Low-flow, low-gradient aortic stenosis with normal and depressed left ventricular ejection fraction. J Am Coll Cardiol. 2012;60:1845-1853. [PMID: 23062546 DOI: 10.1016/j.jacc.2012.06.051]

Temporal Trends in Transcatheter Aortic Valve Replacement Outcomes in Patients With Low-Flow, Low-Gradient Aortic Stenosis: Insights From the TOPAS-TAVI Registry

BACKGROUND

Transcatheter aortic valve replacement (TAVR) technology and techniques have continuously improved, but data on their impact in low-flow, low-gradient aortic stenosis (LFLG-AS) remain limited. In particular, scarce data exist comparing the results of TAVR with new-generation devices vs early-generation devices in these patients. This study evaluated the temporal trends in TAVR practices among LFLG-AS patients.

METHODS

This multicentre registry included 424 consecutive LFLG-AS patients undergoing TAVR from 2007 to 2023, stratified by device generation: new-generation devices (n = 193) and early-generation devices (n = 231). All-cause mortality or heart failure hospitalisation (HFH) at 1-year follow-up was the primary end point.

RESULTS

The median Society of Thoracic Surgeons score was lower in the new-generation group (5.3% [interquartile range [IQR] 3.4%-8.2%] vs 7.4% [IQR 5.0%-12.1%]; P < 0.001), whereas left ventricular ejection fractions(LVEFs) were similar (new: 31.2 ± 8.3%; early: 30.0 ± 8.8%; P = 0.16). New-generation devices were associated with a significant reduction in moderate-to-severe paravalvular leak after TAVR (2.6% vs 9.1%; P = 0.005), but 30-day mortality was similar (new: 1.6%; early: 3.9%; P = 0.15). At 1 year, new-generation devices were associated with a greater LVEF improvement (43.8 ± 12.5% vs 39.8 ± 11.5%; P = 0.003), but without a significant reduction in all-cause mortality or HFH (new: 23.8%; early: 28.1%; P = 0.32). Chronic kidney disease and low hemoglobin independently predicted worse outcomes (P < 0.05).

CONCLUSIONS

Despite procedural improvements with new-generation TAVR devices, clinical outcomes in LFLG-AS patients remain suboptimal. LVEF significantly improved after TAVR with new-generation devices but failed to translate into improved clinical outcomes. These findings suggest that TAVR alone may not suffice in this population and underscore the need for a comprehensive therapeutic approach that integrates TAVR with optimised medical management and cardiac rehabilitation.

Quantitative feasibility of aortic-valve agatston score derived from 5 ​mm-thick non-electrocardiography-gated noncontrast body computed tomography for evaluating severe aortic stenosis

BACKGROUND

The aortic-valve Agatston score (AVAS) is valuable for evaluating severe aortic stenosis (AS). While visual assessment of AS using chest computed tomography (CT) during lung cancer screening facilitates qualitative evaluation, it remains unclear whether AVAS derived from body CT that are neither electrocardiography (ECG)-triggered nor ECG-gated can quantitatively evaluate severe AS. This study aims to investigate the quantitative feasibility of AVAS derived from the 5 ​mm-thick noncontrast body CT for evaluating severe AS.

METHODS

In this retrospective study, data were collected from participants who underwent both cardiac CT scans that were either ECG-gated or ECG-triggered and noncontrast body CT scans that were neither ECG-triggered nor ECG-gated prior to AS treatment. We quantified AVAS from the body CT scan with a slice thickness of 5 ​mm (body CT AVAS) and AVAS from the cardiac CT scan with a slice thickness of 3 ​mm (cardiac CT AVAS). Regression analysis was performed between body CT AVAS and cardiac CT AVAS. Receiver-operating characteristic (ROC) curve analysis of body CT AVAS was conducted to detect cardiac CT AVAS of ≥2000 and ​≥1300.

RESULTS

A total of 265 participants (90 males; median age, 84 years [interquartile range, 80-88 years]) were analyzed. Regression analysis between body CT AVAS and cardiac CT AVAS yielded an R2 of 0.92. Body CT AVAS of 2540 and 1440 corresponded to cardiac CT AVAS of 2000 and 1300, respectively. The areas under the ROC curves were 0.99 and 0.98, respectively.

CONCLUSION

Five mm-thick noncontrast body CT AVAS is a quantitatively feasible tool for evaluating severe AS.

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.

Reevaluating Normal-Flow Low-Gradient Severe Aortic Stenosis: Clinical Phenotypes and Outcomes in Severe Aortic Stenosis Among Transcatheter Aortic Valve Replacement Patients

BACKGROUND

Aortic stenosis (AS) is a complex condition with various hemodynamic subtypes, each with distinct clinical profiles and outcomes. The aim of this study was to assess the characteristics and outcomes of different AS phenotypes on the basis of flow and gradient patterns.

METHODS

In this retrospective cohort study, 930 patients who underwent transcatheter aortic valve replacement for severe symptomatic AS at Mayo Clinic sites from 2012-2017 were included. Patients were classified into three groups: high gradient (HG), low-flow low-gradient (LFLG), and normal-flow low-gradient (NFLG). Baseline clinical, echocardiographic, and computed tomographic characteristics, including aortic valve area, aortic valve calcium score, left ventricular ejection fraction, and the prevalence of tricuspid regurgitation, and atrial fibrillation were analyzed. One- and 5-year all-cause mortality outcomes were compared using Kaplan-Meier analysis and Cox proportional-hazards models.

RESULTS

The final cohort included 273 patients in the NFLG group (29.4%), 563 in the HG group (60.5%), and 94 in the LFLG group (10.1%). After reevaluation and careful review of the echocardiograms, 41 patients with NFLG AS were reclassified into the LFLG group. Patients with LFLG AS had the highest prevalence of atrial fibrillation or flutter (60%) and tricuspid regurgitation (17%). Aortic valve calcium score was significantly lower in the NFLG group compared with the HG and LFLG groups. One-year mortality was highest in the LFLG group (17.4%), followed by the HG (13.9%) and NFLG (10.9%) groups, but the difference was not statistically significant (P = .20). The 5-year mortality rate was higher in the LFLG group (55.6%) compared with the NFLG (47.2%) and HG (47.9%) groups but did not reach statistical significance (P = .20).

CONCLUSIONS

LFLG AS was associated with more comorbidities and higher mortality compared with HG and NFLG AS, though differences in mortality were not statistically significant. The NFLG group, after close review and reclassification, showed the least significant AS. Randomized trials are needed to clarify the prognosis and management of NFLG AS.

Outcomes of aortic stenosis in patients with cardiac amyloidosis: A systematic review and meta-analysis

BACKGROUND

Cardiac amyloidosis (CA) results from the deposition of abnormally folded protein fibrils, leading to restrictive cardiomyopathy, valvular heart disease, and arrhythmias. Up to 15 % of patients with severe aortic stenosis (AS) have concomitant CA (AS-CA). We conducted this systematic review and meta-analysis to compare medical management, transcatheter aortic valve replacement (TAVR), and surgical AVR (SAVR) in AS-CA.

METHODS

A comprehensive literature search was conducted for relevant studies from inception through January 20, 2024. Studies exploring outcomes in adult AS patients with and without CA receiving medical therapy, TAVR, or SAVR were included in this analysis.

RESULTS

Fifteen studies including 253,334 patients (AS-CA 6704; AS alone 246,630) were identified. AS-CA patients had significantly higher all-cause mortality (RR = 2.60, 95 % CI 1.48-4.57, P = 0.0009) compared to AS alone. Among patients with AS-CA, TAVR was associated with lower all-cause mortality compared to both medical therapy (RR = 0.50, 95 % CI 0.29-0.89, P = 0.02) and SAVR (RR = 0.41, 95 % CI 0.22-0.78, P = 0.007). AS-CA patients undergoing TAVR were more likely to have paradoxical low-flow, low-gradient AS (RR = 1.56, 95 % CI 1.15-2.12, P = 0.04) at baseline and had a higher risk of post-TAVR acute kidney injury (RR = 1.95, 95 % CI 1.35-2.80, P = 0.0003) compared to patients undergoing TAVR for AS alone. There were similar risks of other post-TAVR complications, including major bleeding, vascular complications, stroke, and new pacemaker implantation between AS-CA and AS alone.

