ACE and Hypertension: By multivariate Cox proportional hazard analysis, Indigenous Australians were at ~ 5-fold greater risk of major cardiovascular events (HR 4.72 [1.41–15.78], p = 0.012), after adjusting for hypertension, current smoking, diabetes, IHD, age, critical limb ischemia, insulin, frusemide, ACE inhibitor, anti-platelet or anti-coagulant prescription (Table 3).