Response by Banovic et al to Letter Regarding Article, "Aortic Valve Replacement Versus Conservative Treatment in Asymptomatic Severe Aortic Stenosis: The AVATAR Trial"

[Update on the treatment of aortic valve stenosis in symptomatic and asymptomatic patients]

Aortic valve stenosis is one of the most frequent valvular heart diseases requiring treatment in industrialized countries. The symptom onset is associated with a significantly increased mortality, so that there is a clear indication for treatment in patients with severe, symptomatic aortic valve stenosis; however, data on the optimal treatment of patients with asymptomatic aortic valve stenosis are scarce. Smaller studies in the field of cardiac surgery suggest that early surgical valve replacement is superior to a conservative approach. For this reason, the results of additional adequately powered randomized trials are awaited with great interest. In this year numerous long-term results from randomized comparisons of the two available treatment options (surgical versus transcatheter aortic valve replacement) were published, which will further guide the heart team to find the best treatment approach for each individual.

Systematic review and meta-analysis of early aortic valve replacement versus conservative therapy in patients with asymptomatic aortic valve stenosis with preserved left ventricle systolic function

BACKGROUND

A quarter of patients with severe aortic stenosis (AS) were asymptomatic, and only a third of them survived at the end of 4 years. Only a select subset of these patients was recommended for aortic valve replacement (AVR) by the current American College of Cardiology/American Heart Association guidelines. We intended to study the effect of early AVR (eAVR) in this subset of asymptomatic patients with preserved left ventricle function.

METHODS AND RESULTS

We searched PubMed and Embase for randomised and observational studies comparing the effect of eAVR versus conservative therapy in patients with severe, asymptomatic AS and normal left ventricular function. The primary outcome was all-cause mortality. The secondary outcomes were composite major adverse cardiac events (MACE) (study defined), myocardial infarction (MI), stroke, cardiac death, sudden death, the development of symptoms, heart failure hospitalisations and major bleeding. We used GRADEPro to assess the certainty of the evidence. In the randomised controlled trial (RCT) only analysis, we found no significant difference in all-cause mortality between the early aortic intervention group versus the conservative arm (CA) (incidence rate ratio, IRR (CI): 0.5 (0.2 to 1.1), I2=31%, p=0.09). However, in the overall cohort, we found mortality benefit for eAVR over CA (IRR (CI): 0.4 (0.3 to 0.7), I2=84%, p<0.01). There were significantly lower MACE, cardiac death, sudden death, development of symptoms and heart failure hospitalisations in the eAVR group. We noticed no difference in MI, stroke and major bleeding.

CONCLUSION

We conclude that there is no reduction in all-cause mortality in the eAVR arm in patients with asymptomatic AS with preserved ejection fraction. However, eAVR reduces heart failure related hospitalisations and death or heart failure hospitalisations.

PROSPERO REGISTRATION NUMBER

CRD42022306132.

Acute Coronary Syndrome Following Transcatheter Aortic Valve Replacement

Extending the indication of transcatheter aortic valve replacement (TAVR) to younger and lower-risk patients naturally results in longer life expectancy and survival rates after the intervention. The longer life expectancy of these patients leads to an increased possibility of future acute coronary events, necessitating the development of effective and appropriate treatment strategies. Acute coronary syndromes (ACS) in patients with previous TAVR procedures present with modified clinical characteristics when compared to the non-TAVR population. In populations with prior TAVR procedures, plaque rupture remains the main cause of ACS. However, unlike the non-TAVR population, there is an increased frequency of nonatherotrombotic mechanisms, like emboli and mechanical obstruction of coronary ostia by valve components. The main observation related to the treatment of ACS TAVR patients is the significantly lower percentage of patients undergoing invasive management. Furthermore, ACS in TAVR patients is associated with poor prognosis, higher long-term mortality rates, and higher incidence of MACE. It is surprising that considering this significant and increasingly recognized issue, there are only a few studies that have investigated ACS after TAVR. The scope of the present review is to address available data about ACS following TAVR, focusing on incidence, timing, mechanism, and causes. We also examined current knowledge regarding optimal invasive treatment and analyzed short and long-term clinical outcomes.

