Just saw this study release today. They have now a 18 year study into Metformin use and it's supposed ability to help with cardiovascular events: They found out it is no more helpful than placebo. Same thing with lifestyle intervention. I'll post a link to the medical article and post a PDF file of it for those of you that may not be able to access it. That way, you can be the judge.
www.medpagetoday.com

No Cardioprotection Seen With Long-Term Metformin or Lifestyle Intervention
Both approaches 'highly effective' in T2D, but not for preventing CV disease, expert says