WITHIN-VISIT AND SHORT- AND LONG-TERM BETWEEN-VISIT BLOOD PRESSURE VARIABILITY AS PREDICTORS OF CARDIOVASCULAR EVENTS AND MORTALITY IN ELDERLY CHINESE

Objective: We investigated the prognostic value of within-visit and short- and long-term between-visit blood pressure variability (BPV) for all-cause and cardiovascular mortality, fatal and nonfatal cardiovascular events and incident atrial fibrillation in an elderly Chinese population. Design and method: The study participants were elderly (>=65 years) inhabitants, enrolled in a trial for atrial fibrillation screen. Blood pressure was measured three times consecutively at baseline and in a subset also at weekly visits during the first month of follow-up or at quarterly visits during follow-up. BPV indices included SD, the coefficient of variation (CV), variability independent of the mean (VIM), average real variability (ARV) and the difference between maximum and minimum BP (MMD). We computed hazard ratios (HR) for the risks of clinical outcomes associated with a 1-SD increase in these BPV indexes, while accounting for confounding factors. Results: The 6711 participants had a mean (±SD) age of 71.5 years (±6.1) and included 3761 (56.0%) women. In adjusted analysis in all participants, diastolic but not systolic within-visit BPV indices were significantly (P<=0.02) and positively associated with the risks of all-cause and cardiovascular mortality, and fatal and nonfatal cardiovascular events, but negatively with the risk of incident atrial fibrillation, with hazard ratios ranging from 1.03-1.10, and from 0.88-0.96 respectively. In 362 participants, none of the short-term between-visit BPV indices were associated with the studied clinical outcomes (P>=0.06). In the analysis on long-term between-visit BPV in 1582 participants, significant associations were observed for systolic BPV indices and cardiovascular mortality (P<=0.04), with the hazard ratios ranging from 1.05-1.13. Conclusions: Our study showed that some of the BPV indices were weakly associated with the risk of mortality and cardiovascular events, highlighting differential clinical significance between within-visit diastolic BPV and between-visit BPV in blood pressure regulation and control.