Guidelines-based treatment of anaemic STEMI patients: practice patterns and effects on in-hospital mortality: a retrospective analysis from the NCDR

BACKGROUND: Anaemia is associated with an increased risk for morbidity and mortality in ST-elevation myocardial infarction (STEMI) patients. While several physiological mechanisms have been proposed to explain this association, decreased receipt of guidelines-based care may also contribute. We examined the relationship between admission haemoglobin (Hgb) level, receipt of ACC/AHA guidelines-based treatments, and in-hospital outcomes among STEMI patients. We also evaluated whether administration of these treatments modified the association between anaemia and in-hospital mortality in this group. METHODS AND RESULTS: We analysed data from 92,686 patients diagnosed with STEMI included in the NCDR ACTION Registry-GWTG database from January 2007 to March 2011. Patients were stratified by initial Hgb value: 83.1% (n=77,035) were classified as non-anaemic (Hgb >13.0 g/dl for men, >12.0 g/dl for women), 11.6% (n=10,710) as mildly anaemic (11.1-13.0 g/dl for men, 11.1-12.0 g/dl for women), 4.4% (n=4059) as moderately anaemic (9.1-11.0 g/dl), and 1.0% (n=882) as severely anaemic (<9.0 g/dl). Anaemia was associated with a significantly increased prevalence of other baseline comorbidities and decreased odds of receiving several class I recommended pharmacological treatments (heparin, beta-blockers, and angiotensin-converting enzyme inhibitors, p<0.01). The overall use of reperfusion therapy (fibrinolytic therapy and/or percutaneous coronary intervention) was also lower in anaemic vs. non-anaemic patients (p<0.01). Anaemia was associated higher in-hospital mortality risk, which remained significant after adjustment for use of guidelines-recommended therapies and interventions (p<0.01). CONCLUSIONS: In a national sample of STEMI patients, anaemia on presentation was associated with decreased receipt of ACC/AHA guidelines-based care and higher in-hospital mortality. However, the higher mortality rates could not be fully explained by differences in in-hospital treatment.