Review: Intensive blood pressure control reduces stroke, but not mortality or MI, in type 2 diabetes

A meta-analysis compared five studies (including the ACCORD trial) that treated adults with type 2 diabetes with antihypertensive therapies to achieve prespecified blood pressure (BP) targets. Intensive BP targets were found to reduce stroke but not mortality or myocardial infarction (MI), and in the one trial that reported details of adverse events, the intensive group had higher rates of serious adverse events.

The study was published by Archives of Internal Medicine (now JAMA Internal Medicine) on Sept. 24. The following commentary by ACP Member Louise Moist, MD, was published in the ACP Journal Club section of the Jan. 15 Annals of Internal Medicine.

More intensive BP control was the goal for patients with diabetes until the recent ACCORD study reported minimal benefit and increased risk for harm.

The meta-analysis by McBrien and colleagues found no reduction in MI or mortality and a small reduction in stroke with intensive BP targets. In the 5 studies analyzed, BP targets varied in the intensive (SBP [systolic BP]< 120 mm Hg, DBP [diastolic BP] ≤ 75 to 80 mm Hg) and standard groups (SBP < 140 mm Hg, DBP ≤ 85 to 90 mm Hg), making conclusions difficult. Only 1 study (ACCORD-BP with target SBP < 120 mm Hg) robustly examined adverse events. No conclusions can be made about SBP targets between 120 and 140 mm Hg, a continued area of controversy in practice and current BP guidelines.

Overall, this meta-analysis does not add any new information beyond the ACCORD study and includes all of its limitations. Not all patients in these [randomized, controlled trials] had a diagnosis of hypertension, and in most the indication to treat was for cardiovascular protection. Accordingly, baseline BP varied substantially among studies. The authors report an association between baseline BP and effect of BP lowering, suggesting that the effect of BP lowering may be greater with higher baseline BP. This highlights an important practice point: BP targets differ from BP thresholds (the criteria used to decide when to initiate therapy), and both are important in management of hypertension and in the interpretation of the targets.

The analysis also does not inform us on important patient subgroups, including the elderly and patients with significant kidney disease and/or proteinuria. The results of this review cannot be extrapolated to these subgroups, which have higher risks for harm.

The review by McBrien and colleagues will probably not affect practice beyond the known results of the ACCORD study. It does not address SBP targets < 130 mm Hg, rather than < 120 mm Hg, and leaves opportunity for further studies to examine these unmet needs.