Low-flow Low-gradient Aortic Stenosis Research Articles

Prognostic impact of cardiac damage staging classification in each aortic stenosis subtype undergoing TAVI.

The prognostic value of cardiac damage staging classifications across the haemodynamic spectrum of severe aortic stenosis (AS) remains unknown. We aimed to investigate the prognostic impact of cardiac damage staging classifications in patients with high-gradient AS (HG-AS) and low-gradient AS (LG-AS) undergoing transcatheter aortic valve implantation (TAVI). In a prospective TAVI registry, five-year mortality was evaluated for early stages of cardiac damage (stage 0, 1, or 2) and advanced stages of cardiac damage (stage 3 or 4) in patients with HG-AS, classical low-flow (LF) LG-AS, LF LG-AS with preserved ejection fraction (pEF), and normal-flow (NF) LG-AS. Among 2,090 patients undergoing TAVI, 1,045 patients had HG-AS, 337 patients had classical LF LG-AS, 394 patients had LF LG-AS with pEF, and 314 patients had NF LG-AS. The majority of patients with classical LF LG-AS exhibited advanced cardiac damage (73.6%), followed by LF LG-AS with pEF (55.6%), NF LG-AS (51.6%), and HG-AS (50.6%). Patients with advanced stage cardiac damage had significantly higher mortality after TAVI than those with early stage cardiac damage in all subtypes of AS (adjusted hazard ratio [HRadjusted] 1.66, 95% confidence interval [CI]: 1.34-2.06 for HG-AS; HRadjusted 1.49, 95% CI: 1.02-2.16 for classical LF LG-AS; HRadjusted 1.69, 95% CI: 1.22-2.35 for LF LG-AS with pEF; and HRadjusted 1.52, 95% CI: 1.04-2.32 for NF LG-AS). Cardiac damage staging classifications stratified mortality after TAVI irrespective of AS subtype.

Impact of cardiac staging classification in transcatheter aortic valve implantation for major subtypes of severe aortic stenosis

Abstract Background Staging classification to quantify the extent of extra-aortic valve cardiac damage is recognized as a useful prognostic tool in patients undergoing transcatheter aortic implantation (TAVI) for aortic stenosis (AS). However, this classification has not been validated in each AS subtype. Objectives The present study aimed to investigate the prognostic impact of staging classification in patients with four major AS subtypes. Methods In a prospective TAVI registry, patients were classified into high gradient AS (HG-AS), classical low flow low gradient AS (LFLG-AS), paradoxical LFLG-AS, and normal flow low gradient AS (NFLG-AS). Five-year mortality was compared between early stage (stage 0, 1, or 2) and advanced stage (stage 3 or 4). Results Among 1,507 patients undergoing TAVI, 812 patients had HG-AS, 186 patients had classical LFLG-AS, 277 patients had paradoxical LFLG-AS, and 232 patients had NFLG-AS. There were much difference in the distribution of cardiac stage among AS subtypes; advanced stage accounting for 54.3% in HG-AS, 58.6% in NFLG-AS, 62.5% in paradoxical LFLG-AS, and 80.6% in classical LFLG-AS. Patients with advanced stage had higher all-cause mortality compared with early stage in HG-AS and paradoxical LFLG-AS (HRadjusted 2.00; 95% CI 1.44-2.78 and HRadjusted 2.15; 95% CI 1.43-3.21), but not in classical LFLG-AS and NFLG-AS (HRadjusted 1.17; 95% CI 0.70-1.95 and HRadjusted 1.43; 95% CI 0.90-2.27). Conclusions Early stage was associated with a reduced risk for five-year mortality in patients with HG-AS and paradoxical LFLG-AS, while there was comparable mortality between early and advanced stages in patients with classical LFLG-AS and NFLG-AS.

Impact of route of access and stenosis subtype on outcome after transcatheter aortic valve replacement.

