Impact of acute blood loss anemia and red blood cell transfusion on mortality after percutaneous coronary intervention

The clinical impact of increasing levels of blood loss has been shown to increase morbidity and mortality after percutaneous coronary intervention (PCI). The impact of red blood cell (RBC) transfusion for severe bleeding is unknown. We systematically collected baseline and 8-h postprocedure hematocrit (HCT) values on patients undergoing PCI. The incidence of adverse events, including death and recurrent myocardial infarction, was correlated to increasing blood loss. A total of 6,799 patients undergoing PCI (January 2000 to April 2002) had serial HCT levels. Negligible, mild, moderate, and severe blood loss occurred in 43, 25, 25, and 8% of patients, respectively. In-hospital mortality was 0.3, 0.5, 1.4, and 5.7% (p < 0.0001) with increasing severity of blood loss. Blood transfusion was independently associated with mortality (relative risk [RR] 2.03, p = 0.028). A case-controlled analysis of 146 transfused patients versus 292 nontransfused patients with severe bleeding found an independent association between RBC transfusion and increased risk of 1-year mortality (RR 2.42, p = 0.0045). Patients receiving blood >35 days old had significantly worse 1-year survival rates compared with patients receiving blood <35 days old and patients not transfused (36 vs. 24 vs. 10%, p < 0.0001). In a general PCI population, increasing levels of blood loss are associated with an increased incidence of major adverse cardiac events and in-hospital mortality. RBC transfusion in the setting of severe bleeding is associated with an increased risk of 1-year mortality. Transfusion of aged RBCs may also be detrimental in this setting.