Association of Baseline Anemia with Mid-Term Clinical Outcomes in Patients Who Underwent Trans-Radial Primary Percutaneous Coronary Intervention

Radial access is recommended for primary percutaneous coronary intervention (PCI), because it has fewer bleeding complications than trans-femoral PCI. However, even if trans-radial PCI is chosen, patients with ST-elevation myocardial infarction (STEMI) presenting with anemia on admission might have poor clinical outcomes. The aim of this retrospective study was to investigate whether anemia on admission was associated with mid-term clinical outcomes in patients who underwent trans-radial primary PCI. The primary endpoint was a composite of all-cause death, recurrent acute myocardial infarction, and readmission for heart failure. A total of 288 consecutive patients with STEMI who underwent trans-radial primary PCI were divided into an anemia group (n = 79) and a non-anemia group (n = 209). The median follow-up duration was 301 days. The anemia group was significantly older than the non-anemia group (77.3 ± 11.9 versus 64.4 ± 12.7 years, respectively; P < 0.001). There were significantly more females in the anemia group than in the non-anemia group (36.7% versus 14.4%, respectively; P < 0.001). Kaplan-Meier analysis revealed that the composite outcome-free survival was significantly worse in the anemia group than in the non-anemia group (P < 0.001). Multivariate Cox hazard model analysis revealed that hemoglobin levels on admission were significantly associated with the composite outcome (per 1 g/dL increase: hazard ratio 0.76, 95% confidence interval 0.66-0.88, P < 0.001) after controlling for confounding factors. In conclusion, baseline anemia was significantly associated with poor clinical outcomes. Patients with STEMI presenting with anemia should be managed carefully, even if trans-radial primary PCI is chosen.