Aortic valve replacement in small aortic root- Bi-leaflet mechanical valve is superior to a Mono-leaflet mechanical valve

Background

Patient prosthetic mismatch is a serious but avoidable complication of surgical aortic valve replacement (SAVR) complicated by a small aortic annulus. This study aims to compare early and midterm outcomes following aortic valve replacement (AVR) with a mono-leaflet (ML) valve and a bi-leaflet (BL) valve in a small aortic root.

Methods and selection

From January 1st, 2017 to December 31st, 2019, 98 patients diagnosed with small aortic root underwent isolated aortic valve replacement with either TTK Chitra valve (Mono-leaflet/ ML group) or St. Jude medical valve (Bi-leaflet/ BL group) of size 17/ 19 mm. Echocardiography was analyzed from medical records and telephonic follow-up.

Results

Baseline parameters were comparable. The ML group had 42 patients and the BL group had 56 patients. Aortic cross-clamp time, the incidence of severe patient prosthetic mismatch (p = 0.002) and mean, peak pressure gradients were high in the ML group. Duration of ventilation, intensive care unit (ICU) stay, the incidence of stroke, need for intra-aortic balloon pump, permanent pacemaker, dialysis, and left ventricular mass index in echocardiography were comparable between the two groups postoperatively. There was no early mortality in both group. Survival at the end of 5 years was 57 ± 14.4% in the ML group; 91.8 ± 4% in the BL group (p = 0.005). Univariate and multivariate analysis revealed elderly age as a risk factor for mortality.

Conclusion

We conclude that aortic valve replacement without any root widening procedure, using a small-sized mechanical valve provides acceptable early outcomes. Bi-leaflet mechanical valves provide better hemodynamics and survival percentage.

Energy loss index as a predictor of all-cause mortality after transcatheter aortic valve replacement: A long-term follow-up

BACKGROUND

As transcatheter aortic valve replacement (TAVR) procedures become more widely available, there is a growing need to monitor and evaluate postoperative outcomes accurately. The energy loss index (ELI) of the ascending aorta has been commonly used to examine the agreement between the echocardiographic and Gorlin measurement of the aortic valve area.

OBJECTIVES

This project aims to demonstrate a link between ELI values and mortality following implanted TAVR valves and determine an ELI cutoff value associated with post-TAVR events.

METHOD

We retrospectively reviewed patients undergoing TAVR from 2012 to 2017. We calculated ELI values for patients immediately postoperative after a TAVR procedure. Using Receiver-Operator Characteristic and Cox Regression analyses, we identified a cutoff value to distinguish between "High ELI" (≥ 1.34) and "Low ELI" (< 1.34) patients.

RESULTS

This study showed low ELI (hazard ratio, 2.30; 95% confidence interval 1.57-3.36, p < .001) as representative of patients with a high risk of mortality post-TAVR. Additionally, post-TAVR, ejection fraction increased by 3.6% (p < .001), and the aortic valve effective orifice area increased by 1.41 cm squared (p < .001) while the mean transvalvular gradient decreased by 32.8 mmHg (p < .001) and the peak transvalvular gradient decreased by 49.0 mmHg (p < .001).

CONCLUSION

ELI is an additional prognostic factor that should be considered during risk assessment before TAVR. This study shows that patients with Low ELI had decreased cumulative survival post-TAVR. These patients almost had a fivefold increased risk of death following TAVR.

Multimodality Imaging to Explore Sex Differences in Aortic Stenosis

The aim of this article is to review sex differences in aortic stenosis (AS) assessed with multimodality imaging. Echocardiography remains the mainstay imaging technique to diagnose AS and provides important insights into the differences between men and women in relation to valve haemodynamic and left-ventricular response. However, echocardiography does not have adequate resolution to provide important insights into sex differences in the degenerative, calcific pathophysiological process of the aortic valve. CT shows that women with AS have more fibrotic changes of the aortic valve whereas men show more calcific deposits. Cardiac magnetic resonance shows that women have left ventricles that are less hypertrophic and smaller compared with those of men, while men have more replacement myocardial fibrosis. These differences may lead to different responses to aortic valve replacement because myocardial diffuse fibrosis but not replacement myocardial fibrosis may regress after the procedure. Sex differences in the pathophysiological process of AS can be assessed using multimodality imaging, assisting in decisionmaking in these patients.

Grading of Aortic Stenosis: Is it More Complicated in Women?

Aortic stenosis (AS) is the most common valvular heart disease and the main indication for valvular replacement in older women. Correct AS grading is mandatory for an adequate selection of patients for both surgical and transcatheter aortic valve replacement. Women and men have different AS severity grades at the same level of aortic valve calcification. Moreover, besides having smaller cardiac volumes, left ventricular outflow tract and aortic size, women have a specific pattern of left ventricular structural and functional remodelling in response to the AS-related chronic pressure overload. Here, the sex-specific cardiac changes in AS that make AS grading more challenging in women, with consequences for the management and outcome of this group of patients, are reviewed.

