AS), low transvalvular flow (LF) and low gradient (LG) with normal ejection fraction (EF)-are referred to as paradoxical LF-LG AS (PLF-LG). PLF-LG patients develop more advanced heart failure symptoms and have a worse prognosis than patients with normal EF and high-gradient AS (NEF-HG). Despite its clinical relevance, the mechanisms underlying PLF-LG are still poorly understood.

Methods

Left ventricular (LV) myocardial biopsies of PLF-LG (n = 5) and NEF-HG patients (n = 6), obtained during transcatheter aortic valve implantation, were analyzed by LC-MS/MS after sequential extraction of cellular and extracellular matrix (ECM) proteins using a three-step extraction method. Proteomic data are available via ProteomeXchange with identifier PXD055391.

Results

73 cellular proteins were differentially abundant between the 2 groups. Among these, a network of proteins related to muscle contraction and arrhythmogenic cardiomyopathy (e.g., cTnI, FKBP1A and CACNA2D1) was found in PLF-LG. Extracellularly, upregulated proteins in PLF-LG were related to ATP synthesis and oxidative phosphorylation (e.g., ATP5PF, COX5B and UQCRB). Interestingly, we observed a 1.3-fold increase in cyclophilin A (CyPA), proinflammatory cytokine, in the extracellular extracts of PLF-LG AS patients (p < 0.05). Consistently, immunohistochemical analysis confirmed its extracellular localization in PLF-LG AS LV sections along with an increase in its receptor, CD147, compared to the NEF-HG AS patients. Levels of core ECM proteins, namely collagens and proteoglycans, were comparable between groups.

Conclusion

Our study pinpointed novel candidates and processes with potential relevance in the pathophysiology of PLF-LG. The role of CyPA in particular warrants further investigation.

Association of Supranormal Left Ventricular Function With Major Adverse Cardiovascular Events: A Systematic Review of Literature

This systematic review aims to assess the prognostic implications of supranormal left ventricular ejection fraction (snLVEF) in cardiovascular disease, particularly heart failure (HF), and explore its association with major adverse cardiovascular events (MACE). A comprehensive search of electronic databases was conducted to identify relevant studies examining the relationship between snLVEF and cardiovascular outcomes. Studies utilizing various imaging modalities, including echocardiography, cardiac positron emission tomography, computed tomography, and cardiac magnetic resonance imaging, were included. Data extraction and quality assessment were performed according to predefined criteria. The review identified several studies investigating the association between snLVEF and cardiovascular outcomes. Findings revealed an increased risk of MACE, including HF hospitalization and stroke, in patients with snLVEF, particularly in women. Coronary microvascular dysfunction and autonomic dysregulation were proposed mechanisms underlying these associations. However, conflicting results were observed when focusing exclusively on snLVEF, with some studies reporting similar outcomes between snLVEF and other HF subgroups. snLVEF (>65%) appears to be associated with an elevated risk of MACE, particularly in women, suggesting a U-shaped mortality curve. However, the prognostic implications may vary among HF patients, necessitating further research to elucidate the specific contributions of HF phenotypes and comorbidities. These findings underscore the importance of tailored risk assessment and management strategies for patients with snLVEF, particularly in the context of HF.

Differences in TAVR Utilization in Aortic Stenosis Among Patients With and Without Psychiatric Comorbidities

Background

Transcatheter aortic valve replacement (TAVR) is one of the primary treatment modalities for aortic stenosis (AS). Disparities affecting certain groups could result in lower utilization of this life-saving procedure. This study aims to investigate the effects of associated psychiatric conditions on the likelihood of TAVR in hospitalized AS patients.

Methods

Our retrospective observational study used the National Inpatient Sample to identify hospitalized patients with AS. Using the International Classification of Diseases, 10th Revision, Clinical Modification patients were stratified into those without psychiatric comorbidities, and those with psychiatric comorbidities. The primary outcome was comparing the odds of TAVR between AS patients with and without psychiatric comorbidities. The secondary outcome assessed the association between TAVR and specific psychiatric comorbidities, using multivariable logistic regression while adjusting for prespecified covariates.

