Wu W (Providence VAMC), Lessard D
(University of Massachussets Medical School), Goldberg RJ
(University of Massachussets Medical School)
It is unknown how anemia may influence the utilization of cardiac catheterization in patients hospitalized with acute myocardial infarction (AMI), and whether the use of cardiac catheterization is associated with distinct mortality outcomes in patients with and without anemia. We examined the utilization rates of cardiac catheterization during hospitalization for AMI in patients with and without anemia, and relate these utilization patterns to hospital episodes of bleeding as well as hospital and 1-year death rates.
This was a retrospective cohort study using data from the population-based Worcester Heart Attack Study. Based on admission hematocrit levels, patients were stratified into four categories of anemia: < 30.0%, 30.0-32.9%, 33.0-35.9%, and 36.0-38.9%; and no anemia: > 39.0%. The study sample consisted of 5,712 greater Worcester (MA) residents hospitalized with AMI at six cardiac catheterization capable facilities in the Worcester metropolitan area between 1995 and 2005. Likelihood of cardiac catheterization use in patients with, as compared to those without anemia, and risks of in-hospital bleeding and death, as well as 1-year mortality according to cardiac catheterization status.
Patients with mild anemia (admission hematocrit categories of 36.0-38.9%) were approximately one-sixth less likely (OR = 0.83; 95% CI 0.70, 1.0) to undergo cardiac catheterization in comparison to AMI patients without anemia; this percentage decreased even further in patients with lower hematocrit levels. Cardiac catheterization use, in patients with and without anemia, was associated with a significantly higher risk of in-hospital bleeding, without increasing the risk of hospital death, and a greater likelihood of one-year survival.
Despite a higher risk for bleeding during hospitalization in patients with and without anemia who underwent cardiac catheterization, the use of this diagnostic procedure was associated with comparable decreases in the risk of 1-year mortality.
This study shows under utilization of an effective treatment for acute myocardial infarction and an area for future improvement.