Abstract 11283: Predictors of One Year Survival After Implantable Cardioverter Defibrillator Implantation: Implications for Guidelines on Device Therapy

Introduction:Guidelines state that candidates for primary prevention implantable cardioverter-defibrillators (ICDs) should have a ?reasonable expectation? of survival > 1 year. However, tools for predicting survival in this population are lacking.Hypothesis:To investigate predictors of 1 year survival after ICD implantation.Methods:We analysed patients with ICDs in Registry of Atrial Tachycardia and Atrial Fibrillation Episodes (n = 2238). Of these, 2198 (98.2%) had complete information on follow-up. The primary endpoint was survival at 1 year after ICD implantation.Results:Over a median follow up of 1.95 (IQR: 1.0-2.1) years, 168 patients (7.5%) died, of whom 96 (4.2%) died within 1 year. Significant differences were noted in multiple variables between those who did or did not survive 1 year. However, in multivariable analysis, only four variables were significantly associated with 1 year survival: higher New York Heart Association class (hazard ratio [HR] 1.71 per increase in class, 95% confidence interval [CI] 1.12-2.63, p = 0.02), age at implant (HR 1.04 per year, 95% CI (1.01-1.06, p=0.002) and diabetes (HR 1.64, 95% CI 1.01-2.66, p=0.05) were associated with increased risk of death at 1 year. Use of angiotensin antagonists was associated with lower risk of 1 year mortality (HR 0.59, 95% CI 0.39-0.91, p = 0.016). Receiver operating characteristic curve analysis to predict 1 year survival using these variables showed modest discrimination, Figure1.Conclusions:Overall, ~4% of ICD recipients died by 1 year. Although many variables differ between those who do and do not survive 1 year, substantial overlap exists and models to predict survival have limited discrimination. Without better tools to identify which ICD candidates are most or least likely to survive 1 year, ICDs may be withheld due to perceptions of limited survival from those who may potentially benefit. These findings have important implications for guidelines recommendations on device therapy.