Results

The study included 1,549,785 AS patients, of which 26% had psychiatric comorbidities. Patients with any psychiatric comorbidity had a significantly reduced likelihood of TAVR (adjusted odds ratio [aOR], 0.76; P < .001). For 2 psychiatric comorbidities, (aOR, 0.80; P < .001), and for more than 2 comorbid mental disorders (aOR, 0.46; P < .001). Lower TAVR odds were observed in patients with depression (aOR, 0.79), anxiety (aOR, 0.79), bipolar disorder (aOR, 0.74), substance use (aOR, 0.73), and psychotic disorders (aOR, 0.61), with P values < .001. There was no significant difference in the odds of surgical aortic valve replacement between those with and without psychiatric comorbidities.

Conclusions

AS patients with psychiatric conditions face reduced TAVR likelihood. Further research is needed to confirm, explore, and address factors contributing to this disparity.

Impact of stroke volume assessment by three-dimensional transesophageal echocardiography on the classification of low-gradient aortic stenosis

BACKGROUND

Accurate assessment of flow status is crucial in low-gradient aortic stenosis (AS). However, the clinical implication of three-dimensional transesophageal echocardiography (3DTEE) on flow status evaluation remains unclear. This study aimed to investigate the assessment of flow status using 3D TEE in low-gradient AS patients.

METHODS

We retrospectively reviewed patients diagnosed with low-gradient AS and preserved ejection fraction at our institution between 2019 and 2022. Patients were categorized into low-flow/low-gradient (LF-LG) AS or normal-flow/low-gradient (NF-LG) AS based on two-dimensional transthoracic echocardiography (2DTTE). We compared the left ventricular outflow tract (LVOT) geometry between the two groups and reclassified them using stroke volume index (SVi) obtained by 3DTEE.

RESULTS

Among 173 patients (105 with LF-LG AS and 68 with NF-LG AS), 54 propensity-matched pairs of patients were analyzed. 3DTEE-derived ellipticity index of LVOT was significantly higher in LF-LG AS patients compared to NF-LG AS patients (p = 0.012). We assessed the discordance in flow status classification between SVi2DTTE and SVi3DTEE in both groups using a cutoff value of 35 ml/m2. The LF-LG AS group exhibited a significantly higher discordance rate compared to the NF-LG AS group, with rates of 50% and 2%, respectively. The optimal cutoff values of SVi3DTEE for identifying low flow status, based on 2DTTE-derived cutoff values, were determined to be 43 ml/m2.

CONCLUSIONS

LVOT ellipticity in low-gradient AS patients varies depending on flow status, and this difference contributes to discrepancies between SVi3DTEE and SVi2DTTE, particularly in LF-LG AS patients. Utilizing SVi3DTEE is valuable for accurately assessing flow status.

Left Ventricular Remodeling in Patients with Low Flow Aortic Stenosis Undergoing Transcatheter Aortic Valve Replacement

Low-flow (LF) aortic stenosis (AS) is common among older adults and associated with worse outcomes than AS with normal stroke volume. It is unknown whether left ventricular (LV) remodeling identifies patients with LF AS at higher risk of complications. LV remodeling was evaluated in 463 patients with severe LF AS referred for transcatheter aortic valve replacement (TAVR) and classified as adaptive (normal geometry and concentric remodeling) or maladaptive (concentric and eccentric hypertrophy) using the American Society of Echocardiography gender-specific criteria. Of these, the 390 patients who underwent TAVR were followed for the end points of heart failure (HF) hospitalization and all-cause mortality. The mean patient age was 79 (74.5 to 84) years. LV remodeling was adaptive in 57.4% (62 normal geometry, 162 concentric remodeling) and maladaptive in 42.6% (127 concentric hypertrophy, 39 eccentric hypertrophy). During a median follow-up of 3 years, 45 patients (11.5%) were hospitalized for HF and 73 (18.7%) died. After adjustment for widely used echocardiographic parameters, maladaptive remodeling was independently associated with HF hospitalization and death (adjusted hazard ratio 1.75, confidence interval 1.03 to 3.00). There was no significant difference between men and women in the association of maladaptive LV remodeling with the composite outcome (p = 0.40 for men and p = 0.06 for women). In conclusion, in patients with LF AS, maladaptive LV remodeling before TAVR is independently associated with higher incidences of postprocedural HF rehospitalization and death in both men and women. Assessment of LV remodeling has prognostic value over and above LV ejection fraction and may improve risk stratification for patients with LF AS.

