title: The lung impedance monitoring in treatment of chronic heart failure (the LIMIT-CHF study).
abstract: OBJECTIVE
  To assess the usefulness of intrathoracic impedance monitoring (IIM) alerts in guiding empirical treatment of chronic heart failure (CHF) patients to prevent heart failure (HF) hospitalizations and unplanned HF care.
  
  
  RESULTS
  Chronic heart failure patients with OptiVol or CorVue capable implantable cardioverter-defibrillators were randomized to either the active group (IIM alarm turned on and diuretic dose increased by 50% for 1 week in the event of alarm sounding) or the control group (IIM alarm turned off). The primary endpoint was the number of HF hospitalizations per patient at 1 year. The NYHA class, 6MWT, B-type natriuretic peptide (BNP), and MLWHF questionnaire score were collected at baseline and follow-up. Eighty patients were included and 71 reached 1-year follow-up. There were 1.7 ± 1.5 alerts in the active group and 1.1 ± 1.0 in the control group, P = 0.07. In the active group, 61% of alerts led to a diuretic dose increase. There was a total of 11 HF hospitalizations in the active group vs. 6 in the control group without significant differences in the number of episodes per patient (0.3 ± 0.9 vs. 0.2 ± 0.4, P = 0.95). There were no unplanned HF visits in the active group vs. 0.1 ± 0.3 per patient in the control group, P = 0.08. The total MLWHF scores were significantly increased at the final follow-up in the control group, whereas a trend towards reduction was observed in the active group.
  
  
  CONCLUSIONS
  In this study, an empirical HF treatment guided by IIM alerts did not reduce emergency treatment of HF. However, it seems to have a positive impact on quality of life. CLINICAL TRIAL REGISTRATIONURL: http://www.clinicaltrials.gov. Unique identifier: NCT01320007.
authors.affiliation: Department of Arrhythmia Services, Barts Heart Centre, St Bartholomew's Hospital, Barts Health NHS Trust, London, EC1A 7BE, UK.
authors.forename: Giulia
authors.initials: G
authors.lastname: Domenichini
authors.affiliation: Department of Arrhythmia Services, Barts Heart Centre, St Bartholomew's Hospital, Barts Health NHS Trust, London, EC1A 7BE, UK.
authors.forename: Tsveta
authors.initials: T
authors.lastname: Rahneva
authors.affiliation: Department of Arrhythmia Services, Barts Heart Centre, St Bartholomew's Hospital, Barts Health NHS Trust, London, EC1A 7BE, UK.
authors.forename: Ihab G
authors.initials: IG
authors.lastname: Diab
authors.affiliation: Department of Arrhythmia Services, Barts Heart Centre, St Bartholomew's Hospital, Barts Health NHS Trust, London, EC1A 7BE, UK.
authors.forename: Onkar S
authors.initials: OS
authors.lastname: Dhillon
authors.affiliation: Department of Arrhythmia Services, Barts Heart Centre, St Bartholomew's Hospital, Barts Health NHS Trust, London, EC1A 7BE, UK.
authors.forename: Niall G
authors.initials: NG
authors.lastname: Campbell
authors.affiliation: Department of Arrhythmia Services, Barts Heart Centre, St Bartholomew's Hospital, Barts Health NHS Trust, London, EC1A 7BE, UK.
authors.forename: Malcolm C
authors.initials: MC
authors.lastname: Finlay
authors.affiliation: Department of Arrhythmia Services, Barts Heart Centre, St Bartholomew's Hospital, Barts Health NHS Trust, London, EC1A 7BE, UK.
authors.forename: Victoria
authors.initials: V
authors.lastname: Baker
authors.affiliation: Department of Arrhythmia Services, Barts Heart Centre, St Bartholomew's Hospital, Barts Health NHS Trust, London, EC1A 7BE, UK.
authors.forename: Ross J
authors.initials: RJ
authors.lastname: Hunter
authors.affiliation: Department of Arrhythmia Services, Barts Heart Centre, St Bartholomew's Hospital, Barts Health NHS Trust, London, EC1A 7BE, UK.
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Earley
authors.affiliation: Department of Arrhythmia Services, Barts Heart Centre, St Bartholomew's Hospital, Barts Health NHS Trust, London, EC1A 7BE, UK r.schilling@qmul.ac.uk.
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Schilling
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D002307:Cardiography, Impedance; D002908:Chronic Disease; D017147:Defibrillators, Implantable; D004232:Diuretics / Q000008:administration & dosage; D004554:Electric Countershock / Q000295:instrumentation*; D017097:Electric Impedance; D004636:Emergency Service, Hospital; D005080:Exercise Test; D017079:Exercise Tolerance; D005260:Female; D006333:Heart Failure / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy*; D006760:Hospitalization; D006801:Humans; D008131:London; D008168:Lung / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D020097:Natriuretic Peptide, Brain / Q000097:blood; D011237:Predictive Value of Tests; D011446:Prospective Studies; D011474:Prosthesis Design; D011788:Quality of Life; D011795:Surveys and Questionnaires; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D015415:Biomarkers; D004232:Diuretics; D020097:Natriuretic Peptide, Brain
keywords: Cardiac resynchronization therapy; Chronic heart failure; Implantable cardioverter-defibrillators; Intrathoracic impedance monitoring systems