Changes in haemoglobin levels during hospital course and long-term outcome after acute myocardial infarction.

Abstract

To study the prevalence and long-term prognostic significance of changes in haemoglobin levels during hospital course in survivors of acute myocardial infarction (AMI). A prospective study involving 1390 patients who were admitted with AMI. Median follow-up was 24 months. Multivariable Cox models were used to evaluate the relationship between nadir and discharge haemoglobin and mortality after hospital discharge. Anaemia was present in 248 patients on admission (17.8%) and in 502 patients at discharge (36.1%). Nadir haemoglobin during hospital course was 1.3 g/dL lower (IQR 0.6-2.2) when compared with baseline haemoglobin (P < 0.0001). Low nadir haemoglobin and discharge haemoglobin were strongly associated with increased mortality. After adjusting for clinical variables and ejection fraction, the hazard ratios for a 1 g/dL decrease in nadir haemoglobin and discharge haemoglobin were 1.36 (95% CI 1.19-1.55; P < 0.0001) and 1.27 (95% CI 1.16-1.40; P < 0.0001), respectively. The development of anaemia during hospitalization for AMI is frequent and is associated with an increased long-term mortality.