Epidemiological, pathophysiological and clinical significance of systolic, diastolic and pulse pressure.

Long-term population surveys and studies of untreated hypertensive patients both strongly suggest that over the age of about 45, the height of the systolic blood pressure is a better predictor of cardiovascular outcome than the diastolic pressure. Research into echocardiographic left ventricular size, endothelial function and thromborheology also back up this supposition. In clinical practice, the treatment of isolated systolic hypertension has been shown to be very worthwhile. There remains some uncertainty as to the relative significance of diastolic blood pressure when it is frankly high, as in severe systo-diastolic hypertension. However some clinicians and epidemiologists have questioned whether diastolic pressure is still worth measuring, given the overwhelming importance of the height of the systolic blood pressure at predicting outcome.