Series "Cardiovascular System" (3) : Antihypertensive Drugs : Up-to-Date Information

Hypertension affects approximately 36 million individuals in Japan. As the population ages, the prevalence of hypertension will increase even further unless broad and effective preventive measures are implemented. The higher the blood pressure (BP), the greater the chance of cardiovascular disease. We overviewed here recent clinical studies which provided evidence supporting the recent several new guidelines for hypertension prevention and management. We focus on progress made in chronotherapy based on a chronodiagnosis. Home blood pressure (HBP) has become quite popular in recent years, offering a number of advantages from the viewpoint of both diagnosis and treatment. One basis of superiority rests on the fact that clinic BP is not representative of BP values outside the clinic. The overshadowing major and unique benefit to be derived stems from a chronobiologic interpretation of HBP monitoring, the ability to observe the acceptability or unacceptability of BP variations in the normal range throughout the day, week, month and year. The morning surge of BP may trigger a number of cardiovascular events, but this is a population phenomenon that has to be individualized and further qualified by population rhythms with frequencies other than circadian. For the purpose of individualization, it should be recognized that BP monitoring for only office is not sufficient for a reliable diagnosis and for providing adequate treatment recommendations to prevent adverse vascular events, because abnormality can be there on some days but not on others. Regarding the evaluation of the treatment, HBP (and heart rate) offers several advantages. One is the possibility of evaluating the duration of efficacy of the current antihypertensive non-drug or drug treatment. When a long-acting antihypertensive drug is administered once in the morning, the BP in the evening corresponds to near the peak effect. Recently, the ratio of morning effect versus evening effect has been used as an indicator of the duration of action of the antihypertensive effect, the morning versus evening (M/E) ratio. This concept is derived from the trough versus peak (T/P) ratio obtained from ambulatory BP monitoring. The T/P ratio is an approach proposed for assessing the homogeneity of the antihypertensive treatment. Such homeostatically devised pharmacotherapy may, however, not be optimal to adequately treat diseases, which vary in risk and severity along the scale of 24 hours. New technology makes chronotherapy possible by increasing the efficacy and safety of medications, by proportioning their concentrations during the week (by HBP) in synchrony with chronome alterations of disease. Such chronotherapy is likely to bring more opportunities for preventing adverse outcomes in the future. With chronobiologic methods applicable to the individual patient, a chronotherapy based on a chronodiagnosis for "prehabilitation" may save much of the cost and may overcome the limitations to rehabilitation, e.g., after a massive stroke