Blood Pressure Variability Predicts Clinical Outcomes: Now What?

Abstract

See related article, pp 599–607 The high prevalence of hypertension means that even small refinements to treatment can have a significant impact on population health.1 However, hypertension treatment seems to have much more benefit for some patients than others, largely because of differences in baseline risk. Thus, 2 patients who achieve similar relative risk reduction can have much different absolute risk reductions based on their baseline level of risk. Table demonstrates this for stroke, using 4 studies that I admittedly chose to make this point.2–5 Age and baseline systolic blood pressure (BP) were the most obvious risk factors generating the widely disparate event rates in these studies. Current guidelines use these and other established risk factors to classify patients as at low, medium, or high risk, but with minimally different recommended approaches to treatment.1,6 Researchers have identified additional potential risk factors more recently, including variability in BP.7 View this table: Table. Progressive Increase in Absolute Risk Reduction With Increasing Baseline Risk and Stable Relative Risk Reduction in a Series of Clinical Trials In this issue of Hypertension , Juhanoja et al8 present research with several methodological strengths to argue that variability over several days in home BP measurements is associated with cardiovascular risk. Previous studies have demonstrated the association of adverse cardiovascular outcomes with variability among BP measurements separated by months and variability that occurs over the course of a single day.7 In particular, their study population combines 4 population-based, geographically diverse cohorts with excellent and long-term (mean 9.3 years) follow-up using validated outcome ascertainment methods. They are able to adjust for the baseline risk factors included in commonly used risk calculators (population averages had be used to estimate total and high-density lipoprotein cholesterol for ≈10% of …