Visit-to-visit variability of blood pressure: current knowledge and future research directions.

Blood pressure (BP) is known to vary over time within individuals. Although variability between office visits has traditionally been regarded as a barrier to the accurate measurement of BP, several recent studies have reported strong associations between visit-to-visit variability (VVV) of BP and increased risk for cardiovascular outcomes. In this article, we review data on VVV of BP and outcomes, determinants of high VVV of BP including demographics, medical history, and antihypertensive medication classes and poor adherence. In addition, we will discuss methodological issues related to interpreting data from studies of VVV of BP and data on BP variability assessed outside of the office setting. In conclusion, we highlight pressing research needs related to VVV of BP including those aimed at determining the mechanism underlying high VVV of BP, assessing interventions that lower VVV of BP and the utility of quantifying VVV of BP using measurements obtained in routine clinical practice.