Understanding the Augmented Blood Pressure Variability as a Clinical Marker of Cardiovascular Risk and Mortality

Abstract

High blood pressure is a leading risk factor for cardiovascular (CV) disease.^[1] Most studies on CV risk assessment have used mean blood pressure as the indicator of risk, measured either in clinic or “out of office” settings.^[2] Nevertheless, blood pressure demonstrates perceptible oscillations in short-term and long-term basis. Blood pressure oscillations during different time scales, known as Blood Pressure Variability (BPV), have become a focus of growing scientific interest. Historically, variability in blood pressure has been viewed as prescribing accurate measurement of mean blood pressure and as a phenomenon to be overcome by improved monitoring. Blood pressure oscillations during different time scales, known as BPV, have become a focus of growing scientific and clinical interest. For at least two decades, this variability has also been recognised as a potential risk factor in its own right.^[2] In 2010, an analysis of three cohort studies and two randomised trials found that long-term variability in blood pressure was a predictor of stroke and coronary events in high-risk patients.^[2] BPV can be measured at long-term (seasonal variability or visit-to-visit), at mid-term (differences in consecutive days or weeks) or at short-term (day-night differences or changes induced by other daily activities and conditions). An increased BPV, either at long, mid or short-term is associated with a poor cardiovascular prognosis independently of the amount of blood pressure elevation.^[3] Nonetheless, there are several aspects of the relationship between BPV, antihypertensive treatment and clinical outcomes that are still unknown in therapeutic targets in clinical practice.