Aortic Valve Replacement Versus Conservative Treatment in Asymptomatic Severe Aortic Stenosis: The AVATAR Trial.

BACKGROUND: Surgical aortic valve replacement (SAVR) represents a class I indication in symptomatic patients with severe aortic stenosis (AS). However, indications for early SAVR in asymptomatic patients with severe AS and normal left ventricular function remain debated. METHODS: The AVATAR trial (Aortic Valve Replacement Versus Conservative Treatment in Asymptomatic Severe Aortic Stenosis) is an investigator-initiated international prospective randomized controlled trial that evaluated the safety and efficacy of early SAVR in the treatment of asymptomatic patients with severe AS, according to common criteria (valve area ≤1 cm2 with aortic jet velocity >4 m/s or a mean transaortic gradient ≥40 mm Hg), and with normal left ventricular function. Negative exercise testing was mandatory for inclusion. The primary hypothesis was that early SAVR would reduce the primary composite end point of all-cause death, acute myocardial infarction, stroke, or unplanned hospitalization for heart failure compared with a conservative strategy according to guidelines. The trial was designed as event-driven to reach a minimum of 35 prespecified events. The study was performed in 9 centers in 7 European countries. RESULTS: Between June 2015 and September 2020, 157 patients (mean age, 67 years; 57% men) were randomly allocated to early surgery (n=78) or conservative treatment (n=79). Follow-up was completed in May 2021. Overall median follow-up was 32 months: 28 months in the early surgery group and 35 months in the conservative treatment group. There was a total of 39 events, 13 in early surgery and 26 in the conservative treatment group. In the early surgery group, 72 patients (92.3%) underwent SAVR with operative mortality of 1.4%. In an intention-to-treat analysis, patients randomized to early surgery had a significantly lower incidence of primary composite end point than those in the conservative arm (hazard ratio, 0.46 [95% CI, 0.23-0.90]; P=0.02). There was no statistical difference in secondary end points, including all-cause mortality, first heart failure hospitalizations, major bleeding, or thromboembolic complications, but trends were consistent with the primary outcome. CONCLUSIONS: In asymptomatic patients with severe AS, early surgery reduced a primary composite of all-cause death, acute myocardial infarction, stroke, or unplanned hospitalization for heart failure compared with conservative treatment. This randomized trial provides preliminary support for early SAVR once AS becomes severe, regardless of symptoms. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT02436655.

Rationale and design of the Aortic Valve replAcemenT versus conservative treatment in Asymptomatic seveRe aortic stenosis (AVATAR trial): A randomized multicenter controlled event-driven trial.

Aortic valve replacement (AVR) therapy is an obvious choice for symptomatic severe aortic stenosis (AS) patients as it improves symptoms, left ventricular function, and survival. The treatment decisions and indication for AVR in asymptomatic patients with severe AS and normal left ventricular ejection fraction are less well established and the subject of ongoing debate. Many efforts have been made to define the best treatment option in asymptomatic AS patients with normal left ventricular ejection fraction. Retrospective and observational data imply that elective AVR for asymptomatic severe AS may lead to improvement in outcomes in comparison to surgery performed after onset of symptoms. The AVATAR trial will aim to assess outcomes among asymptomatic AS patients randomized to either elective early AVR or medical management with vigilant follow-up. In the latter group, AVR would be delayed until either the onset of symptoms or changes in predefined echocardiographic parameters. To the best of the authors' knowledge, it will be the first large prospective, randomized, controlled, multicenter clinical trial that will evaluate the safety and efficacy of elective AVR in this specific group of patients.

Treatment Strategies in Symptomatic Intermediate, Low-Risk, and Asymptomatic Patients With Severe Aortic Stenosis.

Survival of symptomatic patients with severe aortic stenosis (AS) is very poor, with an average mortality reaching up to 2% per month. Approach to diagnosis and treatment of patients with AS was conservative; patients were referred to surgery only if the AS-induced symptoms become apparent and significantly limit the quality of patient' life. In the past 15 years, the novel treatment strategy in subgroups of symptomatic patients with AS have been the subject of extensive research, starting from introduction of transcatheter aortic valve implant (TAVI) in inoperable symptomatic patients with severe AS and continuing further to patients with very high and high operative risk. In the past few years, the focus has further shifted toward the patients with lower operative risk, as well as to asymptomatic patients with severe AS. In the former group, the question relates to whether TAVI is beneficial when compared to SAVR in intermediate- to low-risk patients with symptomatic AS. In the latter group, the main issue is if and when the SAVR should be performed. This article analyzes current status and evidences regarding treatment strategies in symptomatic high, intermediate, low-risk, and asymptomatic patients with isolated severe AS.

Percutaneous Treatment of Aortic Valve Disease: Contemporary Overview and Future Trends.

Efforts to develop and refine percutaneous approaches to cardiac valve repair and replacement have advanced rapidly over the past several years, having exceeded even the most optimistic expectations. New innovations have been predominantly directed toward the most frequent form of valvular heart disease (VHD) in the industrialized world; aortic stenosis (AS). Approximately 250,000 transcatheter aortic valve implantation (TAVI) procedures have been done so far addressing this significant medical need. Because of the predominance of degenerative etiologies, the prevalence of VHD increases markedly in population above the age of 65 years, in particular with regard to severe AS. As the populations of the industrialized countries continue to be older, the need for less invasive and safer methods of treating severe AS will continue to grow. In this review we provide comprehensive and up-to-date overview of TAVI in current clinical practice. We have also addressed dilemmas and unanswered questions related to TAVI procedures in different groups of patients and highlighted opportunities and trends related to future TAVI implementation.