CONCLUSION

CA is associated with a higher mortality in patients with severe AS. In patients with concomitant AS and CA, TAVR is safe and associated with better survival than medical therapy or SAVR. SOCIAL MEDIA ABSTRACT: #Meta-Analysis: Cardiac amyloidosis is associated with increased mortality in severe AS. #TAVR is safe in amyloidosis & improves survival more than medical therapy or SAVR.

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 nonsevere). 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 nonsevere 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 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.

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.

Hemodynamic Factors Driving Peripheral Chemoreceptor Hypersensitivity: Is Severe Aortic Stenosis Treated with Transcatheter Aortic Valve Implantation a Valuable Human Model?

Background: A reduction in carotid artery blood flow (CABF) and ultimately in wall shear stress (WSS) is a major driver of heightened peripheral chemoreceptor (PCh) activity in animal models of heart failure. However, it is yet to be translated to humans. To provide more insight into this matter, we considered severe aortic stenosis (AS) before and after transcatheter aortic valve implantation (TAVI) as a human model of carotid and aortic body function under dramatically different hemodynamic conditions. Materials and Methods: A total of 26 severe AS patients (aged 77 ± 6 y, body mass index: 29.1 ± 5.1 kg/m2, left ventricular ejection fraction (LVEF): 50 ± 15%) were subjected to a transient hypoxia test twice: immediately before vs. 1-4 months after TAVI (median follow-up: 95 days). PCh function was analyzed in terms of ventilatory (HVR, L/min/SpO2%) and heart rate responses to hypoxia (HR slope, bpm/SpO2%). Standard ultrasound (inc. aortic valve area [AVA], mean aortic valve gradient, peak aortic jet velocity, LVEF, and CABF), respiratory, hemodynamic, and blood parameters were collected at both visits. Pre- vs. post-TAVI data regarding HVR and HR slopes were available for N = 26 and N = 10 patients, respectively. Results: HVR did not change following TAVI (pre- vs. post-TAVI: 0.42 ± 0.29 vs. 0.39 ± 0.33 L/min/SpO2%, p = 0.523). The HR slope increased after TAVI (pre- vs. post-TAVI: 0.26 ± 0.23 vs. 0.37 ± 0.30 bpm/SpO2%, p = 0.019), and the magnitude of the increase was strongly associated with an increase in AVA (Spearman's R = 0.80, p = 0.006). No other significant relations between pre- vs. post-TAVI changes in PCh activity measures vs. hemodynamic parameters were found (all p > 0.12). Conclusions: The ventilatory component of the PCh reflex (defined as HVR) in severe AS patients is not affected by TAVI, and pre-TAVI values in this group are fairly comparable to those reported previously for healthy subjects. On the contrary, HR responses to hypoxia are increased after TAVI, and pre-TAVI values appear to be lower compared to the healthy population. An extraordinarily strong correlation between post-TAVI increases in HR slope and AVA may suggest that hemodynamic repercussions of the surgery in the aortic body area (most likely reduced WSS) play a critical role in determining aortic body function with a negligible effect on the carotid bodies. However, caution is needed when interpreting the results of the HR response to hypoxia in our study due to the small sample size (N = 10).

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.

Eight-Year Outcomes of Patients With Reduced Left Ventricular Ejection Fraction Who Underwent Transcatheter Aortic Valve Replacement With a Self-Expanding Bioprosthesis

Data deriving from patients who underwent TAVR between 2007 and 2017 in 13 Italian centers were prospectively collected. Patients were stratified in those with normal LVEF and reduced LVEF. The latter was further classified according to ischemic or nonischemic etiology. The primary end point was a composite of all-cause death and rehospitalizations; the secondary end points were the isolated composers of the primary end point and cardiac death. Overall, 2,626 patients were included in the analysis: 68.1% with normal LVEF and 31.9% with reduced LVEF. At 8 years, reduced LVEF was significantly associated with the primary end point (adjusted hazard ratio 1.17, 95% confidence interval 1.06 to 1.29). Consistent findings were evident for the composite end point. No differences in these trends were found at the 30-day landmark analyses. Compared with nonischemic etiology, ischemic reduced LVEF was associated with an increased risk of cardiac death (adjusted hazard ratio 1.43, 95% confidence interval 1.02 to 2.02). In conclusion, patients with reduced LVEF who underwent TAVR are exposed to a progressively increased risk of death and rehospitalizations, even at very long-term follow-up.

Prevalence and Prognostic Significance of Right Ventricular Dysfunction in Patients With Severe Low-Flow, Low-Gradient Aortic Stenosis Undergoing Transcatheter Aortic Valve Replacement

BACKGROUND

Whether the presence of right ventricular (RV) dysfunction may influence the clinical outcome of patients with low-flow, low-gradient aortic stenosis (LFLG-AS) undergoing transcatheter aortic valve replacement (TAVR) has not yet been established.

METHODS AND RESULTS

This study included consecutive patients with LFLG-AS undergoing TAVR at 2 high-volume Italian centers. RV dysfunction before TAVR procedure was defined as tricuspid annular plane systolic excursion assessed by transthoracic echocardiography lower than <17 mm. The primary outcome was all-cause death at 1 year. The propensity score weighting technique was implemented to account for potential selection bias between patients with and without RV dysfunction. A prespecified subgroup analysis was conducted to evaluate the consistency of the results in patients with classical and paradoxical LFLG-AS forms. This study included 392 patients; of them, 97 (24.7%) patients showed RV dysfunction before TAVR. At propensity score-weighted adjusted Cox regression analysis, RV dysfunction, according to dichotomous definition, was associated with an increased risk for the primary outcome (adjusted hazard ratio [HR], 3.11 [95% CI, 1.58-6.13]), cardiovascular death (adjusted HR, 3.26 [95% CI, 1.58-6.72]), and major adverse cardiovascular and cerebrovascular events (adjusted HR, 3.39 [95% CI, 1.76-6.53]). Conversely, no difference was detected for the risk of stroke and of permanent pacemaker implantation. No significant interaction of the classical and paradoxical LFLG-AS subgroups was detected for all the outcomes of interest.

CONCLUSIONS

This study suggests that RV dysfunction echocardiographically assessed by tricuspid annular plane systolic excursion may improve the prognostic stratification of patients with LFLG-AS undergoing TAVR.

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.

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.

Changes and Prognostic Implications of Myocardial Work in Aortic Stenosis Subtypes Undergoing Transcatheter Valve Implantation

Background

Evaluation of left ventricle (LV) systolic function in patients with aortic stenosis (AS) undergoing transcatheter aortic valve implantation (TAVI) is challenging, as LV ejection fraction (LVEF) and global longitudinal strain are afterload dependent. LV global work indices (GWIs) estimate the afterload corrected systolic function.

Objectives

The purpose of this study was to evaluate changes in and prognostic implications of GWIs in subtypes of AS patients before and 1 month after TAVI.

Methods

We included 473 patients undergoing TAVI. GWI was estimated using strain imaging and by adding the aortic valve mean gradient to the systolic blood pressure. The primary endpoint was all-cause mortality, evaluated by Cox proportional hazards and Kaplan-Meier curves.

Results

High gradient, low flow/low gradient, and normal flow/low gradient AS was found in 48%, 27%, and 25%. In patients with LVEF ≥50% delta GWI decreased from preoperative assessment to 1-month follow-up across all subtypes; high gradient (-353 ± 589 mm Hg%, P < 0.01), low flow/low gradient (-151 ± 652 mm Hg%, P = 0.13), and normal flow/low gradient (-348 ± 606 mm Hg%, P < 0.01). For patients with LVEF <50% delta GWI increased; high gradient 127 ± 491 mm Hg%, P = 0.05; low flow/low gradient 106 ± 510 mm Hg%, P = 0.06; normal flow/low gradient 107 ± 550 mm Hg%, P < 0.27. The median follow-up time was 60 months (IQR: 45-69 months). Each step of 100 mm Hg% higher GWI at pre-TAVI assessment was associated with a reduction in all-cause mortality in multivariable analysis (HR: 0.96 [95% CI: 0.92-1.00], P = 0.033).

