Short-term BP variability predicts mortality in hypertensive individuals

Short-term, reading-to-reading ambulatory blood pressure (BP) variability appears to be associated with total and cardiovascular mortality among individuals with hypertension, according to data from the Spanish ABPM Registry.

The study included 63,910 individuals who underwent 24-hour ambulatory BP monitoring at baseline, from whom the following data were collected: systolic and diastolic BP over 24 hours, at daytime and at night-time. Researchers calculated the weighted standard deviation (SD; mean of daytime and night-time SD weighted for period duration), average real variability (mean of differences between consecutive readings), variation independent of the mean, and BP variability ratio (ratio between systolic and diastolic 24-hour SD).

Over a median follow-up of 4.7 years, a total of 3,808 deaths occurred, of which 1,295 were cardiovascular. The individuals who died were older, more likely to be women and obese, diabetic, dyslipidaemic, or have a previous history of cardiovascular disease. They also had a longer duration of hypertension and higher values of BP variability compared with individuals who remained alive.

Multivariable Cox regression models showed that values of daytime, night-time, and weighted SD systolic and diastolic BP, as well as diastolic average real variability, all had a significant association with total and cardiovascular mortality. Hazard ratios (HRs) per 1-SD increase in the valued ranged from 1.05 to 1.09 for total mortality and from 1.07 to 1.12 for cardiovascular mortality.

Furthermore, a night-time systolic SD of ≥12 mm Hg showed an independent association with total (HR, 1.13, 95 percent confidence interval [CI], 1.06–1.21) and cardiovascular mortality (HR, 1.21, 95 percent CI, 1.09–1.36).