Background Previous studies have demonstrated a relationship between pre-existing anaemia and inpatient mortality after percutaneous coronary intervention (PCI). There is limited data looking at the impact of baseline Haemoglobin and long term outcome after primary PCI.
Methods Clinical information was analysed from a prospective database on 2357 STEMI patients who underwent Primary PCI between January 2004 and May 2010 at a London centre. Information was entered at the time of procedure and outcome assessed by all-cause mortality information provided by the Office of National Statistics via the BCIS/CCAD national audit. Anaemia was defined according to WHO definition of Hb greater than or equal to 12 g/dl for females and 13 g/dl for males.
Results 471 (20%) patients were anaemic at presentation. The anaemic cohort, were older (72.2 vs 62.4, p<0.0001), had higher incidence of diabetes (27% vs 15%, p<0.0001), hypertension (42 vs 35%, p=0.01), hypercholesterolaemia (40 vs 30%, p=0.007), previous PCI (13 vs 7%, p=0.01), and previous MI (23% vs 12%, p<0.0001). There were similar incidences of three-vessel disease and cardiogenic shock. Over a 3-year follow-up period there was significantly higher all cause mortality in the anaemic group compared to the normal Hb group (20.4% vs 13.5%, p<0.0001). See Abstract 18 figure 1. After adjusting for comorbidities, anaemia remained an independent predictor of long-term adverse outcome (OR=2.4, 95% CI=1.1 to 3.7, p<0.001). Patients with baseline anaemia who received a blood transfusion were significantly more likely to suffer an adverse outcome than those that did not receive a transfusion (21% vs 6%, p<0.0001).
Conclusion Patients presenting with anaemia undergoing primary PCI appear at significantly higher risk of an adverse outcome. This risk increases further in population receiving RBC transfusions during index hospitalisation.