Conclusions

GWI increases in patients with reduced LVEF after TAVI across AS subtypes whereas GWI decreases in patients with preserved LVEF. Assessment of GWI offers additional prognostic implications beyond LVEF and global longitudinal strain.

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.

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.

Predictors of outcome in patients with moderate mixed aortic valve disease

OBJECTIVES

Grading the severity of moderate mixed aortic stenosis and regurgitation (MAVD) is challenging and the disease poorly understood. Identifying markers of haemodynamic severity will improve risk stratification and potentially guide timely treatment. This study aims to identify prognostic haemodynamic markers in patients with moderate MAVD.

METHODS

Moderate MAVD was defined as coexisting moderate aortic stenosis (aortic valve area (AVA) 1.0-1.5 cm2) and moderate aortic regurgitation (vena contracta (VC) 0.3-0.6 cm). Consecutive patients diagnosed between 2015 and 2019 were included from a multicentre registry. The primary composite outcome of death or heart failure hospitalisation was evaluated among these patients. Demographics, comorbidities, echocardiography and treatment data were assessed for their prognostic significance.

RESULTS

207 patients with moderate MAVD were included, aged 78 (66-84) years, 56% male sex, AVA 1.2 (1.1-1.4) cm2 and VC 0.4 (0.4-0.5) cm. Over a follow-up of 3.5 (2.5-4.7) years, the composite outcome was met in 89 patients (43%). Univariable associations with the primary outcome included older age, previous myocardial infarction, previous cerebrovascular event, atrial fibrillation, New York Heart Association >2, worse renal function, tricuspid regurgitation ≥2 and mitral regurgitation ≥2. Markers of biventricular systolic function, cardiac remodelling and transaortic valve haemodynamics demonstrated an inverse association with the primary composite outcome. In multivariable analysis, peak aortic jet velocity (Vmax) was independently and inversely associated with the composite outcome (HR: 0.63, 95% CI 0.43 to 0.93; p=0.021) in an adjusted model along with age (HR: 1.05, 95% CI 1.03 to 1.08; p<0.001), creatinine (HR: 1.002, 95% CI 1.001 to 1.003; p=0.005), previous cerebrovascular event (85% vs 42%; HR: 3.04, 95% CI 1.54 to 5.99; p=0.001) and left ventricular ejection fraction (LVEF) (HR: 0.97, 95% CI 0.95 to 0.99; p=0.007). Patients with Vmax ≤2.8 m/s and LVEF ≤50% (n=27) had the worst outcome compared with the rest of the population (72% vs 41%; HR: 3.87, 95% CI 2.20 to 6.80; p<0.001).

CONCLUSIONS

Patients with truly moderate MAVD have a high incidence of death and heart failure hospitalisation (43% at 3.5 (2.5-4.7) years). Within this group, a high-risk group characterised by disproportionately low aortic Vmax (≤2.8 m/s) and adverse remodelling (LVEF ≤50%) have the worst outcomes.

Italian Association of Hospital Cardiologists Position Paper 'Gender discrepancy: time to implement gender-based clinical management'

It has been well assessed that women have been widely under-represented in cardiovascular clinical trials. Moreover, a significant discrepancy in pharmacological and interventional strategies has been reported. Therefore, poor outcomes and more significant mortality have been shown in many diseases. Pharmacokinetic and pharmacodynamic differences in drug metabolism have also been described so that effectiveness could be different according to sex. However, awareness about the gender gap remains too scarce. Consequently, gender-specific guidelines are lacking, and the need for a sex-specific approach has become more evident in the last few years. This paper aims to evaluate different therapeutic approaches to managing the most common women's diseases.

Diastolic dysfunction and clinical outcomes after transcatheter or surgical aortic valve replacement in patients with atypical aortic valve stenosis

BACKGROUND

Diastolic dysfunction is a predictor of poor outcomes in many cardiovascular conditions. At present, it is unclear whether diastolic dysfunction predicts adverse outcomes in patients with atypical aortic stenosis who undergo aortic valve replacement (AVR).

METHODS

Five hundred and twenty-three patients who underwent transcatheter AVR (TAVR) (n = 303) and surgical AVR (SAVR) (n = 220) at a single institution were included in our analysis. Baseline left and right heart invasive hemodynamics were assessed. Baseline transthoracic echocardiograms were reviewed to determine aortic stenosis subtype and parameters of diastolic dysfunction. Aortic stenosis subtype was categorized as typical (normal flow, high-gradient) aortic stenosis, classical, low-flow, low-gradient (cLFLG) aortic stenosis, and paradoxical, low-flow, low-gradient (pLFLG) aortic stenosis. Cox proportional hazard models were utilized to examine the relation between invasive hemodynamic or echocardiographic variables of diastolic dysfunction, aortic stenosis subtype, and all-cause mortality. Propensity-score analysis was performed to study the relation between aortic stenosis subtype and the composite outcome [death/cerebrovascular accident (CVA)].

RESULTS

The median STS risk was 5.3 and 2.5% for TAVR and SAVR patients, respectively. Relative to patients with typical aortic stenosis, patients with atypical (cLFLG and pLFLG) aortic stenosis displayed a significantly higher prevalence of diastolic dysfunction (LVEDP ≥ 20mmHg, PCWP ≥ 20mmHg, echo grade II or III diastolic dysfunction, and echo-PCWP ≥ 20mmHg) and, independently of AVR treatment modality, had a significantly increased risk of death. In propensity-score analysis, patients with atypical aortic stenosis had higher rates of death/CVA than typical aortic stenosis patients, independently of diastolic dysfunction and AVR treatment modality.

CONCLUSION

We demonstrate the novel observation that compared with patients with typical aortic stenosis, patients with atypical aortic stenosis have a higher burden of diastolic dysfunction. We corroborate the worse outcomes previously reported in atypical versus typical aortic stenosis and demonstrate, for the first time, that this observation is independent of AVR treatment modality. Furthermore, the presence of diastolic dysfunction does not independently predict outcome in atypical aortic stenosis regardless of treatment type, suggesting that other factors are responsible for adverse clinical outcomes in this higher risk cohort.

Carotid Duplex Ultrasonography to Assess Severity of Low-Flow Low-Gradient Aortic Stenosis

BACKGROUND

Patients with low-flow, low-gradient aortic valve stenosis constitute a substantial subset of all severe aortic stenosis patients. However, assessment of true severity of these patients can be challenging. In this analysis, we study the utility of the common carotid artery waveforms to distinguish true from pseudo-severe low-flow low-gradient aortic stenosis.

METHODS

This is an observational analysis that included patients who underwent a transthoracic echocardiogram (TTE) and duplex carotid ultrasonography (DCUS) and had low-flow, low-gradient aortic stenosis with reduced left ventricular ejection fraction (LVEF) on the index TTE (LVEF <50%, calculated aortic valve area [AVA] of ≤1.0 cm2, mean and peak gradient of <40 and <64 mm Hg, respectively, and stroke volume index <35 mL/m2). Patients were classified as pseudo-severe and true-severe aortic stenosis based on additional subsequent testing. Differences in various TTE and DCUS waveform parameters across the aortic valve and the common carotid artery were compared between the 2 groups.

RESULTS

The study included 30 patients (60 carotid arteries). Fifteen patients were categorized as pseudo-severe and 15 as true severe aortic stenosis. There were no significant differences in calculated AVA, LVEF, stroke volume/stroke volume index, and Doppler Velocity Index in the 2 groups. Mean and peak gradient were higher in patients with true-severe aortic stenosis. Carotid acceleration time (cAT) was significantly prolonged in patients with true-severe compared with pseudo-severe aortic stenosis. A cAT ≥80 ms was 83.3% sensitive and 83.3% specific for true-severe aortic stenosis.

CONCLUSION

cAT acceleration time may be used to distinguish true from pseudo-severe low-flow, low-gradient aortic valve stenosis.

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.

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.

Prognostic value of flow-status in severe aortic stenosis patients undergoing percutaneous intervention

PURPOSE

Low-flow status is a mortality predictor in severe aortic stenosis (SAS) patients, including after transcatheter aortic valve implantation (TAVI) treatment. However, the best parameter to assess flow is unknown. Recent studies suggest that transaortic flow rate (FR) is superior to currently used stroke volume index (SVi) in defining low-flow states. Therefore, we aimed to evaluate the prognostic value of FR and SVi in patients undergoing TAVI.

