The value of a BP determination method using a novel non-invasive BP device against the invasive catheter measurement

The aim of this study was to evaluate the accuracy of a new blood pressure (BP) measurement method (Pulse method).

This study enrolled 45 patients for selective percutaneous coronary intervention (PCI) via right radial artery. A BP device using either oscillometric (Microlife 3AC1-1) or Pulse method(RG-BP11)was used. At the beginning of each PCI, intra-radial BP was measured before Microlife BP or Pulse BP measurement as its own reference, respectively. At the end of PCI, BP was measured again with the measurement order of Microlife BP and Pulse BP reversed. The differences between intra-radial and Microlife (BPi-M) or Pulse BP (BPi-P) on SBP, DBP and mean artery pressure (MAP) were calculated. Meanwhile, in 48 patients the intra-brachial BP and intra-radial artery BP were measured to calculate the brachial -radial BP difference (BPr-b).

The intra-radial SBP references used prior to both the Microlife and Pulse SBP that were similar (145.1±27.7 vs 145.8±24.2 mmHg), but the Microlife SBP was significantly lower than the Pulse SBP (127.7±20.5 vs 130.3±22.7 mmHg, P<0.05), thus the SBPi-M was higher than SBPi-P (18.1±11.8 vs 14.8±12.8 mmHg, P<0.05). As the mean SBPr-b was 12.4 mmHg, the Pulse SBP was closer to expected intra-brachial SBP by about 3.3 mmHg than was Microlife SBP to expected intra-brachial SBP. Meanwhile, Bland-Altman plots showed that the 95% limits of agreement for intra-radial SBP by Pulse SBP were narrower than those by Microlife SBP (12.0∼17.5 vs 15.5∼20.6 mmHg). However, the 95% limits of agreement for Pulse DBP and MAP were similar to those for Microlife DBP and MAP.

Against the invasive BP measurement, the pulse method may provide more accurate SBP and comparable DBP and MAP as compared with the oscillometric method.