Medical journalist Stephen Klaidman is Senior Research Fellow at the Kennedy Institute of Ethics. His new book “Saving the Heart: The Battle to Conquer Coronary Disease” (Oxford) takes a look at the treatments developed -- like angiography and balloon angioplasty -- to help patients recover from the damages of heart disease. He also charts the way the field of cardiology has become a multi-billion dollar business, and the conflict that arises between medical ambition and financial incentive and the best treatment options for patients.