AoS-SEDAI study is an observational, multicenter, retrospective and prospective clinical study.

This study aims to assess Willem Artificial Intelligence (AI) ability to distinguish between aortic stenosis (AS) and non-AS patients from 12-lead electrocardiogram (ECG) data.

Aortic Stenosis (AS) is a common and progressive valvular heart disease, especially in older adults, yet significantly underdiagnosed. Many individuals with significant AS may remain asymptomatic for extended periods or experience vague symptoms, delaying diagnosis for several years. In some cases, sudden cardiac events or decompensation may be the first indication of advanced AS, particularly in those who have not undergone regular cardiovascular evaluation.

The primary method for diagnosing AS is echocardiography, which allows visualization of valve anatomy and assessment of transvalvular gradients. However, reliance on symptom reporting or late-stage signs, that trigger a provider to order an echo, can result in missed opportunities for earlier detection. Additionally, electrocardiographic changes-such as left ventricular hypertrophy or strain patterns-can often be detected before structural abnormalities are visible on imaging studies. This delay between electrical changes evolution and later structural findings creates a valuable opportunity to intervene sooner, for example with a valve replacement. This diagnostic latency highlights a critical window where early identification through Artificial Intelligence (AI) analysis of electrocardiograms (ECGs) and timely referral to cardiology can significantly alter disease trajectory and improve outcomes, especially in primary care and community health settings.

AoS-SEDAI study is an observational, retrospective and prospective, multicenter clinical study. Even though controls will be distinguished from AS patients for ground truth and performance evaluation, this is a single-arm study since there are no differences in study interventions.

Inclusion Criteria:

• Age ≥ 18 years;
• All available 12-lead ECG with a 10 seconds minimum length on raw data digital format will be included
• Available clinical data corresponding to each ECG to confirm patient demographics and Aortic Stenosis diagnosis
• Available transthoracic echocardiogram (TTE) within +/- 90 days of each ECG recording

No exclusion criteria are defined for this study.

The target population consists of patients under assessment of Aortic Stenosis (AS).

Screened patients need to have 12-lead ECG recordings within 90 days of a transthoracic echocardiogram (TTE). In the case of multiple ECGs and TTEs per patient, all of them will be selected and analysed accordingly considering the corresponding PI diagnosis at each time. In the event of a patient with a different diagnosis over time (e.g. non-AS confirmed diagnosis later on diagnosed with AS), multiple timepoint ECGs will be categorized so that the same patient is not included both in the control and in the AS populations.

Controls will include non-AS patients with relevant TTE and clinical findings during AS differential diagnosis (such as hypertensive heart disease, structural heart diseases, hypertrophic cardiomyopathy among other cardiomyopathies, mild aortic stenosis, and no significant aortic leaflet calcification).