METHODS

A single-centre retrospective analysis of all consecutive patients treated with TAVI for SAS between 2011 and 2019 was conducted. Low-FR was defined as < 200 mL/s and low-SVi as < 35 mL/m2. Primary endpoint was all-cause five-year mortality, analyzed using Kaplan-Meier curves and Cox regression models. Secondary endpoint was variation of NYHA functional class six months after procedure. Patients were further stratified according to ejection fraction (EF < 50%).

RESULTS

Of 489 cases, 59.5% were low-FR, and 43.1% low-SVi. Low-flow patients had superior surgical risk, worse renal function, and had a higher prevalence of coronary artery disease. Low-FR was associated with mortality (hazard ratio 1.36, p = 0.041), but not after adjustment to EuroSCORE II. Normal-SVi was not associated with survival, despite a significative p-trend for its continuous value. No associations were found for flow-status and NYHA recovery. When stratifying according to preserved and reduced EF, both FR and SVi did not predict all-cause mortality.

CONCLUSION

In patients with SAS undergoing TAVI, a low-FR state was associated with higher mortality, as well as SVi, but not at a 35 mL/m2 cut off.

Valvular Heart Disease in the Cardiac Intensive Care Unit

Valvular heart disease pathologies are commonly encountered in the cardiac intensive care unit (CICU). Clinical presentations may range from an acute pathology of the aortic or mitral valve necessitating emergency intervention to a more subtle decompensation of longstanding valvular disease. With growing numbers of transcatheter valvular interventions, CICU providers must recognize and manage common complications after transcatheter aortic, mitral, and tricuspid interventions. In addition, prosthetic valve dysfunction should always be excluded in a CICU patient presenting with an acute cardiopulmonary decompensation. Multidisciplinary valve teams can assist with challenging valvular pathologies to determine candidacy for potential interventions.

Prognostic Impact of Mitral Regurgitation Before and After Transcatheter Aortic Valve Replacement in Patients With Severe Low-Flow, Low-Gradient Aortic Stenosis

Background There is little evidence about the prognostic role of mitral regurgitation (MR) in patients with low-flow, low-gradient aortic stenosis undergoing transcatheter aortic valve replacement (TAVR). The aim of this study was to assess the prevalence and outcome implications of MR severity in patients with low-flow, low-gradient aortic stenosis undergoing TAVR, and to evaluate whether MR improvement after TAVR could influence clinical outcome. Methods and Results This study included consecutive patients with low-flow, low-gradient aortic stenosis undergoing TAVR at 2 Italian high-volume centers. The study population was categorized according to the baseline MR severity and to the presence of MR improvement at discharge. The primary outcome was the composite of all-cause death and hospitalization for worsening heart failure up to 1 year. The study included 268 patients; 57 (21%) patients showed MR >2+. Patients with MR >2+ showed a lower 1-year survival free from the primary outcome (P<0.001), all-cause death (P<0.001), and heart failure hospitalization (P<0.001) compared with patients with MR ≤2+. At multivariable analysis, baseline MR >2+ was an independent predictor of the primary outcome (P<0.001). Among patients with baseline MR >2+, MR improvement was reported in 24 (44%) cases after TAVR. The persistence of MR was associated with a significantly reduced survival free from the primary outcome, all-cause death, and heart failure hospitalization up to 1 year. Conclusions In this study, the presence of moderately severe to severe MR in patients with low-flow, low-gradient aortic stenosis undergoing TAVR portends a worse clinical outcome at 1 year. TAVR may improve MR severity in nearly half of the patients, resulting in a potential outcome benefit after discharge.

Asymptomatic Severe and Moderate Aortic Stenosis: Time for Appraisal of Treatment Indications

Over the last decades, we have witnessed considerable improvements in diagnostics and risk stratification of patients with significant aortic stenosis (AS), paralleled by advances in operative and anesthetic techniques. In addition, accumulating evidence points to the potential benefit of early valve replacement in such patients prior to the onset of symptoms. In parallel, interventional randomized trials have proven the benefit of transcatheter aortic valve replacement in comparison to a surgical approach to valve replacement over a broad risk spectrum in symptomatic patients with AS. This article reviews contemporary management approaches and scrutinizes open questions regarding timing and mode of intervention in asymptomatic patients with severe AS. We also discuss the challenges surrounding the management of symptomatic patients with moderate AS as well as emerging dilemmas related to the concept of a life-long treatment strategy for patients with AS.

Pitfalls and Tips in the Assessment of Aortic Stenosis by Transthoracic Echocardiography

Aortic stenosis (AS) is a valvular heart disease that significantly contributes to cardiovascular morbidity and mortality worldwide. The condition is characterized by calcification and thickening of the aortic valve leaflets, resulting in a narrowed orifice and increased pressure gradient across the valve. AS typically progresses from a subclinical phase known as aortic sclerosis, where valve calcification occurs without a transvalvular gradient, to a more advanced stage marked by a triad of symptoms: heart failure, syncope, and angina. Echocardiography plays a crucial role in the diagnosis and evaluation of AS, serving as the primary non-invasive imaging modality. However, to minimize misdiagnoses, it is crucial to adhere to a standardized protocol for acquiring echocardiographic images. This is because, despite continuous advances in echocardiographic technology, diagnostic errors still occur during the evaluation of AS, particularly in classifying its severity and hemodynamic characteristics. This review focuses on providing guidance for the imager during the echocardiographic assessment of AS. Firstly, the review will report on how the echo machine should be set to improve image quality and reduce noise and artifacts. Thereafter, the review will report specific emphasis on accurate measurements of left ventricular outflow tract diameter, aortic valve morphology and movement, as well as aortic and left ventricular outflow tract velocities. By considering these key factors, clinicians can ensure consistency and accuracy in the evaluation of AS using echocardiography.

Risk prediction in patients with classical low-flow, low-gradient aortic stenosis undergoing surgical intervention

Introduction

Classical low-flow, low-gradient aortic stenosis (LFLG-AS) is an advanced stage of aortic stenosis, which has a poor prognosis with medical treatment and a high operative mortality after surgical aortic valve replacement (SAVR). There is currently a paucity of information regarding the current prognosis of classical LFLG-AS patients undergoing SAVR and the lack of a reliable risk assessment tool for this particular subset of AS patients. The present study aims to assess mortality predictors in a population of classical LFLG-AS patients undergoing SAVR.

Methods

This is a prospective study including 41 consecutive classical LFLG-AS patients (aortic valve area ≤1.0 cm2, mean transaortic gradient <40 mmHg, left ventricular ejection fraction <50%). All patients underwent dobutamine stress echocardiography (DSE), 3D echocardiography, and T1 mapping cardiac magnetic resonance (CMR). Patients with pseudo-severe aortic stenosis were excluded. Patients were divided into groups according to the median value of the mean transaortic gradient (≤25 and >25 mmHg). All-cause, intraprocedural, 30-day, and 1-year mortality rates were evaluated.

Results

All of the patients had degenerative aortic stenosis, with a median age of 66 (60-73) years; most of the patients were men (83%). The median EuroSCORE II was 2.19% (1.5%-4.78%), and the median STS was 2.19% (1.6%-3.99%). On DSE, 73.2% had flow reserve (FR), i.e., an increase in stroke volume ≥20% during DSE, with no significant differences between groups. On CMR, late gadolinium enhancement mass was lower in the group with mean transaortic gradient >25 mmHg [2.0 (0.0-8.9) g vs. 8.5 (2.3-15.0) g; p = 0.034), and myocardium extracellular volume (ECV) and indexed ECV were similar between groups. The 30-day and 1-year mortality rates were 14.6% and 43.8%, respectively. The median follow-up was 4.1 (0.3-5.1) years. By multivariate analysis adjusted for FR, only the mean transaortic gradient was an independent predictor of mortality (hazard ratio: 0.923, 95% confidence interval: 0.864-0.986, p = 0.019). A mean transaortic gradient ≤25 mmHg was associated with higher all-cause mortality rates (log-rank p = 0.038), while there was no difference in mortality regarding FR status (log-rank p = 0.114).

