title: Device monitoring of heart failure in cardiac resynchronization therapy device recipients: a single-center experience with a novel multivector impedance monitoring system.
abstract: OBJECTIVE
  We investigated the performance of a new intrathoracic multivector impedance monitoring system for the prediction of heart failure events in consecutive device-implanted patients.
  
  
  METHODS
  Eighty heart failure patients implanted with biventricular defibrillators with multivector impedance monitoring capability were prospectively enrolled. Clinical heart failure status and impedance data were assessed during follow-up and if patients presented with an alert or heart failure deterioration.
  
  
  RESULTS
  During follow-up (8.0 ± 4.4 months), 56 events of device alert for fluid index increase were identified in 29 patients, and a total of 39 heart failure events (defined by worsening of heart failure signs and symptoms) occurred in 23 patients. The sensitivity and positive predictive value (PPV) for heart failure deterioration was 61.5 and 42.9%, respectively. False-positive alerts occurred in 23 of 80 patients (28.8%), for an episode rate of 0.60 a year. Among all clinical heart failure events, decompensation caused hospitalization in 13 cases (33.3%), seven of them were preceded by an alert condition (53.8%) resulting in a sensitivity of 53.8% and a PPV of 17.9%.
  
  
  CONCLUSIONS
  The present study confirms the feasibility and clinical usefulness of this novel multivector impedance monitoring system. It would be worthwhile to perform larger studies to assess its actual clinical value in heart failure patients.
authors.affiliation: aDivision of Cardiology, Department of Internal Medicine, University of Rome 'Tor Vergata',, Rome, Italy bElectrophysiology, Pacemaker and ICD Unit, Hygeia Hospital, Athens, Greece cNational Research Council (CNR), Institute of Clinical Physiology, Section of Rome, Rome, Italy.
authors.forename: Giovanni B
authors.initials: GB
authors.lastname: Forleo
authors.forename: Germana
authors.initials: G
authors.lastname: Panattoni
authors.forename: Valentina
authors.initials: V
authors.lastname: Schirripa
authors.forename: Lida P
authors.initials: LP
authors.lastname: Papavasileiou
authors.forename: Domenico G
authors.initials: DG
authors.lastname: Della Rocca
authors.forename: Alessandro
authors.initials: A
authors.lastname: Politano
authors.forename: Fabio
authors.initials: F
authors.lastname: Ticconi
authors.forename: Carmine
authors.initials: C
authors.lastname: Biscione
authors.forename: Domenico
authors.initials: D
authors.lastname: Sergi
authors.forename: Arianna
authors.initials: A
authors.lastname: Di Molfetta
authors.forename: Luca
authors.initials: L
authors.lastname: Santini
authors.forename: Ambrogio
authors.initials: A
authors.lastname: Capria
authors.forename: Francesco
authors.initials: F
authors.lastname: Romeo
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D058406:Cardiac Resynchronization Therapy / Q000009:adverse effects; D058409:Cardiac Resynchronization Therapy Devices; D002307:Cardiography, Impedance / Q000295:instrumentation*; D017147:Defibrillators, Implantable; D018450:Disease Progression; D017097:Electric Impedance; D004867:Equipment Design; D004868:Equipment Failure; D005189:False Positive Reactions; D005240:Feasibility Studies; D005260:Female; D006333:Heart Failure / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy*; D006801:Humans; D007558:Italy; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies; D013997:Time Factors; D016896:Treatment Outcome