In the propensity score-matched prior MI cohort , after 28 months of follow-up , - blocker use was associated with a 31 % lower risk of the primary outcome ( 70 [ 7.1 % ] versus 100 [ 10.2 % ] ; hazards ratio , 0.69 ; 95 % confidence interval , 0.50-0 .94 ; P = 0.021 ) , driven by a lower risk of recurrent MI ( 33 [ 3.4 % ] versus 48 [ 4.9 % ] ; hazards ratio , 0.62 ; 95 % confidence interval , 0.39-1 .00 ; P = 0.049 ) with no difference in mortality ( 52 [ 5.3 % ] versus 66 [ 6.7 % ] ; P = 0.20 ) .