Amiodarone therapy tied to increased all-cause mortality in ICD recipients: Study

The data suggested an increase in all-cause mortality with amiodarone therapy, particularly in the subgroups of patients with severely reduced left ventricular function or sinus rhythm. The rates of arrhythmic events were found to be similar in surviving patients.

Amiodarone is frequently used for antiarrhythmic therapy in ICD or CRT-D systems (cardiac resynchronization therapy defibrillator) recipients due to the lack of alternatives and owing to its antiarrhythmic potency. However, robust data on the safety and clinical utility of amiodarone therapy in these patients still need to be included. Therefore, Felix Wiedman from University Hospital Heidelberg, in Heidelberg, Germany, designed a study to evaluate the outcomes (periprocedural and post-procedural) of combined therapy with beta-blockers and amiodarone versus treatment with single beta-blockers in the recipients of ICD.

For this purpose, the researchers enrolled 4,499 patients who underwent ICD implantation, upgrade or revision in 49 centres who were participants of the German DEVICE Registry.

The study led to the following findings:

· The authors showed no significant effect of amiodarone on the success of defibrillation testing.

· Early implantation-associated complications were comparable between the groups.

· One-year overall mortality was notably higher in the beta-blocker plus amiodarone cohort (adjusted HR 2.09).

· Among the surviving patients, amiodarone was not associated with a remarkably reduced risk of ICD discharges or syncopal events.

· Among both groups, VT storm or incessant VT occurrence and the number of patients scheduled for intracardiac ablation did not differ. At the same time, the rehospitalization rate was lower in the people with sole beta-blockers.

"While amiodarone has no unfavourable effect on the defibrillation testing's success, our data indicate an increased all-cause mortality with amiodarone therapy, particularly in the subgroups of patients with severely reduced left ventricular function or sinus rhythm," the researchers wrote. "Rates of arrhythmic events were comparable in surviving patients."

Reference:

The study titled, "Single beta-blocker or combined amiodarone therapy in implantable cardioverter-defibrillator and cardiac resynchronization therapy defibrillator patients – insights from the German DEVICE-registry," was published in Heart Rhythm. DOI: https://doi.org/10.1016/j.hrthm.2022.12.009