Grading of Aortic Valve Calcification Severity and Risk Stratification in Aortic Stenosis

BACKGROUND

Thresholds of aortic valve calcification (AVC) to define hemodynamically moderate aortic stenosis (AS) from mild are lacking. We aimed to establish a novel grading classification of AVC as quantified by computed tomography and determine its prognostic value.

METHODS AND RESULTS

This study included 915 patients with at least mild AS (mean age 70±12 years, 30% women) from a multicenter prospective registry. All patients underwent Doppler-echocardiography and noncontrast computed tomography within 3 months. Primary end point was the occurrence of all-cause death. Receiver operating characteristic curves analyses were used to determine the sensitivity and specificity of sex-specific thresholds of AVC to identify hemodynamically moderate AS. Optimal thresholds (ie, with best sensitivity/specificity) of AVC to distinguish moderate (aortic valve area 1.0-1.5 cm2 and mean gradient 20-39 mm Hg) from mild AS (aortic valve area >1.5 cm2 and mean gradient <20 mm Hg) were AVC ≥360 arbitrary units in women and ≥1037 arbitrary units in men. Based on the guidelines' thresholds for severe AS and the new thresholds in our study for moderate AS, 312 (34%) patients had mild, 253 (28%) moderate, and 350 (38%) severe AVC. During a mean follow-up of 5.6±3.9 years, 183 (27%) deaths occurred. In Cox multivariable models, AVC remained associated with an increased risk of death (adjusted hazard ratio per grade increase, 1.94 [95% CI, 1.53-2.56]; P<0.001).

CONCLUSIONS

A novel grading classification of anatomic AS severity based on sex-specific thresholds of AVC provides significant prognostic value for predicting mortality. These findings support the complementarity of computed tomography-calcium scoring to Doppler-echocardiography to corroborate AS severity and enhance risk stratification in patients with AS.

2023 Korean Society of Echocardiography position paper for diagnosis and management of valvular heart disease, part I: aortic valve disease

This manuscript represents the official position of the Korean Society of Echocardiography on valvular heart diseases. This position paper focuses on the clinical management of valvular heart diseases with reference to the guidelines recently published by the American College of Cardiology/American Heart Association and the European Society of Cardiology. The committee tried to reflect the recently published results on the topic of valvular heart diseases and Korean data by a systematic literature search based on validity and relevance. In part I of this article, we will review and discuss the current position of aortic valve disease in Korea.

Sex Differences in Aortic Stenosis: From the Pathophysiology to the Intervention, Current Challenges, and Future Perspectives

Calcific aortic stenosis (AS) is a major cause of morbidity and mortality in high-income countries. AS presents sex-specific features impacting pathophysiology, outcomes, and management strategies. In women, AS often manifests with a high valvular fibrotic burden, small valvular annuli, concentric left ventricular (LV) remodeling/hypertrophy, and, frequently, supernormal LV ejection fraction coupled with diastolic dysfunction. Paradoxical low-flow low-gradient AS epitomizes these traits, posing significant challenges post-aortic valve replacement due to limited positive remodeling and significant risk of patient-prosthesis mismatch. Conversely, men present more commonly with LV dilatation and dysfunction, indicating the phenotype of classical low-flow low-gradient AS, i.e., with decreased LV ejection fraction. However, these distinctions have not been fully incorporated into guidelines for AS management. The only treatment for AS is aortic valve replacement; women are frequently referred late, leading to increased heart damage caused by AS. Therefore, it is important to reassess surgical planning and timing to minimize irreversible cardiac damage in women. The integrity and the consideration of sex differences in the management of AS is critical. Further research, including sufficient representation of women, is needed to investigate these differences and to develop individualized, sex-specific management strategies.

Patients with paradoxical low-flow, low-gradient aortic stenosis gain the least benefit from TAVI among all hemodynamic subtypes

BACKGROUND

Substantial controversy exists regarding the clinical benefit of patients with severe paradoxical low-flow, low-gradient aortic stenosis (PLF-LG AS) from TAVI. Therefore, we compared post-TAVI benefit by long-term mortality (all-cause, CV and SCD), clinical improvement of heart failure symptoms, and cardiac reverse remodelling in guideline-defined AS subtypes.

METHODS

We prospectively included 250 consecutive TAVI patients. TTE, 6mwt, MLHFQ, NYHA status and NT-proBNP were recorded at baseline and 6 months. Long-term mortality and causes of death were assessed.