Conclusions

In patients with classical LFLG-AS undergoing SAVR, the mean transaortic gradient was the only independent mortality predictor in patients with LFLG-AS, especially if ≤25 mmHg. The absence of left ventricular FR had no prognostic impact on long-term outcomes.

Clinical Outcomes in High-Gradient, Classical Low-Flow, Low-Gradient, and Paradoxical Low-Flow, Low-Gradient Aortic Stenosis After Transcatheter Aortic Valve Implantation: A Report From the SwissTAVI Registry

Background In view of the rising global burden of severe symptomatic aortic stenosis, its early recognition and treatment is key. Although patients with classical low-flow, low-gradient (C-LFLG) aortic stenosis have higher rates of death after transcatheter aortic valve implantation (TAVI) when compared with patients with high-gradient (HG) aortic stenosis, there is conflicting evidence on the death rate in patients with severe paradoxical low-flow, low-gradient (P-LFLG) aortic stenosis. Therefore, we aimed to compare outcomes in real-world patients with severe HG, C-LFLG, and P-LFLG aortic stenosis undergoing TAVI. Methods and Results Clinical outcomes up to 5 years were addressed in the 3 groups of patients enrolled in the prospective, national, multicenter SwissTAVI registry. A total of 8914 patients undergoing TAVI at 15 heart valve centers in Switzerland were analyzed for the purpose of this study. We observed a significant difference in time to death at 1 year after TAVI, with the lowest observed in HG (8.8%) aortic stenosis, followed by P-LFLG (11.5%; hazard ratio [HR], 1.35 [95% CI, 1.16-1.56]; P<0.001) and C-LFLG (19.8%; HR, 1.93 [95% CI, 1.64-2.26]; P<0.001) aortic stenosis. Cardiovascular death showed similar differences between the groups. At 5 years, the all-cause death rate was 44.4% in HG, 52.1% in P-LFLG (HR, 1.35 [95% CI, 1.23-1.48]; P<0.001), and 62.8% in C-LFLG aortic stenosis (HR, 1.7 [95% CI, 1.54-1.88]; P<0.001). Conclusions Up to 5 years after TAVI, patients with P-LFLG have higher death rates than patients with HG aortic stenosis but lower death rates than patients with C-LFLG aortic stenosis.

ESC/EACTS vs. ACC/AHA guidelines for the management of severe aortic stenosis

Aortic stenosis (AS) is a serious and complex condition, for which optimal management continues to evolve rapidly. An understanding of current clinical practice guidelines is critical to effective patient care and shared decision-making. This state of the art review of the 2021 European Society of Cardiology/European Association for Cardio-Thoracic Surgery Guidelines and 2020 American College of Cardiology/American Heart Association Guidelines compares their recommendations for AS based on the evidence to date. The European and American guidelines were generally congruent with the exception of three key distinctions. First, the European guidelines recommend intervening at a left ventricular ejection fraction of 55%, compared with 60% over serial imaging by the American guidelines for asymptomatic patients. Second, the European guidelines recommend a threshold of ≥65 years for surgical bioprosthesis, whereas the American guidelines employ multiple age categories, providing latitude for patient factors and preferences. Third, the guidelines endorse different age cut-offs for transcatheter vs. surgical aortic valve replacement, despite limited evidence. This review also discusses trends indicating a decreasing proportion of mechanical valve replacements. Finally, the review identifies gaps in the literature for areas including transcatheter aortic valve implantation in asymptomatic patients, the appropriateness of Ross procedures, concomitant coronary revascularization with aortic valve replacement, and bicuspid AS. To summarize, this state of the art review compares the latest European and American guidelines on the management of AS to highlight three areas of divergence: timing of intervention, valve selection, and surgical vs. transcatheter aortic valve replacement criteria.

Evidence for a sigmoidal flow-to-valve opening relation in low-flow low-gradient aortic stenosis

We analyzed the relationship between flow (Q) and aortic valve opening area (AVA) using a sequence of echocardiographic stress tests of increasing strength. Low-dose dobutamine stress echocardiography (DSE) has been used to differentiate pseudo-severe from true severe aortic stenoses. Because the Q-response to DSE is so variable between individuals, AVA has been projected to a standardized flow (AVA_proj) using linear interpolation. A linear Q-to-AVA relation implies that AVA shows an unconstrained increase. We applied three stress maneuvers of increasing strength to investigate whether AVA shows signs of saturation. We performed an echocardiographic examination at rest, during the passive leg raise maneuver ("PLR"), maximal dobutamine infusion ("Dmax"), and their combination ("Dmax + PLR") in 45 patients with severe low-flow, low-gradient aortic stenosis. We analyzed the effect of the stress maneuver on Q, AVA, valve compliance (VC), and AVA_proj. We also compared the proportion of patients with nonconclusive test (ΔQ < 20%) between stress maneuvers. We computed the Akaike information criterion (AIC) to compare a linear with a saturating function for the Q-AVA relation. Q gradually increased from "PLR" to "Dmax" to "Dmax + PLR" (P < 0.0001), whereas the number of nonconclusive tests concomitantly diminished from n = 35 to n = 3. The stress sequence increased AVA (P < 0.001) but decreased AVA_proj (P = 0.006) and VC (P = 0.005). In the pooled Q-AVA data, the AIC value was lower for the saturating (sigmoidal) model compared with the linear model fitting (-1,593 vs. -1,504). "Dmax + PLR" is capable of reducing the number of nonconclusive DSE tests. With increasing stress strength, the Q-AVA relation progressively flattens, indicating saturation.NEW & NOTEWORTHY The relation between transaortic flow (Q) and aortic valve opening area (AVA) shows a saturation when three different stress maneuvers are used to increase Q as much as possible. This has implications for the assessment of aortic stenosis severity.

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.

Comprehensive myocardial characterization using cardiac magnetic resonance associates with outcomes in low gradient severe aortic stenosis

AIMS

This study sought to compare cardiac magnetic resonance (CMR) characteristics according to different flow/gradient patterns of aortic stenosis (AS) and to evaluate their prognostic value in patients with low-gradient AS.

METHODS AND RESULTS

This international prospective multicentric study included 147 patients with low-gradient moderate to severe AS who underwent comprehensive CMR evaluation of left ventricular global longitudinal strain (LVGLS), extracellular volume fraction (ECV), and late gadolinium enhancement (LGE). All patients were classified as followings: classical low-flow low-gradient (LFLG) [mean gradient (MG) < 40 mmHg and left ventricular ejection fraction (LVEF) < 50%]; paradoxical LFLG [MG < 40 mmHg, LVEF ≥ 50%, and stroke volume index (SVi) < 35 ml/m2]; and normal-flow low-gradient (MG < 40 mmHg, LVEF ≥ 50%, and SVi ≥ 35 ml/m2). Patients with classical LFLG (n = 90) had more LV adverse remodelling including higher ECV, and higher LGE and volume, and worst LVGLS. Over a median follow-up of 2 years, 43 deaths and 48 composite outcomes of death or heart failure hospitalizations occurred. Risks of adverse events increased per tertile of LVGLS: hazard ratio (HR) = 1.50 [95% CI, 1.02-2.20]; P = 0.04 for mortality; HR = 1.45 [1.01-2.09]; P < 0.05 for composite outcome; per tertile of ECV, HR = 1.63 [1.07-2.49]; P = 0.02 for mortality; HR = 1.54 [1.02-2.33]; P = 0.04 for composite outcome. LGE presence also associated with higher mortality, HR = 2.27 [1.01-5.11]; P < 0.05 and composite outcome, HR = 3.00 [1.16-7.73]; P = 0.02. The risk of mortality and the composite outcome increased in proportion to the number of impaired components (i.e. LVGLS, ECV, and LGE) with multivariate adjustment.

CONCLUSIONS

In this international prospective multicentric study of low-gradient AS, comprehensive CMR assessment provides independent prognostic value that is cumulative and incremental to clinical and echocardiographic characteristics.

