Usefulness of Blood Pressure Variability Indices Derived From 24‐Hour Ambulatory Blood Pressure Monitoring in Detecting Autonomic Failure

Abstract

Background Increased blood pressure ( BP ) variability and nondipping status seen on 24‐hour ambulatory BP monitoring are often observed in autonomic failure ( ATF ). Methods and Results We assessed BP variability and nocturnal BP dipping in 273 patients undergoing ambulatory BP monitoring at Southwestern Medical Center between 2010 and 2017. SD , average real variability, and variation independent of mean were calculated from ambulatory BP monitoring. Patients were divided into a discovery cohort (n=201) and a validation cohort (n=72). ATF was confirmed by formal autonomic function test. In the discovery cohort, 24‐hour and nighttime average real variability, SD , and variation independent of mean did not differ significantly between ATF (n=25) and controls (n=176, all P >0.05). However, daytime SD, daytime coefficient of variation, and daytime variation independent of mean of systolic BP ( SBP ) were all significantly higher in patients with ATF than in controls in both discovery and validation cohorts. Nocturnal BP dipping was more blunted in ATF patients than controls in both cohorts (both P <0.01). Using the threshold of 16 mm Hg, daytime SD SBP yielded a sensitivity of 77% and specificity of 82% in detecting ATF in the validation cohort, whereas nondipping status had a sensitivity of 80% and specificity of 44%. The area under the receiver operator characteristic of daytime SD SBP was greater than the area under the receiver operator characteristic of nocturnal SBP dipping (0.79 [0.66‐0.91] versus 0.73 [0.58‐0.87], respectively). Conclusions Daytime SD of SBP is a better screening tool than nondipping status in detecting autonomic dysfunction.

Machine learning applied to ambulatory blood pressure monitoring: a new tool to diagnose autonomic failure?

“…The present analyses confirm the previous finding that hypotensive episodes and reverse dipping are accurate markers of AF in PD [ 9 , 20 ], while increased BPV seems to be less effective in predicting AF, despite the multiple hypotensive episodes (expected to increase BPV) observed in this patient population. While this result partly conflicts with a previous study [ 10 ] suggesting that exaggerated SD of diurnal systolic BP could be used to detect primary or secondary AF, the authors did not confirm the association between AF and increased SD-SBP when the PD status and dopaminergic treatment were included in the multivariate analysis. This suggests that AF in PD (and possibly other forms of primary AF) may be characterized by a peculiar BP profile, different from the one observed in secondary AF.…”

“…Recent studies showed that selected abnormalities in the 24-h BP profiles, such as a reversed circadian rhythm [ 9 ] and increased BPV [ 10 ], are associated with AF. The central hypothesis of the present study is that ABPM effectively predicts adrenergic AF in patients with PD.…”

Ambulatory blood pressure and drug treatment for orthostatic hypotension as predictors of mortality in patients with multiple system atrophy

“…It is also worth noting that the prognostic role of daytime BP variability can be detected from ABPM carried out during the first hospitalization for diagnostic investigations (i.e., at an early stage of the disease). In this respect, it has been shown in other disorders than MSA that increased daytime BP variability was associated with autonomic failure [26]. Thus, this observation substantiates previous reports showing that early severe CV autonomic dysfunction is a negative prognostic factor in MSA patients [7,12,13].…”

The Multiscale Dynamics of Beat-to-Beat Blood Pressure Fluctuation Links to Functions in Older Adults

“…The BP was measured only in a short term at resting state in this study. While this suggests that this BP complexity metric can be obtained conveniently, previous studies, on the contrary, showed that the ambulatory BP across hours or days was also associated with important functional status (e.g., cognitive function) in older adults (45,46). It is thus worthwhile to characterize the BP complexity of the ambulatory BP recordings over larger scales.…”