Value of blood transfusion in patients with a blood hematocrit of 24% to 30% after percutaneous coronary intervention.

Bleeding is a serious complication after percutaneous coronary intervention (PCI). Red blood cell transfusions are liberally administered for a hematocrit decrease to <30% after PCI. However, the utility of transfusion for these hematocrit levels and its effect on the clinical outcome remains unclear. We investigated how red blood cell transfusion affects the clinical outcomes in patients with a hematocrit nadir of 24% to 30% after PCI. From a cohort of 5,538 consecutive patients who underwent PCI from 2003 to 2007, 625 patients who presented with nadir hematocrit levels of 24% to 30% after PCI were detected. Death and myocardial infarction were compared between the transfused (n = 189) and nontransfused (n = 436) patients at 30 days and 1 year. The clinical characteristics were similar in both groups, except for the incidence of myocardial infarction and cardiogenic shock as the initial clinical presentations, which were more frequent in the transfused patients: 30.7% versus 14% and 25.4% versus 8.1%, respectively (p <0.001). The mean hematocrit decrease was greater in the transfused patients: 13.23% versus 2.99% (p <0.001). The angiographic characteristics were also similar, except for the number of diseased vessels, which was greater in the transfused patients (2.43 vs 2.16, p = 0.01). The occurrence of death and myocardial infarction was greater in the transfused patients at 30 days (14.8% vs 7.1%, p <0.001) and 1 year (28.6% vs 19.6%, p = 0.01). After adjustment for the different co-morbidities and the mean hematocrit decrease, transfusion was no longer associated with worse outcomes at 30 days (hazard ratio 1.5, p = 0.2) or at 1 year (hazard ratio 1.4, p = 0.1). In conclusion, our data do not support the routine use of transfusion in patients who present with a nadir hematocrit of 24% to 30% after PCI.