Aggressive BP control not effective, possibly harmful, in patients with diabetes

American College of Cardiology 59th Annual Scientific Sessions

ATLANTA – Tight systolic BP control in high-risk patients with diabetes appears to be no more effective in avoiding myocardial infarction, stroke or death compared with standard BP treatment, and may be hazardous when BP is lowered below 110 mm Hg, according to new data from the INVEST trial.

“Contrary to the usual blood pressure treatment approach where we thought lower was always better, we believe the clear the take-home message from these data is that it is not necessary to aggressively lower BP in order to achieve some benefit, since there was no difference,” Rhonda M. Cooper-Dehoff PharmD, MS, division of cardiovascular medicine and associate director of Cardiovascular Clinical Research Program at University of Florida, told CardiologyToday.

The INVEST study included 6,400 patients with diabetes and CAD. Researchers randomly assigned patients to two BP-reducing treatment arms: calcium-channel blocker or beta blocker, plus an ACE inhibitor and/or thiazide diuretic. The primary target was systolic BP ,130 mm Hg/85 mm Hg. Patients were categorized according to BP control achieved: very tight control (<110 mm Hg) tight control (<130 mm Hg), usual control (>130 mm Hg to <140 mm Hg) or no control (>140 mm Hg).

“For this analysis, we wanted to further explore the effects of lower BP on outcomes, particularly in high-risk patients with diabetes. There is no evidence to suggest that the recommended <130 mm Hg systolic BP is beneficial, and we saw a risk for increase in all-cause mortality when systolic BP was lowered to <115 mm Hg,” Cooper-Dehoff, also a Cardiology Today Editorial Board member, said in a press conference.

During a follow-up of more than 16,893 patient-years, patients with uncontrolled BP levels had a nearly 50% increased risk for experiencing an adverse CV outcome (death, MI or stroke) compared with patients deemed as having usual control (OR=2.1; 95% CI, 1.3-3.6). Similarly, patients with very tight BP control had a significantly elevated risk compared with those with usual control (OR=1.5; 95% CI, 1.2-1.7). However, patients with tight BP control had a similar risk to those with usual control (OR=1.08; 95% CI, 0.91-1.28).

Lowering systolic BP ,130 mm Hg significantly increased the risk for all-cause death when compared with usual BP control. This increase became apparent about 30 months into the study and persisted for an additional five years of follow-up. When the researchers analyzed BP in 5-mm Hg increments in patients with tight BP control, they discovered that a systolic BP <115 mm Hg was associated with increased mortality.

"We concluded that, in a population of diabetics with documented CAD, systolic BP <130 mm Hg did not provide any benefit compared with lowering systolic BP to between 130 mm Hg and <140 mm Hg, and it is probably time to rethink lower goals in this particular population … and put our efforts toward lifestyle modifications and other areas where we can achieve greater benefits," Cooper-Dehoff said. – by Matthew Brannon

This was a very interesting and well-done study. Many of us had thought that since prior guidelines recommended a systolic BP of <130 mm Hg we would see a clear benefit in patients with diabetes. These results were surprising. The lesson is if that we can use an agent such as an ACE inhibitor or renin-angiotensin system blocker plus either a diuretic and amlodipine to get to a systolic BP in the 130 mm Hg to 139 mm Hg range, then that is sufficient. This study tells us that we do not need to add on yet another medication to get down to systolic BP in the 120 mm Hg range. This is a study that will help us because it tells us that in just over five years, it makes sense to aim somewhere in the 130 mm Hg to 139 mm Hg range for patients with diabetes.

– Roger S. Blumenthal, MD

Cardiology Today Editorial Board member

For more information:

Cooper-Dehoff RM. LBCT I Presented at: American College of Cardiology 59th Annual Scientific Sessions; March 14-16, 2010; Atlanta

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