Prevalence and Predictors of Appropriate Implantable Cardioverter Defibrillator Therapy in Chronic Left Ventricular Dysfunction Patients for Primary Prevention of Sudden Cardiac Death in Siriraj Hospital
Ply Chichareon MD*, Rungroj Krittayaphong MD*, Ahthit Yindeengam BSc**
Affiliation : * Division of Cardiology, Department of Medicine, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand ** Her Majesty Cardiac Center, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
Objective : The purpose of the present study was to identify the prevalence and predictors of first appropriate implantable
cardioverter defibrillator (ICD) therapy in patients with chronic LV dysfunction after placement of ICD for primary prevention.
Material and Method: Retrospective design was used. Patients (n = 115) from Siriraj Hospitals with ischemic or
non-ischemic cardiomyopathy who underwent ICD implantation for primary prevention were studied. Clinical data and
ICD therapy data were obtained from medical records and ICD interrogation reports.
Results : First appropriate ICD therapy for ventricular tachycardia (VT) or ventricular fibrillation (VF) were seen in
22 patients (19%) of whom 11 (9.5%) received ICD shock and 11 patients (9.5%) received anti-tachycardic pacing. Lack
of beta-blocker use and lack of aldosterone antagonist use were identified as significant predictors of appropriate therapy.
There was no difference in prevalence of appropriate ICD therapy between ischemic and non-ischemic groups. The
freedom from first appropriate therapy at 1, 2 and 3 years was 88%, 80% and 78%. The freedom rate was constant after
the third year
Conclusion : Nearly one-fifth of chronic LV dysfunction patients with primary prevention ICD implantation experience
appropriate ICD therapy. Most first appropriate ICD therapy occurs within 2 years after implantation. Lack of beta-blocker
use and lack of aldosterone antagonist use were significant predictors of appropriate therapy.
Keywords : Implantable cardioverter defibrillator, Sudden cardiac death, Primary prevention, Predictors
