Prognostic Relevance of Short-Term Blood Pressure Variability: The Spanish ABPM Registry

The prognostic relevance of short-term blood pressure (BP) variability in hypertension is not clearly established. We aimed to evaluate the association of short-term BP variability, assessed through ambulatory BP monitoring, with total and cardiovascular mortality in a large cohort of patients with hypertension. We selected 63 910 subjects from the Spanish ABPM Registry from 2004 to 2014, with a median follow-up of 4.7 years. Systolic and diastolic BP SD from 24 hours, daytime, and nighttime, weighted SD (mean of daytime and nighttime 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) were calculated through 24-hour ambulatory BP monitoring performed at baseline. Association with total and cardiovascular mortality (obtained through death certificates) were assessed by Cox regression models adjusted for clinical confounders and BP. Patients who died during follow-up had higher values of BP variability compared with those remaining alive. In fully adjusted models, daytime, nighttime, and weighted SD, systolic and diastolic, as well as diastolic average real variability, were all significantly associated with total and cardiovascular mortality. Hazard ratios for 1 SD increase ranged from 1.05 to 1.09 for total mortality and from 1.07 to 1.12 for cardiovascular mortality. A nighttime systolic SD ≥12 mm Hg was independently associated with total (hazard ratio: 1.13 [95% CI, 1.06-1.21]) and cardiovascular mortality (hazard ratio: 1.21 [95% CI, 1.09-1.36]). We conclude that short-term BP variability is independently associated with total and cardiovascular mortality in patients with hypertension.