In a more recent study involving review of adverse cardiovascular events through 30 days in 39,922 patients enrolled in clinical trials of acute coronary syndromes, when Hb was the fixed variable – not transfusion – cardiovascular mortality increased as Hb levels fell below 14 g/dl, with an adjusted odds ratio of 1.21 (95% CI 1.12 to 1.30, P < 0.001) for each 1 g/dl decrement in Hb [63]. Here, GSTM1 is linked to acute coronary syndrome.