METHODS .- Prospective study during 12 months of 200 patients > 74 years old with severe symptomatic AS. During the index visit the main clinical characteristics will be recorded and in addition we will perform a comprehensive geriatric assessment, FS assessmet according to Fried et al criteria (strength, walking speed, physical activity, fatigue, unintentional weight loss) and determination of inflammatory markers (C-reactive protein and interleukin-6). During follow-up, measures of functional impairment (basic and instrumental activities of daily living, walking speed and timed set up & go test), hospitalizations, death and quality of life will be determined.