GSTM1 and angina pectoris: In 1999, the Transfusion Requirements In Critical Care (TRICC trial), reported a restrictive (Hb < 7.0 g/dL; n = 418) PRBC transfusion strategy is as effective as a liberal (Hb < 10.0 g/dL; n = 420) transfusion strategy in critical illness with no significant differences in 30-day mortality from all causes (p = 0.11) except for patients with active coronary ischaemic syndromes such as acute myocardial infarction and unstable angina [13].