Unreliable Estimation of Aortic Pulse Wave Velocity Provided by the Mobil‐O‐Graph Algorithm‐Based System in Marfan Syndrome

Abstract

Background Several devices have been proposed to assess arterial stiffness in clinical daily use over the past few years, by estimating aortic pulse wave velocity (PWV) from a single measurement of brachial oscillometric blood pressure, using patented algorithms. It is uncertain if these systems are able to provide additional elements, beyond the contribution carried by age and blood pressure levels, in the definition of early vascular damage expressed by the stiffening of the arterial wall. Methods and Results The aim of our study was to compare the estimated algorithm‐based PWV values, provided by the Mobil‐O‐Graph system, with the standard noninvasive assessment of aortic PWV in patients with Marfan syndrome (ie, in subjects characterized by premature aortic stiffening and low blood pressure values). Aortic stiffness was simultaneously evaluated by carotid‐femoral PWV with a validated arterial tonometer and estimated with an arm cuff–based ambulatory blood pressure monitoring Mobil‐O‐Graph device on 103 patients with Marfan syndrome (50 men; mean± SD age, 38±15 years). Aortic PWV, estimated by the Mobil‐O‐Graph, was significantly ( P <0.0001) lower (mean± SD, 6.1±1.3 m/s) than carotid‐femoral PWV provided by arterial tonometry (mean± SD , 8.8±3.1 m/s). The average of differences between PWV values provided by the 2 methods (±1.96×SD) was −2.7±5.7 m/s. Conclusions The Mobil‐O‐Graph provides PWV values related to an ideal subject for a given age and blood pressure, but it is not able to evaluate early vascular aging expressed by high PWV in the individual patient. This is well shown in patients with Marfan syndrome.

Comparing oscillometric and tonometric methods to assess pulse wave velocity: a population-based study

“…Previous studies have demonstrated that oscillometric PWV measurements (in-office and 24-h) underestimate cf-PWV, with differences more pronounced for the 24 h o-PWV (in-office mean difference 0.3 ± 1.1; 24-h mean difference 0.6 ± 1.3) [17]. In addition recent findings confirmed significantly lower 24-h o-PWV mean values compared with SphygmoCor inoffice [21].…”

“…The reliability of o-PWVs provided by Mobil-O-Graph in specific subgroups of patients was recently questioned. In certain conditions exposing to early vascular aging, the oscillometric method was found to be inadequate in assessing arterial stiffness [ 21 ]. Moreover, a reduced agreement between PWV methods at higher levels of arterial stiffness was highlighted [ 28 ].…”

“…Nevertheless, these studies were performed in small selected sample populations and to date comparison studies in the general population are lacking. Furthermore, recently, it has been shown that the Mobil-O-Graph provides unreliable estimations of PWV, delivering significantly lower PWV values than cf-PWV, in a selected population of young patients affected by an early and accelerated vascular aging [ 21 ]. Last but not least, in a sub-analysis of the Masked Hypertension Study on 188 patients, it was found that age and systolic blood pressure (SBP) explain about 99% of the PWVs estimated by Mobil-O-Graph, and a scarce correlation between o-PWVs and cf-PWVs [ 22 ].…”

Improvement of Arterial Stiffness One Month after Bariatric Surgery and Potential Mechanisms

“…Our study has some limitations and several strengths. First, there is some debate about the reliability or not of the Mobile-O-Graph device for measuring AS in the general population and in patients with obesity or with Marfan’s syndrome [ 34 ]. Recently, a couple of studies have concluded that the oscillometric PWV of Mobil-O-Graph is explained almost entirely by age and SBP compared to carotid-femoral PWV [ 35 ] or to the invasive aortic PWV measurement [ 36 ], since their relationship is explained by shared associations with age and SBP.…”

Ambulatory blood pressure monitoring over 24 h: A Latin American Society of Hypertension position paper—accessibility, clinical use and cost effectiveness of ABPM in Latin America in year 2020

“…Recent evidence emphasizes the limitations of the algorithmic approach used by these ABPM devices in measuring central BP and PWV, because in some devices the algorithmic estimate of PWV is only based on squared age values and arm cuff systolic BP and is not really measured, thus being unable to pick‐up alterations in aortic wall properties in specific types of patients, for example, in Marfan's syndrome patients …”