⛱ Aortic Stenosis Practice Essentials ================= Obstruction of Blood Flow Across the Aortic Valve . Among symptomatic patients with Medically treated Moderate-to-Severe aortic stenosis, Mortality from the onset of symptoms is approximately 25% at 1 year and 50% at 2 years. Symptoms of aortic stenosis usually develop gradually after Asymptomatic Latent Period of 10-20 years.