GSTM1 and myocardial ischemia: In a study of 3,600 patients published last year examining the specific relationship of Hb level and postoperative myocardial ischemia, the results showed that postoperative Hb levels within the intermediate tertile (10.3 to 11.6 g/dl) (odds ratio, 5.8; 95% CI, 1.6 to 20.9) and the lowest tertile (7.9 to 10.2 g/dl) (odds ratio, 12.9; 95% CI, 3.0 to 55.5) carried the highest odds-ratio risk for coronary ischemia, greater than even a prior history of ischemic heart disease (odds ratio, 4.2; 95% CI, 1.0 to 17.8) [65].