Long-term prognostic impact of paravalvular leakage on coronary artery disease requires patient-specific quantification of hemodynamics

Transcatheter aortic valve replacement (TAVR) is a frequently used minimally invasive intervention for patient with aortic stenosis across a broad risk spectrum. While coronary artery disease (CAD) is present in approximately half of TAVR candidates, correlation of post-TAVR complications such as paravalvular leakage (PVL) or misalignment with CAD are not fully understood. For this purpose, we developed a multiscale computational framework based on a patient-specific lumped-parameter algorithm and a 3-D strongly-coupled fluid-structure interaction model to quantify metrics of global circulatory function, metrics of global cardiac function and local cardiac fluid dynamics in 6 patients. Based on our findings, PVL limits the benefits of TAVR and restricts coronary perfusion due to the lack of sufficient coronary blood flow during diastole phase (e.g., maximum coronary flow rate reduced by 21.73%, 21.43% and 21.43% in the left anterior descending (LAD), left circumflex (LCX) and right coronary artery (RCA) respectively (N = 6)). Moreover, PVL may increase the LV load (e.g., LV load increased by 17.57% (N = 6)) and decrease the coronary wall shear stress (e.g., maximum wall shear stress reduced by 20.62%, 21.92%, 22.28% and 25.66% in the left main coronary artery (LMCA), left anterior descending (LAD), left circumflex (LCX) and right coronary artery (RCA) respectively (N = 6)), which could promote atherosclerosis development through loss of the physiological flow-oriented alignment of endothelial cells. This study demonstrated that a rigorously developed personalized image-based computational framework can provide vital insights into underlying mechanics of TAVR and CAD interactions and assist in treatment planning and patient risk stratification in patients.

Incidence, Outcomes, and Risk Factors for Preincision Cardiac Arrest in Cardiac Surgery Patients

BACKGROUND

We examined the incidence, postoperative outcomes, and patient-related factors associated with preincision cardiac arrest in patients undergoing cardiac surgery.

METHODS

We retrospectively examined adult patients undergoing elective or urgent cardiac surgery at the Cleveland Clinic between 2008 and 2019. The incidence of preincision cardiac arrest, defined as arrest between induction of general anesthesia and surgical incision, was reported. In a secondary analysis, we assessed the association between preincision cardiac arrest and major postoperative outcomes. In a tertiary analysis, we used adjusted linear regression models to explore the association between preincision cardiac arrest and prespecified patient risk factors, including severe left main coronary artery stenosis, left ventricular ejection fraction, moderate/severe right ventricular dysfunction, low-flow low-gradient aortic stenosis, and moderate/severe pulmonary hypertension.

RESULTS

Preincision cardiac arrests occurred in 75 of 41,238 (incidence of 0.18%; 95% CI, 0.17-0.26) patients who had elective or urgent cardiac surgery. Successful cardiopulmonary resuscitation with return of spontaneous circulation or bridge to cardiopulmonary bypass occurred in 74 of 75 (98.6%) patients. Patients who experienced preincision cardiac arrest had significantly higher in-hospital mortality than those who did not (11% vs 2%; odds ratio [OR] (95% CI), 4.14 (1.94-8.84); P < .001). They were also more likely to suffer postoperative respiratory failure (46% vs 13%; OR [95% CI], 3.94 [2.40-6.47]; P < .001), requirement for renal replacement therapy (11% vs 2%; OR [95% CI], 3.90 [1.82-8.35]; P < .001), neurologic deficit (7% vs 2%; OR [95% CI], 2.49 (1.00-6.21); P = .05), and longer median hospital stay (15 vs 8 days; hazard ratio (HR) [95% CI], 0.68 [0.55-0.85]; P < .001). Reduced left ventricular ejection fraction (per 5% decrease) (OR [95% CI], 1.13 [1.03-1.22]; P = .006) and moderate/severe pulmonary hypertension (OR [95% CI], 3.40 [1.95-5.90]; P < .001) were identified as independent risk factors for cardiac arrest.

CONCLUSIONS

Cardiac arrest after anesthetic induction is rare in cardiac surgical patients in our investigation. Though most patients are rescued, morbidity and mortality remain higher. Reduced left ventricular ejection fraction and moderate/severe pulmonary hypertension are associated with greater risk for preincision cardiac arrest.

Sex-Specific Considerations in Degenerative Aortic Stenosis for Female-Tailored Transfemoral Aortic Valve Implantation Management

The impact of sex on pathophysiological processes, clinical presentation, treatment options, as well as outcomes of degenerative aortic stenosis remain poorly understood. Female patients are well represented in transfemoral aortic valve implantation (TAVI) trials and appear to derive favorable outcomes with TAVI. However, higher incidences of major bleeding, vascular complications, and stroke have been reported in women following TAVI. The anatomical characteristics and pathophysiological features of aortic stenosis in women might guide a tailored planning of the percutaneous approach. We highlight whether a sex-based TAVI management strategy might impact on clinical outcomes. This review aimed to evaluate the impact of sex from diagnosis to treatment of degenerative aortic stenosis, discussing the latest evidence on epidemiology, pathophysiology, clinical presentation, therapeutic options, and outcomes. Furthermore, we focused on technical sex-oriented considerations in TAVI including the preprocedural screening, device selection, implantation strategy, and postprocedural management.

Acute Decompensated Aortic Stenosis: State of the Art Review

Aortic stenosis (AS) is a progressive disease that carries a poor prognosis. Patients are managed conservatively until satisfying an indication for transcatheter aortic valve implantation (TAVI) or surgical aortic valve replacement (SAVR) based on AS severity and the presence of symptoms or adverse impact on the myocardium. Up to 1 in 3 TAVIs are performed for patients with acute symptoms of dyspnoea at rest, angina, and/or syncope - termed acute decompensated aortic stenosis (ADAS) and require urgent aortic valve replacement. These patients have longer hospital length of stay, undergo physical deconditioning, have a higher rate of acute kidney injury and mortality compared to stable patients with less severe symptoms. There is an urgent need to prevent ADAS and to deliver pathways to manage and improve ADAS-related outcomes. We provide here a contemporary review on epidemiological and pathophysiological aspects of ADAS, with a focus on the impact of ADAS from clinical and economic perspectives. We will offer also a global overview of the available evidence for treatment of ADAS and with priorities suggested for addressing current gaps in the literature and unmet clinical needs to improve outcomes for AS patients.

Echocardiographic Investigation of Low-Flow State in a Hispanic/Latino Population

Objective

To assess the prevalence of low-flow state (LFS) with left ventricular (LV) stroke volume index of less than 35 mL/m² and the demographics, clinical and echocardiographic characteristics associated with LV remodeling and function in a Hispanic/Latino population.

Participants and Methods

The study included 1346 asymptomatic participants from the Hispanic Community Health Study/Study of Latinos with normal LV ejection fraction (≥55%) and no valvular heart disease. LV volume, mass and left atrial volume, LV ejection fraction, global longitudinal strain, and myocardial contraction fraction were measured by echocardiography. The participants were divided into LFS or normal flow state (NFS: stroke volume index ≥35 mL/m²). Demographics, clinical and echocardiographic characteristics, and measures of LV remodeling and function were compared between the LFS and NFS groups.

Results

The prevalence of LFS was 41%. In comparison with NFS, the LFS had lower LV mass index (77.2±0.96 g/m² vs 84.6±0.86 g/m²; P<.001), left atrial volume index (20.6±0.35 mL/m² vs 23.5±0.37 mL/m²; P<.001), global longitudinal strain (−16.8±0.16% vs −17.7±0.17%; P<.001), and myocardial contraction fraction (43.3±0.63% vs 55.7±0.64%; P<.001). There was no significant difference in the relative wall thickness (LFS: 0.40±0.004 vs NFS: 0.40±0.005; P=.57). The LFS group had significantly higher hemoglobin A1c (6.18±0.07% vs 5.97±0.04%; P=.01) than the NFS group.

Conclusion

A high prevalence of LFS associated with echocardiographic characteristics reflecting unfavorable LV remodeling and function was observed in a Hispanic/Latino population. Further studies of the prognostic significance of LFS in a large multiethnic population are warranted.

Patient- and Process-Related Contributors to the Underuse of Aortic Valve Replacement and Subsequent Mortality in Ambulatory Patients With Severe Aortic Stenosis

Background

Many patients with severe aortic stenosis (AS) and an indication for aortic valve replacement (AVR) do not undergo treatment. The reasons for this have not been well studied in the transcatheter AVR era. We sought to determine how patient‐ and process‐specific factors affected AVR use in patients with severe AS.

