Mac Master vs. mcgill which university is better for future cardiac surgeon? and what percentage to get in?

im 17 and i just graduated from highschool with 70 above % (wasnt serious about my studies)....im so so sooo much inspired by some1 that i truly want to be a cardiac surgeon...so i narrowed all the universities to these 2......can any1 help me with choosing??? and also could u tell me the % needed to get in???????