The purpose of this study is to evaluate if ataciguat slows the progression of moderate calcific aortic valve stenosis in adults.
Adult male or female at least 50 years of age
An AVA of ≥1.0 cm2 to ≤1.50 cm2
An AVC score between >300 to 1200 Agatston units (AU) for women and between >300 to 2000 AU for men
Has a left ventricular ejection fraction (EF) of ≥45% at the time of Screening as determined by the echocardiography Imaging Core Laboratory
For participants in the CPET sub-study in Part A and all participants in Part B: Has any medical or physical condition that, in the Investigator's opinion, could lead to an inability to complete Protocol-required CPET procedures (eg, pulmonary disease, joint, leg, hip, back conditions that limit physical activity, or other absolute contraindications for CPET)
Anticipated or planned prior aortic valve replacement, repair, surgery, or intervention in the next 6 months
Has moderate, moderate-to-severe, or severe (Grade 2 or higher) mitral stenosis, mitral regurgitation, and/or aortic regurgitation
Has suspected or known congenital aortic valve disease including bicuspid aortic valve