What is the clinical evidence from this study?

Study design: Observational. Population: Hypertension and healthy normotensive (n=22). Intervention: Brachial reconstruction technique (reBAP) via waveform filtering and level correction vs. Uncorrected finger arterial pressure (FAP). Primary outcome: Difference from intrabrachial artery pressure (BAP) over 24 hours and nocturnal dip estimation.

October 1, 2002

Variable day/night bias in 24-h non-invasive finger pressure against intrabrachial artery pressure is removed by waveform filtering and level correction

Key Result

Applying a brachial reconstruction technique to 24-hour non-invasive finger arterial pressure reduced the overestimation of nocturnal systolic blood pressure dips from +8 mmHg to -1 mmHg.

Study Design

Type

Observational (n=22)

Structured PICO

Does a brachial reconstruction technique (reBAP) improve the accuracy of 24-hour non-invasive finger arterial pressure compared to intrabrachial artery pressure?

Population

22 participants (8 healthy normotensive volunteers and 14 patients with hypertension) aged 19-60 years undergoing simultaneous 24-hour finger and intrabrachial arterial pressure recordings.

Exposure

Brachial reconstruction technique (reBAP) consisting of a waveform filter and level correction applied to 24-hour non-invasive finger arterial pressure (FAP)

Comparator

Uncorrected 24-hour finger arterial pressure (FAP)

Outcome

Bias against intrabrachial artery pressure (BAP) over 24 hours and estimation of nocturnal blood pressure dipsurrogate

Applying a waveform filter and level correction to non-invasive finger arterial pressure recordings removes day/night bias and accurately tracks diurnal blood pressure changes compared to intrabrachial pressure.

Abstract

BACKGROUND Twenty-four-hour finger arterial pressure (FAP) recordings show a negative bias against intrabrachial artery pressure (BAP) and the bias is greater during the night, thereby overestimating the nocturnal blood pressure dip. We have available a methodology with which to reconstruct BAP from FAP by waveform filtering (transfer function) and generalized level (bias) correction that reduces the bias for short-term blood pressure records. OBJECTIVE To investigate if this methodology also decreases the extra bias during the night, thereby yielding a better estimate of the nocturnal dip. METHODS Twenty-four-hour FAP and BAP blood pressure recordings were simultaneously obtained in eight healthy normotensive volunteers and 14 patients with hypertension (ages 19-60 years), during standardized scheduled activities. The data were analysed off-line, applying the brachial reconstruction technique (reBAP) consisting of a waveform filter and level correction. Simultaneous beats yielded systolic, diastolic and mean pressures that were averaged per 30 min, per day, per night, per activity, over the 24-h period, and for volunteers and patients separately. RESULTS Over the full 24 h, FAP systolic, diastolic and mean values for the total group differed from BAP by +1 +/- 10, -8 +/- 7 and -10 +/- 8 mmHg (mean +/- SD), respectively. Similarly, reBAPs differed by +1 +/- 11, -2 +/- 7 and -2 +/- 7 mmHg. BAPs dipped by 20 +/- 8, 13 +/- 6 and 15 +/- 6 mmHg, respectively, during the night. These dips were overestimated by +8, +4 and +4 mmHg by FAP, but not by reBAP: -1, +1 and +1 mmHg. The volunteer and the patient groups showed slight differences in results, but these were not statistically significant. CONCLUSIONS The generalized reconstruction technique to obtain near-brachial pressure from non-invasive FAP almost completely removed bias over the full 24-h day-night period and improved tracking of diurnal changes for all three blood pressure values.

Bookmark