Benefit of Transcatheter Aortic Valve Replacement in Patients With Paradoxical Low-Flow Low-Gradient Versus High-Gradient Aortic Stenosis and Preserved Left Ventricular Function

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

AIMS

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.

METHODS AND RESULTS

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 ± 8.5 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). 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).

CONCLUSION

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.

CLINICAL TRIAL REGISTRATION

https://www.clinicaltrials.gov. NCT01368250.

Impact of left ventricular ejection fraction and aortic valve gradient on mortality following transcatheter aortic valve intervention

BACKGROUND

Data regarding the impact of reduced left ventricular ejection fraction (LVEF) and/or reduced mean aortic valve gradient (AVG) on outcomes following transcatheter aortic valve intervention (TAVI) have been conflicting. We sought to assess the relationship between LVEF, AVG, and 1-year mortality in patients undergoing TAVI.

METHODS

We prospectively evaluated 298 consecutive adults undergoing TAVI from 2015 to 2018 at an academic tertiary medical center. Patients were categorized according to LVEF and mean AVG. The primary outcome of interest was all-cause mortality at 1 year.

RESULTS

Of 298 adults undergoing TAVI, 66 (22.1%) had baseline LVEF ≤45% while 232 (77.9%) had baseline LVEF >45%; 173 (58.1%) had baseline AVG < 40mmHg while 125 (41.9%) had baseline AVG ≥ 40mmHg. Rates of 1-year all-cause mortality were significantly higher in patients with LVEF ≤45% (28.8% vs 12.1%, p = 0.001) and those with AVG < 40mmHg (19.7% vs 10.4%, p = 0.031) compared to those with LVEF >45% and AVG ≥ 40mmHg respectively. In multivariable analysis, higher AVG (per mmHg) (OR 0.97, 95% CI 0.94-0.99, p = 0.026) was noted to be independently associated with lower rates of 1-year mortality, while LVEF was not (OR 0.98, 95% CI 0.96-1.01).

CONCLUSIONS

In this prospective, contemporary registry of adults undergoing TAVI, while 1-year unadjusted mortality rates are significantly higher in patients with reduced LVEF and reduced AVG, risk-adjusted mortality at 1 year is only higher in those with reduced AVG - not in those with reduced LVEF.

Transcatheter Aortic Valve Replacement Improves Quality of Life and Ventricular Function With Low-Flow/Low-Gradient Aortic Stenosis

Background

D2 aortic stenosis (AS) is the highest risk AS subtype with worse operative and mortality outcomes. This study aimed to investigate the quality of life (QoL) and left ventricular ejection fraction (LVEF) in patients with classic (D2 subtype) low-flow/low-gradient AS who underwent transcatheter aortic valve replacement (TAVR).

Methods

In total, 634 patients with severe AS underwent TAVR at our institution from 2014 to 2020, of whom 76 met criteria for classic D2 AS with reduced LVEF. Echocardiographic and clinical outcomes including mortality, stroke, pacemaker placement (PPM), and readmission at baseline were compared with those at 30 days and 1 year. QoL data were extracted from the Kansas City Cardiomyopathy Questionnaire (KCCQ-12).

Results

The average baseline Society of Thoracic Surgeons risk score for patients with D2 AS was 7.66 ± 6.76. Patients with D2 AS reported improved QoL post-TAVR. The average baseline KCCQ-12 score was 39.5 ± 20, with improvement to 68.9 ± 20.6 at 30 days (P < .01) and 74.9 ± 17.5 at 1 year (P < .01). Mortality was 0% at 30 days and 18.4% at 1 year. The average baseline LVEF was 36.1 ± 9.4. Left ventricular function improved to 43.5 ± 12.9 (P <.001) at 30 days and 46.3 ± 11.2 (P = .03) at 1 year. Complications post-TAVR at 30 days included stroke (1.3%) and PPM (11.8%). Patients with D2 AS exhibited higher baseline conduction defects including atrial fibrillation and higher postoperative PPM than those with other subtypes.

Conclusions

Patients with D2 AS had significantly improved LVEF and QoL following TAVR at 30 days and 1 year. Postoperative rates of new PPM were higher than other subtypes, while stroke, dialysis, and mortality were lower than expected, supporting the benefit of TAVR in this high-risk group.

Transcatheter aortic valve replacement in heart failure

Patients with severe aortic stenosis (AS) may develop heart failure (HF), the presence of which has traditionally been deemed as a final stage in AS progression with poor outcomes. The use of transcatheter aortic valve replacement (TAVR) has become the preferred therapy for most patients with AS and concomitant HF. With its instant afterload reduction, TAVR offers patients with HF significant haemodynamic benefits, with corresponding changes in left ventricular structure and improved mortality and quality of life. The prognostic covariates and optimal timing of TAVR in patients with less than severe AS remain unclear. The purpose of this review is to describe the association between TAVR and outcomes in patients with HF, particularly in the setting of left ventricular systolic dysfunction, acute HF, and right ventricular systolic dysfunction, and to highlight areas for future research.

