Warfarin is an old fashioned drug for thinning the blood. Many people will regard old fashioned as inferior, you may also associate it only with much older, frail people than children. It is however a well tried and tested method for thinning the blood. Your cardiologist may want to do this if you have abnormal or mechanical valves, artificial pipes or stents or for a number of other reasons. Importantly you will need regular blood tests to ensure the amount of Warfarin you are taking is correct, this may also very on a daily basis especially if you are unwell or taking an antibiotic.