Methods and Results

We identified ambulatory patients from 2016 to 2018 demonstrating severe AS, defined by aortic valve area ≤1.0 cm². Propensity scoring analysis with inverse probability of treatment weighting was used to evaluate associations between predictors and the odds of undergoing AVR at 365 days and subsequent mortality at 730 days. Of 324 patients with an indication for AVR (79.3±9.7 years, 57.4% men), 140 patients (43.2%) did not undergo AVR. The odds of AVR were reduced in patients aged >90 years (odds ratio [OR], 0.24 [95% CI, 0.08–0.69]; P=0.01), greater comorbid conditions (OR, 0.88 per 1‐point increase in Combined Comorbidity Index [95% CI, 0.79–0.97]; P=0.01), low‐flow, low‐gradient AS with preserved left ventricular ejection fraction (OR, 0.11 [95% CI, 0.06–0.21]), and low‐gradient AS with reduced left ventricular ejection fraction (OR, 0.18 [95% CI, 0.08–0.40]) and were increased if the transthoracic echocardiogram ordering provider was a cardiologist (OR, 2.46 [95% CI, 1.38–4.38]). Patients who underwent AVR gained an average of 85.8 days of life (95% CI, 40.9–130.6) at 730 days.

Conclusions

The proportion of ambulatory patients with severe AS and an indication for AVR who do not receive AVR remains significant. Efforts are needed to maximize the recognition of severe AS, especially low‐gradient subtypes, and to encourage patient referral to multidisciplinary heart valve teams.

Impaired Left Ventricular Circumferential Midwall Systolic Performance Appears Linked to Depressed Preload, but Not Intrinsic Contractile Dysfunction or Excessive Afterload, in Paradoxical Low-Flow/Low-Gradient Severe Aortic Stenosis

Paradoxical low-flow/low-gradient aortic stenosis (P-LFLG-AS) occurs in about one-third of patients with severe AS and preserved left ventricular (LV) ejection fraction (EF). Our aim was to differentiate between altered LV loading conditions and contractility as determinants of subtle LV systolic dysfunction in P-LFLG-AS. We retrospectively analyzed medical records of patients with isolated severe degenerative AS and preserved EF (30 subjects with P-LFLG-AS and 30 patients with normal-flow/high-gradient severe AS (NFHG-AS)), without relevant coexistent diseases (e.g., diabetes, coronary artery disease and chronic kidney disease) or any abnormalities which could account for a low-flow state. Patients with P-LFLG-AS and NFHG-AS did not differ in aortic valve area index and most clinical characteristics. Compared to NFHG-AS, subjects with P-LFLG-AS exhibited smaller LV end-diastolic diameter (LVd) (44 ± 5 vs. 54 ± 5 mm, p < 0.001) (consistent with lower LV preload) with pronounced concentric remodeling, higher valvulo-arterial impedance (3.8 ± 1.1 vs. 2.2 ± 0.5 mmHg per mL/m2, p < 0.001) and diminished systemic arterial compliance (0.45 ± 0.11 vs. 0.76 ± 0.23 mL/m2 per mmHg, p < 0.001), while circumferential end-systolic LV midwall stress (cESS), an estimate of afterload at the LV level, was similar in P-LFLG-AS and NFHG-AS (175 ± 83 vs. 198 ± 69 hPa, p = 0.3). LV midwall fractional shortening (mwFS) was depressed in P-LFLG-AS vs. NFHG-AS (12.3 ± 3.5 vs. 14.7 ± 2.9%, p = 0.006) despite similar EF (61 ± 6 vs. 59 ± 8%, p = 0.4). By multiple regression, the presence of P-LFLG-AS remained a significant predictor of lower mwFS compared to NFHG-AS upon adjustment for cESS (β ± SEM: −2.35 ± 0.67, p < 0.001); however, the significance was lost after further correction for LVd (β = −1.10 ± 0.85, p = 0.21). In conclusion, the association of P-LFLG-AS with a lower cESS-adjusted mwFS, an index of afterload-corrected LV circumferential systolic function at the midwall level, appears secondary to a smaller LV end-diastolic cavity size according to the Frank−Starling law. Thus, low LV preload, not intrinsic contractile dysfunction or excessive afterload, may account for impaired LV circumferential midwall systolic performance in P-LFLG-AS.

Classification of severe aortic stenosis and outcomes after aortic valve replacement

Aortic valve calcium scoring by cardiac computed tomographic (CT) has been recommended as an alternative to classify the AS (aortic stenosis) severity, but it is unclear that whether CT findings would have additional value to discriminate significant AS subtypes including high gradient severe AS, classic low-flow, low gradient (LF-LG) AS, paradoxical LF-LG AS, and moderate AS. In this study, we examined the preoperative clinical and cardiac CT findings of different subtypes of AS in patients with surgical aortic valve replacement (AVR) and evaluated the subtype classification as a factor affecting post-surgical outcomes. This study included 511 (66.9 ± 8.8 years, 55% men) consecutive patients with severe AS who underwent surgical AVR. Aortic valve area (AVA) was obtained by echocardiography (AVAecho) and by CT (AVACT) using each modalities measurement of the left ventricular outflow tract. Patients with AS were classified as (1) high-gradient severe (n = 438), (2) classic LF-LG (n = 18), and (3) paradoxical LF-LG (n = 55) based on echocardiography. In all patients, 455 (89.0%) patients were categorized as severe AS according to the AVACT. However, 56 patients were re-classified as moderate AS (43 [9.8%] high-gradient severe AS, 5 [27.8%] classic LF-LG AS, and 8 [14.5%] paradoxical LF-LG AS) by AVACT. The classic LF-LG AS group presented larger AVACT and aortic annulus than those in high-gradient severe AS group and one third of them had AVACT ≥ 1.2 cm2. After multivariable adjustment, old age (hazard ratio [HR], 1.04, P = 0.049), high B-type natriuretic peptide (BNP) (HR, 1.005; P < 0.001), preoperative atrial fibrillation (HR, 2.75; P = 0.003), classic LF-LG AS (HR, 5.53, P = 0.004), and small aortic annulus on CT (HR, 0.57; P = 0.002) were independently associated with major adverse cardiac and cerebrovascular events (MACCE) after surgical AVR.

Novel Application of Milrinone in the Evaluation of Classical Low-Flow, Low-Gradient Aortic Stenosis

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Classical LFLG AS should be classified as either true-severe or pseudosevere AS.

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DSE is the recognized imaging modality for making this distinction.

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Milrinone at steady state may be considered in classical LFLG AS evaluation.

Surgical aortic valve replacement for low-gradient aortic stenosis

AIMS

Low-gradient aortic stenosis is a challenging entity that needs accurate preoperative evaluation. For this high-risk patient population, ad hoc predictive scores are not available and profile risk is currently revealed by the EuroSCOREs. Aims of this study are to verify the suitability of the ES II as predictor of mortality in low-gradient aortic stenosis and to analyse the role of surgery as a treatment.

METHODS

From June 2013 to August 2019, 414 patients underwent surgical aortic valve replacement for low-gradient aortic stenosis. Mean age was 75.78 ± 6.77 years and 190 were women. The prognostic value of Logistic EuroSCORE and EuroSCORE II were compared by receiver-operating characteristics (ROC) curve analysis.

RESULTS

In-hospital, 30-day and 1-year mortality rates were respectively 3.4, 2.9 and 4.8% (14, 12 and 20 patients over 414). In-hospital mortality risk calculated by the Additive EuroSCORE was 7.2 ± 2.7%, by the Logistic EuroSCORE was 9 ± 5.2% and by the ES II was 4.13 ± 2.56%. The prognostic values of the EuroSCORE II and of the EuroSCORE were analysed in a ROC curve analysis for the prediction of in-hospital mortality [area under the curve (AUC): 0.62 vs. 0.58], 30-day mortality (AUC: 0.63 vs. 0.64) and 1-year mortality (AUC: 0.79 vs. 0.65). Both scores did not show significant differences with the only exception of 1-year mortality, for which EuroSCORE II had a better predictive ability than the Logistic EuroSCORE (P < 0.05).

CONCLUSION

In low-gradient aortic stenosis undergoing surgery, the EuroSCORE II is a strong predictor of 1-year mortality.