Previous analyses have reported the outcomes of transcatheter aortic valve replacement (TAVR) for patients with low-flow, low-gradient (LFLG) aortic stenosis (AS), without stratifying according to the route of access. Differences in mortality rates among access routes have been established for high-gradient (HG) patients and hypothesized to be even more pronounced in LFLG AS patients. This study aims to compare the outcomes of patients with LFLG or HG AS following transfemoral (TF) or transapical (TA) TAVR. A total of 910 patients, who underwent either TF or TA TAVR with a median follow-up of 2.22 (IQR: 1.22-4.03) years, were included in this multicenter cohort study. In total, 146 patients (16.04%) suffered from LFLG AS. The patients with HG and LFLG AS were stratified according to the route of access and compared statistically. The operative mortality rates of patients with HG and LFLG were found to be comparable following TF access. The operative mortality rate was significantly increased for patients who underwent TA access [odds ratio (OR): 2.91 (1.54-5.48), p = 0.001] and patients with LFLG AS [OR: 2.27 (1.13-4.56), p = 0.02], which could be corroborated in a propensity score-matched subanalysis. The observed increase in the risk of operative mortality demonstrated an additive effect [OR for TA LFLG: 5.45 (2.35-12.62), p < 0.001]. LFLG patients who underwent TA access had significantly higher operative mortality rates (17.78%) compared with TF LFLG (3.96%, p = 0.016) and TA HG patients (6.36%, p = 0.024). HG patients experienced a twofold increase in operative mortality rates following TA compared with TF access, while LFLG patients had a fivefold increase in operative mortality rates. TA TAVR appears suboptimal for patients with LFLG AS. Prospective studies should be conducted to evaluate alternative options in cases where TF is not possible.

Dobutamine stress echocardiography remains indispensable for the diagnosis of low-flow low-gradient severe aortic stenosis

Abstract Background In patients with low-gradient aortic stenosis (AS) and low transvalvular flow, current guidelines recommend dobutamine stress echocardiography (DSE) to determine valve stenosis severity. Additionally, aortic valve calcification (AVC) scores are also used with this intent. Previous studies have determined cut-off values of ≥2000AU for men and ≥1200AU for women to distinguish between true severe AS and pseudosevere AS. Purpose To assess the relationship between AVC and DSE in low-flow low-gradient aortic stenosis. Methods We performed a multicenter international registry study including patients that underwent DSE to determine AS severity and multi-slice computed tomography (MSCT) of sufficient quality to determine AVC scores. Severe AS was diagnosed when resting peak aortic valve velocity was ≥4.0 m/s, or stress aortic valve area (AVA) remained &amp;lt;1.0cm2 at peak dobutamine stress levels; moderate AS was diagnosed when resting AVA was ≥1.0cm2 and peak velocity was &amp;lt; 4.0m/s or stress AVA exceeded 1.0cm² at peak stress. Using the previous cut-off values, MSCT-AVC scores were compared to DSE-derived AS diagnoses to determine sensitivity and specificity of AVC, and the positive and negative predictive values of high and low scores. Subsequently, we performed a receiver-operating characteristics (ROC)-curve analysis for men and women separately. Results We included 271 patients from 8 centers, of which 231 patients had sufficiently interpretable DSE and MSCT. Median age was 79 years (Interquartile range (IQR): 71-84), median BMI was 26.4 kg/m2 (IQR: 24.1-30.0) and median BSA was 1.9 m2(IQR: 1.8-2.1). Left ventricular ejection fraction was reduced (&amp;lt;50%) in 209 (90.5%) patients. Bicuspid valve morphology was present in 20 patients (8.7%). DSE confirmed severe AS in 103 patients, 4 of whom already had resting peak aortic valve velocity ≥4.0m/s. Moderate AS was diagnosed in 128 patients, of which 76 had a resting AVA ≥ 1.0cm2. Characteristics of these patients are summarized the table. Of the patients with severe AS, 49 (47.6%) had a high AVC score (≥2000 for men or ≥1200 for women) and of patients with moderate AS, 75 (58.6%) had an AVC score below those cut-off values. This corresponds to a sensitivity of 47.6%, a specificity of 58.4% and positive and negative predictive values of 53.5% and 51.6%, respectively. The ROC-curves are shown in the figure; the area under the curve was 0.55 for men and 0.52 for women, signifying poor discriminative performance. Conclusion In this multicenter international registry we found that aortic valve calcification scores correlated poorly with AS severity and therefore DSE remains the preferred technique to assess borderline AS severity.Table.Patient characteristicsFigure.ROC curve

The potential role of the aortic valve calcium score by computed tomography scan in the diagnosis of concomitant cardiac amyloidosis in patients with severe aortic stenosis

