The Prevalence and Impact of Preoperative Anemia in Patients Undergoing Cardiac Surgery for Rheumatic Heart Disease.

Abstract

Many observational studies have demonstrated an association between preoperative anemia and adverse outcomes after cardiac surgery. However, there is a paucity of data on the impact of anemia in patients undergoing cardiac surgeries for rheumatic heart disease (RHD). This study was designed to examine the prevalence and impact of preoperative anemia in patients undergoing cardiac surgery for RHD. Retrospective observational data analysis. Tertiary-care hospital. 335 consecutive patients undergoing cardiac surgery for RHD from January 2009 to November 2014. No interventions. Prevalence of preoperative anemia as per World Health Organization (WHO) definition was 51.95%. Mild and moderate anemias were present in 33.15% and 18.80%, respectively. The primary endpoint was in-hospital mortality, with an incidence of 26 (6.9%); the incidence of mortality in non-anemic, mildly anemic, and moderately anemic patients was 5.59%, 4.50%, and 19.04% (p = 0.003), respectively. Patients with moderate anemia utilized an average of 3 units of packed cells compared to 1 in non-anemic patients (p = 0.0001). A multiple regression analysis was performed to predict mortality from variables including anemia, EuroSCORE II, and perioperative blood transfusion. On adjusting for EuroSCORE II and severity of anemia, perioperative packed cell transfusion was associated with significant odds (odds ratio 2.218; confidence interval 1.517-2.986; p<0.0001) for mortality. In patients undergoing cardiac surgery for RHD, there was high prevalence of preoperative anemia. Despite higher transfusion rates in moderately anemic patients, they had significantly lower Hb on CPB and in the postoperative period. Perioperative packed cell transfusion was associated significantly with mortality.