S-37-1: PROGNOSTIC UTILITY OF MORNING BLOOD PRESSURE SURGE

Abstract

Morning blood pressure surge (MBPS), defined as the difference between morning systolic blood pressure and the lowest nighttime systolic blood pressure, is a normal physiological phenomenon of diurnal blood pressure variability (BPV). Exaggerated MBPS is associated with morning hypertension and has been associated with adverse cardiovascular and cerebrovascular events, especially hemorrhagic stroke. However, MBPS has low reproducibility and there is an ethnic difference in the amplitude of MBPS and its prognostic value. More evidence is needed to prove its clinical usefulness in the management of hypertension. Since the risk of MBPS is mainly attributable to the elevated morning blood pressure, the focus therefore has shifted from MBPS to the control of morning hypertension. Because MBPS focuses only on the amplitude rather than the rate of blood pressure rise, we calculated the MBPS rate as the slope of linear regression of sequential systolic blood pressure measures on the time intervals within the MBPS period. We found the reproducibility for the MBPS rate was better than the MBPS amplitude. The MBPS rate was a more sensitive and reliable prognostic factor of long term mortality than the MBPS amplitude. The prognostic values of MBPS rate were comparable in subjects with or without morning and nocturnal hypertension. Because the MBPS rate can easily be calculated from the ambulatory blood pressure monitoring data, it could become a routine parameter in daily practice in conjunction with other routinely derived parameters including MBPS amplitude.