The clinical significance of hematocrit values before and after percutaneous coronary intervention

BackgroundThe presence of anemia before percutaneous coronary intervention (PCI) and/or the development of bleeding or anemia after PCI has been shown to increase mortality and morbidity rates. However, the definition of severe anemia varies among reports. In this context, the roles of hematocrit at baseline and hematocrit drop after PCI, both treated as continuous variables, have not yet been described in the risk assessment of patients undergoing PCI.MethodsWe analyzed 6,025 consecutive patients who underwent PCI from 2003 to 2007 at our institution. In the entire population, we analyzed by multivariable Cox analysis the clinical value of both hematocrit at baseline and hematocrit drop after PCI as continuous variables. The primary end point was the composite of death and myocardial infarction at 1-year follow-up.ResultsThe rate of the 1-year composite end point death/myocardial infarction increased continuously every time hematocrit at baseline decreased and/or hematocrit dropped after PCI. After multivariable adjustment using the relevant covariables, both hematocrit at baseline (hazard ratio = 0.92, P < .001) and hematocrit drop after PCI (hazard ratio = 1.11, P < .001) strongly predicted the primary end point at 1-year follow-up.ConclusionHematocrit at baseline and the drop after PCI should be recognized as important risk factors for adverse outcomes after PCI. The inclusion of hematocrit or hemoglobin values as continuous variables in a risk-stratification scheme should be strongly considered.