Background: Anemia is associated with an increased risk of mortality in patients who underwent percutaneous coronary intervention (PCI) in the bare-metal stent era. However, there have been no data concerning the clinical importance of anemia improvement during the follow-up period after discharge from the hospital during the drug-eluting stent era.
Methods and results: To assess anemia, the hemoglobin level was measured at the time of index PCI with drug-eluting stents and at the subsequent outpatient visit between 3 and 12 months later. Improvement of anemia was defined by the normalization of the hemoglobin level at the follow-up laboratory examination. We analyzed 4300 patients who were tested for initial and follow-up hemoglobin levels. We compared major adverse cardiac and cerebrovascular events (MACCE) between the normal group and the anemia group and between the improved anemia group and the sustained anemia group. The median follow-up period was 25.4 months. There was poorer clinical outcome in the anemia group than in the normal group in terms of MACCE (adjusted hazard ratio 1.479, 95% confidence interval 1.025-2.134, P=0.037). Furthermore, the sustained anemia group showed poorer MACCE than did the improved anemia group (hazard ratio 3.558, 95% confidence interval 2.285-5.539, P<0.0001). On the basis of the multivariate Cox hazard regression model and propensity-score matching, the overall findings were consistent between sustained and improved anemia groups.
Conclusion: The follow-up of hemoglobin level is important, and improvement of anemia is associated with favorable long-term clinical outcomes.