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Implantable cardioverter-defibrillator therapy improves long-term survival in patients with unexplained syncope,

José Mauricio Sánchez1, William T Katsiyiannis, Brian F Gage

  • 1Cardiovascular Division, Department of Internal Medicine, Washington University School of Medicine, St. Louis, Missouri 63110, USA.

Heart Rhythm
|April 27, 2005
PubMed

Insights

Implantable cardioverter-defibrillators (ICDs) significantly reduce mortality in patients with unexplained syncope and cardiomyopathy after a negative electrophysiologic study (EPS). This therapy offers improved long-term outcomes compared to conventional treatment.

Area of Science:

  • Cardiology
  • Electrophysiology
  • Medical Devices

Background:

  • Electrophysiologic studies (EPS) are used to assess syncope in patients with left ventricular dysfunction.
  • Long-term data on all-cause mortality and implantable cardioverter-defibrillator (ICD) benefits in this population are limited.

Purpose of the Study:

  • To evaluate long-term outcomes in patients experiencing unexplained syncope.
  • To assess patients with cardiomyopathy and a negative electrophysiologic study (EPS).
  • To determine the efficacy of implantable cardioverter-defibrillator (ICD) therapy in this patient group.

Main Methods:

  • A cohort of 102 patients with unexplained syncope, cardiomyopathy, and negative EPS was evaluated.
  • A blinded, matched case-control analysis included 51 patients (19 ICD, 32 conventional therapy).
  • Primary endpoint was death or cardiac arrest, comparing ICD therapy to conventional treatment.

Main Results:

  • The ICD group experienced fewer primary events (2 vs. 12) over a mean follow-up of 44.3 months.
  • The hazard ratio for events in the ICD group was 0.18 (P = .04), indicating a significant risk reduction.
  • Appropriate ICD shocks occurred in 26% of patients within 2 years; other factors did not predict outcomes.

Conclusions:

  • Empiric implantable cardioverter-defibrillator (ICD) therapy demonstrates improved long-term outcomes.
  • This benefit was observed in patients with unexplained syncope, cardiomyopathy, and a negative electrophysiologic study (EPS).
  • ICD therapy is a viable option for reducing mortality in this specific patient cohort.
Abstract

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