I have two references that might help: Kondo et al, 2001, Biosci Biotechnol Biochem 65, 2690-4; & WebMD as of 2014 warned effects not fully studied per http://www.reference.com/health/apple-cider-vinegar-affect-high-blood-pressure-d855804466625639f#.
In rats it seems that acetic acid reduces renin activity.