Abstract Background Cardiac amyloidosis (CA) and aortic stenosis (AS) are two related, but the diagnosis of both these condition is challenging because of the common phenotype. Different predictors of CA in AS have been proposed in the last years. Purpose To identify a new red-flag of concomitant CA in patients with severe AS analyzing aortic valve calcium burden using calcium score, calcium mass and calcium volume by computed tomography scan (CT). Methods 55 patients with severe AS and suspicion of concomitant CA were retrospectively enrolled from 2009 to 2022. 5 Patients with a bicuspid aortic valve, previous aortic valve replacement, or an incomplete diagnostic workup for CA were excluded. 50 patients underwent CT-scan and were included in the final analysis. Results Of the 50 patients, 21 patients (AS-CA) had positive 99m Tc-DPD bone scintigraphy (19 with score 2 and 2 with score 3), none of the patients presented laboratory suspicion for AL amyloidosis, so all the patients had a diagnosis of transthyetin related CA. 29 patients (AS alone) had negative bone scintigraphy. AVA indexed were comparable between AS-CA and AS alone groups (0.3 mm2/m2, in both the group p: 0.88). Stroke volume, maximum and mean gradient were significatively lower in AS-CA group (29 vs 36 ml/m2, p: 0.01, 60 vs 72 mmHg, p: 0.016 and 34 vs 45 mmHg, p:0.01) with a higher percentage of low flow-low gradient aortic stenosis in AS-CA group (11 patients,52% vs 5 patients in AS-alone 17%, p: 0.014)ECG in AS-CA group showed atrial fibrillation in 12 patients (57%), versus 3 patients in the AS-alone group (10%), and lower QRS voltages (peripheral QRS score 44 mV vs 58 mV, p-value:0.017; total QRS score 120 mV versus 160 mV, p-value: 0.005). The echocardiogram showed a more thickened IVS and PW in AS-CA patients (17 versus 15 mm, p: 0.03 and 15 versus 14 mm, p: 0.01) with a decreases longitudinal systolic function (septal S wave at TDI 4.4 vs 5.1 cm/s, p: 0.011, lateral S wave 4.5 versus 5.6 cm/s, p: 0.014).CT- aortic valve calcium was quantified by an experienced operator. A statistically significant difference between AS-CA and AS-alone groups was observed in calcium score (3569 vs 4480 Agatston units, p: 0.017) calcium volume (2575 vs 3445 mm3, p: 0.012) and calcium mass (798 vs 1082 g, p: 0.016).At logistic regression analyses,confirmed perdictors of concomitant CA in AS were: AS low flow- low gradient (p:0.011), atrial fibrillation (p:0.001), lower QRS score periferical(p:0.004) and total (p:0.002) and a decreased longitudinal systolic function (p:0.028). Regarding the aortic valve calcium burden, calcium score( p:0.031) and calcium volume(p:0.026) were confirmed predictor of CA in AS. Conclusions This study shows that calcium burden at CT scan in patients with concomitant CA-AS is significatily lower than in patients with AS alone. Calcium burden at CT scan could be used in addition to the classical parameters as a potential red-flag of concomitant CA in AS severe.

Right-ventricular/pulmonary artery coupling predicts long-term mortality in aortic stenosis patients with different flow types

Abstract Background Right-ventricular (RV) dysfunction in aortic stenosis (AS) patients undergoing transcatheter aortic valve implantation (TAVI) has long been neglected. Right-ventricular to pulmonary artery coupling (RV/PAc), a parameter of RV function, can be determined by echocardiography (tricuspid annular plane systolic excursion over systolic pulmonary artery pressure). Its use for mortality prediction in contemporary AS patients warrants further evaluation, data for different flow types of AS are lacking. Purpose To assess the impact of pathological RV/PAc on long-term mortality in AS patients with different flow types. Methods All 1577 consecutive patients from our registry from 2018 to 2020 were assessed. Patients without tricuspid regurgitation (n=523) or inconclusive echocardiography images (n=111) were excluded. RV/PAc could be analysed in 862 patients. To dichotomize the cohort, a receiver operator curve (ROC) analysis for 2-year mortality was used. Primary endpoint was 2-year mortality. Patients were further analysed according to the Valve Academic Research Consortium (VARC) 3 endpoint definitions. Results By ROC analysis, 0.512 mm/mmHg was defined as a cut-off, dividing the cohort into 428 patients with physiological RV/PAc (above cut-off) and 434 patients with pathological RV/PAc. Patients with pathological RV/PAc were more often male, had more comorbidities, a lower ejection fraction (50% [40-55%] vs. 55% [53-58%], p&amp;lt;0.01) and a higher Society of Thoracic Surgeons (STS) score (4.0 [2.5-6.0] vs. 2.8 [2.0-4.0], p&amp;lt;0.01). Procedural outcomes according to VARC-3 were comparable: the composite endpoints technical failure and device failure at 30 days occurred in 3.9% and 3.5% (p=0.75) and 11.3% and 13.3% (p=0.42) in the pathological and physiological group, respectively. Clinical outcomes in terms of New York Heart Association functional class were comparable at follow-up, with an improvement by at least one class in 76.2% (pathological group) and 79.9% (physiological group, p=0.33). All-cause 2-year mortality was significantly higher in the pathological group (34.9% [30.2-39.2%] vs. 15.4% [11.9-18.8%], p&amp;lt;0.01, hazard ratio, HR, 2.5 [1.9-3.4], Figure 1). The result persisted when adjusted for STS score (HR 2.3 [1.7-3.1]) or in a multivariate Cox regression. Cardiovascular mortality was increased too (pathological, 23.7% [19.3-27.8%], vs. physiological, 8.5% [5.8-11.2%], HR 2.9 [2.0-4.2], p&amp;lt;0.01). The fraction of patients with pathological RV/PAc differed significantly across the AS flow types (high-gradient, 40.3%, classical low-flow low-gradient (LFLG), 73.9%, paradoxical LFLG, 58.9%, and normal-flow low-gradient, 36.6%, p&amp;lt;0.01). Mortality differences persisted in high-gradient and LFLG groups (Figure 2A-D), which was consistent after statistical adjustment. Conclusions RV dysfunction defined as low RV/PAc is a strong predictor for long-term mortality in TAVI patients, with a strong prognostic value also in LFLG AS.

