Early Surgery Versus Conventional Treatment in Very Severe Aortic Stenosis (RECOVERY)

• Cardiac mortality [ Time Frame: Entire follow-up ( a minimum of 4 years) ] [ Designated as safety issue: No ]
  defined as death from complications of myocardial infarction, heart failure, shock, complications of cardiac surgery or intervention, other cardiovascular diseases including sudden cardiac death
• Operative mortality [ Time Frame: up to 30 days after surgery ] [ Designated as safety issue: Yes ]
  Operative mortality is defined as death within 30 days of surgery.

• Cardiac mortality [ Time Frame: up to 4 years after enrollment ] [ Designated as safety issue: No ]
• Operative mortality [ Time Frame: up to 30 days after surgery ] [ Designated as safety issue: Yes ]
  Operative mortality is defined as death within 30 days of surgery.

• All-cause death [ Time Frame: Entire follow-up (a minimum of 4 years) ] [ Designated as safety issue: No ]
• Repeat aortic valve surgery [ Time Frame: Entire follow-up (a minimum of 4 years) ] [ Designated as safety issue: Yes ]
• Clinical thromboembolic events [ Time Frame: Entire follow-up (a minimum of 4 years) ] [ Designated as safety issue: Yes ]
  Diagnosis of thromboembolic events is based on clinical symptoms, signs and imaging studies.
• Hospitalization due to congestive heart failure [ Time Frame: Entire follow-up (a minimum of 4 years) ] [ Designated as safety issue: No ]
  A hospitalization due to congestive heart failure is defined as an unplanned, urgent admission for the management of congestive heart failure.

• All-cause death [ Time Frame: up to 4 years after enrollment ] [ Designated as safety issue: No ]
• Repeat aortic valve surgery [ Time Frame: up to 4 years after enrollment ] [ Designated as safety issue: Yes ]
• Clinical thromboembolic events [ Time Frame: up to 4 years after enrollment ] [ Designated as safety issue: Yes ]
  Diagnosis of thromboembolic events is based on clinical symptoms, signs and imaging studies.
• Hospitalization due to congestive heart failure [ Time Frame: up to 4 years after enrollment ] [ Designated as safety issue: Yes ]
  A hospitalization due to congestive heart failure is defined as an unplanned, urgent admission for the management of congestive heart failure.

The optimal timing of surgical intervention remains controversial in asymptomatic patients with very severe aortic stenosis. The investigators therefore try to compare long-term clinical outcomes of early surgery with those of conventional treatment strategy in a prospective randomized trial.

Management of asymptomatic patients with severe aortic stenosis (AS) remains controversial, and the combined risks of aortic valve surgery and late complications of aortic valve prosthesis need to be balanced against the possibility of preventing sudden death and lowering cardiac mortality. Considering that sudden cardiac death occurs at a rate of approximately 1% per year and that the average postoperative mortality of isolated AV replacement is 3.0-4.0%, the 2007 European Society of Cardiology guidelines do not recommend aortic valve surgery for asymptomatic patients with severe AS and the 2006 American College of Cardiology/American Heart Association guidelines recommend surgery as a class IIb indication only in patients with extremely severe AS and who are at low operative risk. Clinical outcomes vary widely according to the severity of stenosis in asymptomatic AS, and asymptomatic patients with very severe AS are often referred for aortic valve replacement in clinical practice despite the lack of data supporting early surgery. Rosenhek et al recently reported a worse prognosis with a higher event rate and a risk of rapid deterioration in very severe AS, and the investigators also recently reported that compared with the conventional treatment strategy, early surgery in patients with very severe AS is associated with an improved long-term survival in a prospective, observational study. However, there have been no prospective,randomized studies comparing early surgery with a watchful waiting strategy in very severe AS. We sought to compare long-term clinical outcomes of early surgery with those of conventional management based on current guidelines.

• No Intervention: Conventional treatment
  In the conventional treatment group, indications for aortic valve replacement surgery are development of symptoms, reduced left ventricular systolic function and an increase in aortic jet velocity > 0.5 m/sec during follow-up.
• Active Comparator: Early Surgery
  Early surgery is performed within 2 months of randomization.
  Intervention: Procedure: Early surgery

Inclusion Criteria:

• asymptomatic patients with very severe aortic stenosis who are potential candidates for early surgery. Very severe aortic stenosis are defined as a critical stenosis in the AV area ≤ 0.75 square centimeter fulfilling one of the following criteria; a peak aortic velocity ≥ 4.5 m/sec or a mean transaortic pressure gradient ≥ 50 mmHg on Doppler echocardiography.

Exclusion Criteria:

• Exertional dyspnea
• Angina
• Syncope
• Left ventricular ejection fraction < 50%
• Significant aortic regurgitation
• Significant mitral valve disease
• Pregnancy
• Age < 20 years or > 80 years
• Coexisting malignancies