A trial of three non-invasive blood pressure monitors compared with invasive blood pressure assessment in atrial fibrillation and sinus rhythm

Int J Clin Pract. 2019 Aug 29:e13410. doi: 10.1111/ijcp.13410. Online ahead of print.

Abstract

Objective: To investigate the accuracy of three non-invasive blood pressure (BP) devices in atrial fibrillation (AF) compared with invasive arterial BP.

Methods: One hundred patients aged 45-90 years, 63% male (50 in AF and 50 age matched controls in sinus rhythm [SR]) were identified with arterial lines measuring beat-to-beat BP fluctuation. Non-invasive BP measurements utilising the manual sphygmomanometer (MS), PulseCor R6.5 (PC) and automated sphygmomanometer (AS) were taken simultaneously with invasive BP in a randomised sequence. This was repeated three times in each patient.

Results: In SR differences in systolic BP (SBP) for MS, AS and PC were -0.34 mm Hg (95% CI -2.31 to 1.63; P = .733), -3.80 mm Hg (95% CI -5.73 to -1.87; P = .0001) and -3.90 mm Hg (95% CI -5.90 to -1.90; P = .0001) and for diastolic BP (DBP) were 6.02 mm Hg (95% CI 4.39-7.64; P < .0001), 8.95 mm Hg (95% CI 7.36-10.55; P < .0001) and 7.54 mm Hg (95% CI 5.89-9.18; P < .0001), respectively. In AF mean differences in SBP for MS, AS and PC were -7.33 mm Hg (95% CI -9.11 to -5.55; P < .0001), -5.29 mm Hg (95% CI -7.08 to -3.50; P < .0001) and -5.75 mm Hg (95% CI -7.54 to -3.96; P < .0001) respectively and for DBP were 5.28 mm Hg (95% CI 4.03-6.54; P < .0001), 6.26 mm Hg (95% CI 5.00-7.52; P < .0001) and 6.89 mm Hg (95% CI 5.64-8.15; P < .0001) respectively.

Conclusions: The MS is accurate in SR because of direct assessment of Korotkoff sounds. Non-invasive BP assessment in AF is significantly less accurate. These findings have important prognostic and therapeutic implications.