Abstract 1544: Early Statin Therapy Reduces Risk Of ICD Shocks In Patients With An Implantable Cardioverter-defibrillator Undergoing Ablation For Ventricular Tachycardia
Background: Lipid lowering therapy reduces mortality in patients with both ischemic and nonischemic cardiomyopathies and recently has been shown to decrease ICD shocks. Radiofrequency ablation (RFA) of recurrent VT in patients with an ICD also reduces shocks following intervention. It is unclear if statin therapy after VT RFA will further impact ICD shock rates.
Methods: All patients from 1993–2005 who underwent a RFA procedure for recurrent VT at the Mayo Clinic with an ICD were included. Patient records were extracted for medical and procedural details and all ICD interrogations were reviewed for VT recurrence and therapies.
Results: 63 patients (age 62±15 years) were followed over 3.9±3.6 years. Comorbid diseases included: coronary artery disease 37(58%, 34 prior myocardial infarction), ARVD/C 6(10%), nonischemic dilated cardiomyopathy 7(11%), moderate-severe valve disease 14(22%), hypertension 34(54%), and hyperlipidemia 35(56%). Ejection fraction was <0.35 in 34(56%). VT was induced in all patients (LV 55 (LVOT 1), RV 8 (RVOT 3) with multiple inducible VTs in 21(33%). VT was noninducible after RFA in 39(62%) patients. Dismissal medications included: statins 19(30%), beta blockers 40(66%), ACE/ARB 37(61%), diuretics 34(55%), and digoxin 23(37%). 5-year overall survival was 63%(95% CI 55–71). Age, diabetes, and renal insufficiency were associated with increased post ablation mortality, with no medication improving survival. 5-year survival free of ICD shocks was 31%(95% CI 24–38). Only statin therapy at discharge was associated with a decreased risk of ICD shocks [5(26%) versus 26(59%), p=0.020]. 7 additional patients received statins during follow-up, but not at discharge, of these 5(71%) had shocks.
Conclusion: Statin use at discharge in patients with an ICD undergoing RFA for refractory VT significantly reduced recurrent ventricular arrhythmias and ICD shocks. Although the mechanism underlying the effects of statins on arrhythmic recurrence early after RFA requires further study, these data support aggressive therapy of the underlying substrate responsible for the VT.