Predictive value of within-visit and visit-to-visit blood pressure variability for all-cause mortality: the Minhang Study

BACKGROUND: Blood pressure variability is a common physiological phenomenon; however, the association between within-visit and visit-to-visit variability in blood pressure and all-cause mortality remains uncertain. METHODS: We conducted a retrospective analysis of blood pressure variability among 11 721 adults who underwent blood pressure measurement on three occasions within a period of 6 months. Within-visit and visit-to-visit variability was quantified using the standard deviation and maximum--minimum difference between measures. The predictive effect of this variability on all-cause mortality was evaluated using Kaplan--Meier survival curves and Cox regression analysis. RESULTS: The incidence of all-cause mortality was significantly higher for participants in the top quintile of within-visit and visit-to-visit blood pressure variability and for those with sustained high within-visit variability. Within-visit variability was not retained as a risk factor after adjustment in Cox regression models. The hazard ratio for mortality increased from 48 to 55% for the top quintile of visit-to-visit blood pressure variability and from 56 to 61% for sustained high within-visit variability. The risk of mortality remained statistically higher even if visit-to-visit blood pressure variability was added to the model, including consistency of within-visit blood pressure variability and vice versa. CONCLUSION: Visit-to-visit and sustained high within-visit blood pressure variability were significant positive prognostic factors for all-cause mortality. Our findings underlined the clinical significance of achieving stable blood pressure in an effective plan of hypertension management.