RESULTS

107 individuals suffered from normal EF, high gradient AS (NEF-HG AS), 36 from low EF, high gradient AS (LEF-HG), 52 from "classic" low-flow, low-gradient AS (LEF-LG AS), and 38 from paradoxical low-flow, low-gradient AS (PLF-LG AS). TAVI lead to a significant decrease in MLHFQ score and NT-proBNP levels in all subtypes except for PLF-LG. Regarding reverse remodelling, a significant increase in EF and decrease in LVEDV was present only in subtypes with reduced baseline EF, whereas a significant decrease in LVMI and LAVI could be observed in all subtypes except for PLF-LG. During a follow-up of 3-5 years, PLF-LG patients exhibited the poorest survival among all subtypes (HR 4.2, P = 0.0002 for CV mortality; HR 7.3, P = 0.004 for SCD, in comparison with NEF-HG). Importantly, PLF-LG was independently predictive for CV mortality (HR 2.9 [1.3-6.9], P = 0.009).

CONCLUSIONS

PLF-LG patients exhibit the highest mortality (particularly CV and SCD), the poorest symptomatic benefit and the least reverse cardiac remodelling after TAVI among all subtypes. Thus, this cohort seems to gain the least benefit.

A call to consider an aortic stenosis screening program

Aortic stenosis (AS) is the most common age-related valvular condition with a prevalence of 13.1% in patients older than 75 years of age. Based on the severity of AS and symptoms, current guidelines recommend interval monitoring with transthoracic echocardiogram (TTE). However, no guidelines exist regarding screening asymptomatic persons for AS. Prevalence of AS is comparable to conditions such as colorectal cancer, lung cancer, breast cancer, and abdominal aortic aneurysm where dedicated screening programs are offered resulting in reduction of overall morbidity and mortality. We review recent advancements in treatment options, and we propose an AS screening program for high-risk individuals without known history of AS including all persons over age 75 and persons aged 70 years and older with dialysis dependent end-stage renal disease (ESRD).

Reducing Left Ventricular Wall Stress through Aortic Valve Enlargement via Transcatheter Aortic Valve Implantation in Severe Aortic Stenosis

Background: In aortic stenosis, the left ventricle exerts additional force to pump blood through the narrowed aortic valve into the downstream arterial vasculature. Adaptive hypertrophy helps to maintain wall stress homeostasis but at the expense of impaired compliance. Advanced ventricular deformation impacts the extent of functional recovery benefits achieved through transcatheter aortic valve implantation. Methods and Results: Subgroups were stratified based on output, with low-flow severe aortic stenosis defined as stroke volume index <35 mL· m-2. Before intervention, the low-flow subgroup exhibited worse effective orifice area index and arterial and global impedance, along with thinner wall thickness and larger chamber volume marginally. LV performance, including stroke volume index, ventricular elastance, and ventricular-arterial coupling, were notably inferior, consistent with worse adverse remodeling. Although the effective orifice area index was similarly augmented after TAVI, inferior recovery benefits were noted. Persistently higher wall stress and energy consumption were observed, along with poorer ventricular-arterial coupling. These changes in wall stress showed an inverse relationship with alterations in wall thickness and were proportional to changes in dimension and volume. Additionally, they were proportional to changes in left ventricular end-systolic pressure, pressure-volume area, and ventricular-arterial coupling but inversely related to ventricular end-systolic elastance. Conclusions: The study revealed that aortic valve enlargement through transcatheter aortic valve implantation reduces left ventricular wall stress in severe aortic stenosis. The reduced recovery benefits in the low-flow subgroup were evident. Wall stress could serve as a marker of mechanical benefit after the intervention.

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.

Asymptomatic Aortic Stenosis: From Risk Stratification to Treatment

Our understanding of the natural history of aortic stenosis has significantly increased over the last decade. There have been considerable advances in the diagnosis and risk stratification of patients with aortic stenosis and in surgical and anesthetic techniques. In addition, transcatheter aortic valve replacement has established itself as a viable alternative to surgical management. Inevitably, these developments have raised questions regarding the merits of waiting for symptom onset in asymptomatic patients with severe aortic stenosis before offering treatment. Recent observational and randomized trial data suggest that early intervention in asymptomatic patients with severe aortic stenosis and normal left ventricular function may confer a prognostic advantage to a watchful waiting strategy. In this review, we highlight advances in the management and risk stratification of patients with asymptomatic severe aortic stenosis with particular consideration of recent findings supporting early valvular intervention.

