JS-HR-7: BLOOD PRESSURE VARIABILITY; THERAPEUTIC TARGET FOR THE PREVENTION OF CARDIOVASCULAR DISEASE

Abstract

In the past three decades, there have been many reports on the associations of various parameters of blood pressure (BP) variability with increased risk of cardiovascular disease (CVD) events; these parameters include short term BP variability (BPV), i.e., beat-by-beat BPV and ambulatory BPV, abnormality of nocturnal BP dipping pattern, and mid- to long-term BPV, i.e., day-by-day BPV, visit-to-visit BPV, and seasonal variations in BP. Several factors that are associated with abnormal BPV, as well as environmental factors such as cold or warm temperatures and seasonal changes in climate, increase fluctuations in BP. Individual intrinsic factors such as sympathetic nervous tone, arterial stiffness, physical activity, and mental stress also contribute to elevated BPV. According to evaluations of BPV abnormalities, out-of-office BP measurements such as ambulatory and home BP monitoring are needed. Although there are issues regarding measurement accuracy, cuffless BP monitoring devices, for example, those using pulse transit time, may be used to estimate nighttime BP levels. Such cuffless BP devices can also evaluate beat-by-beat BPV. Moreover, by using the multisensor-equipped ambulatory BP monitoring device developed by our research group, it is possible to evaluate BPV associated with changes in temperature, physical activity, and/or atmospheric pressure. Based on the mechanism(s) behind a given patients BPV abnormality, several methods may be considered for the management of that abnormality (Figure). For example, improving excessive sympathetic nervous system activation may be useful in the management of BPV abnormality, and renal denervation has been reported to decrease ambulatory BPV. Abnormal nocturnal BP dipping may be treated by decreasing nighttime BP. Moreover, early adjustment of antihypertensive drugs has been reported to be useful in suppressing seasonal variations in BP, leading to a decreased risk of CVD events. Furthermore, housing conditions and room temperature are closely related to BP levels, and adaptive control of room temperature would be useful to suppress winter increases in BP. In clinical practice, we must not forget that BPV parameters are interrelated. For instance, frequent evaluation of BP levels and adjustment of antihypertensive drugs can suppress visit-to-visit BPV, which in turn leads to the suppression of seasonal variations in BP. Over the next decade, greater data on how to manage and control BPV need to be accumulated. Additionally, future studies should be conducted to verify whether the different types of BVP management are useful in preventing CVD events.