Prognostic impact of atrial fibrillation in patients with paradoxical low-flow low-gradient aortic stenosis undergoing TAVI

Abstract Background Atrial fibrillation (AF) has been associated with adverse clinical outcomes after transcatheter aortic valve implantation (TAVI). However, the impact of AF on post-TAVI flow status and clinical outcomes in patients with paradoxical low-flow low-gradient aortic stenosis (PLFLG-AS) is still unclear. Objectives The present study aimed to investigate the effect of AF on post-TAVI flow status and clinical outcomes in patients with PLFLG-AS undergoing TAVI. Methods In a prospective TAVI registry, patients with preserved left ventricular ejection fraction (LVEF ≥50%) were stratified according to the flow-gradient status and presence of AF. Results Among 2,259 TAVI patients with preserved LVEF between August 2007 and June 2021, 765 had high-gradient AS (HG-AS) (mean gradient ≥40 mmHg) and 444 had PLFLG-AS (mean gradient &amp;lt;40 mmHg and stroke volume index [SVi] &amp;lt;35 ml/m2). AF was observed in 199 patients with HG-AS (26.0%) and 190 patients with PLFLG-AS (42.8%). At 1 year after TAVI, SVi was significantly improved in PLFLG-AS patients with no AF, whereas those with AF remained low-flow status (from 25.9 ± 8.5 mL/m2 to 37.2 ± 9.9 mL/m2 and from 26.8 ± 5.1 mL/m2 to 26.1 ± 9.1 mL/m2, respectively). PLFLG-AS patients had an increased risk of all-cause mortality at 1 year after TAVI compared with those without AF (HRadjust 2.79; 95% CI 1.58-4.93). Whereas PLFLG-AS patients with no AF had a similar mortality compared with HG-AS patients with no AF (HRadjust 0.84; 95% CI 0.49-1.44). Conclusions AF was associated with worse flow status and impaired prognosis after TAVI in patients with PLFLG-AS.

Abstract 18349: The Impact of Concomitant Mitral Regurgitation on Aortic Valve Intervention Outcomes 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 rates due to reduced stroke volumes, while maintaining preserved left ventricular ejection fraction (LVEF). The presence of mitral regurgitation (MR) adds complexity to this already challenging diagnosis, by further lowering flow rate. However, the impact of aortic valve intervention in this patient population remains uncertain. Methods: A total of 1178 patients were included from an institutional echo database with adjudicated aortic valve area (AVA &lt;1.0 cm2), transaortic gradients (mean gradient&lt; 40 mmHg) and low flow rate (Q ≤210 ml/sec), to confirm the diagnosis of LFLGAS and preserved LVEF (&gt;50%). Subgroups were formed based on the presence of severe MR and subsequent surgical and transcatheter aortic valve intervention (SAVR/TAVR). Patients who underwent mitral valve intervention were censored. All-cause mortality was assessed as the primary outcome. Results: Patients with severe MR had significantly lower flow rates compared to patients w/o severe MR (166.5 ± 26.3 vs 174.7 ± 25, p=0.006). During a median follow up of 1.3 years, 745 deaths (62.2%) were identified, with a cumulative incidence significantly lower in the intervention groups (Figure). After multivariate propensity adjustment for age, sex, aortic valve area and comorbidities, aortic valve intervention showed a significant reduction in mortality risk in both intervention groups, which was more pronounced in the severe MR group compared to patients w/o severe MR (AdjHR 0.334, p=0.015 vs 0.436, p&lt;0.001, p for interaction =0.24). Conclusions: In paradoxical low-flow low-gradient severe aortic stenosis, aortic valve intervention results in a survival benefit, especially among patients with concomitant severe MR. Our findings highlight the importance of recognizing severe MR as a flow-diverting lesion that can impact outcomes in LFLGAS.

