I don't know the entire history of AD however You could ask KIng George V , or Lucille Ball the comic, or Maybe Albert Einstein, more recently Actors John Ritter and ALan Thicke, Porn Star Ron Jeremy (is Still with us)
2 generations ago People died of Aortic disease period they had no idea why or what cause it , you didn't know what it was when it happened... and it wasn't Until very recently with Ultrasound , sonigrams and later MRI & CT 's that allow them to be seen...did anyone catch on ... if it was found during Open heart surgery they would attempt repairs which is impossible to do , like replacing a auto Radiator hose with the car Running (your gonna get wet) until Dr Michael Debakey, a former Army surgeon in practice in Texas used a Heart Lung Bypass machine to be able to actually stop the heart and allow the Blood to pump through the machine instead of the heart.... With time, Debakey expanded the group of Knowledge and experience with others also getting involved , increasing positive outcomes manyfold by cooling the blood and body well below normal human temperature which has been found to improve the brain cell function following surgery, Feel free to search Post Perfusion Syndrome