Impact of aortic annular size and valve type on haemodynamics and clinical outcomes after transcatheter aortic valve implantation

Introduction: Data on patients with small aortic annuli (SAA) undergoing transcatheter aortic valve implantation (TAVI) are limited. We aim to describe the impact of aortic annular size, particularly SAA and TAVI valve type on valve haemodynamics, durability and clinical outcomes. Method: All patients in National Heart Centre Singapore who underwent transfemoral TAVI for severe symptomatic native aortic stenosis from July 2012 to December 2019 were included. Outcome measures include valve haemodynamics, prosthesis-patient mismatch (PPM), structural valve degeneration (SVD) and mortality. Results: A total of 244 patients were included. The mean Society of Thoracic Surgeons score was 6.22±6.08, with 52.5% patients with small aortic annulus (<23mm), 33.2% patients with medium aortic annulus (23–26mm) and 14.3% patients with large aortic annulus (>26mm). There were more patients with self-expanding valve (SEV) (65.2%) versus balloon-expandable valve (BEV) (34.8%). There were no significant differences in indexed aortic valve area (iAVA), mean pressure gradient (MPG), PPM, SVD or mortality across all aortic annular sizes. However, specific to the SAA group, patients with SEV had larger iAVA (SEV 1.19±0.35cm2/m2 vs BEV 0.88±0.15cm2/m2, P<0.01) and lower MPG (SEV 9.25±4.88 mmHg vs BEV 14.17±4.75 mmHg, P<0.01) at 1 year, without differences in PPM or mortality. Aortic annular size, TAVI valve type and PPM did not predict overall mortality up to 7 years. There was no significant difference in SVD between aortic annular sizes up to 5 years. Conclusion: Valve haemodynamics and durability were similar across the different aortic annular sizes. In the SAA group, SEV had better haemodynamics than BEV at 1 year, but no differences in PPM or mortality. There were no significant differences in mortality between aortic annular sizes, TAVI valve types or PPM. Keywords: Aortic stenosis, small aortic annulus, transcatheter aortic valve implantation

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 (AVA_echo) and by CT (AVA_CT) 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 AVA_CT. 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 AVA_CT. The classic LF-LG AS group presented larger AVA_CT and aortic annulus than those in high-gradient severe AS group and one third of them had AVA_CT ≥ 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.

New Evidence About Aortic Valve Stenosis and Cardiovascular Hemodynamics

Aortic stenosis (AS) is the most common degenerative valvular disease in western word. In patients with severe AS, small changes in aortic valve area can lead to large changes in hemodynamics. The correct understanding of cardiac hemodynamics and its interaction with vascular function is of paramount importance for correct identification of severe AS and to plan effective strategies for its treatment. In the current review with highlight the importance of pressure recovery phenomenon and valvular arterial impedance as novel tools in the evaluation of patients with aortic stenosis.

Expansion of TAVR into Low-Risk Patients and Who to Consider for SAVR

Transcatheter aortic valve replacement (TAVR) has revolutionized the treatment of severe aortic stenosis (AS) over the last decade. The results of the Placement of Aortic Transcatheter Valves (PARTNER) 3 and Evolut Low Risk trials demonstrated the safety and efficacy of TAVR in low-surgical-risk patients and led to the approval of TAVR for use across the risk spectrum. Heart teams around the world will now be faced with evaluating a deluge of younger, healthier patients with severe AS. Prior to the PARTNER 3 and Evolut Low Risk studies, this heterogenous patient population would have undergone surgical aortic valve replacement (SAVR). It is unlikely that TAVR will completely supplant SAVR for the treatment of severe AS in patients with a low surgical risk, as SAVR has excellent short- and long-term outcomes and years of durability data. In this review, we outline the critical role that SAVR will continue to play in the treatment of severe AS in the post-PARTNER 3/Evolut Low Risk era.

Low systemic arterial compliance is associated with increased cardiovascular morbidity and mortality in aortic valve stenosis

Objective

Lower systemic arterial compliance (SAC) is associated with increased cardiovascular morbidity and mortality in hypertension, but this has not been assessed in a prospective study in aortic valve stenosis (AS).

Methods

Data from 1641 patients (38% women) with initially asymptomatic mild-moderate AS enrolled in the Simvastatin and Ezetimibe in Aortic Stenosis study was used. Median follow-up was 4.3 years. SAC was assessed from Doppler stroke volume index to central pulse pressure ratio and considered low if ≤0.64 mL/m², corresponding to the lower tertile in the population. The association of SAC with outcome was assessed in Cox regression analysis and reported as HR and 95% CI.

Results

Low SAC at baseline was characterised by older age, female sex, hypertension, obesity, presence of a small aortic root, lower mean aortic gradient and more severe AS by effective aortic valve area (all p<0.01). In Cox regression analysis adjusting for factors, low SAC was associated with higher HRs for cardiovascular death (HR 2.13(95% CI 1.34 to 3.40) and all-cause mortality (HR 1.71(95% CI 1.23 to 2.38)), both p=0.001). The results did not change when systolic or diastolic blood pressure, other measures of AS severity or presence of discordantly graded AS were included in subsequent models. Presence of low SAC did not improve mortality prediction in reclassification analysis.

Conclusions

In patients with AS without diabetes and known cardiovascular disease, but a high prevalence of hypertension, low SAC was associated with higher cardiovascular and all-cause mortality independent of well-known prognosticators.

Trial registration number

NCT00092677; Post-results.