After a median follow-up of 27.8 months , there was no significant difference between the ivabradine group and the placebo group in the incidence of the primary end point ( 6.8 % and 6.4 % , respectively ; hazard ratio , 1.08 ; 95 % confidence interval , 0.96 to 1.20 ; P = 0.20 ) , nor were there significant differences in the incidences of death from cardiovascular causes and nonfatal myocardial infarction .