Typical blood pressure measurements include a systolic and diastolic value, which represent the extremes of pressure fluctuation within the circulation during the cardiac cycle. There has been much debate about which increased value alone, either systolic or diastolic hypertension, is more predictive of adverse cardiovascular outcomes in various patient populations. (See "Blood pressure measurement in the diagnosis and management of hypertension in adults" and "Hypertension: Who should be treated?".)
Mean arterial pressure measurements, which provide another indication of overall circulatory pressure load, have also been proposed as predictive for adverse cardiovascular outcomes. This is either determined directly by catheterization or can be estimated by formulas (such as diastolic blood pressure + 1/3 x [systolic pressure – diastolic pressure]). However, the mean arterial pressure provides less discriminatory power as patients age. The diastolic pressure peaks at and subsequently declines after age 55 years, while the systolic pressure rises relentlessly with each decade of life . Thus, depending upon the respective changes in systolic and diastolic pressures with older age, the mean blood pressure may actually tend to change less as individuals age.
Since the diastolic pressure in a population rises until the sixth decade and then subsequently declines with increasing age, an elevation in the diastolic pressure alone is less useful as an outcome predictor in older patients. Increasing emphasis has therefore been placed upon systolic pressure alone as the most useful predictor of cardiovascular disease in these individuals. (See "Treatment of hypertension in the elderly patient, particularly isolated systolic hypertension".)
Several guidelines have supported the use of systolic blood pressure (such as JNC-7) and strongly encourage the use of systolic blood pressure goals in antihypertensive treatment .
There is also an enhanced risk for cardiovascular events associated with increases in pulse pressure (defined below). This topic review will discuss the factors that determine pulse pressure and will present some of the evidence for and against the suggestion that there is an independent link between an increased pulse pressure and adverse cardiovascular outcomes.