title: Early Indication of Decompensated Heart Failure in Patients on Home-Telemonitoring: A Comparison of Prediction Algorithms Based on Daily Weight and Noninvasive Transthoracic Bio-impedance.
abstract: BACKGROUND
  Heart Failure (HF) is a common reason for hospitalization. Admissions might be prevented by early detection of and intervention for decompensation. Conventionally, changes in weight, a possible measure of fluid accumulation, have been used to detect deterioration. Transthoracic impedance may be a more sensitive and accurate measure of fluid accumulation.
  
  
  OBJECTIVE
  In this study, we review previously proposed predictive algorithms using body weight and noninvasive transthoracic bio-impedance (NITTI) to predict HF decompensations.
  
  
  METHODS
  We monitored 91 patients with chronic HF for an average of 10 months using a weight scale and a wearable bio-impedance vest. Three algorithms were tested using either simple rule-of-thumb differences (RoT), moving averages (MACD), or cumulative sums (CUSUM).
  
  
  RESULTS
  Algorithms using NITTI in the 2 weeks preceding decompensation predicted events (P<.001); however, using weight alone did not. Cross-validation showed that NITTI improved sensitivity of all algorithms tested and that trend algorithms provided the best performance for either measurement (Weight-MACD: 33%, NITTI-CUSUM: 60%) in contrast to the simpler rules-of-thumb (Weight-RoT: 20%, NITTI-RoT: 33%) as proposed in HF guidelines.
  
  
  CONCLUSIONS
  NITTI measurements decrease before decompensations, and combined with trend algorithms, improve the detection of HF decompensation over current guideline rules; however, many alerts are not associated with clinically overt decompensation.
authors.affiliation: Personal Health Solutions, Philips Research, Eindhoven, Netherlands. illapha@gmail.com.
authors.forename: Illapha
authors.identifier: http://orcid.org/0000-0002-9241-3763
authors.initials: I
authors.lastname: Cuba Gyllensten
authors.forename: Alberto G
authors.identifier: http://orcid.org/0000-0002-6731-005X
authors.initials: AG
authors.lastname: Bonomi
authors.forename: Kevin M
authors.identifier: http://orcid.org/0000-0003-1963-345X
authors.initials: KM
authors.lastname: Goode
authors.forename: Harald
authors.identifier: http://orcid.org/0000-0002-4333-4460
authors.initials: H
authors.lastname: Reiter
authors.forename: Joerg
authors.identifier: http://orcid.org/0000-0002-3343-9285
authors.initials: J
authors.lastname: Habetha
authors.forename: Oliver
authors.identifier: http://orcid.org/0000-0001-6811-3659
authors.initials: O
authors.lastname: Amft
authors.forename: John Gf
authors.identifier: http://orcid.org/0000-0002-1471-7016
authors.initials: JG
authors.lastname: Cleland
keywords: Heart failure; alert algorithms; ambulatory monitoring; deterioration detection; impedance; telemonitoring