Impact of left ventricular ejection fraction on occurrence of ventricular events in defibrillator patients with coronary artery disease

Europace. 2011 Nov;13(11):1562-7. doi: 10.1093/europace/eur169. Epub 2011 Jun 28.

Abstract

Aims: Primary preventive implantable cardioverter defibrillator (ICD) therapy is indicated in patients with coronary artery disease (CAD) and left ventricular ejection fraction (LVEF) of ≤ 35%, but some patients in the major trials had LVEF in the range of 30-35%. We hypothesized that these patients constitute a lower-risk population and might derive less benefit from ICD therapy.

Methods and results: In this retrospective study, patients with CAD in whom an ICD was implanted for primary prevention were studied. We determined the incidence of ICD therapies in two predefined LVEF cut-off groups (≤/>20%; ≤/>30%), predictors of ICD therapies, and overall mortality. A total of 536 patients were included: 88% male, age 63 ± 10 years, follow-up 30 ± 25 months. In all, 115 patients (22%) experienced appropriate ICD interventions; in 36% of them, the arrhythmia was treated with shock. Inappropriate therapy was delivered in 8%. Cumulative mortality at 5 years was 20%. Using our two cut-off levels, more ICD-therapies occurred in patients with poorer LVEF, but the difference was significant only with the cut-off value of ≤/>20%. Only 2 of 12 parameters were predictors of appropriate ICD therapy: age, odds ratio (OR) 1.047 (1.015-1.079) per year and QRS width, OR 1.014 per ms (1.004-1.024).

Conclusion: Refined risk stratification using different LVEF cut-off levels is not helpful in patients with CAD and LVEF ≤ 35%. Mortality was lower than in randomized trials in this real-world setting, probably due to better drug treatment at implant.

Publication types

  • Multicenter Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Atrial Fibrillation / epidemiology
  • Coronary Artery Disease / therapy*
  • Death, Sudden, Cardiac / epidemiology
  • Death, Sudden, Cardiac / prevention & control*
  • Defibrillators, Implantable*
  • Female
  • Follow-Up Studies
  • Humans
  • Incidence
  • Kaplan-Meier Estimate
  • Male
  • Middle Aged
  • Primary Prevention*
  • Retrospective Studies
  • Risk Factors
  • Stroke Volume / physiology*
  • Tachycardia, Sinus / epidemiology
  • Tachycardia, Supraventricular / epidemiology
  • Ventricular Dysfunction, Left / physiopathology*