Abstract 2289: Charlson Comorbidity Index Predicts Early Mortality Among ICD patients
Background Limitations of current methods to predict who will benefit from an implantable cardioverter-defibrillator (ICD) are widely recognized. Prediction of early mortality could identify patients with a diminished likelihood of benefiting from an ICD.
Objective We sought to determine whether the Charlson comorbidity index (CCI) could be utilized to predict mortality in patients with primary prevention ICDs.
Methods We retrospectively evaluated 229 consecutive patients implanted with an ICD for primary prevention of sudden cardiac death (SCD). The CCI was calculated at the time of implant. The CCI is a well-validated weighted index of cardiac and non-cardiac disease states that influence survival. Patients were divided into those with a CCI ≥ 4 (Group A) and those with a CCI < 4 (Group B) for further survival analysis. Vital status was ascertained using the Social Security Death Index.
Results The cohort was followed over a mean of 1.47±1.25 years. Over this period 33 patients died and 196 were still alive. Those still living had a mean CCI of 3.51 compared to those who died with a mean of 4.97, p value of 0.0001. Kaplan Meier analysis demonstrated the survival advantage of Group B compared to Group A (p value of < 0.00001 by log rank). Group A had significantly increased all-cause mortality over the follow-up period compared to Group B on univariate analysis (hazard ratio, 5.01; 95% confidence interval, 2.17 to 11.57; p value of < 0.0001). Cox regression analysis controlling for age, sex, race, concomitant medical illnesses, and medications demonstrated CCI as a significant independent predictor of all-cause mortality (hazard ratio, 1.96 per single increase in index; 95% confidence interval, 1.47 to 2.60; p value of < 0.001). Covariate adjusted analysis confirmed that Group A had an increased all-cause mortality over the follow-up period compared to Group B (hazard ratio, 4.10; 95% confidence interval, 1.71 to 9.85; p value of 0.002).
Conclusions This is the first study to show CCI calculated at time of implant as an independent predictor of mortality in patients receiving ICD for primary prevention of SCD. CCI identifies patients with poor prognosis who may have limited benefit from ICD therapy.