Mild and moderate aortic stenosis. Natural history and risk stratification by echocardiography

To define the natural history and predictors of outcome in mild and moderate aortic stenosis (AS).

One hundred and seventy-six consecutive asymptomatic patients (73 women, age 58+/-19 years) with mild to moderate AS (jet velocity 2.5 to 3.9m/s) were followed for 48+/-19 months. Haemodynamic progression and clinical outcome was analysed. Event-free survival with end-points defined as death (n=34) or aortic valve surgery (n=33), was 95+/-2%, 75+/-3% and 60+/-5% at 1, 3 and 5 years, respectively. Both, cardiac and non-cardiac mortality were significantly increased, resulting in a 1.8 times higher mortality than expected (P<0.005). By multivariate analysis, moderate to severe aortic valve calcification, coronary artery disease (CAD) and peak jet velocity were independent predictors of outcome. Event-free survival for patients with moderate or severe valve calcification was 92+/-4%, 61+/-7% and 42+/-7% at 1, 3 and 5 years versus 100%, 90+/-4% and 82+/-5% for patients with no or mild calcification. Patients with calcified aortic valves, CAD or with an event had a significantly faster haemodynamic progression. Of 129 patients with a follow-up echocardiographic exam, 59 (46%) developed severe stenosis during follow-up.

Outcome of mild and moderate AS is worse than commonly assumed. Rapid progression and excess mortality have to be considered. Significant valve calcification, CAD and rapid progression of aortic jet velocity indicate poor outcome. Patients with these characteristics may require closer follow-up than generally assumed.