In CHOIR, 125 endpoint events (composite of death, myocardial infarction, hospitalized CHF without dialysis, or stroke) occurred in the high-Hb group versus 97 events in the low-Hb group (HR, 1.34; 95% CI, 1.03 to 1.74; P = 0.03). This evidence concerns the gene GSTM1 and Stroke.