Among the secondary end-points , the amiodarone group showed significantly lower rate of atrial tachyarrhythmia-related hospitalizations [ rate ratio = 0.43 ; 95 % confidence interval ( CI ) = 0.23-0 .77 , P = 0.006 ] and cardioversions ( rate ratio = 0.36 ; 95 % CI = 0.20-0 .62 , P = 0.0004 ) within the blanking period .