Short-Term Outcomes Following Transcatheter Aortic Valve Implantation: Classical Low-Flow Low-Gradient Versus Normal-Flow Low-Gradient Severe Aortic Stenosis

Background: Both classical severe low-flow low-gradient aortic stenosis (LFLG-AS) and severe normal-flow low-gradient aortic stenosis (NFLG-AS) patients undergo transcatheter aortic valve implantation (TAVI). However, few studies have compared outcomes between the two groups. Our study aimed to assess short term post-TAVI outcomes between classical LFLG-AS and NFLG-AS. Methods: We conducted a retrospective, single-center, analysis of 206 patients who underwent TAVI between January 2011 to September 2020. Of these, 44 (males: 33) had classical LFLG-AS and 162 (males: 89) had NFLG-AS. Six-month primary outcomes included all-cause and cardiovascular mortality. Multiple secondary outcomes were assessed including stroke, myocardial infarction (MI), new-onset atrial fibrillation, acute kidney injury (AKI), major bleeding, vascular complications, and repeat hospitalizations from cardiac causes. Results: The cumulative six-month all-cause and cardiovascular mortality were similar between classical severe LFLG-AS and NFLG-AS patients (6.81 % vs. 4.32 %, P = 0.49 and 2.27 % vs. 2.47 %, P = 0.93 respectively). All secondary outcomes were also similar, except for a statistically significant higher rate of AKI in patients with classical LFLG-AS (P = &lt; 0.0001). Conclusion: Except for a higher incidence of AKI in patients with severe classical LFLG-AS, six-month post-TAVI outcomes did not differ between classical LFLG-AS and NFLG-AS.

Outcomes of Transcatheter Aortic Valve Replacement Patients With Different Transvalvular Flow-Gradient Patterns

Low-flow low-gradient (LF-LG) aortic stenosis (AS) may occur with preserved or depressed left ventricular ejection fraction (LVEF). Both situations represent the most challenging subset of patients to manage and generally have a poor prognosis. Few and controversial data exist on the outcomes of these patients compared with normal flow-high gradient (NF-HG) AS after transcatheter aortic valve replacement (TAVR). We sought to characterize different transvalvular flow-gradient patterns and to examine their prognostic value after TAVR. We enrolled 1,208 patients with severe AS and categorized as follow: 976 patients NF-HG (mean aortic pressure gradient [MPG] ≥40mm Hg), 107 paradoxical LF-LG (pLF-LG, MPG <40mm Hg, LVEF ≥50%, stroke volume index <35ml/m2), and 125 classical LF-LG (cLF-LG) (MPG <40mm Hg, LVEF <50%, stroke volume index <35ml/m2). When compared with NF-HG and pLF-LG, cLF-LG had a worse symptomatic status (New York Heart Association III to IV 86% vs 62% and 67%, p <0.001), a higher prevalence of eccentric hypertrophy and a higher level of LV global afterload reflected by a higher valvuloarterial impedance. Valvular function after TAVR was excellent over time in all patients. While 30-day mortality (p=0.911) did not differ significantly among groups, cLF-LG had a lower 5-year survival rate (LF-LG 50% vs pLF-LG 62% and NF-HG 68%, p <0.05). cLF-LG was associated with a hazard ratio for mortality of 2.41 (95% confidence interval 1.65 to 3.52, p <0.001). In conclusion, TAVR is an effective procedure regardless of transvalvular flow-gradient patterns. However, special care should be given to characterized hemodynamic of AS, as patients with pLF-LG had similar survival rates than patients with NF-HG, whereas cLF-LG is associated with a twofold increased risk of mortality at 5-year follow-up.

