Is pre-operative anaemia a risk marker for in-hospital mortality and morbidity after valve replacement?

To assess the level of pre-operative haemoglobin (HB) as a risk marker for morbidity and mortality in the early post-operative period of patients who underwent elective valve replacement.

Between January 1998 and March 2004, clinical and outcomes data were collected for the 201 patients who had elective valve replacement. For each gender, the criterion to choose the best cut-off point was that which achieved the maximum likelihood after several General Additive Model models performed in a Bootstrap procedure. The best cut-off point obtained for pre-operative HB was 12 g/dL. Overall peri-operative mortality (deaths occurring during hospital period or within 30 days) was 9.5%. After adjusting well-known independent pre-operative risk factors for operative mortality, pre-operative HB <12 g/dL was identified as an independent predictor for in-hospital mortality (OR, 3.23; 95% CI, 1.09-9.55; P = 0.03). Also adjusting for EuroScore, pre-operative HB remained significant (OR, 3.64; 95% CI, 1.32-10.06; P = 0.01). The same model was applied to post-operative morbidity, and pre-operative HB <12 g/dL was identified as an independent predictor with and without EuroScore (OR, 4.67; 95% CI, 2.03-10.71; P < 0.001), (OR, 5.18; 95% CI, 2.18-12.3; P < 0.001), respectively.

In patients undergoing elective valve replacement pre-operative HB <12 g/dL is a risk marker of in-hospital mortality and serious adverse outcomes.