Europace Advance Access published online on October 28, 2009
Europace, doi:10.1093/europace/eup314
CLINICAL RESEARCH
Ventricular arrhythmia in coronary artery disease: limits of a risk stratification strategy based on the ejection fraction alone and impact of infarct localization
1 Service of Cardiology, Centre Hospitalier Universitaire Vaudois, University of Lausanne, 1011 Lausanne, Switzerland; 2 Intensive Care Unit, Centre Hospitalier Universitaire Vaudois, University of Lausanne, 1011 Lausanne, Switzerland
Aims: Estimates of the left ventricular ejection fraction (LVEF) in patients with life-threatening ventricular arrhythmias related to coronary artery disease (CAD) have rarely been reported despite it has become the basis for determining patient's eligibility for prophylactic defibrillator. We aimed to determine the extent and distribution of reduced LVEF in patients with sustained ventricular tachycardia or ventricular fibrillation.
Methods and results: 252 patients admitted for ventricular arrhythmia related to CAD were included: 149 had acute myocardial infarction (MI) (Group I, 59%), 54 had significant chronic obstructive CAD suggestive of an ischaemic arrhythmic trigger (Group II, 21%) and 49 patients had an old MI without residual ischaemia (Group III, 19%). 34% of the patients with scar-related arrhythmias had an LVEF 
40%. Based on pre-event LVEF evaluation, it can be estimated that less than one quarter of the whole study population had a known chronic MI with severely reduced LVEF. In Group III, the proportion of inferior MI was significantly higher than anterior MI (81 vs. 19%; absolute difference, –62; 95% confidence interval, –45 to –79; P 
0.0001), though median LVEF was higher in inferior MI (0.37 ± 10 vs. 0.29 ± 10; P = 0.0499).
Conclusion: Patients included in defibrillator trials represent only a minority of the patients at risk of sudden cardiac death. By applying the current risk stratification strategy based on LVEF, more than one third of the patients with old MI would not have qualified for a prophylactic defibrillator. Our study also suggests that inferior scars may be more prone to ventricular arrhythmia compared to anterior scars.
Key Words: Ventricular arrhythmia, Myocardial infarction, Sudden death, Arrhythmic risk, Ejection fraction
* Corresponding author. Tel: +41 213140069, Fax: +41 213140013, Email: patrizio.pascale{at}chuv.ch
Presented in part at the 56th annual scientific session of the American College of Cardiology in New Orleans, LA, March 2007.
Manuscript submitted 29 July 2009. Accepted after revision 16 September 2009.