Prognostic Implication of Pulmonary Hypertension in Low-Flow Low-Gradient Aortic Stenosis After Transcatheter Aortic Valve Replacement

Prognostic implications of pulmonary hypertension (PH) in low-flow low-gradient (LG) aortic stenosis (AS) after transcatheter aortic valve replacement (TAVR) remains unexplored. We aimed to investigate the impact of baseline and changes in PH after TAVR. In this single-center retrospective study, we included patients who underwent TAVR for low-flow LG AS. Patients were categorized into 2 groups: baseline pulmonary artery systolic pressure (PASP) <46mm Hg (no-to-mild PH) and PASP ≥46mm Hg (moderate-to-severe PH). On the basis of changes in PASP after TAVR, patients were stratified into increased (ΔPASP ≥+5 mm Hg), no change (-4 to +4 mm Hg), and decreased (≤ -5 mm Hg) groups. Primary end point was a composite of all-cause mortality and heart failure rehospitalization. In total, 210 patients were included, 148 in the no-to-mild PH group and 62 in the moderate-to-severe PH group. Median follow-up was 13.2 months. The moderate-to-severe PH group was at an increased risk of composite end point (adjusted hazard ratio [HR] 3.5, 95% confidence interval [CI] 1.8 to 6.9), all-cause mortality (HR 2.4, 95% CI 1.1 to 5.6), and heart failure rehospitalization (HR 8.3, 95% CI 2.9 to 23.7). There were no differences in clinical outcomes among those with increased (32%), no change (28%), and decreased (39%) PASP after TAVR. In conclusion, moderate-to-severe PH at baseline is an independent predictor of worse clinical outcomes in patients with low-flow LG AS who undergo TAVR, and this cohort of patients do not seem to derive the benefits of postoperative reduction of PASP.

TCT-121 Change in Pulmonary Artery Systolic Pressure After Transcatheter Aortic Valve Replacement in Patients With Low-Flow Low-Gradient Aortic Stenosis and its Prognostic Implications

TCT-121 Change in Pulmonary Artery Systolic Pressure After Transcatheter Aortic Valve Replacement in Patients With Low-Flow Low-Gradient Aortic Stenosis and its Prognostic Implications

TCT-95 Association of Chronic Kidney Disease on Outcomes After Transcatheter Aortic Valve Replacement in Low-Flow Low-Gradient Aortic Stenosis

TCT-95 Association of Chronic Kidney Disease on Outcomes After Transcatheter Aortic Valve Replacement in Low-Flow Low-Gradient Aortic Stenosis

TCT-661 Outcomes of Patients With High Gradient and Low-Flow Low-Gradient Aortic Valve Stenosis Undergoing Transcatheter Aortic Valve Implantation: Results From the CENTER2 Collaboration

TCT-661 Outcomes of Patients With High Gradient and Low-Flow Low-Gradient Aortic Valve Stenosis Undergoing Transcatheter Aortic Valve Implantation: Results From the CENTER2 Collaboration

Transcatheter aortic valve replacement outcomes in patients with low-flow very low-gradient aortic stenosis.

In patients with severe aortic stenosis (AS), low-flow low-gradient (LG) is a known predictor of worse outcomes. However, very LG may represent a distinct population with further cardiac dysfunction. It is unknown whether this population benefits from transcatheter aortic valve replacement (TAVR). We aimed to describe the patient characteristics and clinical outcomes of low-flow very LG severe AS. This single-centre study included all patients with low-flow severe AS between 2019 and 2021. Patients were divided into groups with very LG [mean pressure gradient (MPG) ≤ 20 mmHg], LG (20 < MPG < 40 mmHg), and high-gradient (HG) (MPG ≥ 40 mmHg). Composite endpoint of all-cause mortality and heart failure rehospitalization was compared. A total of 662 patients [very LG 130 (20%); LG 339 (51%); HG 193 (29%)] were included. Median follow-up was 12 months. Very LG cohort had a higher prevalence of comorbid conditions with lower left ventricular ejection fraction (45% vs. 57% vs. 60%; P < 0.001). There was a graded increase in the risk of composite endpoint in the lower MPG strata (P < 0.001). Among those who underwent TAVR, very LG was an independent predictor of the composite endpoint (adjusted HR 2.42 [1.29-4.55]). While LG and HG cohorts had decreased risk of composite endpoint after TAVR compared with conservative management, very LG was not associated with risk reduction (adjusted HR 0.69 [0.35-1.34]). Low-flow very LG severe AS represents a distinct population with significant comorbidities and worse outcomes. Further studies are needed to evaluate the short- and long-term benefits of TAVR in this population.

