|   | 
        The number of cusps involved by HO | 
        The number of AVs | 
       
      
        | Total classified    AVs with HO (n=20) | 
        1 cusp only | 
        9  | 
       
      
        |   | 
        ≥2 cusps | 
        11  | 
       
      
        | Classified tricuspid AVs with HO (n=14) | 
        1 cusp only | 
        6  | 
       
      
        |   | 
        2 cusps | 
        6  | 
       
      
        |   | 
        All 3 cusps | 
        2 | 
       
      
        | Classified bicuspid AVs with HO (n=6) | 
        1 cusp only | 
        3  | 
       
      
        |   | 
        All 2 cusps | 
        3  | 
       
     
    AV: aortic valve; HO: heterotopic ossification  |