The Flow Rate in Patients With Low-Gradient Aortic Stenosis

PURPOSE

 The decision to assess the severity and determine the ideal timing of intervention for low-gradient aortic stenosis poses a greater challenge. Recently, a novel method for determining the flow status of patients with aortic stenosis has been introduced, utilizing flow rate measurements. In this study, we investigated whether the flow status of patients with low-gradient aortic stenosis is linked to mortality within a three-year timeframe.

METHODS

Twenty-nine patients diagnosed with low-gradient aortic stenosis and valve area ≤ 1 cm were identified during 2010-2015. Each patient's flow rate across the aortic valve was computed, and the study scrutinized echocardiographic parameters to ascertain their correlation with mortality over a three-year timeframe.

RESULTS

 We observed that among patients with low-gradient aortic stenosis and a valve area of ≤1 cm, a decreased flow rate across the aortic valve emerged as an independent predictor of mortality. A flow rate < 210 ml/s was linked with a three-year mortality rate of 66.7%, whereas a low stroke volume index < 35 ml/m² did not show an association with three-year mortality. This observation might be attributed to the smaller body sizes prevalent among these older patients, particularly females, which could influence the calculation of the stroke volume index.

CONCLUSION

 In older patients with low-gradient aortic stenosis, the flow rate can better reflect flow status than the stroke volume index, and it also suggests a prognostic significance in predicting mortality. Additional studies are warranted to validate these findings across broader patient populations and to assess the potential efficacy of early intervention strategies in this particular patient cohort.

Functional aortic valve area differs significantly between sexes: A phase-contrast cardiac MRI study in patients with severe aortic stenosis

Background

Aortic stenosis (AS) is one of the most prevalent valvular heart-diseases in Europe. Currently, diagnosis and classification are not sex-sensitive; however, due to a distinctly different natural history of AS, further investigations of sex-differences in AS-patients are needed. Thus, this study aimed to detect sex-differences in severe AS, especially concerning flow-patterns, via phase-contrast cardiac magnetic resonance imaging (PC-CMR).

Methods

Forty-four severe AS-patients (20 women, 45 % vs. 24 men, 55 %) with a median age of 72 years underwent transthoracic echocardiography (TTE), cardiac catheterization (CC) and CMR. Aortic valve area (AVA) and stroke volume (SV) were determined in all modalities, with CMR yielding geometrical AVA via cine-planimetry and functional AVA via PC-CMR, the latter being also used to examine flow-properties.

Results

Geometrical AVA showed no sex-differences (0.91 cm2, IQR: 0.61-1.14 vs. 0.94 cm2, IQR: 0.77-1.22, p = 0.322). However, functional AVA differed significantly between sexes in all three modalities (TTE: p = 0.044; CC/PC-CMR: p < 0.001). In men, no significant intermethodical biases in functional AVA-measurements between modalities were found (p = 0.278); yet, in women the particular measurements differed significantly (p < 0.001). Momentary flowrate showed sex-differences depending on momentary opening-degree (at 50 %, 75 % and 90 % of peak-AVA, all p < 0.001), with men showing higher flowrates with increasing opening-area. In women, flowrate did not differ between 75 % and 90 % of peak-AVA (p = 0.191).

Conclusions

In severe AS-patients, functional AVA showed marked sex-differences in all modalities, whilst geometrical AVA did not differ. Inter-methodical biases were negligible in men, but not in women. Lastly, significant sex-differences in flow-patterns fit in with the different pathogenesis of AS.

Low-Flow, Low-Gradient Severe Aortic Stenosis in patients with preserved or reduced ejection fraction: a systematic literature review

OBJECTIVES

A systematic review of the literature was conducted to analyze the current evidence on low-flow, low-gradient severe aortic stenosis. This analysis aimed to differentiate between subgroups of patients with reduced and preserved left ventricular ejection fraction (LVEF).

METHODS

After conducting a systematic literature review, 35 observational studies were included. Out of these, 28 were prospective and 7 retrospective. The studies that included a mortality risk stratification of low-flow, low-gradient aortic stenosis (LF- LG AS) with both preserved and reduced LVEF were reviewed.

RESULTS

The importance of considering multiple clinical and echocardiographic variables in diagnostic evaluation and therapeutic decision-making was highlighted.