Effects of Chronic Kidney Disease on Transcatheter Aortic Valve Replacement Outcomes in Low-Flow Low-Gradient Aortic Stenosis

Effects of Chronic Kidney Disease on Transcatheter Aortic Valve Replacement Outcomes in Low-Flow Low-Gradient Aortic Stenosis

Association of atrial fibrillation with survival in patients with low-flow low-gradient aortic stenosis with preserved ejection fraction undergoing TAVI.

There is limited evidence on the prognostic significance of atrial fibrillation (AF) in patients with low flow, low-gradient aortic stenosis with preserved ejection fraction (LFLG-pEF AS). We aimed to evaluate the recovery of stroke volume after transcatheter aortic valve implantation (TAVI) and clinical outcomes in patients with LFLG-pEF AS stratified by presence or absence of AF. In a prospective TAVI registry, patients with preserved left ventricular ejection fraction (LVEF≥50%) were stratified according to flow-gradient status and presence of AF. Among 2259 TAVI patients with preserved LVEF between August 2007 and June 2021, 765 had high-gradient AS (HG AS) and 444 had LFLG-pEF AS. AF was observed in 199 patients with HG AS (26.0%) and 190 patients with LFLG-pEF AS (42.8%). At 1 year, stroke volume index (SVi) was significantly improved in LFLG-pEF AS patients without AF, while SVi remained low in patients with AF (from 25.9±8.5mL/m2 to 37.2±9.9mL/m2 and from 26.8±5.1mL/m2 to 26.1±9.1mL/m2, respectively). LFLG-pEF AS patients with AF had an increased risk of 1-year all-cause mortality compared with those without AF (adjusted hazard ratio (HRadjusted) 2.57; 95% confidence interval [CI] 1.44-4.59). LFLG-pEF AS patients without AF had similar mortality compared with HG AS patients without AF (HRadjusted 0.85; 95% CI 0.49-1.46). Patients with LFLG-pEF AS and AF experienced no relevant recovery of stroke volume after TAVI, but a more than two-fold increased risk of death compared to patients with HG AS or LFLG-pEF AS without AF. https://www.clinicaltrials.gov. NCT01368250.

Changes in echocardiographic parameters over time in paradoxical low-flow low-gradient aortic stenosis

Abstract Funding Acknowledgements Type of funding sources: None. Background Although paradoxical low-flow low-gradient (LFLG) aortic stenosis (AS) has been considered a more severe form of AS with a worse prognosis than high-gradient (HG) AS, data on the natural history of this entity are scant. Objectives To assess the progression of the disease and evolution of the main echocardiographic variables for quantifying AS in patients with severe LFLG AS compared to HG and normal-flow low-gradient (NFLG) AS. Methods A longitudinal, observational, multicenter study including consecutive asymptomatic patients with severe AS (AVA&amp;lt;1.0cm²) and normal LVEF (≥50%) was conducted. Patients were classified according to baseline echocardiography into one of three groups: HG (mean gradient≥40 mmHg), NFLG (mean gradient&amp;lt;40 mmHg, indexed systolic volume (SVi)&amp;gt;35ml/m²), or LFLG (mean gradient&amp;lt;40mmHg, SVi≤35ml/m²). AS progression was analyzed by comparing patients’ baseline measurements and their last follow-up measurements or those taken prior to aortic valve replacement (AVR). Results Of the 903 included patients, 401 (44.4%) were HG, 405 (44.9%) NFLG, and 97 (10.7%) LFLG. The median total follow-up time was 60.2 months (IQR 44.7–83.4). Progression of the mean gradient in a linear mixed regression model was greater in low-gradient groups: LFLG vs. HG (regression coefficient 0.124, p = 0.005) and NFLG vs. HG (regression coefficient 0.068, p = 0.018). No differences were observed between the LFLG and NFLG groups (regression coefficient 0.056, p = 0.195). However, aortic valve area (AVA) reduction was slower in the LFLG group compared to the NFLG (p&amp;lt;0.001). During follow-up, 19.1% (n=9) of LFLG patients evolved to having NFLG AS and 44.7% (n=21) to having HG AS. 58.0% of patients underwent AVR with HG AS (n=29). Conclusions LFLG AS shows an intermediate AVA and gradient progression compared to NFLG and HG AS. The majority of patients initially classified as having LFLG AS changed over time to having other severe forms of AS, and most of them received AVR with HG AS.

