[Systolic, diastolic and pulse pressure: prognostic implications]

Over the past decades, diastolic blood pressure (BP) has been traditionally considered superior to systolic BP for cardiovascular risk stratification. However, the Framingham Heart Study, the Physicians' Health Study and several other studies published over the last few years, provided convincing evidence that pulse pressure (i.e., the difference between systolic and diastolic BP) is the most important BP component for prediction of cardiovascular risk, particularly in subjects over 55 years of age. Evidence is accumulating that pulse pressure is a powerful predictor of cardiovascular risk in different clinical settings including the general population, elderly subjects, patients with essential hypertension and patients with systolic dysfunction. Elevated pulse pressure may be considered a reliable marker of stiff arteries, possibly due to diffuse atherosclerotic lesions, aging processes of the artery wall and other mechanisms. Brachial pulse pressure, however, might not be a reliable marker of central pulse pressure because of the progressive amplification of the pressure wave from the aorta to the peripheral arteries, a phenomenon which tends to decrease with age and to increase with height. Since the state of increased emotional stress associated with physical examination leads to a bigger rise in systolic than in diastolic BP, the clinical visit may lead to an overestimation of the usual levels of pulse pressure. In fact, ambulatory pulse pressure proved to be more potent than office pulse pressure for cardiovascular risk stratification. An average 24-hour ambulatory pulse pressure >53 mmHg identifies subjects with a markedly increased cardiovascular risk. An increase in pulse pressure apparently predicts cardiac ischemic events better than cerebrovascular events. On the other hand, the latter are better predicted by the mean BP. The effects of antihypertensive drugs and drug combinations on the mean BP and pulse pressure, and the potential prognostic implications, deserve further evaluation.