Abstract 83: Association of Preoperative Anemia with Heart Failure Hospitalization and Mortality among Veterans Undergoing Cardioverter-Defibrillator

Abstract

Introduction: Anemia is associated with worse outcomes in many medical conditions, including congestive heart failure. Whether anemia is associated with heart failure hospitalization or mortality among patients undergoing implantable cardioverter-defibrillator (ICD) implantation is unclear. Methods: Among veterans enrolled in the Outcomes among Veterans with Implantable Defibrillators (OVID) registry between 2003 and 2009, 3,918 were identified as within 3 months of initial ICD implantation and having hemoglobin measured at the time of implantation. Baseline clinical characteristics and clinical outcomes were abstracted from the electronic medical record and social security death index. Association of anemia with heart failure hospitalization and mortality was examined using Cox proportional hazards regression. Results: The mean blood hemoglobin level was 13.7 grams per deciliter (g/dl), and 674 patients (17.5%) had anemia as defined by a blood hemoglobin level less than 12 g/dl. The rate of hospitalization for heart failure was 18.8 per 100 person-years, and mortality was 13.1 per 100 person-years for subjects with anemia at the time of implantation, compared with 9.2 per 100 person-years and 5.8 per 100 person-years, respectively, for those subjects with hemoglobin levels greater than 12 g/dl. After adjusting for potential confounding factors (including the baseline severity of heart failure, coronary disease, left ventricular ejection fraction, cardiac resynchronization therapy, chronic kidney disease, age, race, and other comorbidities), a hemoglobin of less than 12 g/dl at the time of implantation was associated with increased risk of both heart failure hospitalization (adjusted HR, 1.5; 95% CI, 1.3 - 1.8; P < 0.001) and mortality (adjusted HR, 1.7; 95% CI, 1.4 - 2.1; P < 0.001). Conclusions: Preoperative anemia is associated with an increased risk of both subsequent heart failure hospitalization and mortality among veterans undergoing ICD implantation even after controlling for comorbidities.