Abstract--We hypothesized that losartan was superior to atenolol in reducing cardiovascular events in a lower-risk group (LRG) versus a higher-risk group (HRG) of patients in a Losartan Intervention For Endpoint reduction (LIFE) substudy, independently of blood pressure (BP) reduction. In a post hoc analysis, we designated 4282 patients as LRG on the basis of: (1) no previous cardiovascular disease (coronary, cerebral, peripheral vascular disease); (2) no diabetes; (3) no isolated systolic hypertension; and (4) inclusion of the lowest 3 quartiles of electrocardiographically documented left ventricular hypertrophy. The HRG consisted of 4911 remaining patients who did not qualify for the LRG. In the LRG, losartan was superior to atenolol in reducing stroke: hazard ratio (HR), 0.72 (95% confidence interval [CI], 0.53 to 0.98); new-onset diabetes (HR, 0.74 [95% CI, 0.58 to 0.93]; and new-onset atrial fibrillation: HR, 0.69 (95% CI, 0.51 to 0.92), all P<0.05 but not composite end points or cardiovascular mortality (both P=NS). In the HRG, losartan was superior to atenolol in reducing composite end points: HR, 0.82 (95% CI, 0.71 to 0.94), P<0.01; cardiovascular mortality: HR, 0.77 (95% CI, 0.62 to 0.95), P<0.05; stroke: HR, 0.75 (95% CI, 0.61 to 0.92), P<0.01; new-onset diabetes: HR, 0.76 (95% CI, 0.60 to 0.96), P<0.05; and new-onset atrial fibrillation: HR, 0.71 (95% CI, 0.58 to 88), P<0.05. Test for interaction of treatment with LRG versus HRG was not significant for composite end point, stroke, or atrial fibrillation, but was for cardiovascular mortality (P=0.018). Achieved systolic BP reduction favored losartan over atenolol by -1.8 mm Hg in LRG (P=NS) and -0.7 mm Hg (P=0.001) in HRG, but no significant differences occurred in diastolic or mean BP in either group. In conclusion, losartan compared with atenolol reduces the risk of stroke, new-onset diabetes, and new-onset atrial fibrillation in the LRG and the HRG.