Managing patients with hypertension and type 2 diabetes to a target systolic blood pressure (BP) of less than 120mmHg did not reduce cardiovascular events compared to a target of 140mmHg in a major randomised controlled trial.

While it is accepted that people with type 2 diabetes are at increased cardiovascular risk compared to those without, and that management of all aspects of cardiovascular risk is important in such people, there is still debate over how best to do this. The ACCORD (Action to Control Cardiovascular Risk in Diabetes) trial investigated two areas of cardiovascular risk management - intensive BP control and combination lipid lowering, as well as intensive vs. standard glycaemic control. All participants in the trial were randomised to one of the two glycaemia management arms, and of the remainder some were assigned in a 2x2 factorial design to the BP arm and some to the lipid-lowering arm: this paper reports the results of the ACCORD-BP arm.

Participants were aged 40 or above, had type 2 diabetes with HbA1c 7.5% or above, and were at high risk for cardiovascular disease. Those with systolic BP between 130 and 180mmHg and taking three or fewer antihypertensive medications were eligible for the BP study. They were randomised to target systolic BP of 120mmHg (intensive) or 140mmHg (standard), to be achieved using standard antihypertensive regimens known to produce benefit in patients with diabetes. The primary outcome was first occurrence of a major cardiovascular event, defined as nonfatal myocardial infarction, nonfatal stroke, or cardiovascular death. Planned average follow-up for participants not having an outcome event was 5.6 years.

ACCORD enrolled 10,251 participants overall, of whom 4,733 were enrolled in the BP study - 2,362 to intensive and 2,371 to standard BP control. Mean age of the participants was 62.2 years, 47.7% were women, and 33.7% had cardiovascular disease at baseline; most were recruited between January 2003 and October 2005. The trial ended in June 2009, at which point the mean duration of follow-up for the primary outcome was 4.7 years.

The intensive and standard strategies resulted in effective control to targets, with average systolic BP in the intensive group being 119.3 mm Hg (95% CI, 118.9 to 119.7) vs. 133.5 mm Hg (95% CI, 133.1 to 133.8) for the standard group. There was, however, no significant difference between the groups in the rate of the primary outcome: this occurred in 445 participants with a rate of 1.87% per year for intensive-therapy vs. 2.09% per year for standard-therapy (hazard ratio [HR] with intensive therapy, 0.88; 95% CI, 0.73 to 1.06; P=0.20). Differences were also not significant for death from any cause (n=294; 1.28% per year vs. 1.19% per year. HR with intensive therapy, 1.07; 95% CI, 0.85 to 1.35; P=0.55) or for cardiovascular death (n=118; 0.52% per year vs. 0.49% per year; HR with intensive therapy, 1.06; 95% CI, 0.74 to 1.52; P=0.74).

The only secondary outcome to show a significant difference was stroke, which was lower in the intensive group: the number of events was small, however. Serious treatment-related adverse events were more frequent in the intensive treatment arm.

The authors conclude that in this study, intensive BP management did not significantly reduce the rate of major cardiovascular events in high-risk individuals with type 2 diabetes, nor did it reduce the rate of death. There was a reduction in stroke, which if real, would be consistent with the degree of stroke reduction expected from the BP difference between the groups according to previous meta-analyses. The authors note that the total number of events recorded was much lower than the expected rate, possibly because the patients were lower-risk than those directed into the lipid-lowering arm.

An accompanying editorial discusses the results of the ACCORD study. Insofar as blood pressure lowering is concerned, the author concludes that at present, a blood pressure target below 120mmHg systolic is not justified in patients with type 2 diabetes.