Aims: To assess the long-term rate of mortality and the recurrence of potentially life-threatening ventricular arrhythmias in secondary prevention implantable cardioverter defibrillator (ICD) patients and to construct a model for baseline risk stratification.
Methods and results: Since 1996, all patients with ischaemic heart disease, receiving ICD therapy for secondary prevention of sudden death, were included in the current study. Patients were evaluated at implantation and during long-term follow-up. A total of 456 patients were included in the analysis and followed for 54 +/- 35 months. During follow-up, 100 (22%) patients died and ICD therapy was noted in 216 (47%) patients, of which 138 (30%) for fast, potentially life-threatening ventricular arrhythmia. Multivariate analysis revealed a history of atrial fibrillation or flutter (AF), ventricular tachycardia as presenting arrhythmia, and wide QRS and poor left ventricular ejection fraction as independent predictors of life-threatening ventricular arrhythmias. The strongest predictor was AF with a hazard ratio of 2.1 (95% confidence interval 1.3-3.2). On the basis of the available clinical data, it was not possible to identify a group which exhibited no risk on recurrence of potentially life-threatening ventricular arrhythmias.
Conclusion: Ischaemic secondary prevention ICD recipients exhibit a high recurrence rate of potentially life-threatening ventricular arrhythmias. Factors that increase risk can be identified but, even with these factors, it was not possible to distinguish a recurrence-free group.