Adjunctive Antiarrhythmic Drug Therapy

Abstract

This chapter briefly reviews the aims and outcome of antiarrhythmic drug therapy in ICD recipients. It should be stated at the outset that very few controlled trials of antiarrhytlunic drug therapy in ICD recipients have been reported. Early ICD trials were designed to allow comparisons between patients randomized to ICD therapy or “conventional therapy”. The conventional therapy groups received heterogeneous treatments with various antiarrhytlunic drugs such as amiodarone (, , , , , , ), dl-sotalol (, ), class I antiarrhytlunics (, , , ), calcium blockers ( ), and beta blockers (Table 1) ( ). In most of these early trials, antiarrhythmic drug therapy in the ICD treatment groups was left to the discretion of the investigators (-). With the exception of the CIDS trial (), few ICD patients received adjunctive amiodarone, dl-sotalol, or class I agents, whereas up to 70% received unspecified beta blockers in unknown dosages (Table 1). Therefore, previous ICD trials provided little specific information on adjunctive drug therapy in ICD groups. Two recent ICD trials still partly in progress, SCD-HeFT and MADIT II (), are also not designed to assess effects of adjunctive drug therapy. Table 1 Adjunctive Antiarrhythmic Drug Therapy in lCD Groups of Major Trials MADIT MADIT II AVID CABGPATCH CIDS CASH Patients randomized 196 1232 1016 900 659 288 LVEFamean 0.27 0.23 0.32 0.27 0.34 0.46 Afib/flutterb -- 9 21 -- -- -- Amiodarone 2(7) 13(--) 2(8) 4(6) 0(17) 0(6)c d,l-Sotalol 1(4) -- 0(2) 1(1) 20(22) 0(3)d Class I drugs 12(11) 3(--) 4(7)e 17(8) 6(8) --(--) Ca-blockers -- 9(--) 18(23) 11(12) -- 26(--) Beta blockers 26(27) 70(--) 42(38) 18(16) 34(37) --(--)