The Impact of Anaemia in Patients with Acute Coronary Syndrome

Background: A significant number of patients with acute coronary syndrome (ACS) are reported to suffer from anaemia. However, data relating to anaemia and clinical outcomes in patients presenting with ACS, particularly in Africa, are scarce. This study thus aimed to assess the prevalence of anaemia and its association with clinical characteristics and in-hospital mortality in patients presenting with ACS to a large urban public hospital in South Africa. Methods: The study is a retrospective analysis of patients 18 years and above admitted with a diagnosis of ACS to the Charlotte Maxeke Johannesburg Hospital (CMJAH) over a two-and-a-half-year period between January 2010 and June 2012. Data on clinical characteristics, blood chemistry including haemoglobin (Hb) level, therapies received and in-hospital mortality was collected. Results: A total of 431 ACS patients fulfilled the diagnostic criteria for ACS during the review period. The majority were males (72.2%) with a mean age of 58 ± 12.4 years. Anaemia was found to be present in 18.8% of all patients. Patients with anaemia were found to be significantly older, more likely to be female, have hypertension or diabetes and were more likely to be in a higher Killip functional class as compared to those not having anaemia. Anaemic patients were also less likely to receive optimal medical therapy for ACS (60.5% vs. 72.7%, p < 0.001). Killip class ≥3 (p < 0.001), atrial fibrillation (p < 0.045) and haemoglobin (Hb) < 11.4 g/dl (p < 0.0001) were significantly associated with mortality. However, only Hb of <11.4 g/dl was found to be an independent predictor of mortality and had more than fourfold increased risk compared to those with normal Hb (CI – 1.393–13.041; RR – 4.262; p < 0.011). Conclusion: Anaemia was present in almost one-fifth of patients presenting with ACS. Furthermore it was significantly associated with diabetes, hypertension, older age, female sex and Killip class ≥3. Anaemic patients were also less likely to receive optimal medical therapy. Importantly, a haemoglobin level <11.4 g/dl was found to be an independent predictor of mortality. Simple serial measurement of Hb is recommended in patients presenting with ACS and should be incorporated into the risk stratification of patients with ACS.