Study to Improve Outcomes in Aortic Stenosis. International, Multi-center, Prospective, Observation and Interventional Cohort Registry

All patients meeting pre-specified criteria (severe aortic stenosis whether with or without symptoms) will be collected. There will be three phases at each site observation A, intervention, observation B. Observation A: In this phase, the nurse identifies cases with severe AS and collects their data. Baseline data for each patient will be collected and a follow-up will be done after three months for each patient to determine his/her outcome and the treatment that was decided on. There will also be an optional telephone follow-up to find out the patient's outcome.

Intervention: In this phase, the physician referring a patient for echocardiography will be notified of a finding of severe aortic stenosis: the nurse brings cases with severe AS to the attention of the referring physician within a week (via phone, e-mail or letter) to make them aware of the diagnosis.

Baseline and follow-up data will be collected for each patient as before. Moreover, more detailed data with regard to the patient's health status will be documented.

Observation B: Same as Observation Phase A