CONCLUSIONS

LF- LG AS, in any of its subgroups, is a common and challenging valve lesion. A careful assessment of severity and, in specific scenarios, a thorough reclassification is important. More high-quality studies are required to more precisely define the classification and prognosis of this entity.

Transcatheter Aortic Valve Replacement Across Hemodynamic Subtypes of Severe Aortic Valve Stenosis: A Network Meta-analysis

Background

Studies assessing outcomes of transcatheter aortic valve replacement (TAVR) in patients with severe aortic valve stenosis (AS) with hemodynamic subtypes have demonstrated mixed results with respect to outcomes and periprocedural complications. This study aimed to assess the outcomes of TAVR in patients across various hemodynamic subtypes of severe AS.

Methods

PubMed, Embase, and Cochrane databases were searched through September 2023 to identify all observational studies comparing outcomes of TAVR in patients with paradoxical low flow low gradient (pLFLG), classic LFLG, and high gradient AS (HGAS). The primary outcome was major adverse cardiovascular events (MACE). The secondary outcomes were components of MACE (mortality, myocardial infarction [MI], stroke). A bivariate, influential, and frequentist network meta-analysis model was used to obtain the net odds ratio (OR) with a 95% CI.

Results

A total of 21 studies comprising 17,298 (8742 experimental and 8556 HGAS) patients were included in the quantitative analysis. TAVR was associated with a significant reduction in the mean aortic gradient, and an increase in the mean aortic valve area irrespective of the AS type. Compared with HGAS, TAVR in classic LFLG had a significantly higher (OR, 1.68; 95% CI, 1.04-2.72), while pLFLG (OR, 0.98; 95% CI, 0.72-1.35) had a statistically similar incidence of MACE at a median follow-up of 1-year. TAVR in LFLG also had a significantly higher need for surgery (OR, 3.57; 95% CI, 1.24-10.32), and a greater risk of periprocedural (OR, 2.00; 95% CI, 1.17-3.41), 1-month (OR, 1.69; 95% CI, 1.08-2.64), and 12-month (OR, 1.41; 95% CI, 1.05-1.88) mortality compared with HGAS. The incidence of MI, major bleeding, vascular complications, paravalvular leak, pacemaker implantation, and rehospitalizations was not significantly different between all other types of AS (HGAS vs LFLG, pLFLG).

Conclusions

TAVR is an effective strategy in severe AS irrespective of the hemodynamic subtypes. Relatively, pLFLG did not have significantly different risk of periprocedural complications compared with HGAS, while classical LFLG AS had higher risk of MACE, primarily driven by the greater mortality risk.

Doppler Echocardiographic Phenotypes in Suspected 'Severe' Aortic Stenosis: Matrix-Based Approach to Diagnosis and Management

BACKGROUND

Among patients with suspected severe aortic stenosis (AS), Doppler echocardiographic (DE) data are often discordant, and further analysis is required for accurate diagnosis and optimal management. In this study, an automated matrix-based approach was applied to an echocardiographic database of patients with AS that identified 5 discrete echocardiographic data patterns, 1 concordant and 4 discordant, each reflecting a particular pathophysiology/measurement error that guides further workup and management.

METHODS

A primary/discovery cohort of consecutive echocardiographic studies with at least 1 DE parameter of severe AS and analogous data from an independent secondary/validation cohort were retrospectively analyzed. Parameter thresholds for inclusion were aortic valve area (AVA) <1.0 cm2, transaortic mean gradient (MG) ≥ 40 mmHg, and/or transaortic peak velocity (PV) ≥ 4.0 m/sec. Doppler velocity index (DVI) was also determined. Logic provided by an in-line SQL query embedded within the database was used to assign each patient to 1 of 5 discrete matrix patterns, each reflecting 1 or more specific pathophysiologies. Feasibility of automated pattern-driven triage of discordant cases was also evaluated.

RESULTS

In both cohorts, data from each patient fitted only 1 data pattern. Of the 4,643 primary cohort patients, 39% had concordant parameters for severe AS and DVI <0.30 (pattern 1); 35% had AVA < 1.0 cm2, MG < 40 mm Hg, PV < 4 m/sec, DVI < 0.30 (pattern 2); 9% had MG ≥ 40 mmHg and/or PV ≥ 4 m/sec, DVI > 0.30 (pattern 3); 10% had AVA < 1.0 cm2, MG < 40 mmHg, PV < 4 m/sec, DVI >0.30 (pattern 4); and 7% had MG > 40 mmHg and/or PV ≥ 4 m/sec, AVA > 1.0 cm2, DVI < 0.30 (pattern 5). Findings were validated among the 387 secondary cohort patients in whom pattern distribution was remarkably similar.

