1. Can progression of valvar aortic stenosis be predicted accurately?
Cornelia Piper, MD, Rito Bergemann, MD, Hagen D Schulte, MD, Reiner Koerfer, MD, Dieter Horstkotte, MD 
The Annals of Thoracic Surgery 
Volume 76, Issue 3, Pages (September 2003)
DOI: /S (03)

2. Fig 1
Recurrent surgery for progressive aortic stenosis in 57 patients (22.2%) at the University of Düsseldorf during a 10-year period (1981 to 1992). (cath = catheterization.)
The Annals of Thoracic Surgery  , DOI: ( /S (03) )