SP 02-5 DO WE NEED A NEW DEFINITION OF HYPERTENSION?

Hypertension has been defined by the levels of BP above which lowering BP will reduce the cardiovascular risk associated with elevated BP. This level has been classically 140/90 mmHg on the basis of actuarial data from the insurance industry. However, we now know that cardiovascular risk rises progressively from levels as low as 115/75 mmHg upward with a doubling of the incidence of both coronary heart disease and stroke for every 20/10-mmHg increment of BP. In uncomplicated hypertension without cardiovascular risk factors or target organ damage, there is little randomized clinical trial evidence that lowering SBP of <160 mmHg reduces cardiovascular risk. The SPRINT trial published recently demonstrated that hypertensive patients at high-risk of cardiovascular disease with SBP >130 mmHg and <180 mmHg, significantly benefited from reduction of SBP to <120 mmHg. In SPRINT, BP was measured as unattended automated office BP (AOBP) after a 5-minute rest period. These data beg the question whether we should change our classical definition of hypertension to ≥130/80 mmHg, at least for high-risk hypertensive individuals. First, we should qualify BP values by the methodology used to measure BP, since unattended AOBP may be up to 15-20 mmHg lower than BP measured manually in the usual clinical practice of a busy general practitioner, which is where most hypertensive subjects will have their BP measured. It could be concluded that the definition of hypertension should remain BPs ≥140/90 mmHg, and that the goal should remain to lower BP in most hypertensive patients to <140/90 mmHg. However, in high-risk hypertensive individuals, including chronic kidney disease patients, elderly individuals and those at a Framingham Risk Score of ≥15%, and perhaps as well diabetic subjects, goal BP should be <130/80 mmHg, when BP measurement is performed manually in usual clinical practice. If BP is measured with guideline-directed unattended AOBP following a 5-minute rest period as in SPRINT, hypertension in high-risk subjects could be defined as BP ≥130/80 mmHg with a threshold for treatment of 130/80 mmHg, and a goal SBP of ≤120 mmHg.