Prognostic implication of anemia on in-hospital outcomes after percutaneous coronary intervention

Background-Although prior studies have shown a relationship between anemia and in-hospital mortality after coronary artery bypass grafting and acute myocardial infarction (MI), the prognostic implication of anemia in patients undergoing percutaneous coronary intervention (PCI) is unknown. Therefore, we evaluated the relationship between anemia and outcomes of PCI. Methods and Results-Clinical and outcome data on 48 851 consecutive PCIs were prospectively collected. Patients were classified as anemic using the World Health Organization definition (<12.0 g/dL in women and <13.0 g/dL in men). A total of 6471 men (21.7%) and 4659 women (30.4%) were anemic. Anemic men and women were older and had a higher percentage of comorbidities compared with their nonanemic cohorts (P<0.0001 for all comparisons). When compared with nonanemic patients, anemic patients had higher in-hospital mortality (3.0% versus 0.8% in men; 2.4% versus 1.5% in women; P≤0.0001) and postprocedural MI (2.0% versus 1.6% in men; 2.4% versus 1.6% in women; P≤0.02) and a higher combined major cardiovascular events end point, including death, MI, and cerebrovascular event (5.0% versus 2.6% in men; 5.1% versus 3.5% in women; P<0.0001). After adjustment for comorbidities, anemia was associated with a higher risk of in-hospital mortality (odds ratio [OR], 2.29; 95% CI, 1.79 to 2.92; P<0.0001) and MI (OR, 1.34; 95% CI, 1.05 to 1.72; P=0.02) and major cardiovascular events (OR, 1.2; 95% CI, 1.05 to 1.34). Significant gender interactions were observed for death in men and for MI in women. Conclusions-Preprocedural anemia is associated with increased adverse in-hospital outcomes after PCI. Whether optimization of hemoglobin before PCI is of clinical benefit will need to be determined in a randomized clinical trial.