Aortic Valve Replacement Versus Conservative Treatment in Asymptomatic Severe Aortic Stenosis: The AVATAR Trial
Authors: Banovic Marko , Putnik Svetozar , Penicka Martin , Doros Gheorghe , Deja Marek A. , Kockova Radka , Kotrc Martin , Glaveckaite Sigita , Gasparovic Hrvoje , Pavlovic Nikola , Velicki Lazar , Salizzoni Stefano , Wojakowski Wojtek , Van Camp Guy , Nikolic Serge D. , Iung Bernard , Bartunek Jozef , Barbato Emanuele , De Bruyne Bernard , Casselman Filip , De Grieck Ivan , Heyse Alex , Stockman Bernard , Vanderheyden Marc , Van Durme Frederik , Van Praet Frank , Wyffels Eric , Biocina Bojan , Manola Sime , Pirk Jan , Cura-Stura Erik , Rinaldi Mauro , Maria De Ferrari Gaetano , Fava Antonella , Maria Richiardi Elena , Celutkiene Jelena , Filipova Marta , Ciosek Joanna , Guzy Michal , Kurzelowski Radoslaw , Wojakowski Wojtek , Bjelobrk Marija , Ilic Aleksandra , Kovacevic Mila , Miljkovic Tatjana , Preveden Andrej , Srdanovic Ilija , Aleksandric Srdjan , Asanin Milika , Beleslin Branko , Bojanic Milica , Boskovic Nikola , Bosic Sladjana , Cvetinovic Natasa , Dedovic Vladimir , Giga Vojislav , Jandric Predrag , Jaukovic Milena , Jovanovic Miodrag , Kovacevic-Kuzmanovic Ana , Loncar Goran , Manojlovic Andrea , Matkovic Milos , Mitrovic Predrag , Nedeljkovic Ivana , Nedeljkovic Milan , Petrovic Olgica , Ristic Arsen , Seper Mirjana , Simic Dragan , Stankovic Sanja , Stojkovic Sinisa , Vukcevic Vladan , Zivic Katarina 
Published: November 2021

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 cm
2
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.