The diagnostic role of acceleration time measurement in patients with classical low flow low gradient aortic stenosis with reduced left ventricular ejection fraction

Abstract Funding Acknowledgements Type of funding sources: None. Background Low-flow, low-gradient (LF-LG) AS can occur with a reduced or preserved left ventricular ejection fraction (LVEF) and is difficult to diagnose in either case(1). The main challenge is to distinguish between true severe and pseudo-severe stenosis. Dobutamine stress echocardiography (DSE) is recommended for the distinction of stenosis severity and LV flow reserve in classical LF-LG AS(2). Individual dissimilarities can be seen in the DSE results depending on the severity of the AS and LV afterload mismatch and/or on the existence of accompanying cardiomyopathy(3). One-third of the classical LF- LG AS with reduced LVEF patients do not have LV flow reserve (an increase of less than 20% in SV during DSE)(2). This patient group with an indeterminate DSE result has high surgical risk, and additional examinations are always required(4). Purpose The aim of our study was to evaluate the role of Acceleration time (AT), Ejection time (ET), and AT/ET ratio in predicting DSE outcome in classical LF-LG AS patients with reduced EF, and to distinguish between true and pseudo AS to determine the cut-off for AT which can be a useful evalu- ation method in clinical practice. Methods Sixty-seven classical LF-LG AS with reduced LVEF patients who underwent dobutamine stress echocardiography (DSE) were included in the study. Patients with ventricular arrhythmia and pace rhythm, moderate and severe mitral stenosis, severe aortic insufficiency, and paradoxical LF-LG AS patients were excluded. According to DSE results, all patients were divided into two groups; true AS and pseudo-severe AS. Aortic valve calcium score was measured in patients with inconclusive DSE results. AT and other ejection dynamics (ET and AT/ET) were calculated by taking baseline echocardiographic records into account for all patients(1,5). The predictive power of AT and other ejection dynamics were evaluated to estimate true and pseudo-severe AS. Results According to DSE results, out of 67 patients, 44 (65.7%) was diagnosed as true severe AS. There was a statistically significant relation between baseline AT and true AS [adjusted OR 4.47 (95% CI 1.93–10.4), p = 0.001]. The best cutoff value of AT was measured as 100 msec according to the Youden index. This value had a sensitivity value of 77%, specificity value of 87%, positive predictive value of 92%, and a negative predictive value of 67%. Conclusion In conclusion, the biggest difference of our study from the other studies in the literature is that we only included LF-LG AS patients with reduced EF in our study. Additionally, the study assesses the predictive strengths of ejection dynamics, one by one, regarding DSE results, and therefore, assesses role of ejection dynamics role to distinguish true and pseudo severe AS. As a result of our analysis, AT has a diagnos- tic role in the determination of true severe AS. Large-scale studies are needed to be carried out regarding true severe AS among LF LG AS patients with reduced LVEF.

Pseudo-discordance mimicking low-flow low-gradient aortic stenosis in transcatheter aortic valve replacement patients with severe symptomatic aortic stenosis.

While the combination of a small aortic valve area (AVA) and low mean gradient is frequently labeled 'low-flow low-gradient aortic stenosis (AS)', there are two potential causes for this finding: underestimation of mean gradient and underestimation of AVA. In order to investigate the prevalence and causes of discordant echocardiographic findings in symptomatic patients with AS and normal left ventricular (LV) function, we evaluated 72 symptomatic patients with AS and normal LV function by comparing Doppler, invasive, computed tomography (CT) LV outflow tract (LVOT) area, and calcium score (CaSc). Thirty-six patients had discordant echocardiographic findings (mean gradient < 40 mmHg, AVA ≤ 1 cm²). Of those, 19 had discordant invasive measurements (true discordant [TD]) and 17 concordant (false discordant [FD]): In 12 of the FD the mean gradient was > 30 mmHg; technical pitfalls were found in 10 patients (no reliable right parasternal Doppler in 6). LVOT area by echocardiography or CT could not differentiate between concordants and discordants nor between TD and FD (p = NS). CaSc was similar in concordants and FD (p = 0.3), and it was higher in true concordants than in TD (p = 0.005). CaSc positive predictive value for the correct diagnosis of severe AS was 95% for concordants and 93% for discordants. Discordant echocardiographic findings are commonly found in patients with symptomatic AS. Underestimation of the true mean gradient due to technical difficulties is an important cause of these discrepant findings. LVOT area by echocardiography or CT cannot differentiate between TD and FD. In the absence of a reliable and compete multi-window Doppler evaluation, patients should undergo CaSc assessment.