Association of Myocardial Fibrosis and Stroke Volume by Cardiovascular Magnetic Resonance in Patients With Severe Aortic Stenosis With Outcome After Valve Replacement: The British Society of Cardiovascular Magnetic Resonance AS700 Study

Importance

Low-flow severe aortic stenosis (AS) has higher mortality than severe AS with normal flow. The conventional definition of low-flow AS is an indexed stroke volume (SVi) by echocardiography less than 35 mL/m2. Cardiovascular magnetic resonance (CMR) is the reference standard for quantifying left ventricular volumes and function from which SVi by CMR can be derived.

Objective

To determine the association of left ventricular SVi by CMR with myocardial remodeling and survival among patients with severe AS after valve replacement.

Design, Setting, and Participants

This multicenter longitudinal cohort study was conducted between January 2003 and May 2015 across 6 UK cardiothoracic centers. Patients with severe AS listed for either surgical aortic valve replacement (SAVR) or transcatheter aortic valve replacement (TAVR) were included. Patients underwent preprocedural echocardiography and CMR. Patients were stratified by echocardiography-derived aortic valve mean and/or peak gradient and SVi by CMR into 4 AS endotypes: low-flow, low-gradient AS; low-flow, high-gradient AS; normal-flow, low-gradient AS; and normal-flow, high-gradient AS. Patients were observed for a median of 3.6 years. Data were analyzed from September to November 2021.

Exposures

SAVR or TAVR.

Main Outcomes and Measures

All-cause and cardiovascular (CV) mortality after aortic valve intervention.

Results

Of 674 included patients, 425 (63.1%) were male, and the median (IQR) age was 75 (66-80) years. The median (IQR) aortic valve area index was 0.4 (0.3-0.4) cm2/m2. Patients with low-flow AS endotypes (low gradient and high gradient) had lower left ventricular ejection fraction, mass, and wall thickness and increased all-cause and CV mortality than patients with normal-flow AS (all-cause mortality: hazard ratio [HR], 2.08; 95% CI, 1.37-3.14; P < .001; CV mortality: HR, 3.06; 95% CI, 1.79-5.25; P < .001). CV mortality was independently associated with lower SVi (HR, 1.64; 95% CI, 1.08-2.50; P = .04), age (HR, 2.54; 95% CI, 1.29-5.01; P = .001), and higher quantity of late gadolinium enhancement (HR, 2.93; 95% CI, 1.68-5.09; P < .001). CV mortality hazard increased more rapidly in those with an SVI less than 45 mL/m2. SVi by CMR was independently associated with age, atrial fibrillation, focal scar (by late gadolinium enhancement), and parameters of cardiac remodeling (left ventricular mass and left atrial volume).

Conclusions and Relevance

In this cohort study, SVi by CMR was associated with CV mortality after aortic valve replacement, independent of age, focal scar, and ejection fraction. The unique capability of CMR to quantify myocardial scar, combined with other prognostically important imaging biomarkers, such as SVi by CMR, may enable comprehensive stratification of postoperative risk in patients with severe symptomatic AS.

Left Ventricle Biomechanics of Low-Flow, Low-Gradient Aortic Stenosis: A Patient-Specific Computational Model

This study aimed to create an imaging-derived patient-specific computational model of low-flow, low-gradient (LFLG) aortic stenosis (AS) to obtain biomechanics data about the left ventricle. LFLG AS is now a commonly recognized sub-type of aortic stenosis. There remains much controversy over its management, and investigation into ventricular biomechanics may elucidate pathophysiology and better identify patients for valve replacement. ECG-gated cardiac computed tomography images from a patient with LFLG AS were obtained to provide patient-specific geometry for the computational model. Surfaces of the left atrium, left ventricle (LV), and outflow track were segmented. A previously validated multi-scale, multi-physics computational human heart model was adapted to the patient-specific geometry, yielding a model consisting of 91,000 solid elements. This model was coupled to a virtual circulatory system and calibrated to clinically measured parameters from echocardiography and cardiac catheterization data. The simulation replicated key physiologic parameters within 10% of their clinically measured values. Global LV systolic myocardial stress was 7.1 ± 1.8 kPa. Mean stress of the basal, middle, and apical segments were 7.7 ± 1.8 kPa, 9.1 ± 3.8 kPa, and 6.4 ± 0.4 kPa, respectively. This is the first patient-specific computational model of LFLG AS based on clinical imaging. Low myocardial stress correlated with low ejection fraction and eccentric LV remodeling. Further studies are needed to understand how alterations in LV biomechanics correlates with clinical outcomes of AS.

Cardiac Computed Tomography: Application in Valvular Heart Disease

The incidence and prevalence of valvular heart disease (VHD) is increasing and has been described as the next cardiac epidemic. Advances in imaging and therapeutics have revolutionized how we assess and treat patients with VHD. Although echocardiography continues to be the first-line imaging modality to assess the severity and the effects of VHD, advances in cardiac computed tomography (CT) now provide novel insights into VHD. Transcatheter valvular interventions rely heavily on CT guidance for procedural planning, predicting and detecting complications, and monitoring prosthesis. This review focuses on the current role and future prospects of CT in the assessment of aortic and mitral valves for transcatheter interventions, prosthetic valve complications such as thrombosis and endocarditis, and assessment of the myocardium.

Trends in Utilization of Aortic Valve Replacement for Severe Aortic Stenosis

BACKGROUND

Despite the rapid growth of aortic valve replacement (AVR) for aortic stenosis (AS), limited data suggest symptomatic severe AS remains undertreated.

OBJECTIVES

This study sought to investigate temporal trends in AVR utilization among patients with a clinical indication for AVR.

METHODS

Patients with severe AS (aortic valve area <1 cm²) on transthoracic echocardiograms from 2000 to 2017 at 2 large academic medical centers were classified based on clinical guideline indications for AVR and divided into 4 AS subgroups: high gradient with normal left ventricular ejection fraction (LVEF) (HG-NEF), high gradient with low LVEF (HG-LEF), low gradient with normal LVEF (LG-NEF), and low gradient with low LVEF (LG-LEF). Utilization of AVR was examined and predictors identified.

RESULTS

Of 10,795 patients, 6,150 (57%) had an indication or potential indication for AVR, of whom 2,977 (48%) received AVR. The frequency of AVR varied by AS subtype with LG groups less likely to receive an AVR (HG-NEF: 70%, HG-LEF: 53%, LG-NEF: 32%, LG-LEF: 38%, P < 0.001). AVR volumes grew over the 18-year study period but were paralleled by comparable growth in the number of patients with an indication for AVR. In patients with a Class I indication, younger age, coronary artery disease, smoking history, higher hematocrit, outpatient index transthoracic echocardiogram, and LVEF ≥0.5 were independently associated with an increased likelihood of receiving an AVR. AVR was associated with improved survival in each AS-subgroup.

CONCLUSIONS

Over an 18-year period, the proportion of patients with an indication for AVR who did not receive AVR has remained substantial despite the rapid growth of AVR volumes.

The role of TAVR in patients with heart failure: do we have the responses to all questions?

Severe aortic stenosis (AS) is the most prevalent valvular heart disease in developed countries. Heart failure (HF) is a frequent comorbidity of this condition and represents a diagnostic and therapeutic challenge. The spectrum of both conditions has become progressively wider in the last decade; HF has been divided in three groups according to left ventricular ejection fraction (LVEF) and severe AS has been reclassified into four groups according to aortic valve (AV) gradient, AV flow measured by LV stroke index, and LVEF. Although all four AS types may be found in patients with signs and symptoms of HF, low-flow AS with low or normal gradient is the most common type in these patients. Several studies have documented that patients with low-flow severe AS have a higher mortality risk than patients with normal-flow and high-gradient AS not only during the natural progression of the disease, but also after either interventional or surgical AV replacement. Existing data support transcatheter AV replacement (TAVR) in patients with severe AS, irrespective of AV gradient, AV flow, and LVEF. Controversial issues, however, are still present on this topic, which has not been adequately addressed by large studies and trials. This clinical review summarizes the epidemiology of the different HF types in patients with severe AS, as well as the impact of HF and LVEF on clinical outcomes of AS patients either untreated or after AV replacement. In particular, we addressed the influence of AV gradient and AV flow on all-cause and cardiovascular mortality in AS patients after TAVR.