Abstract 17922: The Impact of Center Volume on One Year Mortality After Orthotopic Heart Transplantation in Elderly Patients

Abstract

Objectives: Elderly patients are more frequently undergoing orthotopic heart transplantation (OHT) for end-stage heart failure. The aim of this study was to determine the impact of center volume on 1-year mortality following OHT in patients over the age of 60. Methods: Data were analyzed from the United Network for Organ Sharing (UNOS) registry. Elderly patients (age≥60) undergoing OHT between 1997-2009 were included. Average annual center volume for OHT in the elderly was calculated. The proportions of 1-year mortality were calculated for those centers with 10 or more average annual transplants and compared to those with less than 10. A multivariate logistic regression model was constructed utilizing significant univariate predictors to evaluate the independent impact of center volume on 1-year mortality. Results: A total of 26,818 adult patients underwent OHT during the study period, with 7,087(26.4%) being over the age of 60. Mean annual volume of OHT in elderly patients was 9.5±7.7 transplants. There were 1,073(15.1%) 1-year mortalities and 5,729(80.8%) 1-year survivors, with the remaining 285(4.0%) patients being alive but with follow-up of less than a year. Mean age of included patients was 63.9±3.1 years, with 5,669(83.3%) males. The most common indications for transplantation were idiopathic dilated cardiomyopathy (n=5,803; 85.3%) and coronary artery disease (n=600; 8.8%). The proportion of 1-year mortality was 17.4% in low volume centers (<10 annual transplants) versus 13.1% at high volume centers (p<0.001). In multivariate analysis, low annual center volume significantly increased the odds of 1-year mortality (OR 0.98, 95% CI 0.96-0.99, p<0.001) [see Table]. Conclusions: In elderly patients undergoing OHT, center volume significantly impacts 1-year mortality. These data strongly suggest that OHT in elderly patients should be performed at centers that have higher volumes in this specific cohort.