Reapplying to Cambridge MedicalWatch
If you are desperate to reapply do make sure it's a different college and tbh you should only do it if you exceed the offer - if you get A*A*A*. Reapplicants and gap year applicants fare much better when they have exceeded the offer as actually, most students do anyway (the offer is set at a grade below what most people actually achieve).
What was your BMAT score?
I would say if you get any offers, then just take the offer that you get, rather than re-applying.
Why do you think you got rejected without interview? What were your GCSEs, BMAT score, A Level subject choices etc?
The fact that you've only mentioned Cambridge and Imperial makes me think you're just going for prestige. It doesn't actually matter where you get your medical degree from as they're all rigourously accredited. What matters at this stage is getting an offer, full stop.
5/6 years is a long time, but its not as long as 45 i.e. your probable career as a doctor.