CONCLUSIONS

Matrix-based pattern recognition permits automated in-line identification of specific pathophysiology and/or measurement error among patients with suspected severe AS and discordant DE data.

Prediction of symptom development and aortic valve replacement in patients with low-gradient severe aortic stenosis

Aims

Current evidence on the prognostic value of exercise stress echocardiography (ESE) in asymptomatic patients with low-gradient severe aortic stenosis (AS) is limited. Therefore, this study aimed to elucidate its prognostic implications for patients with low-gradient severe AS and determine the added value of ESE in risk stratification for this population.

Methods and results

This retrospective observational study included 122 consecutive asymptomatic patients with either moderate [mean pressure gradient (MPG) < 40 mmHg and aortic valve area (AVA) 1.0-1.5 cm2] or low-gradient severe (MPG < 40 mmHg and AVA < 1.0 cm2) AS and preserved left ventricular ejection fraction (≥50%) who underwent ESE. All patients were followed up for AS-related events. Of 143 patients, 21 who met any exclusion criteria, including early interventions, were excluded, and 122 conservatively managed patients [76.5 (71.0-80.3) years; 48.3% male] were included in this study. During a median follow-up period of 989 (578-1571) days, 64 patients experienced AS-related events. Patients with low-gradient severe AS had significantly lower event-free survival rates than those with moderate AS (log-rank test, P < 0.001). Multivariable Cox regression analysis showed that the mitral E/e' ratio during exercise was independently associated with AS-related events (hazard ratio = 1.075, P < 0.001) in patients with low-gradient severe AS.

Conclusion

This study suggests that asymptomatic patients with low-gradient severe AS have worse prognoses than those with moderate AS. Additionally, the mitral E/e' ratio during exercise is a useful parameter for risk stratification in patients with low-gradient severe AS.

Effect of Sex and Flow Status on Outcomes After Surgical or Transcatheter Aortic Valve Replacement

Background

Low stroke volume index <35 ml/m2 despite preserved ejection fraction (paradoxical low flow [PLF]) is associated with adverse outcomes in patients with aortic stenosis undergoing transcatheter aortic valve replacement (TAVR) or surgical aortic valve replacement (SAVR). However, whether the risk associated with PLF is similar in both sexes is unknown.

Objectives

The purpose of this study was to analyze the risk associated with PLF in severe aortic stenosis for men and women randomized to TAVR or SAVR.

Methods

Patients with ejection fraction ≥50% from the PARTNER (Placement of Aortic Transcatheter Valves) 2 and 3 trials were stratified by sex and treatment arm. The impact of PLF on the 2-year occurrence of the composite of death or heart failure hospitalization (primary endpoint) and of all-cause mortality alone (secondary endpoint) was analyzed. Analysis of variance was used to assess baseline differences between groups. Multivariate Cox regression analysis was used to identify predictors of the endpoint.

Results

Out of 2,242 patients, PLF was present in 390 men and 239 women (30% vs 26%, P = 0.06). PLF was associated with a higher rate of NYHA functional class III to IV dyspnea (60% vs 54%, P < 0.001) and a higher prevalence of atrial fibrillation (39% vs 24%, P < 0.001). PLF was a significant predictor of the primary endpoint among women undergoing SAVR in multivariate analysis (adjusted HR: 2.25 [95% CI: 1.14-4.43], P = 0.02) but was not associated with a worse outcome in any of the other groups (all P > 0.05).

Conclusions

In women with PLF, TAVR may improve outcomes compared to SAVR. PLF appears to have less impact on outcomes in men.

