"This is the ultimate personalized medicine, " says Dr. Andrew Parsa, the neurosurgeon who is running the trial.

CNN: Vaccine may shift odds against deadly brain cancer

Outside researchers running the trial for Merck set this number high in order to maximize the trials' chances of showing even a slight difference in heart attack rates between Zetia and placebo.

FORBES: Pharmaceuticals

One patient, who lives an hour and a half away from the medical centre running the trial, has had regular adjustments to her medication and treatment as a result of her transmissions back to her doctor's office.

BBC: Telephone heart sensor under test