wgu,
i was not really bme, i did electrical/computer engineering instead.
i dont know if there is any specific advice i'd give to an engineering applicant, it seems to me the regular advice to everyone else applies here.
one thing I think that really helped me a lot was letters of rec. Make sure the people who write them know you very well. I think for engineering majors, you can also get letters of rec from them (especially if they are BME profs).
GPA/MCAT are important, but you dont have to have super high scores to get in somewhere. I think the MSTP MCAT average around the country is around a 36 or so. But the range is somewhat broad, and there are people who get admitted with significantly lower MCATs (i.e. 30 or so).
Make sure you really try to become as involved as you possibly can in your research in undergrad. Dont be content just to take a position where you really dont contribute to the front-line research of the lab. The MSTP admissions people will want to see that you put in a lot of your own contributions into the research of your lab, and you need to be able to express your specific committment to each of your research experiences in undergrad.
Knowing exactly why you want to do MD/PhD is also a big deal. I know a lot of people think about this for a few seconds and come up with some sort of canned response (i.e. i want to do research and treat patients) but you need to think about why you want to do this and express clear convincing personal reasons that it fits your career goals and not just broad generalizations.
