Amiodarone for the prevention of sudden cardiac death: a meta-analysis of randomized controlled trials

Not all patients at risk for sudden cardiac death (SCD) are eligible for, or have access to implantable cardioverter defibrillator (ICD) implantation. There are conflicting data regarding the efficacy and safety of amiodarone for the prevention of SCD. We conducted a meta-analysis of all randomized controlled trials examining the use of amiodarone vs. placebo/control for the prevention of SCD. We identified 15 trials, which randomized 8522 patients to amiodarone or placebo/control. Amiodarone decreased the incidence of SCD [7.1 vs. 9.7%; OR 0.71 (0.61-0.84), P < 0.001] and cardiovascular death (CVD) [14.0 vs. 16.3%; OR 0.82 (0.71-0.94), P = 0.004]. There was a 1.5% absolute risk reduction in all-cause mortality which did not meet statistical significance (P = 0.093). Amiodarone therapy increased the risk of pulmonary [2.9 vs. 1.5%; OR 1.97, (1.27-3.04), P = 0.002], and thyroid [3.6 vs. 0.4%; OR 5.68, (2.94-10.98), P < 0.001] toxicity. Amiodarone reduces the risk of SCD by 29% and CVD by 18%, and therefore, represents a viable alternative in patients who are not eligible for or who do not have access to ICD therapy for the prevention of SCD. However, amiodarone therapy is neutral with respect to all-cause mortality and is associated with a two- and five-fold increased risk of pulmonary and thyroid toxicity.