Visit-to-visit blood pressure variability (VVBPV) has been associated with adverse cardiovascular outcomes, but uncertainty remains regarding whether risk increases progressively or only beyond specific variability thresholds. A meta-analysis published in the European Journal of Preventive Cardiology evaluated the dose-response relationship between VVBPV and mortality  outcomes and assessed the influence of the number of visits used to estimate variability.

The analysis included 50 studies involving 10,624,740 individuals. Pooled hazard ratios were calculated according to outcome type and the number of visits used for VVBPV assessment, while restricted cubic spline meta-regression models were used to evaluate threshold effects. 

Findings

• Systolic VVBPV measured as standard deviation (SD) showed threshold values of 11.8 mmHg for all-cause mortality and 12.1 mmHg for cardiovascular mortality.
• Diastolic VVBPV SD showed threshold values of 5.8 mmHg for all-cause mortality and 5.25 mmHg for cardiovascular mortality.
• The risk of both all-cause and cardiovascular mortality increased significantly only when VVBPV exceeded the identified threshold values.
• Analyses indicated that at least  three clinic visits was required to reliably assess the prognostic value of VVBPV.

The findings suggest that the association between visit-to-visit blood pressure variability and mortality is non-linear, with distinct threshold values above which risk increases significantly.