Cardiovascular outcomes with antihypertensive therapy in type 2 diabetes: an analysis of intervention trials

In studies of antihypertensive therapy, relative cardiovascular (CV) risk reduction is largely independent of attained systolic blood pressure (SBP). How this translates to absolute risk reduction (ARR) in diabetes is not clear. We have compared 5-year CV outcomes in 10 studies of intensive versus moderate or active versus placebo therapy in subjects with type 2 diabetes and attained SBP < or ⩾ 140 mm Hg. Attained SBP ⩾ 140 mm Hg occurred in five early studies (HOT n = 1001, UKPDS n = 1148, SHEP n = 583, SYSTEUR n = 422, MICRO_HOPE n = 3377) and attained SBP<140 mm Hg occurred in five recent studies (ABCD-NT n = 480, ADVANCE n = 11,140 INVEST n = 4266, ACCORD n = 4733, ROADMAP n= 4447). In each study, ARR was calculated from group mean data and expressed as % change in CV events over 5 years per 10 mm Hg decrease in attained SBP. In studies with attained SBP ⩾ 140 mm Hg, ARR was 13 ± 2.6% per 10 mm Hg, and the number needed to treat (NNT) to prevent one event in 5 years was 8. In studies with attained SBP < 140 mm Hg, ARR was 1.6 ± 1 .9% per 10 mm Hg (P = 0.0007), and NNT was 68. The present analysis indicates that CV outcomes reach a plateau after attaining SBP of 140 mm Hg in patients with type 2 diabetes.