Blood pressure and orthostatic hypotension as measures of autonomic dysfunction in patients from the transthyretin amyloidosis outcomes survey (THAOS)

Abstract

Introduction: Autonomic dysfunction, an early symptom of transthyretin amyloidosis (ATTR amyloidosis), requires investigations not readily available in many clinics. Although monitoring of orthostatic hypotension (OH) will not be a substitute for more specialized tests, it can add important information about initiation of dysautonomia. The aim of this study was to investigate whether simple blood pressure (BP) monitoring may be a useful tool for evaluation of disease progression and an early sign of autonomic dysfunction.

Methods: BP and OH data were from subjects enrolled in the Transthyretin Amyloidosis Outcomes Survey (THAOS). Characteristics associated with changes in BP and orthostatic difference were identified by regression analyses.

Results: OH tended to be present relatively early in the course of disease and was more common at enrollment (11.7%) than either diarrhea (2.4%) or unintentional weight loss (3.1%). In subjects with OH at enrollment, progressive increase in systolic and diastolic orthostatic difference was observed. OH was also associated with significantly worse quality of life.

Discussion: BP variability is a useful tool for assessing disease onset and severity in ATTR amyloidosis, particularly in patients with OH. Trial registration ClinicalTrials.gov: NCT00628745.

Keywords: Amyloidosis; Autonomic neuropathy; Blood pressure; Orthostatic hypotension; Registry; Transthyretin amyloidosis.