Single beta-blocker or combined amiodarone therapy in ICD and CRT-D patients - Insights from the German DEVICE-registry

Abstract Background Because of its antiarrhythmic potency and due to the lack of alternatives, amiodarone is often used for antiarrhythmic therapy in patients with ICD or CRT-D systems. To date, robust data on the safety and clinical benefit of amiodarone therapy in these patients are missing. Objective This study was designed to assess the periprocedural and post-procedural outcome of combined therapy with beta-blockers plus amiodarone compared to treatment with single beta-blockers in this "real life" cohort of ICD recipients of the German DEVICE registry. Methods 4,499 patients who underwent ICD implantation, revision, or upgrade in 49 centers participating in the German DEVICE Registry were enrolled 03/2007-02/2014. Patients' characteristics, procedural data, periprocedural complications, and post-procedural clinical outcome, were analyzed. Results 12.7 % (572 patients) received amiodarone in addition to beta-blocker therapy. These patients were slightly older and more frequently male than the 3,927 patients with sole betablocker therapy. The two cohorts of patients had no relevant differences in terms of underlying cardiomyopathy. Stroke, and chronic kidney disease were more often present in the patient group receiving amiodarone. Early implantation-associated complications were similar between the groups. One-year overall mortality was, however, significantly higher in the beta-blocker plus amiodarone cohort (adjusted HR 2.09; p<0.001). This was particularly pronounced in the subgroups of patients with sinus rhythm or severely reduced left ventricular function. Interestingly, amongst the surviving patients, amiodarone was not associated with a significantly reduced risk of ICD discharges, syncopal events. Further, the occurrence of VT storm or incessant VTs and the number of patients scheduled for intracardiac ablation did not differ among both groups while the rate of rehospitalization was lower in the cohort with sole beta-blockers. Conclusions Taken together, these retrospective "real-word" data suggest an increased all-cause mortality under amiodarone therapy, particularly in the subgroups of patients with sinus rhythm or severely reduced left ventricular function. In surviving patients, rates of arrhythmic events were comparable.Abstract Figure