Challenges in oscillometric blood pressure measurement in atrial fibrillation: looking for practical solutions

Hypertension is the most prevalent concomitant condition in patients with atrial fibrillation (AF) [1–3]. Both uncontrolled hypertension and AF are major risk factors for stroke and heart failure [4]. In patients receiving anticoagulant therapy, good control of blood pressure (BP) reduces the bleeding events [5]. Therefore, successful antihypertensive treatment is a cornerstone of AF management [6,7].

Whatever the device, accurate BP measurement always remains challenging in AF patients and particularly so with easy-to-use devices [8]. While automated oscillometric BP measurements have dominated the market, the role of these devices in AF management is still controversial [9]. BP measurement in AF patients is difficult [10], as this arrhythmia is associated with increased beat-to-beat BP variability, reflecting variations in ventricular filling time, stroke volume, and contractility [11]. To address this problem, better understanding of the AF-related hemodynamic alterations resulted in development of a high-accuracy embedded algorithm, which became a useful screening tool for the detection of asymptomatic AF during routine automated BP measurement [12].

Previous studies that assessed automated BP measurements in AF suggest that this method might be more accurate for SBP than DBP measurement [8]. While most AF patients have primarily systolic hypertension, imprecise assessment of DBP is of concern, as too aggressive DBP lowering might result in coronary hypoperfusion and myocardial ischaemia. Furthermore, it has been stressed [11] that published evidence regarding the role of ambulatory blood pressure monitoring (ABPM) in AF patients is scarce. In this issue of Blood Pressure, two original papers address the issue of oscillometric BP measurement in AF. Halfon et al. [13] assessed the reliability of three oscillometric BP devices, and the agreement with invasive arterial blood pressure. Miszkowska-Nagórna et al. [14] estimated the accuracy of the oscillometric ABPM device (SpaceLabs 90207) with reference to mercury manometer-based readings.

In the Swiss study [13], OmronR7TM wrist device failed to obtain any BP readings. These results are consistent with a previous report [15] indicating that wrist devices are not suitable to measure BP in patients in AF. BP measurement using the two arm oscillometric devices (OmronHEM907TM and Microlife WatchBPhome) achieved a high reliability for SBP. The agreement between intra-arterial and oscillometric measurements was substantially improved when the average of three consecutive measurements was taken into account. In the Polish study [14], diastolic BP tended to be slightly overestimated when assessed with SpaceLabs 90207. In spite of these limitations, the study supports the ESH Working Group statement [11] that there is no reason to exclude AF patients from the ABPM procedures.

In conclusion, first, wrist devices should not be used in AF patients. Second, if an automated oscillometric arm device is used, BP should be derived from at least three consecutive measurements. Third, the oscillometric measurement is more reliable for SBP than DBP. In case of doubts regarding DBP level, the physicians should refer to auscultatory method. Fourth, there is no agreed procedure for BP monitor validation in AF. Clearly, further technological improvement, specific validation protocols and larger trials in AF patients are needed, but precise BP measurements will probably remain difficult because of the intrinsic nature of AF. Hopefully, next generation arrhythmia-sensitive BP devices will facilitate future hypertension management and lead to better prevention of cardiovascular events in AF patients.

Disclosure statement

KN, SEK, MB and SO are editors of Blood Pressure and report no relevant conflicts of interest to disclose related to this commentary.