What is the clinical evidence from this study?

Study design: Cross-Sectional. Population: Hypertension (n=161). Intervention: Beat-to-beat blood pressure variability vs. Normotensive adults. Primary outcome: Total arterial compliance (TAC) (β = -0.100, p=0.040).

August 10, 2017Open Access

Influence of beat-to-beat blood pressure variability on vascular elasticity in hypertensive population

Key Result

Elevated beat-to-beat systolic blood pressure variability, specifically variation independent of mean, was independently correlated with reduced vascular elasticity in hypertensive patients (β = -0.100, p = 0.040).

Study Design

Type

Cross-Sectional (n=161)

Multicenter

Structured PICO

Does elevated beat-to-beat blood pressure variability correlate with reduced vascular elasticity in hypertensive patients?

Population

161 adults aged 28-75 years, comprising 81 hypertensive patients and 80 normotensive controls free of diabetes and cardiovascular disease, evaluated in a cross-sectional study.

Comparator

Normal adult control population (n=80) without hypertension.

Outcome

Correlation between beat-to-beat blood pressure variability (assessed by SD, ARV, RSD, and VIM) and vascular elasticity (estimated by total arterial compliance [TAC] using stroke volume/pulse-pressure method).surrogate

Elevated beat-to-beat systolic blood pressure variability is independently associated with reduced vascular elasticity in hypertensive patients, suggesting it may serve as an early marker of vascular damage.

Main Result

Effect estimate: β = -0.100

p-value: p=0.040

Limitations

The SV/PP method used to assess TAC assumes a constant pressure-to-volume ratio, which may not be valid in certain disease states.
Peripheral pulse pressure was used instead of central pulse pressure, which might underestimate TAC in some subjects.
The cross-sectional design precludes establishing a causal link between beat-to-beat BPV and TAC.
The sample size was relatively small.
The age range of the populations was relatively large, which might affect the accuracy of the results.

Abstract

Whether elevated beat-to-beat blood pressure variability (BPV) has an influence on vascular elasticity is confounded and poorly understood. This study hypothesized that the increased BPV could have an adverse effect on the vascular elasticity, as estimated by total arterial compliance (TAC), independent of blood pressure (BP) values. Beat-to-beat BP and TAC were measured in 81 hypertensive patients (experimental population) and in 80 normal adults (control population). Beat-to-beat BPV was assessed by standard deviation (SD), average real variability (ARV), residual standard deviation (RSD) and variation independent of mean (VIM). In experimental population, systolic BPV (SBPV) showed a significant correlation with TAC (SD, r = -0.326, p < 0.001; ARV, r = -0.277, p = 0.003; RSD, r = -0.382, p < 0.001; VIM, r = -0.274, p = 0.003); similarly, SD, RSD and VIM of diastolic BP (DBP) also showed explicit correlation with TAC (r = -0.255, p = 0.006; r = -0.289, p = 0.002; r = -0.219, p = 0.019; respectively). However, in the control population, neither SBPV nor diastolic BPV (DBPV) showed a significant correlation with TAC. Furthermore, in the experimental population, VIM of systolic BP (SBP) was also a determinant of TAC (β = -0.100, p = 0.040) independent of average SBP, DBP, age and body mass index. In conclusion, these data imply that beat-to-beat BPV, especially SBPV, shows an independent correlation with vascular elasticity in hypertensive population.

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