Optimal treatment of asymptomatic patients with severe aortic stenosis: protocol of a prospective, multicentre, registry study

INTRODUCTION

Decisions regarding the optimal timing of intervention for asymptomatic aortic stenosis (AS) are controversial. The study aims to identify potential risk factors for asymptomatic patients with severe AS that are associated with worse prognosis and to evaluate the benefits of early interventions for asymptomatic patients presenting with one or more additional risk factors.

METHODS AND ANALYSIS

This is a non-interventional, prospective, open-label, multicentre registry study across China. A total of 1000 patients will be enrolled and categorised as symptomatic or asymptomatic. The primary endpoint is the occurrence of all-cause mortality, stroke, acute myocardial infarction and heart failure-related hospitalisation at 1-year follow-up. In asymptomatic severe AS patients presenting with one or more risk factors, the occurrence rate of the primary endpoint between those who undergo transcatheter aortic valve replacement (TAVR) and those who do not will be compared. We will also compare the occurrence rate of the primary endpoint for asymptomatic severe AS patients with additional risk factors who undergo TAVR with those presenting with symptoms. This study is believed to provide additional evidence to help clinicians identify and refer severe AS patients who are asymptomatic but present with additional risk factors for early intervention of TAVR.

ETHICS AND DISSEMINATION

The study protocol has been approved by the local ethics committee of each participating site: West China Hospital, Sichuan University; Sir Run Run Shaw Hospital, Zhejiang University School of Medicine; Second Hospital of Hebei Medical University; Tianjin Chest Hospital; and First Affiliated Hospital of Nanchang University. All participants will provide written informed consent. Study results will be published through academic conferences and peer-reviewed journals.

TRIAL REGISTRATION

This study was registered at the Chinese Clinical Trial Registry (https:// www.chictr.org.cn), with the registration number ChiCTR2200064853.

Ultra-low radiation dose and contrast volume CT protocol and TAVI-CT score for TAVI planning and outcome

OBJECTIVE

To investigate the feasibility of an ultra-low radiation dose and contrast volume protocol using third-generation dual-source (DS) CT for transcatheter aortic valve implantation (TAVI) planning with coronary artery disease (CAD) assessment, coronary artery calcium score (CACS) and aortic valve calcium score (AVCS) quantification and to evaluate their relationship with TAVI outcome.

METHODS

In this retrospective study were selected 203 patients (131 males, 79.4 ± 5.4 years) underwent to TAVI and at 30- and 90-day follow-up. All patients had performed a third-generation 2 × 192-slices DSCT. The CT protocol included a non-contrast and a contrast high-pitch aortic acquisition for TAVI planning and CAD assessment. Semi-qualitative and quantitative image analysis were performed; the performance in CAD assessment was compared with ICA; the relationship between AVCS and CACS and paravalvular aortic regurgitation (PAR) and major cardiovascular events (MACEs) were evaluated. Mean radiation dose were calculated. Non-parametric tests were used.

RESULTS

Semi-qualitative image analysis was good. Contrast enhancement >500 Hounsfield unit (HU) and contrast-to-noise ratio <20 were obtained in all segments. The diagnostic accuracy in CAD was 89.0%. AVCS was significantly higher in patients with 30-day severe PAR. AVCS and CACS were higher in patients with 90-day MACE complications, respectively, 1904.5 ± 621.3 HU (p < 0.0001) and 769.2 ± 365.5 HU (p < 0.0230). Mean radiation dose was 2.8 ± 0.3 mSv.

CONCLUSION

A TAVI planning ultra-low radiation dose and contrast volume protocol using third-generation DSCT provides highly diagnostic images with CAD assessment, AVCS and CACS quantification and these latter were related with TAVI outcomes.

ADVANCES IN KNOWLEDGE

The proposed protocol using third-generation 2 × 192-slices DSCT allows with an ultra-low radiation dose and contrast volume the TAVI planning and the coronary artery assessment.