ICD therapy significantly reduced cardiac mortality compared with placebo ( adjusted hazard ratio , 0.76 ; 95 % confidence interval , 0.60 to 0.95 ) and tachyarrhythmia mortality ( adjusted hazard ratio , 0.40 ; 95 % confidence interval , 0.27 to 0.59 ) and had no impact on mortality resulting from heart failure or noncardiac causes .
