The disclosure relates to the use of an O-acetylated amino acid or pharmaceutically acceptable salt thereof or Zwitterion thereof for the manufacture of a medicament for treating or preventing a condition selected from stroke, heart attack, thromboembolism, or ischemia, wherein the O-acetylated amino acid is O-acetylated-L-hydroxyproline, O-acetylated-L-threonine, O-acetyl-L-serine or O-acetyl-L-tyrosine.