High Short-Term Blood Pressure Variability Predicts Long-Term Cardiovascular Mortality in Untreated Hypertensives But Not in Normotensives

Abstract

Background: The prognostic value of the short-term blood pressure variability (BPV) from the 24-hour ambulatory blood pressure monitoring (ABPM) remains controversial. The present study aimed to investigate the long-term prognostic value of a high BPV in normotensive and hypertensive subjects from a community-based population.

Methods: A cohort of 624 normotensive and 633 untreated hypertensive Taiwanese participants (overall 669 men, aged 30-79 years) with baseline ABPM and 20-year all-cause and cardiovascular mortality data was drawn from a community-based survey. BPV was assessed by the read-to-read average real variability of the 24-hour diastolic and systolic blood pressure (SBP) (ARVd and ARVs, respectively).

Results: In Cox proportional hazards analysis, ARVd predicted cardiovascular mortality independently of office SBP (hazard ratios (HRs) and 95% confidence intervals (CIs) per 1 SD: 1.31 (1.10-1.55), respectively, bivariate analysis), 24-hour SBP (HR: 1.19, 95% CI: 1.00-1.43), and conventional risk factors (age, sex, smoking, total cholesterol, high-density lipoprotein cholesterol, and fasting blood glucose, HR: 1.40, 95% CI: 1.18-1.67). In subjects with hypertension, a high vs. low ARVd (median: 8.8mm Hg) significantly predicted cardiovascular mortality (HR: 2.11, 95% CI: 1.23-3.62 and HR: 2.04, 95% CI: 1.19-3.51, respectively), when the conventional risk factors plus office SBP or 24-hour SBP were accounted for, respectively. Similar but less significant results were obtained with ARVs. A high ARVd or ARVs did not significantly predict cardiovascular mortality in the normotensive subjects.

Conclusions: A high short-term BPV is significantly predictive of long-term cardiovascular mortality in untreated hypertensive but not normotensive community-based subjects, independently of office or 24-hour SBP.

Keywords: ambulatory blood pressure; blood pressure variability; cardiovascular mortality; hypertension..