Implantable CRT device diagnostics identify patients with increased risk for heart failure hospitalization

Giovanni B. Perego, Maurizio Landolina, Giuseppe Vergara, Maurizio Lunati, Gabriele Zanotto, Alessia Pappone, Gabriele Lonardi, Giancarlo Speca, Saverio Iacopino, Annamaria Varbaro, Shantanu Sarkar, Doug A. Hettrick, Alessandra Denaro

Research output: Contribution to journalArticlepeer-review


Purpose: To determine the association between device-determined diagnostic indices, including intrathoracic impedance, and heart failure (HF) hospitalization. Methods: Clinical and device diagnostic data of 558 HF patients indicated for CRT-D therapy (In Sync Sentry, Medtronic Inc.) were prospectively collected from 34 centers. Device-recorded intrathoracic impedance fluid index threshold crossing event (TCE), mean activity counts, tachyarrhythmia events, night heart rate (NHR) and heart rate variability (HRV) were compared within patients with vs. without documented HF hospitalization. Results: Mean follow-up was 326±216 days. Patients hospitalized for HF had significantly higher rates of TCE, a higher percentage of days with the thoracic impedance fluid index above the programmed threshold, a higher percentage of days with low activity, with low HRV or with high NHR. Multivariate analysis showed that TCE resulted in a 36% increased probability of HF hospitalization. Both TCE duration and patient activity were also significantly associated with hospitalization. Kaplan Meier analysis indicated that patients with more TCE events were significantly more likely to be hospitalized (log rank test, p=0.005). Conclusions: Decreased intrathoracic impedance, low patient activity and low HRV were all independently associated with increased risk for HF hospitalization in HF patients treated with resynchronization therapy. Device-derived diagnostic data may provide valuable and reliable indices for the prognostic stratification of HF patients.

Original languageEnglish
Pages (from-to)235-242
Number of pages8
JournalJournal of Interventional Cardiac Electrophysiology
Issue number3
Publication statusPublished - Dec 2008


  • Activity
  • Arrhythmias
  • Cardiac resynchronization therapy
  • Heart failure
  • Heart rate
  • Heart rate variability
  • Impedance

ASJC Scopus subject areas

  • Cardiology and Cardiovascular Medicine
  • Physiology (medical)


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