Prehypertension. To Treat, or not to Treat: That Is the Question

Individuals with prehypertension, especially the elderly, are at increased risk of progressing to hypertension and suffering cardiovascular (CV) events.1,2 Hansen et al3 provide further evidence concerning the natural history of patients with “optimal” (<120/80 mm Hg), “normal” (120 to 129/80 to 84 mm Hg), and “high normal” (130 to 139/85 to 89 mm Hg) blood pressure (BP). In the first part of this study more than 2300 individuals without a prior history of CV complications, aged 30 to 60 years, were followed for a median of 10.9 years to observe the progression to hypertension. In the second part of this study these individuals were followed for an additional 9.4 years to determine the effect of progression from one category to another on CV events. They found that progression from optimal or normal to high normal or hypertension carries nearly the same risk for CV events as sustained high normal BP or hypertension. On the basis of their findings they suggest that patients with prehypertension without a history of CV disease be followed periodically but not be treated unless they develop hypertension or further data show that therapy reduces CV events and is cost effective. Although I would agree that there is insufficient evidence to treat individuals with prehypertension to reduce CV events, the TROPHY study4 has suggested that treatment with an angiotensin receptor blocker might be effective in slowing the rate of progression to hypertension. This study was not, however, powered to provide information on the effect of treatment on CV events. A larger-scale, randomized trial powered to show whether therapy with an inhibitor of the renin-angiotensin-aldosterone system (RAAS) is effective in preventing CV events in patients with borderline hypertension and risk factors for CV disease is currently being planned. Before considering therapy in individuals with prehypertension, further information is needed on a number of questions, including: prediction of who will progress; which individuals will develop target organ damage; how the presence of target organ damage relates to subsequent CV events; and whether strategies can be developed to implement and sustain exercise, diet, and lifestyle changes before pharmacologic therapy. The fact that 70 million individuals in the US alone >20 years of age were estimated to have prehypertension in the 1999–2000 National Health and Nutrition Examination Survey (NHANES),5 along with the likelihood that this number will increase in the near future, makes the effort to answer these questions imperative.