Simulating impaired left ventricular-arterial coupling in aging and disease: a systematic review

Aortic stenosis, hypertension, and left ventricular hypertrophy often coexist in the elderly, causing a detrimental mismatch in coupling between the heart and vasculature known as ventricular-vascular (VA) coupling. Impaired left VA coupling, a critical aspect of cardiovascular dysfunction in aging and disease, poses significant challenges for optimal cardiovascular performance. This systematic review aims to assess the impact of simulating and studying this coupling through computational models. By conducting a comprehensive analysis of 34 relevant articles obtained from esteemed databases such as Web of Science, Scopus, and PubMed until July 14, 2022, we explore various modeling techniques and simulation approaches employed to unravel the complex mechanisms underlying this impairment. Our review highlights the essential role of computational models in providing detailed insights beyond clinical observations, enabling a deeper understanding of the cardiovascular system. By elucidating the existing models of the heart (3D, 2D, and 0D), cardiac valves, and blood vessels (3D, 1D, and 0D), as well as discussing mechanical boundary conditions, model parameterization and validation, coupling approaches, computer resources and diverse applications, we establish a comprehensive overview of the field. The descriptions as well as the pros and cons on the choices of different dimensionality in heart, valve, and circulation are provided. Crucially, we emphasize the significance of evaluating heart-vessel interaction in pathological conditions and propose future research directions, such as the development of fully coupled personalized multidimensional models, integration of deep learning techniques, and comprehensive assessment of confounding effects on biomarkers.

Long-Term Outcomes of Aortic Stenosis Patients with Different Flow/Gradient Patterns Undergoing Transcatheter Aortic Valve Implantation

Background: Few data exist on the comparative long-term outcomes of severe aortic stenosis (AS) patients with different flow-gradient patterns undergoing transcatheter aortic valve implantation (TAVI). This study sought to evaluate the impact of the pre-TAVI flow-gradient pattern on long-term clinical outcomes after TAVI and assess changes in the left ventricular ejection fraction (LVEF) of different subtypes of AS patients following TAVI. Methods: Consecutive patients with severe AS undergoing TAVI in our institution were screened and prospectively enrolled. Patients were divided into four subgroups according to pre-TAVI flow/gradient pattern: (i) low flow-low gradient (LF-LG): stroke volume indexed (SVi) ≤ 35 mL/m2 and mean gradient (MG) < 40 mmHg); (ii) normal flow-low gradient (NF-LG): SVi > 35 mL/m2 and MG < 40 mmHg; (iii) low flow-high gradient (LF-HG): Svi 35 mL/m2 and MG ≥ 40 mmHg and (iv) normal flow-high gradient (NF-HG): SVi > 35 mL/m2 and MG ≥ 40 mmHg. Transthoracic echocardiography was repeated at 1-year follow-up. Clinical follow-up was obtained at 12 months, and yearly thereafter until 5-year follow-up was complete for all patients. Results: A total of 272 patients with complete echocardiographic and clinical follow-up were included in our analysis. Their mean age was 80 ± 7 years and the majority of patients (N = 138, 50.8%) were women. 62 patients (22.8% of the study population) were distributed in the LF-LG group, 98 patients (36%) were LF-HG patients, 95 patients (34.9%) were NF-HG, and 17 patients (6.3%) were NF-LG. There was a greater prevalence of comorbidities among LF-LG AS patients. One-year all-cause mortality differed significantly between the four subgroups of AS patients (log-rank p: 0.022) and was more prevalent among LF-LG patients (25.8%) compared to LF-HG (11.3%), NF-HG (6.3%) and NF-LG patients (18.8%). At 5-year follow-up, global mortality remained persistently higher among LF-LG patients (64.5%) compared to LF-HG (47.9%), NF-HG (42.9%), and NF-LG patients (58.8%) (log-rank p: 0.029). At multivariable Cox hazard regression analysis, baseline SVi (HR: 0.951, 95% C.I.; 0.918-0.984), the presence of at least moderate tricuspid regurgitation at baseline (HR: 3.091, 95% C.I: 1.645-5.809) and at least moderate paravalvular leak (PVL) post-TAVI (HR: 1.456, 95% C.I.: 1.106-1.792) were significant independent predictors of late global mortality. LF-LG patients and LF-HG patients exhibited a significant increase in LVEF at 1-year follow-up. A lower LVEF (p < 0.001) and a lower Svi (p < 0.001) at baseline were associated with LVEF improvement at 1-year. Conclusions: Patients with LF-LG AS have acceptable 1-year outcomes with significant improvement in LVEF at 1-year follow-up, but exhibit exceedingly high 5-year mortality following TAVI. The presence of low transvalvular flow and at least moderate tricuspid regurgitation at baseline and significant paravalvular leak post-TAVI were associated with poorer long-term outcomes in the entire cohort of AS patients. The presence of a low LVEF or a low SVi predicts LVEF improvement at 1-year.