Skip to content

Aortic Valve Replacement Versus Conservative Treatment in Asymptomatic Severe Aortic Stenosis

Aortic Valve Replacement Versus Conservative Treatment in Asymptomatic Severe Aortic Stenosis: (AVATAR Trial): A Multicentre Randomized Controlled Trial

Status
Completed
Phases
NA
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT02436655
Acronym
AVATAR
Enrollment
157
Registered
2015-05-07
Start date
2015-06-30
Completion date
2021-05-31
Last updated
2022-01-12

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Aortic Stenosis

Keywords

aortic stenosis, normal ejection fraction, asymptomatic

Brief summary

Whether to intervene in asymptomatic patients with severe aortic stenosis and normal left ventricular ejection fraction remains controversial. The investigators therefore try to compare clinical outcomes of elective aortic valve replacement to conventional treatment and watchful waiting strategy in a prospective randomized trial.

Detailed description

Aortic valve replacement (AVR) therapy is obvious choice in symptomatic severe aortic stenosis (AS) patients, because it improves symptoms, LV function and survival. Therefore, the accurate diagnosis of the disease, determination of its severity and precise evaluation of patients' clinical status is essential. However, the treatment decisions and indication for AVR in asymptomatic patients with severe AS and normal left ventricular ejection fraction (LV EF) are vague and the subject of ongoing debate. The most recent European and American guidelines have class I indication for AVR in asymptomatic severe AS patients with normal LV EF only in patients already scheduled for other cardiac surgery (for example by-pass surgery). In the case of symptom positive stress test American and European guideline differs, with European guidelines having class I indication and American guidelines only IIb indication. In all those cases of asymptomatic severe AS patients with normal LV EF the level of evidence is C, in other words there are no randomized trials. The consequence is that the decisions are made individually, patient by patient, and for this reason a patient with identical echocardiographic/clinical characteristics might be operated in USA but not in Europe (or any other part in the world), and vice-versa. With the experience that has accumulated so far, there are retrospective and observational data that elective AVR might lead to favorable outcome compared to late (after symptom onset) surgery. This may especially come to attention with the understanding that annual risk of sudden cardiac death in asymptomatic severe AS patients with normal LV EF might be very similar or even a bit higher than operative mortality in experienced cardiac surgery centers. Nevertheless, the majority of cardiologist worldwide are reluctant to send their asymptomatic patient with isolated severe AS and normal LV EF to AVR, and it will probably stay like that till randomized trials give us an answer whether elective AVR is beneficial.

Interventions

open heart aortic valve replacement

Sponsors

Clinical Centre of Serbia
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
NONE

Eligibility

Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No

Inclusion criteria

* men and women of any ethnic origin aged ≥18 years * Written informed consent * V max across the aortic valve \> 4m/s or Pmean ≥ 40mmHg and AVA ≤ 1cm2 or AVAi ≤ 0.6cm2/m2 at rest * Without reported symptoms * Society of Thoracic Surgeons (STS) score \< 8%

Exclusion criteria

* Participation in another clinical trial within 30 days prior randomization * Pregnant or nursing women * Mental condition rendering the patient unable to understand the nature, scope and possible consequences of the study or to follow the protocol * Positive stress-test defined as: 1. Anginal chest pain during testing 2. Syncope, dizziness during testing 3. Decrease in systolic blood pressure during exercise ≥ 20mmHg 4. Malignant arrhythmia during exercise testing (VT or VF) * Left ventricular ejection fraction \< 50% at rest * Very severe AS (defined as Vmax \> 5.5 m/s at rest) * Significant disease of other valves (Mitral stenosis with Pmean \> 5mg, or any significant regurgitation ≥ 3+ * Recent AMI (\< 1 year) * Need for additional by-pass surgery or for aortic root replacement (i.e Bentall) or ascending aorta in asymptomatic patients undergoing AVR * Previous by-pass surgery * Previous any heart valve surgery * Impaired renal function, i.e. creatinine \>200 µmol/L or glomerular filtration rate \< 30 mL/min/1.73 m2 * Significant pulmonary hypertension at rest (PASP \> 50mmHg) * Uncontrolled hypertension at rest (systolic \>180 mmHg and diastolic \>100 mmHg) * Significant co-morbidity with reduced life expectance (\< 3 years) * Uncontrolled Diabetes Mellitus (HbA1C \> 9 %) * Significant COPD (FEV1 \< 70% of predicted value) * Permanent or paroxysmal atrial fibrillation

Design outcomes

Primary

MeasureTime frame
all cause death, Major Adverse Cardiac Event (MACE) including: ( Acute Myocardial Infarction - AMI, Stroke - CVI, unplanned hospitalization for Heart failure (HF) needing intravenous treatment36 months

Secondary

MeasureTime frame
repeat aortic valve surgery in operated patients in both groups5 years
major bleeding according to consensus report from the Bleeding Academic Research Consortium5 years
in-hospital and 30 days operative mortality in operated patients in both groups30 days
repeated major adverse cardiovascular events5 years
all-cause death + heart failure hospitalization5 years
thromboembolic complications based on clinical symptoms, signs and imaging studies5 years

Countries

Belgium, Croatia, Czechia, France, Ireland, Italy, Lithuania, Poland, Serbia

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 26, 2026