Does admission anaemia still predict mortality six years after myocardial infarction?

Anaemia is present in 12-30% of patients with acute coronary syndromes (ACS). Many studies have shown that admission anaemia is an independent predictor of in-hospital or short-term mortality in patients with ACS. However, there is limited data on the long-term prognostic importance of anaemia in this group of patients.

To establish the relation between haemoglobin concentration on admission and six-year all-cause mortality in patients with ST-segment elevation myocardial infarction (STEMI) treated invasively.

We retrospectively studied 551 patients with the diagnosis of STEMI referred to the catheterisation laboratory of our hospital and treated with successful primary percutaneous coronary intervention. Patients were divided into two groups according to admission haemoglobin concentration (< 13 g/dL in males and < 12 g/dL in females).

A total of 551 patients with STEMI (164 female, 30%) were included in the analysis, mean age was 63 ± 12 years. Anaemia on admission was present in 11% (n = 61) of the patients. Of the entire cohort, renal failure was present in 25% (n = 138), and diabetes in 16% (n = 88). Admission haemoglobin concentration was significantly associated with age (r = -0.2663, p < 0.05), blood pressure (systolic blood pressure [SBP]: r = 0.1940, diastolic blood pressure [DBP]: r = 0.2023, p < 0.05), glucose concentration (r = -0.1218, p < 0.05), white blood cells count (r = 0.1230, p < 0.05), cholesterol concentration (r = 0.1253,p < 0.05), estimated glomerular filtration rate (eGFR; r = 0.1819, p < 0.05), Killip-Kimball class (r = -0.1387, p < 0.05) and TIMI risk score for STEMI (r = -0.2647, p < 0.05). During follow-up, 27% (n = 130) of the patients died. The mortality rate was significantly higher in the patients with admission anaemia (47% vs. 24%, p = 0.0002). The patients with anaemia were older (p = 0.0007), had lower blood pressure (SBP: p = 0.007; DBP: p = 0.01), higher heart rate (p = 0.03), higher glycaemia concentration (p = 0.003), higher C-reactive protein concentration (p = 0.0007) and lower white blood cells count (p = 0.03). Patients with anaemia had more frequently renal failure (eGFR < 60 mL/min/1.73 m²) (p = 0.02) and a significantly higher TIMI risk score for STEMI (p = 0.01). In multivariate analysis, all-cause mortality was associated with: anaemia on admission (OR = 2.29; 95% CI 1.20-4.36; p = 0.011), low ejection fraction (OR = 2.97; 95% CI 1.78-4.96; p < 0.001) and age (OR = 1.65 [per 10 years]; 95% CI 1.34-2.03; p < 0.001). Anaemia on admission remained an independent predictor of six-year mortality.

Admission anaemia significantly influences all-cause mortality in patients with STEMI treated invasively ina six-year follow-up and may be used for risk stratification in this population.