What is the clinical evidence from this study?

Study design: Observational. Intervention: Noninvasive 24-h aortic ABPM vs. Repeat assessment. Primary outcome: Average 24-h aortic systolic blood pressure (ICC 0.80, 95% CI 0.58-0.90, p=0.48).

June 7, 2012Open Access

Feasibility and Reproducibility of Noninvasive 24-h Ambulatory Aortic Blood Pressure Monitoring With a Brachial Cuff-Based Oscillometric Device

Key Result

Noninvasive 24-h ambulatory aortic blood pressure monitoring was feasible and reproducible, with an intraclass coefficient of variation of 0.80 (95% CI 0.58-0.90) for systolic BP.

Study Design

Type

Observational (n=30)

Structured PICO

Does a brachial cuff-based oscillometric device provide feasible and reproducible noninvasive 24-h ambulatory aortic blood pressure monitoring in adult subjects?

Population

30 consecutive subjects (mean age 53.6 years, 43% female) undergoing test-retest 24-hour ambulatory blood pressure monitoring with at least a 1-week interval.

Exposure

Noninvasive 24-h ambulatory brachial BP monitoring (ABPM) using a brachial cuff-based automatic oscillometric device (Mobilo-O-Graph) to assess aortic BP via mathematical transformation

Comparator

Repeat assessment with the same device at least 1 week later (test-retest design)

Outcome

Feasibility (average number of valid readings) and reproducibility (intraclass coefficient of variation and standard deviation of differences) of 24-h aortic BP valuessurrogate

Noninvasive 24-h ambulatory aortic blood pressure monitoring using a brachial cuff-based oscillometric device is feasible and provides reproducible values.

Main Result

Effect estimate: ICC 0.80 (95% CI 0.58-0.90)

Absolute Event Rate: 115.9% vs 115.1%

p-value: p=0.48

Abstract

BACKGROUND: Accumulating evidence suggests the potential superiority of office aortic blood pressure (BP) over brachial in the management of arterial hypertension. The noninvasive aortic 24-h ambulatory brachial BP monitoring (ABPM) is potentially the optimal method for assessing BP profile. The objective of the present study was to investigate the feasibility and reproducibility to perform noninvasively 24-h aortic ABPM with a novel validated brachial cuff-based automatic oscillometric device (Mobilo-O-Graph) which records brachial BP and waveforms and assesses aortic BP via mathematical transformation. METHODS: Thirty consecutive subjects (mean age: 53.6 ± 11.6 years, 17 men) had a test-retest ABPM with at least 1-week interval. No modification of vasoactive drug treatment during the interval was allowed while similar 24-h activity during both recording days was recommended. RESULTS: The average number of valid readings for brachial vs. aortic BP were 69.9 ± 10.4 vs. 58.0 ± 13.3 in the initial 24-h assessment (P < 0.001) and 68.3 ± 10.8 vs. 56.4 ± 13.6 in the repeat assessment (P < 0.001). No differences in average 24 h aortic BP values were observed between the two assessments (systolic blood pressure (SBP) 115.9 ± 7.7 vs. 115.1 ± 6.0 mm Hg, respectively, P = 0.48, and diastolic 79.7 ± 7.4 vs. 79.2 ± 8.7, P = 0.54). Reproducibility indices of aortic pressure including, intraclass coefficient of variation (SBP: 0.80 (95% confidence interval 0.58-0.90); diastolic: 0.92 (0.83-0.96)) and s.d. of differences (SBP/diastolic: 6.0/4.5 mm Hg) indicated acceptable reproducibility. The Bland-Altman plots indicated no evidence of systemic bias. CONCLUSIONS: In conclusion, these data suggest that noninvasive 24-h ABPM is feasible and provides reproducible values. Future studies should validate the prognostic ability of 24-h aortic hemodynamics.