Abstract 10511: A Baseline Risk Score for Ventricular Arrhythmias in Patients Undergoing Cardiac Resynchronization Therapy
Background Patients undergoing cardiac resynchronization therapy (CRT) are at risk for ventricular tachycardia/fibrillation (VT/VF), but risk stratification in this population is poorly defined and controversy exists regarding which CRT patients will require appropriate defibrillator therapy.
Methods We performed a multivariate (Cox proportional hazards) analysis of 216 patients implanted with CRT for standard indications to assess for baseline predictors of appropriate defibrillator therapy for VT/VF. Continuous variables were assessed via previously published partitions or using an upper quartile cut-off. Age, gender, baseline medications, echocardiographic parameters (LVEF, LVEDD, LVESD, LV wall thickness, RV systolic pressure, LA size, mitral regurgitation), renal function, prior history of VT/VF, nonischemic vs. ischemic cardiomyopathy, NYHA class, and comorbidities were analyzed. Incident VT/VF requiring ICD therapy after CRT implant was recorded and follow-up was censored at 5 years.
Results Forty-six (29%) patients had VT/VF. Beta-blocker non-use, LVEF<20%, prior VT/VF, and increased LV dimensions (LVEDD ≥ 68 mm and LVESD ≥ 61 mm) were significant univariate predictors of VT/VF after CRT. In multivariate analysis, prior VT/VF (HR 2.10 p=0.0198), LVEF<20% (HR 2.58 p=0.0019), and beta-blocker non-use (HR 2.92 p = 0.0107) remained predictive of VT/VF. Patients with 0 (n=111), 1 (n=73), or 2 (n=18) risk factors (no patient had all 3) demonstrated progressively higher risk of VT/VF during follow up. The overall survival curve and all pairwise comparisons were statistically significant (p<0.05)(figure).
Conclusions Prior VT/VF, severely depressed LVEF (<20%), and lack of beta-blocker therapy are independent predictors of incident VT/VF in patients after CRT, which can be used in combination for risk stratification in this population.
- Ventricular arrhythmia
- Resynchronization therapy
- Implantable cardioconvert defibrillator
- Risk factors
- Heart failure
- © 2011 by American Heart Association, Inc.