What is the effect of treating prehypertension with an angiotensin-receptor blocker?

This study tells us what we already know (that is, that blood pressure medications reduce blood pressure), but says nothing about what really matters: Does intervention in patients with prehypertension improve patient-oriented outcomes? The choice to study such an expensive drug is also disappointing, but not surprising. Given that the number needed to treat [NNT] to prevent 1 stroke, heart attack, or death in patients with mild hypertension is 140 for 5 years (http://www.jr2.ox.ac.uk/bandolier/index.html), it is likely that the actual clinical benefit of treating prehypertension is even smaller. (LOE = 1b)

Julius S, Nesbitt SD, Egan BM, et al, for the Trial of Preventing Hypertension (TROPHY) Study Investigators. Feasibility of treating prehypertension with an angiotensin-receptor blocker. N Engl J Med 2006;354:1685-1697.  [PMID:16537662]

Randomized controlled trial (double-blinded)

Industry

Concealed

Outpatient (any)

There is an increasing push to define patients as prehypertensive or prediabetic, and patients and their physicians often feel pressure to initiate treatment despite the absence of evidence that active treatment improves outcomes for these "prediseased" patients. In this industry-sponsored study, patients with prehypertension (systolic blood pressure [BP] of between 130 and 139 mm Hg and diastolic BP of less than 89 mm Hg or a systolic reading of less than 139 mm Hg and a diastolic reading of between 85 and 89 mm Hg) were randomized to receive either candasartan 16 mg daily or matching placebo. After 2 years, all patients were given placebo for 2 years to see if there was any residual effect of treatment. The primary outcome during the 4-year study was the incidence of hypertension, defined as an average BP of 140/90 or higher during any 3 visits, a BP of 160/100 or higher at any 1 visit, or a BP of 140/90 or higher at the final visit. The average age of patients was 49 years, 59% were men, and 82% were white. Analysis was by intention to treat, with the last observation carried forward in the event of missing data. Not surprisingly, giving BP medication lowers blood pressure: Patients receiving candasartan were less likely to have hypertension during the first 2 active treatment years of the study (13.6% vs 40.4%; P < .001; NNT = 4). After 2 additional years of treatment with placebo there was still a small residual decrease in the incidence of hypertension requiring treatment (53.2% vs 63%; P = .007; NNT = 10). There was no difference between groups in adverse events, and cardiovascular morbidity or mortality were not reported.