Decreased expression of RPL15 and RPL18 exacerbated the calcification of valve interstitial cells during aortic valve calcification

Calcific aortic valve disease (CAVD) is the most common valvular heart disease, with an increasing prevalence due to an aging population. The pathobiology of CAVD is a multifaceted and actively regulated process, but the detailed mechanisms have not been elucidated. The present study aims to identify the differentially expressed genes (DEGs) in calcified aortic valve tissues, and to analyze the correlation between DEGs and clinical features in CAVD patients. The DEGs were screened by microarray in normal and CAVD groups (n = 2 for each group), and confirmed by quantitative real-time polymerase chain reaction in normal (n = 12) and calcified aortic valve tissues (n = 34). A total of 1048 DEGs were identified in calcified aortic valve tissues, including 227 upregulated mRNAs and 821 downregulated mRNAs. Based on multiple bioinformatic analyses, three 60S ribosomal subunit components (RPL15, RPL18, and RPL18A), and two 40S ribosomal subunit components (RPS15 and RPS21) were identified as the top 5 hub genes in the protein-protein interaction network of DEGs. The expression of RPL15 and RPL18 was also found significantly decreased in calcified aortic valve tissues (both p < .01), and negatively correlated with the osteogenic differentiation marker OPN in CAVD patients (both p < .01). Moreover, inhibition of RPL15 or RPL18 exacerbated the calcification of valve interstitial cells under osteogenic induction conditions. The present study proved that decreased expression of RPL15 and RPL18 was closely associated with aortic valve calcification, which provided valuable clues to find therapeutic targets for CAVD.

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.

TAVI in patients with low-flow low-gradient aortic stenosis-short-term and long-term outcomes

OBJECTIVES

The study objective was to characterize different groups of low-flow low-gradient (LFLG) aortic stenosis (AS) and determine short-term outcomes and long-term mortality according to Valve Academic Research Consortium-3 (VARC-3) endpoint definitions.

BACKGROUND

Characteristics and outcomes of patients with LFLG AS undergoing transcatheter aortic valve implantation (TAVI) are poorly understood.

METHODS

All patients undergoing TAVI at our center between 2013 and 2019 were screened. Patients were divided into three groups according to mean pressure gradient (dPmean), ejection fraction (LVEF), and stroke volume index (SVi): high gradient (HG) AS (dPmean ≥ 40 mmHg), classical LFLG (cLFLG) AS (dPmean < 40 mmHg, LVEF < 50%), and paradoxical LFLG (pLFLG) AS (dPmean < 40 mmHg, LVEF ≥ 50%, SVi ≤ 35 ml/m²).

RESULTS

We included 1776 patients (956 HG, 447 cLFLG, and 373 pLFLG patients). Most baseline characteristics differed significantly. Median Society of Thoracic Surgeons (STS) score was highest in cLFLG, followed by pLFLG and HG patients (5.0, 3.9 and 3.0, respectively, p < 0.01). Compared to HG patients, odds ratios for the short-term VARC-3 composite endpoints, technical failure (cLFLG, 0.76 [95% confidence interval, 0.40-1.36], pLFLG, 1.37 [0.79-2.31]) and device failure (cLFLG, 1.06 [0.74-1.49], pLFLG, 0.97 [0.66-1.41]) were similar, without relevant differences within LFLG patients. NYHA classes improved equally in all groups. Compared to HG, LFLG patients had a higher 3-year all-cause mortality (STS score-adjusted hazard ratios, cLFLG 2.16 [1.77-2.64], pLFLG 1.53 [1.22-193]), as well as cardiovascular mortality (cLFLG, 2.88 [2.15-3.84], pLFLG, 2.08 [1.50-2.87]).

CONCLUSIONS

While 3-year mortality remains high after TAVI in LFLG compared to HG patients, symptoms improve in all subsets after TAVI.

Echocardiography and EuroSCORE II for the stratification of low-gradient severe aortic stenosis and preserved left ventricular ejection fraction

The purpose of this study was to explore the utility of echocardiography and the EuroSCORE II in stratifying patients with low-gradient severe aortic stenosis (LG SAS) and preserved left ventricular ejection fraction (LVEF ≥ 50%) with or without aortic valve intervention (AVI). The study included 323 patients with LG SAS (aortic valve area ≤ 1.0 cm² and mean pressure gradient < 40 mmHg). Patients were divided into two groups: a high-risk group (EuroSCORE II ≥ 4%, n = 115) and a low-risk group (EuroSCORE II < 4%, n = 208). Echocardiographic and clinical characteristics were analyzed. All-cause mortality was used as a clinical outcome during mean follow-up of 2 ± 1.3 years. Two-year cumulative survival was significantly lower in the high-risk group than the low-risk patients (62.3% vs. 81.7%, p = 0.001). AVI tended to reduce mortality in the high-risk patients (70% vs. 59%; p = 0.065). It did not significantly reduce mortality in the low-risk patients (82.8% with AVI vs. 81.2%, p = 0.68). Multivariable analysis identified heart failure, renal dysfunction and stroke volume index (SVi) as independent predictors for mortality. The study suggested that individualization of AVI based on risk stratification could be considered in a patient with LG SAS and preserved LVEF.