The purpose of this study is to narrow the gap between patients being diagnosed with severe aortic stenosis and those being appropriately monitored and treated. For this purpose a prospective survey of current practice (3 months) will be conducted followed by a six month period of intervention during which a variety of quality improvements measures will be implemented. There will then be a 3 month follow-up period during which the legacy of this initiative will be monitored during which no intervention will be carried out.

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

Inclusion Criteria:

• Aortic valve area < 1cm2
• Indexed aortic valve area <0.6 cm/m2
• Maximum Jet velocity > 4.0 m/sec
• Mean transvalvular gradient > 40 mmHg

Exclusion Criteria:

• Non-severe aortic Stenosis (AS)
• Previous aortic valve replacement (AVR)

Adults aged over 18years identified on echocardiography with severe AS