Morning Surge in Blood Pressure as a Predictor of Silent and Clinical Cerebrovascular Disease in Elderly Hypertensives

HypertensivesTo the Editor:We read with interest the paper by Kario et al, 1 indicating that an excessive morning surge in blood pressure is a predictor of subsequent stroke in a sample population of elderly Japanese hypertensives.On one hand, the evident diurnal variation in the onset of many acute cardiovascular events, eg, myocardial infarction, angina, cardiac arrest, sudden death, and pulmonary embolism, is closely related to the circadian pattern of blood pressure.2 On the other, there is no doubt that hypertension plays a key role as a risk factor for cerebrovascular accidents.However, recent studies from our group found that patients with and without hypertension had the same 24-hour pattern of onset of both ischemic 3 and hemorrhagic 4 stroke, characterized by a morning peak.Moreover, other cardiovascular events, eg, acute aortic dissection, show an evident diurnal variation as well.Recent data from the large worldwide population of the International Registry of Acute Aortic Dissection 5 found a significant morning peak quite similar in both hypertensive and normotensive subjects.Taken together, all of these data strengthen the suggestion that the morning surge in blood pressure (irrespective of presence or absence of hypertension) may be crucial in determining the rupture of a critically weakened arterial wall.We agree that the morning surge in blood pressure should be a therapeutic target for preventing unfavorable cardiovascular events in hypertensive patients, and the medications should provide 24-hour efficacy.However, because a morning surge in blood pressure may also be harmful for normotensive subjects, an accurate evaluation of the range of early morning blood pressure might be useful for normotensives as well.