Background: The risk of cardiovascular disease rises as systolic blood pressure increases in patients with type 2 diabetes mellitus. Current guidelines from the Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure advise lowering systolic blood pressure to less than 130 mm Hg in patients with diabetes; however, there is little evidence to indicate that this improves clinical outcomes. The Action to Control Cardiovascular Risk in Diabetes (ACCORD) Study Group evaluated the effects of intensive blood pressure control on cardiovascular events in patients with diabetes.
The Study: A total of 4,733 patients with type 2 diabetes were randomized to one of two blood pressure control groups: intensive therapy (target systolic blood pressure of less than 120 mm Hg) or a control group (target systolic blood pressure of less than 140 mm Hg). Patients were followed for an average of 4.7 years. Blood pressure was managed using standard antihypertensive agents, but no specific strategy was enforced. The primary outcome was a composite of the first occurrence of a major fatal or nonfatal cardiovascular event (i.e., myocardial infarction or stroke). Various secondary outcomes (i.e., separate assessments for myocardial infarction, stroke, congestive heart failure, and all-cause mortality) also were evaluated.
Results: Baseline traits between groups were similar, including initial blood pressure and incidence of previous cardiovascular events. No significant difference in the primary outcome was noted between groups, despite the intensive treatment group maintaining significantly lower blood pressure than the control group (mean blood pressures: 119.3/64.4 mm Hg versus 133.5/70.5 mm Hg, respectively). Most secondary outcomes showed no differences between groups, including all-cause or cardiovascular-related mortality, congestive heart failure, or myocardial infarction. However, the intensive therapy group had a lower incidence of total strokes than did the control group (0.32 versus 0.53 percent per year, respectively; hazard ratio = 0.59; P = .01) and nonfatal strokes (0.30 versus 0.47 percent per year, respectively; hazard ratio = 0.63; P = .03).
Conclusion: The authors conclude that a more stringent blood pressure goal for patients with type 2 diabetes does not significantly reduce the primary cardiovascular outcome or most secondary outcomes compared with standard blood pressure goals. In this study, the number of total and nonfatal strokes was lower in the intensive therapy group, although the clinical benefit was limited (number needed to treat = 89 for five years to prevent one stroke).